2023-06-13 17:32:27

by Elliot Berman

[permalink] [raw]
Subject: [PATCH v14 00/25] Drivers for Gunyah hypervisor

Gunyah is a Type-1 hypervisor independent of any
high-level OS kernel, and runs in a higher CPU privilege level. It does
not depend on any lower-privileged OS kernel/code for its core
functionality. This increases its security and can support a much smaller
trusted computing base than a Type-2 hypervisor.

Gunyah is an open source hypervisor. The source repo is available at
https://github.com/quic/gunyah-hypervisor.

The diagram below shows the architecture.

::

VM A VM B
+-----+ +-----+ | +-----+ +-----+ +-----+
| | | | | | | | | | |
EL0 | APP | | APP | | | APP | | APP | | APP |
| | | | | | | | | | |
+-----+ +-----+ | +-----+ +-----+ +-----+
---------------------|-------------------------
+--------------+ | +----------------------+
| | | | |
EL1 | Linux Kernel | | |Linux kernel/Other OS | ...
| | | | |
+--------------+ | +----------------------+
--------hvc/smc------|------hvc/smc------------
+----------------------------------------+
| |
EL2 | Gunyah Hypervisor |
| |
+----------------------------------------+

Gunyah provides these following features.

- Threads and Scheduling: The scheduler schedules virtual CPUs (VCPUs) on
physical CPUs and enables time-sharing of the CPUs.
- Memory Management: Gunyah tracks memory ownership and use of all memory
under its control. Memory partitioning between VMs is a fundamental
security feature.
- Interrupt Virtualization: All interrupts are handled in the hypervisor
and routed to the assigned VM.
- Inter-VM Communication: There are several different mechanisms provided
for communicating between VMs.
- Device Virtualization: Para-virtualization of devices is supported using
inter-VM communication. Low level system features and devices such as
interrupt controllers are supported with emulation where required.

This series adds the basic framework for detecting that Linux is running
under Gunyah as a virtual machine, communication with the Gunyah Resource
Manager, and a sample virtual machine manager capable of launching virtual machines.

The series relies on two other patches posted separately:
- https://lore.kernel.org/all/[email protected]/
- https://lore.kernel.org/all/[email protected]/


Changes in v14:
- Coding/cosmetic tweaks suggested by Alex
- Mark IRQs as wake-up capable

Changes in v13: https://lore.kernel.org/all/[email protected]/
- Tweaks to message queue driver to address race condition between IRQ and mailbox registration
- Allow removal of VM functions by function-specific comparison -- specifically to allow
removing irqfd by label only and not requiring original FD to be provided.

Changes in v12: https://lore.kernel.org/all/[email protected]/
- Stylistic/cosmetic tweaks suggested by Alex
- Remove patch "virt: gunyah: Identify hypervisor version" and squash the
check that we're running under a reasonable Gunyah hypervisor into RM driver
- Refactor platform hooks into a separate module per suggestion from Srini
- GFP_KERNEL_ACCOUNT and account_locked_vm() for page pinning
- enum-ify related constants

Changes in v11: https://lore.kernel.org/all/[email protected]/
- Rename struct gh_vm_dtb_config:gpa -> guest_phys_addr & overflow checks for this
- More docstrings throughout
- Make resp_buf and resp_buf_size optional
- Replace deprecated idr with xarray
- Refconting on misc device instead of RM's platform device
- Renaming variables, structs, etc. from gunyah_ -> gh_
- Drop removal of user mem regions
- Drop mem_lend functionality; to converge with restricted_memfd later

Changes in v10: https://lore.kernel.org/all/[email protected]/
- Fix bisectability (end result of series is same, --fixups applied to wrong commits)
- Convert GH_ERROR_* and GH_RM_ERROR_* to enums
- Correct race condition between allocating/freeing user memory
- Replace offsetof with struct_size
- Series-wide renaming of functions to be more consistent
- VM shutdown & restart support added in vCPU and VM Manager patches
- Convert VM function name (string) to type (number)
- Convert VM function argument to value (which could be a pointer) to remove memory wastage for arguments
- Remove defensive checks of hypervisor correctness
- Clean ups to ioeventfd as suggested by Srivatsa

Changes in v9: https://lore.kernel.org/all/[email protected]/
- Refactor Gunyah API flags to be exposed as feature flags at kernel level
- Move mbox client cleanup into gunyah_msgq_remove()
- Simplify gh_rm_call return value and response payload
- Missing clean-up/error handling/little endian fixes as suggested by Srivatsa and Alex in v8 series

Changes in v8: https://lore.kernel.org/all/[email protected]/
- Treat VM manager as a library of RM
- Add patches 21-28 as RFC to support proxy-scheduled vCPUs and necessary bits to support virtio
from Gunyah userspace

Changes in v7: https://lore.kernel.org/all/[email protected]/
- Refactor to remove gunyah RM bus
- Refactor allow multiple RM device instances
- Bump UAPI to start at 0x0
- Refactor QCOM SCM's platform hooks to allow CONFIG_QCOM_SCM=Y/CONFIG_GUNYAH=M combinations

Changes in v6: https://lore.kernel.org/all/[email protected]/
- *Replace gunyah-console with gunyah VM Manager*
- Move include/asm-generic/gunyah.h into include/linux/gunyah.h
- s/gunyah_msgq/gh_msgq/
- Minor tweaks and documentation tidying based on comments from Jiri, Greg, Arnd, Dmitry, and Bagas.

Changes in v5: https://lore.kernel.org/all/[email protected]/
- Dropped sysfs nodes
- Switch from aux bus to Gunyah RM bus for the subdevices
- Cleaning up RM console

Changes in v4: https://lore.kernel.org/all/[email protected]/
- Tidied up documentation throughout based on questions/feedback received
- Switched message queue implementation to use mailboxes
- Renamed "gunyah_device" as "gunyah_resource"

Changes in v3: https://lore.kernel.org/all/[email protected]/
- /Maintained/Supported/ in MAINTAINERS
- Tidied up documentation throughout based on questions/feedback received
- Moved hypercalls into arch/arm64/gunyah/; following hyper-v's implementation
- Drop opaque typedefs
- Move sysfs nodes under /sys/hypervisor/gunyah/
- Moved Gunyah console driver to drivers/tty/
- Reworked gh_device design to drop the Gunyah bus.

Changes in v2: https://lore.kernel.org/all/[email protected]/
- DT bindings clean up
- Switch hypercalls to follow SMCCC

v1: https://lore.kernel.org/all/[email protected]/

Elliot Berman (25):
docs: gunyah: Introduce Gunyah Hypervisor
dt-bindings: Add binding for gunyah hypervisor
gunyah: Common types and error codes for Gunyah hypercalls
virt: gunyah: Add hypercalls to identify Gunyah
virt: gunyah: msgq: Add hypercalls to send and receive messages
mailbox: Add Gunyah message queue mailbox
gunyah: rsc_mgr: Add resource manager RPC core
gunyah: rsc_mgr: Add VM lifecycle RPC
gunyah: vm_mgr: Introduce basic VM Manager
gunyah: rsc_mgr: Add RPC for sharing memory
gunyah: vm_mgr: Add/remove user memory regions
gunyah: vm_mgr: Add ioctls to support basic non-proxy VM boot
samples: Add sample userspace Gunyah VM Manager
gunyah: rsc_mgr: Add platform ops on mem_lend/mem_reclaim
virt: gunyah: Add Qualcomm Gunyah platform ops
docs: gunyah: Document Gunyah VM Manager
virt: gunyah: Translate gh_rm_hyp_resource into gunyah_resource
gunyah: vm_mgr: Add framework for VM Functions
virt: gunyah: Add resource tickets
virt: gunyah: Add IO handlers
virt: gunyah: Add proxy-scheduled vCPUs
virt: gunyah: Add hypercalls for sending doorbell
virt: gunyah: Add irqfd interface
virt: gunyah: Add ioeventfd
MAINTAINERS: Add Gunyah hypervisor drivers section

.../bindings/firmware/gunyah-hypervisor.yaml | 82 ++
.../userspace-api/ioctl/ioctl-number.rst | 1 +
Documentation/virt/gunyah/index.rst | 114 +++
Documentation/virt/gunyah/message-queue.rst | 71 ++
Documentation/virt/gunyah/vm-manager.rst | 143 +++
Documentation/virt/index.rst | 1 +
MAINTAINERS | 13 +
arch/arm64/Kbuild | 1 +
arch/arm64/gunyah/Makefile | 3 +
arch/arm64/gunyah/gunyah_hypercall.c | 142 +++
arch/arm64/include/asm/gunyah.h | 24 +
drivers/mailbox/Makefile | 2 +
drivers/mailbox/gunyah-msgq.c | 219 +++++
drivers/virt/Kconfig | 2 +
drivers/virt/Makefile | 1 +
drivers/virt/gunyah/Kconfig | 59 ++
drivers/virt/gunyah/Makefile | 11 +
drivers/virt/gunyah/gunyah_ioeventfd.c | 130 +++
drivers/virt/gunyah/gunyah_irqfd.c | 180 ++++
drivers/virt/gunyah/gunyah_platform_hooks.c | 80 ++
drivers/virt/gunyah/gunyah_qcom.c | 153 +++
drivers/virt/gunyah/gunyah_vcpu.c | 470 +++++++++
drivers/virt/gunyah/rsc_mgr.c | 909 ++++++++++++++++++
drivers/virt/gunyah/rsc_mgr.h | 19 +
drivers/virt/gunyah/rsc_mgr_rpc.c | 500 ++++++++++
drivers/virt/gunyah/vm_mgr.c | 791 +++++++++++++++
drivers/virt/gunyah/vm_mgr.h | 70 ++
drivers/virt/gunyah/vm_mgr_mm.c | 252 +++++
include/linux/gunyah.h | 207 ++++
include/linux/gunyah_rsc_mgr.h | 162 ++++
include/linux/gunyah_vm_mgr.h | 153 +++
include/uapi/linux/gunyah.h | 293 ++++++
samples/Kconfig | 10 +
samples/Makefile | 1 +
samples/gunyah/.gitignore | 2 +
samples/gunyah/Makefile | 6 +
samples/gunyah/gunyah_vmm.c | 266 +++++
samples/gunyah/sample_vm.dts | 68 ++
38 files changed, 5611 insertions(+)
create mode 100644 Documentation/devicetree/bindings/firmware/gunyah-hypervisor.yaml
create mode 100644 Documentation/virt/gunyah/index.rst
create mode 100644 Documentation/virt/gunyah/message-queue.rst
create mode 100644 Documentation/virt/gunyah/vm-manager.rst
create mode 100644 arch/arm64/gunyah/Makefile
create mode 100644 arch/arm64/gunyah/gunyah_hypercall.c
create mode 100644 arch/arm64/include/asm/gunyah.h
create mode 100644 drivers/mailbox/gunyah-msgq.c
create mode 100644 drivers/virt/gunyah/Kconfig
create mode 100644 drivers/virt/gunyah/Makefile
create mode 100644 drivers/virt/gunyah/gunyah_ioeventfd.c
create mode 100644 drivers/virt/gunyah/gunyah_irqfd.c
create mode 100644 drivers/virt/gunyah/gunyah_platform_hooks.c
create mode 100644 drivers/virt/gunyah/gunyah_qcom.c
create mode 100644 drivers/virt/gunyah/gunyah_vcpu.c
create mode 100644 drivers/virt/gunyah/rsc_mgr.c
create mode 100644 drivers/virt/gunyah/rsc_mgr.h
create mode 100644 drivers/virt/gunyah/rsc_mgr_rpc.c
create mode 100644 drivers/virt/gunyah/vm_mgr.c
create mode 100644 drivers/virt/gunyah/vm_mgr.h
create mode 100644 drivers/virt/gunyah/vm_mgr_mm.c
create mode 100644 include/linux/gunyah.h
create mode 100644 include/linux/gunyah_rsc_mgr.h
create mode 100644 include/linux/gunyah_vm_mgr.h
create mode 100644 include/uapi/linux/gunyah.h
create mode 100644 samples/gunyah/.gitignore
create mode 100644 samples/gunyah/Makefile
create mode 100644 samples/gunyah/gunyah_vmm.c
create mode 100644 samples/gunyah/sample_vm.dts


base-commit: 858fd168a95c5b9669aac8db6c14a9aeab446375
--
2.40.0



2023-06-13 17:32:36

by Elliot Berman

[permalink] [raw]
Subject: [PATCH v14 12/25] gunyah: vm_mgr: Add ioctls to support basic non-proxy VM boot

Add remaining ioctls to support non-proxy VM boot:

- Gunyah Resource Manager uses the VM's devicetree to configure the
virtual machine. The location of the devicetree in the guest's
virtual memory can be declared via the SET_DTB_CONFIG ioctl.
- Trigger start of the virtual machine with VM_START ioctl.

Reviewed-by: Alex Elder <[email protected]>
Co-developed-by: Prakruthi Deepak Heragu <[email protected]>
Signed-off-by: Prakruthi Deepak Heragu <[email protected]>
Signed-off-by: Elliot Berman <[email protected]>
---
drivers/virt/gunyah/vm_mgr.c | 215 ++++++++++++++++++++++++++++++++
drivers/virt/gunyah/vm_mgr.h | 11 ++
drivers/virt/gunyah/vm_mgr_mm.c | 20 +++
include/uapi/linux/gunyah.h | 15 +++
4 files changed, 261 insertions(+)

diff --git a/drivers/virt/gunyah/vm_mgr.c b/drivers/virt/gunyah/vm_mgr.c
index 297427952b8c7..562ae6ed4a5f1 100644
--- a/drivers/virt/gunyah/vm_mgr.c
+++ b/drivers/virt/gunyah/vm_mgr.c
@@ -17,6 +17,68 @@

static void gh_vm_free(struct work_struct *work);

+static int gh_vm_rm_notification_status(struct gh_vm *ghvm, void *data)
+{
+ struct gh_rm_vm_status_payload *payload = data;
+
+ if (le16_to_cpu(payload->vmid) != ghvm->vmid)
+ return NOTIFY_OK;
+
+ /* All other state transitions are synchronous to a corresponding RM call */
+ if (payload->vm_status == GH_RM_VM_STATUS_RESET) {
+ down_write(&ghvm->status_lock);
+ ghvm->vm_status = payload->vm_status;
+ up_write(&ghvm->status_lock);
+ wake_up(&ghvm->vm_status_wait);
+ }
+
+ return NOTIFY_DONE;
+}
+
+static int gh_vm_rm_notification_exited(struct gh_vm *ghvm, void *data)
+{
+ struct gh_rm_vm_exited_payload *payload = data;
+
+ if (le16_to_cpu(payload->vmid) != ghvm->vmid)
+ return NOTIFY_OK;
+
+ down_write(&ghvm->status_lock);
+ ghvm->vm_status = GH_RM_VM_STATUS_EXITED;
+ up_write(&ghvm->status_lock);
+ wake_up(&ghvm->vm_status_wait);
+
+ return NOTIFY_DONE;
+}
+
+static int gh_vm_rm_notification(struct notifier_block *nb, unsigned long action, void *data)
+{
+ struct gh_vm *ghvm = container_of(nb, struct gh_vm, nb);
+
+ switch (action) {
+ case GH_RM_NOTIFICATION_VM_STATUS:
+ return gh_vm_rm_notification_status(ghvm, data);
+ case GH_RM_NOTIFICATION_VM_EXITED:
+ return gh_vm_rm_notification_exited(ghvm, data);
+ default:
+ return NOTIFY_OK;
+ }
+}
+
+static void gh_vm_stop(struct gh_vm *ghvm)
+{
+ int ret;
+
+ down_write(&ghvm->status_lock);
+ if (ghvm->vm_status == GH_RM_VM_STATUS_RUNNING) {
+ ret = gh_rm_vm_stop(ghvm->rm, ghvm->vmid);
+ if (ret)
+ dev_warn(ghvm->parent, "Failed to stop VM: %d\n", ret);
+ }
+ up_write(&ghvm->status_lock);
+
+ wait_event(ghvm->vm_status_wait, ghvm->vm_status == GH_RM_VM_STATUS_EXITED);
+}
+
static __must_check struct gh_vm *gh_vm_alloc(struct gh_rm *rm)
{
struct gh_vm *ghvm;
@@ -26,17 +88,130 @@ static __must_check struct gh_vm *gh_vm_alloc(struct gh_rm *rm)
return ERR_PTR(-ENOMEM);

ghvm->parent = gh_rm_get(rm);
+ ghvm->vmid = GH_VMID_INVAL;
ghvm->rm = rm;

mmgrab(current->mm);
ghvm->mm = current->mm;
mutex_init(&ghvm->mm_lock);
INIT_LIST_HEAD(&ghvm->memory_mappings);
+ init_rwsem(&ghvm->status_lock);
+ init_waitqueue_head(&ghvm->vm_status_wait);
INIT_WORK(&ghvm->free_work, gh_vm_free);
+ ghvm->vm_status = GH_RM_VM_STATUS_NO_STATE;

return ghvm;
}

+static int gh_vm_start(struct gh_vm *ghvm)
+{
+ struct gh_vm_mem *mapping;
+ u64 dtb_offset;
+ u32 mem_handle;
+ int ret;
+
+ down_write(&ghvm->status_lock);
+ if (ghvm->vm_status != GH_RM_VM_STATUS_NO_STATE) {
+ up_write(&ghvm->status_lock);
+ return 0;
+ }
+
+ ghvm->nb.notifier_call = gh_vm_rm_notification;
+ ret = gh_rm_notifier_register(ghvm->rm, &ghvm->nb);
+ if (ret)
+ goto err;
+
+ ret = gh_rm_alloc_vmid(ghvm->rm, 0);
+ if (ret < 0) {
+ gh_rm_notifier_unregister(ghvm->rm, &ghvm->nb);
+ goto err;
+ }
+ ghvm->vmid = ret;
+ ghvm->vm_status = GH_RM_VM_STATUS_LOAD;
+
+ mutex_lock(&ghvm->mm_lock);
+ list_for_each_entry(mapping, &ghvm->memory_mappings, list) {
+ mapping->parcel.acl_entries[0].vmid = cpu_to_le16(ghvm->vmid);
+ ret = gh_rm_mem_share(ghvm->rm, &mapping->parcel);
+ if (ret) {
+ dev_warn(ghvm->parent, "Failed to share parcel %d: %d\n",
+ mapping->parcel.label, ret);
+ mutex_unlock(&ghvm->mm_lock);
+ goto err;
+ }
+ }
+ mutex_unlock(&ghvm->mm_lock);
+
+ mapping = gh_vm_mem_find_by_addr(ghvm, ghvm->dtb_config.guest_phys_addr,
+ ghvm->dtb_config.size);
+ if (!mapping) {
+ dev_warn(ghvm->parent, "Failed to find the memory_handle for DTB\n");
+ ret = -EINVAL;
+ goto err;
+ }
+
+ mem_handle = mapping->parcel.mem_handle;
+ dtb_offset = ghvm->dtb_config.guest_phys_addr - mapping->guest_phys_addr;
+
+ ret = gh_rm_vm_configure(ghvm->rm, ghvm->vmid, ghvm->auth, mem_handle,
+ 0, 0, dtb_offset, ghvm->dtb_config.size);
+ if (ret) {
+ dev_warn(ghvm->parent, "Failed to configure VM: %d\n", ret);
+ goto err;
+ }
+
+ ret = gh_rm_vm_init(ghvm->rm, ghvm->vmid);
+ if (ret) {
+ ghvm->vm_status = GH_RM_VM_STATUS_INIT_FAILED;
+ dev_warn(ghvm->parent, "Failed to initialize VM: %d\n", ret);
+ goto err;
+ }
+ ghvm->vm_status = GH_RM_VM_STATUS_READY;
+
+ ret = gh_rm_vm_start(ghvm->rm, ghvm->vmid);
+ if (ret) {
+ dev_warn(ghvm->parent, "Failed to start VM: %d\n", ret);
+ goto err;
+ }
+
+ ghvm->vm_status = GH_RM_VM_STATUS_RUNNING;
+ up_write(&ghvm->status_lock);
+ return ret;
+err:
+ /* gh_vm_free will handle releasing resources and reclaiming memory */
+ up_write(&ghvm->status_lock);
+ return ret;
+}
+
+static int gh_vm_ensure_started(struct gh_vm *ghvm)
+{
+ int ret;
+
+ ret = down_read_interruptible(&ghvm->status_lock);
+ if (ret)
+ return ret;
+
+ /* Unlikely because VM is typically started */
+ if (unlikely(ghvm->vm_status == GH_RM_VM_STATUS_NO_STATE)) {
+ up_read(&ghvm->status_lock);
+ ret = gh_vm_start(ghvm);
+ if (ret)
+ return ret;
+ /** gh_vm_start() is guaranteed to bring status out of
+ * GH_RM_VM_STATUS_LOAD, thus infinitely recursive call is not
+ * possible
+ */
+ return gh_vm_ensure_started(ghvm);
+ }
+
+ /* Unlikely because VM is typically running */
+ if (unlikely(ghvm->vm_status != GH_RM_VM_STATUS_RUNNING))
+ ret = -ENODEV;
+
+ up_read(&ghvm->status_lock);
+ return ret;
+}
+
static long gh_vm_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct gh_vm *ghvm = filp->private_data;
@@ -61,6 +236,24 @@ static long gh_vm_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
r = gh_vm_mem_alloc(ghvm, &region);
break;
}
+ case GH_VM_SET_DTB_CONFIG: {
+ struct gh_vm_dtb_config dtb_config;
+
+ if (copy_from_user(&dtb_config, argp, sizeof(dtb_config)))
+ return -EFAULT;
+
+ if (overflows_type(dtb_config.guest_phys_addr + dtb_config.size, u64))
+ return -EOVERFLOW;
+
+ ghvm->dtb_config = dtb_config;
+
+ r = 0;
+ break;
+ }
+ case GH_VM_START: {
+ r = gh_vm_ensure_started(ghvm);
+ break;
+ }
default:
r = -ENOTTY;
break;
@@ -72,8 +265,30 @@ static long gh_vm_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
static void gh_vm_free(struct work_struct *work)
{
struct gh_vm *ghvm = container_of(work, struct gh_vm, free_work);
+ int ret;
+
+ if (ghvm->vm_status == GH_RM_VM_STATUS_RUNNING)
+ gh_vm_stop(ghvm);
+
+ if (ghvm->vm_status != GH_RM_VM_STATUS_NO_STATE &&
+ ghvm->vm_status != GH_RM_VM_STATUS_LOAD &&
+ ghvm->vm_status != GH_RM_VM_STATUS_RESET) {
+ ret = gh_rm_vm_reset(ghvm->rm, ghvm->vmid);
+ if (ret)
+ dev_err(ghvm->parent, "Failed to reset the vm: %d\n", ret);
+ wait_event(ghvm->vm_status_wait, ghvm->vm_status == GH_RM_VM_STATUS_RESET);
+ }

gh_vm_mem_reclaim(ghvm);
+
+ if (ghvm->vm_status > GH_RM_VM_STATUS_NO_STATE) {
+ gh_rm_notifier_unregister(ghvm->rm, &ghvm->nb);
+
+ ret = gh_rm_dealloc_vmid(ghvm->rm, ghvm->vmid);
+ if (ret)
+ dev_warn(ghvm->parent, "Failed to deallocate vmid: %d\n", ret);
+ }
+
gh_rm_put(ghvm->rm);
mmdrop(ghvm->mm);
kfree(ghvm);
diff --git a/drivers/virt/gunyah/vm_mgr.h b/drivers/virt/gunyah/vm_mgr.h
index 434ef9f662a7a..4173bd51f83fe 100644
--- a/drivers/virt/gunyah/vm_mgr.h
+++ b/drivers/virt/gunyah/vm_mgr.h
@@ -10,6 +10,8 @@
#include <linux/list.h>
#include <linux/miscdevice.h>
#include <linux/mutex.h>
+#include <linux/rwsem.h>
+#include <linux/wait.h>

#include <uapi/linux/gunyah.h>

@@ -31,8 +33,16 @@ struct gh_vm_mem {
};

struct gh_vm {
+ u16 vmid;
struct gh_rm *rm;
struct device *parent;
+ enum gh_rm_vm_auth_mechanism auth;
+ struct gh_vm_dtb_config dtb_config;
+
+ struct notifier_block nb;
+ enum gh_rm_vm_status vm_status;
+ wait_queue_head_t vm_status_wait;
+ struct rw_semaphore status_lock;

struct work_struct free_work;
struct mm_struct *mm; /* userspace tied to this vm */
@@ -42,5 +52,6 @@ struct gh_vm {

int gh_vm_mem_alloc(struct gh_vm *ghvm, struct gh_userspace_memory_region *region);
void gh_vm_mem_reclaim(struct gh_vm *ghvm);
+struct gh_vm_mem *gh_vm_mem_find_by_addr(struct gh_vm *ghvm, u64 guest_phys_addr, u32 size);

#endif
diff --git a/drivers/virt/gunyah/vm_mgr_mm.c b/drivers/virt/gunyah/vm_mgr_mm.c
index 6974607f02edd..f8a09e86d6bc1 100644
--- a/drivers/virt/gunyah/vm_mgr_mm.c
+++ b/drivers/virt/gunyah/vm_mgr_mm.c
@@ -75,6 +75,26 @@ void gh_vm_mem_reclaim(struct gh_vm *ghvm)
mutex_unlock(&ghvm->mm_lock);
}

+struct gh_vm_mem *gh_vm_mem_find_by_addr(struct gh_vm *ghvm, u64 guest_phys_addr, u32 size)
+{
+ struct gh_vm_mem *mapping;
+
+ if (overflows_type(guest_phys_addr + size, u64))
+ return NULL;
+
+ mutex_lock(&ghvm->mm_lock);
+
+ list_for_each_entry(mapping, &ghvm->memory_mappings, list) {
+ if (gh_vm_mem_overlap(mapping, guest_phys_addr, size))
+ goto unlock;
+ }
+
+ mapping = NULL;
+unlock:
+ mutex_unlock(&ghvm->mm_lock);
+ return mapping;
+}
+
int gh_vm_mem_alloc(struct gh_vm *ghvm, struct gh_userspace_memory_region *region)
{
struct gh_vm_mem *mapping, *tmp_mapping;
diff --git a/include/uapi/linux/gunyah.h b/include/uapi/linux/gunyah.h
index 91d6dd26fcc89..4b63d0b9b8ba7 100644
--- a/include/uapi/linux/gunyah.h
+++ b/include/uapi/linux/gunyah.h
@@ -57,4 +57,19 @@ struct gh_userspace_memory_region {
#define GH_VM_SET_USER_MEM_REGION _IOW(GH_IOCTL_TYPE, 0x1, \
struct gh_userspace_memory_region)

+/**
+ * struct gh_vm_dtb_config - Set the location of the VM's devicetree blob
+ * @guest_phys_addr: Address of the VM's devicetree in guest memory.
+ * @size: Maximum size of the devicetree including space for overlays.
+ * Resource manager applies an overlay to the DTB and dtb_size should
+ * include room for the overlay. A page of memory is typicaly plenty.
+ */
+struct gh_vm_dtb_config {
+ __u64 guest_phys_addr;
+ __u64 size;
+};
+#define GH_VM_SET_DTB_CONFIG _IOW(GH_IOCTL_TYPE, 0x2, struct gh_vm_dtb_config)
+
+#define GH_VM_START _IO(GH_IOCTL_TYPE, 0x3)
+
#endif
--
2.40.0


2023-06-13 17:33:21

by Elliot Berman

[permalink] [raw]
Subject: [PATCH v14 22/25] virt: gunyah: Add hypercalls for sending doorbell

Gunyah doorbells allow two virtual machines to signal each other using
interrupts. Add the hypercalls needed to assert the interrupt.

Reviewed-by: Alex Elder <[email protected]>
Signed-off-by: Elliot Berman <[email protected]>
---
arch/arm64/gunyah/gunyah_hypercall.c | 25 +++++++++++++++++++++++++
include/linux/gunyah.h | 3 +++
2 files changed, 28 insertions(+)

diff --git a/arch/arm64/gunyah/gunyah_hypercall.c b/arch/arm64/gunyah/gunyah_hypercall.c
index 7d96491f84e00..e178b5a0f6917 100644
--- a/arch/arm64/gunyah/gunyah_hypercall.c
+++ b/arch/arm64/gunyah/gunyah_hypercall.c
@@ -35,6 +35,8 @@ EXPORT_SYMBOL_GPL(arch_is_gh_guest);
fn)

#define GH_HYPERCALL_HYP_IDENTIFY GH_HYPERCALL(0x8000)
+#define GH_HYPERCALL_BELL_SEND GH_HYPERCALL(0x8012)
+#define GH_HYPERCALL_BELL_SET_MASK GH_HYPERCALL(0x8015)
#define GH_HYPERCALL_MSGQ_SEND GH_HYPERCALL(0x801B)
#define GH_HYPERCALL_MSGQ_RECV GH_HYPERCALL(0x801C)
#define GH_HYPERCALL_VCPU_RUN GH_HYPERCALL(0x8065)
@@ -57,6 +59,29 @@ void gh_hypercall_hyp_identify(struct gh_hypercall_hyp_identify_resp *hyp_identi
}
EXPORT_SYMBOL_GPL(gh_hypercall_hyp_identify);

+enum gh_error gh_hypercall_bell_send(u64 capid, u64 new_flags, u64 *old_flags)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_1_1_hvc(GH_HYPERCALL_BELL_SEND, capid, new_flags, 0, &res);
+
+ if (res.a0 == GH_ERROR_OK && old_flags)
+ *old_flags = res.a1;
+
+ return res.a0;
+}
+EXPORT_SYMBOL_GPL(gh_hypercall_bell_send);
+
+enum gh_error gh_hypercall_bell_set_mask(u64 capid, u64 enable_mask, u64 ack_mask)
+{
+ struct arm_smccc_res res;
+
+ arm_smccc_1_1_hvc(GH_HYPERCALL_BELL_SET_MASK, capid, enable_mask, ack_mask, 0, &res);
+
+ return res.a0;
+}
+EXPORT_SYMBOL_GPL(gh_hypercall_bell_set_mask);
+
enum gh_error gh_hypercall_msgq_send(u64 capid, size_t size, void *buff, u64 tx_flags, bool *ready)
{
struct arm_smccc_res res;
diff --git a/include/linux/gunyah.h b/include/linux/gunyah.h
index cd5704a82c6a5..1f1685518bf3c 100644
--- a/include/linux/gunyah.h
+++ b/include/linux/gunyah.h
@@ -171,6 +171,9 @@ static inline u16 gh_api_version(const struct gh_hypercall_hyp_identify_resp *gh

void gh_hypercall_hyp_identify(struct gh_hypercall_hyp_identify_resp *hyp_identity);

+enum gh_error gh_hypercall_bell_send(u64 capid, u64 new_flags, u64 *old_flags);
+enum gh_error gh_hypercall_bell_set_mask(u64 capid, u64 enable_mask, u64 ack_mask);
+
#define GH_HYPERCALL_MSGQ_TX_FLAGS_PUSH BIT(0)

enum gh_error gh_hypercall_msgq_send(u64 capid, size_t size, void *buff, u64 tx_flags, bool *ready);
--
2.40.0


2023-06-13 17:33:35

by Elliot Berman

[permalink] [raw]
Subject: [PATCH v14 17/25] virt: gunyah: Translate gh_rm_hyp_resource into gunyah_resource

When booting a Gunyah virtual machine, the host VM may gain capabilities
to interact with resources for the guest virtual machine. Examples of
such resources are vCPUs or message queues. To use those resources, we
need to translate the RM response into a gunyah_resource structure which
are useful to Linux drivers. Presently, Linux drivers need only to know
the type of resource, the capability ID, and an interrupt.

On ARM64 systems, the interrupt reported by Gunyah is the GIC interrupt
ID number and always a SPI.

Reviewed-by: Alex Elder <[email protected]>
Signed-off-by: Elliot Berman <[email protected]>
---
arch/arm64/include/asm/gunyah.h | 24 +++++
drivers/virt/gunyah/rsc_mgr.c | 164 +++++++++++++++++++++++++++++++-
include/linux/gunyah.h | 3 +
include/linux/gunyah_rsc_mgr.h | 3 +
4 files changed, 193 insertions(+), 1 deletion(-)
create mode 100644 arch/arm64/include/asm/gunyah.h

diff --git a/arch/arm64/include/asm/gunyah.h b/arch/arm64/include/asm/gunyah.h
new file mode 100644
index 0000000000000..c83d983b0f4e0
--- /dev/null
+++ b/arch/arm64/include/asm/gunyah.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+#ifndef _ASM_GUNYAH_H
+#define _ASM_GUNYAH_H
+
+#include <linux/irq.h>
+#include <dt-bindings/interrupt-controller/arm-gic.h>
+
+static inline int arch_gh_fill_irq_fwspec_params(u32 virq, struct irq_fwspec *fwspec)
+{
+ /* Assume that Gunyah gave us an SPI; defensively check it */
+ if (WARN_ON(virq < 32 || virq > 1019))
+ return -EINVAL;
+
+ fwspec->param_count = 3;
+ fwspec->param[0] = GIC_SPI;
+ fwspec->param[1] = virq - 32;
+ fwspec->param[2] = IRQ_TYPE_EDGE_RISING;
+ return 0;
+}
+
+#endif
diff --git a/drivers/virt/gunyah/rsc_mgr.c b/drivers/virt/gunyah/rsc_mgr.c
index a0faf126ee56e..3255ae1855990 100644
--- a/drivers/virt/gunyah/rsc_mgr.c
+++ b/drivers/virt/gunyah/rsc_mgr.c
@@ -17,6 +17,8 @@
#include <linux/platform_device.h>
#include <linux/miscdevice.h>

+#include <asm/gunyah.h>
+
#include "rsc_mgr.h"
#include "vm_mgr.h"

@@ -133,6 +135,7 @@ struct gh_rm_connection {
* @send_lock: synchronization to allow only one request to be sent at a time
* @nh: notifier chain for clients interested in RM notification messages
* @miscdev: /dev/gunyah
+ * @irq_domain: Domain to translate Gunyah hwirqs to Linux irqs
*/
struct gh_rm {
struct device *dev;
@@ -151,6 +154,7 @@ struct gh_rm {
struct blocking_notifier_head nh;

struct miscdevice miscdev;
+ struct irq_domain *irq_domain;
};

/**
@@ -191,6 +195,135 @@ static inline int gh_rm_error_remap(enum gh_rm_error rm_error)
}
}

+struct gh_irq_chip_data {
+ u32 gh_virq;
+};
+
+static struct irq_chip gh_rm_irq_chip = {
+ .name = "Gunyah",
+ .irq_enable = irq_chip_enable_parent,
+ .irq_disable = irq_chip_disable_parent,
+ .irq_ack = irq_chip_ack_parent,
+ .irq_mask = irq_chip_mask_parent,
+ .irq_mask_ack = irq_chip_mask_ack_parent,
+ .irq_unmask = irq_chip_unmask_parent,
+ .irq_eoi = irq_chip_eoi_parent,
+ .irq_set_affinity = irq_chip_set_affinity_parent,
+ .irq_set_type = irq_chip_set_type_parent,
+ .irq_set_wake = irq_chip_set_wake_parent,
+ .irq_set_vcpu_affinity = irq_chip_set_vcpu_affinity_parent,
+ .irq_retrigger = irq_chip_retrigger_hierarchy,
+ .irq_get_irqchip_state = irq_chip_get_parent_state,
+ .irq_set_irqchip_state = irq_chip_set_parent_state,
+ .flags = IRQCHIP_SET_TYPE_MASKED |
+ IRQCHIP_SKIP_SET_WAKE |
+ IRQCHIP_MASK_ON_SUSPEND,
+};
+
+static int gh_rm_irq_domain_alloc(struct irq_domain *d, unsigned int virq, unsigned int nr_irqs,
+ void *arg)
+{
+ struct gh_irq_chip_data *chip_data, *spec = arg;
+ struct irq_fwspec parent_fwspec = {};
+ struct gh_rm *rm = d->host_data;
+ u32 gh_virq = spec->gh_virq;
+ int ret;
+
+ if (nr_irqs != 1)
+ return -EINVAL;
+
+ chip_data = kzalloc(sizeof(*chip_data), GFP_KERNEL);
+ if (!chip_data)
+ return -ENOMEM;
+
+ chip_data->gh_virq = gh_virq;
+
+ ret = irq_domain_set_hwirq_and_chip(d, virq, chip_data->gh_virq, &gh_rm_irq_chip,
+ chip_data);
+ if (ret)
+ goto err_free_irq_data;
+
+ parent_fwspec.fwnode = d->parent->fwnode;
+ ret = arch_gh_fill_irq_fwspec_params(chip_data->gh_virq, &parent_fwspec);
+ if (ret) {
+ dev_err(rm->dev, "virq translation failed %u: %d\n", chip_data->gh_virq, ret);
+ goto err_free_irq_data;
+ }
+
+ ret = irq_domain_alloc_irqs_parent(d, virq, nr_irqs, &parent_fwspec);
+ if (ret)
+ goto err_free_irq_data;
+
+ return ret;
+err_free_irq_data:
+ kfree(chip_data);
+ return ret;
+}
+
+static void gh_rm_irq_domain_free_single(struct irq_domain *d, unsigned int virq)
+{
+ struct irq_data *irq_data;
+
+ irq_data = irq_domain_get_irq_data(d, virq);
+ if (!irq_data)
+ return;
+
+ kfree(irq_data->chip_data);
+ irq_data->chip_data = NULL;
+}
+
+static void gh_rm_irq_domain_free(struct irq_domain *d, unsigned int virq, unsigned int nr_irqs)
+{
+ unsigned int i;
+
+ for (i = 0; i < nr_irqs; i++)
+ gh_rm_irq_domain_free_single(d, virq);
+}
+
+static const struct irq_domain_ops gh_rm_irq_domain_ops = {
+ .alloc = gh_rm_irq_domain_alloc,
+ .free = gh_rm_irq_domain_free,
+};
+
+struct gh_resource *gh_rm_alloc_resource(struct gh_rm *rm, struct gh_rm_hyp_resource *hyp_resource)
+{
+ struct gh_resource *ghrsc;
+ int ret;
+
+ ghrsc = kzalloc(sizeof(*ghrsc), GFP_KERNEL);
+ if (!ghrsc)
+ return NULL;
+
+ ghrsc->type = hyp_resource->type;
+ ghrsc->capid = le64_to_cpu(hyp_resource->cap_id);
+ ghrsc->irq = IRQ_NOTCONNECTED;
+ ghrsc->rm_label = le32_to_cpu(hyp_resource->resource_label);
+ if (hyp_resource->virq) {
+ struct gh_irq_chip_data irq_data = {
+ .gh_virq = le32_to_cpu(hyp_resource->virq),
+ };
+
+ ret = irq_domain_alloc_irqs(rm->irq_domain, 1, NUMA_NO_NODE, &irq_data);
+ if (ret < 0) {
+ dev_err(rm->dev,
+ "Failed to allocate interrupt for resource %d label: %d: %d\n",
+ ghrsc->type, ghrsc->rm_label, ret);
+ kfree(ghrsc);
+ return NULL;
+ } else {
+ ghrsc->irq = ret;
+ }
+ }
+
+ return ghrsc;
+}
+
+void gh_rm_free_resource(struct gh_resource *ghrsc)
+{
+ irq_dispose_mapping(ghrsc->irq);
+ kfree(ghrsc);
+}
+
static int gh_rm_init_connection_payload(struct gh_rm_connection *connection, void *msg,
size_t hdr_size, size_t msg_size)
{
@@ -660,6 +793,8 @@ static int gh_identify(void)

static int gh_rm_drv_probe(struct platform_device *pdev)
{
+ struct irq_domain *parent_irq_domain;
+ struct device_node *parent_irq_node;
struct gh_msgq_tx_data *msg;
struct gh_rm *rm;
int ret;
@@ -700,15 +835,41 @@ static int gh_rm_drv_probe(struct platform_device *pdev)
if (ret)
goto err_cache;

+ parent_irq_node = of_irq_find_parent(pdev->dev.of_node);
+ if (!parent_irq_node) {
+ dev_err(&pdev->dev, "Failed to find interrupt parent of resource manager\n");
+ ret = -ENODEV;
+ goto err_msgq;
+ }
+
+ parent_irq_domain = irq_find_host(parent_irq_node);
+ if (!parent_irq_domain) {
+ dev_err(&pdev->dev, "Failed to find interrupt parent domain of resource manager\n");
+ ret = -ENODEV;
+ goto err_msgq;
+ }
+
+ rm->irq_domain = irq_domain_add_hierarchy(parent_irq_domain, 0, 0, pdev->dev.of_node,
+ &gh_rm_irq_domain_ops, NULL);
+ if (!rm->irq_domain) {
+ dev_err(&pdev->dev, "Failed to add irq domain\n");
+ ret = -ENODEV;
+ goto err_msgq;
+ }
+ rm->irq_domain->host_data = rm;
+
+ rm->miscdev.parent = &pdev->dev;
rm->miscdev.name = "gunyah";
rm->miscdev.minor = MISC_DYNAMIC_MINOR;
rm->miscdev.fops = &gh_dev_fops;

ret = misc_register(&rm->miscdev);
if (ret)
- goto err_msgq;
+ goto err_irq_domain;

return 0;
+err_irq_domain:
+ irq_domain_remove(rm->irq_domain);
err_msgq:
gh_msgq_remove(&rm->msgq);
err_cache:
@@ -721,6 +882,7 @@ static int gh_rm_drv_remove(struct platform_device *pdev)
struct gh_rm *rm = platform_get_drvdata(pdev);

misc_deregister(&rm->miscdev);
+ irq_domain_remove(rm->irq_domain);
gh_msgq_remove(&rm->msgq);
kmem_cache_destroy(rm->cache);

diff --git a/include/linux/gunyah.h b/include/linux/gunyah.h
index 982e27d10d57f..4b398b59c2c5a 100644
--- a/include/linux/gunyah.h
+++ b/include/linux/gunyah.h
@@ -27,6 +27,9 @@ struct gh_resource {
enum gh_resource_type type;
u64 capid;
unsigned int irq;
+
+ struct list_head list;
+ u32 rm_label;
};

/**
diff --git a/include/linux/gunyah_rsc_mgr.h b/include/linux/gunyah_rsc_mgr.h
index cac4476b46ade..c0cf8b4dc7beb 100644
--- a/include/linux/gunyah_rsc_mgr.h
+++ b/include/linux/gunyah_rsc_mgr.h
@@ -139,6 +139,9 @@ int gh_rm_get_hyp_resources(struct gh_rm *rm, u16 vmid,
struct gh_rm_hyp_resources **resources);
int gh_rm_get_vmid(struct gh_rm *rm, u16 *vmid);

+struct gh_resource *gh_rm_alloc_resource(struct gh_rm *rm, struct gh_rm_hyp_resource *hyp_resource);
+void gh_rm_free_resource(struct gh_resource *ghrsc);
+
struct gh_rm_platform_ops {
int (*pre_mem_share)(struct gh_rm *rm, struct gh_rm_mem_parcel *mem_parcel);
int (*post_mem_reclaim)(struct gh_rm *rm, struct gh_rm_mem_parcel *mem_parcel);
--
2.40.0


2023-06-13 17:33:48

by Elliot Berman

[permalink] [raw]
Subject: [PATCH v14 19/25] virt: gunyah: Add resource tickets

Some VM functions need to acquire Gunyah resources. For instance, Gunyah
vCPUs are exposed to the host as a resource. The Gunyah vCPU function
will register a resource ticket and be able to interact with the
hypervisor once the resource ticket is filled.

Resource tickets are the mechanism for functions to acquire ownership of
Gunyah resources. Gunyah functions can be created before the VM's
resources are created and made available to Linux. A resource ticket
identifies a type of resource and a label of a resource which the ticket
holder is interested in.

Resources are created by Gunyah as configured in the VM's devicetree
configuration. Gunyah doesn't process the label and that makes it
possible for userspace to create multiple resources with the same label.
Resource ticket owners need to be prepared for populate to be called
multiple times if userspace created multiple resources with the same
label.

Reviewed-by: Alex Elder <[email protected]>
Signed-off-by: Elliot Berman <[email protected]>
---
drivers/virt/gunyah/vm_mgr.c | 117 +++++++++++++++++++++++++++++++++-
drivers/virt/gunyah/vm_mgr.h | 4 ++
include/linux/gunyah_vm_mgr.h | 31 +++++++++
3 files changed, 151 insertions(+), 1 deletion(-)

diff --git a/drivers/virt/gunyah/vm_mgr.c b/drivers/virt/gunyah/vm_mgr.c
index cfd79bc9900fd..d6aa1731148ae 100644
--- a/drivers/virt/gunyah/vm_mgr.c
+++ b/drivers/virt/gunyah/vm_mgr.c
@@ -183,6 +183,99 @@ void gh_vm_function_unregister(struct gh_vm_function *fn)
}
EXPORT_SYMBOL_GPL(gh_vm_function_unregister);

+int gh_vm_add_resource_ticket(struct gh_vm *ghvm, struct gh_vm_resource_ticket *ticket)
+{
+ struct gh_vm_resource_ticket *iter;
+ struct gh_resource *ghrsc, *rsc_iter;
+ int ret = 0;
+
+ mutex_lock(&ghvm->resources_lock);
+ list_for_each_entry(iter, &ghvm->resource_tickets, vm_list) {
+ if (iter->resource_type == ticket->resource_type && iter->label == ticket->label) {
+ ret = -EEXIST;
+ goto out;
+ }
+ }
+
+ if (!try_module_get(ticket->owner)) {
+ ret = -ENODEV;
+ goto out;
+ }
+
+ list_add(&ticket->vm_list, &ghvm->resource_tickets);
+ INIT_LIST_HEAD(&ticket->resources);
+
+ list_for_each_entry_safe(ghrsc, rsc_iter, &ghvm->resources, list) {
+ if (ghrsc->type == ticket->resource_type && ghrsc->rm_label == ticket->label) {
+ if (ticket->populate(ticket, ghrsc))
+ list_move(&ghrsc->list, &ticket->resources);
+ }
+ }
+out:
+ mutex_unlock(&ghvm->resources_lock);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(gh_vm_add_resource_ticket);
+
+void gh_vm_remove_resource_ticket(struct gh_vm *ghvm, struct gh_vm_resource_ticket *ticket)
+{
+ struct gh_resource *ghrsc, *iter;
+
+ mutex_lock(&ghvm->resources_lock);
+ list_for_each_entry_safe(ghrsc, iter, &ticket->resources, list) {
+ ticket->unpopulate(ticket, ghrsc);
+ list_move(&ghrsc->list, &ghvm->resources);
+ }
+
+ module_put(ticket->owner);
+ list_del(&ticket->vm_list);
+ mutex_unlock(&ghvm->resources_lock);
+}
+EXPORT_SYMBOL_GPL(gh_vm_remove_resource_ticket);
+
+static void gh_vm_add_resource(struct gh_vm *ghvm, struct gh_resource *ghrsc)
+{
+ struct gh_vm_resource_ticket *ticket;
+
+ mutex_lock(&ghvm->resources_lock);
+ list_for_each_entry(ticket, &ghvm->resource_tickets, vm_list) {
+ if (ghrsc->type == ticket->resource_type && ghrsc->rm_label == ticket->label) {
+ if (ticket->populate(ticket, ghrsc))
+ list_add(&ghrsc->list, &ticket->resources);
+ else
+ list_add(&ghrsc->list, &ghvm->resources);
+ /* unconditonal -- we prevent multiple identical
+ * resource tickets so there will not be some other
+ * ticket elsewhere in the list if populate() failed.
+ */
+ goto found;
+ }
+ }
+ list_add(&ghrsc->list, &ghvm->resources);
+found:
+ mutex_unlock(&ghvm->resources_lock);
+}
+
+static void gh_vm_clean_resources(struct gh_vm *ghvm)
+{
+ struct gh_vm_resource_ticket *ticket, *titer;
+ struct gh_resource *ghrsc, *riter;
+
+ mutex_lock(&ghvm->resources_lock);
+ if (!list_empty(&ghvm->resource_tickets)) {
+ dev_warn(ghvm->parent, "Dangling resource tickets:\n");
+ list_for_each_entry_safe(ticket, titer, &ghvm->resource_tickets, vm_list) {
+ dev_warn(ghvm->parent, " %pS\n", ticket->populate);
+ gh_vm_remove_resource_ticket(ghvm, ticket);
+ }
+ }
+
+ list_for_each_entry_safe(ghrsc, riter, &ghvm->resources, list) {
+ gh_rm_free_resource(ghrsc);
+ }
+ mutex_unlock(&ghvm->resources_lock);
+}
+
static int gh_vm_rm_notification_status(struct gh_vm *ghvm, void *data)
{
struct gh_rm_vm_status_payload *payload = data;
@@ -265,6 +358,9 @@ static __must_check struct gh_vm *gh_vm_alloc(struct gh_rm *rm)
init_waitqueue_head(&ghvm->vm_status_wait);
INIT_WORK(&ghvm->free_work, gh_vm_free);
kref_init(&ghvm->kref);
+ mutex_init(&ghvm->resources_lock);
+ INIT_LIST_HEAD(&ghvm->resources);
+ INIT_LIST_HEAD(&ghvm->resource_tickets);
INIT_LIST_HEAD(&ghvm->functions);
ghvm->vm_status = GH_RM_VM_STATUS_NO_STATE;

@@ -274,9 +370,11 @@ static __must_check struct gh_vm *gh_vm_alloc(struct gh_rm *rm)
static int gh_vm_start(struct gh_vm *ghvm)
{
struct gh_vm_mem *mapping;
+ struct gh_rm_hyp_resources *resources;
+ struct gh_resource *ghrsc;
u64 dtb_offset;
u32 mem_handle;
- int ret;
+ int ret, i, n;

down_write(&ghvm->status_lock);
if (ghvm->vm_status != GH_RM_VM_STATUS_NO_STATE) {
@@ -336,6 +434,22 @@ static int gh_vm_start(struct gh_vm *ghvm)
}
ghvm->vm_status = GH_RM_VM_STATUS_READY;

+ ret = gh_rm_get_hyp_resources(ghvm->rm, ghvm->vmid, &resources);
+ if (ret) {
+ dev_warn(ghvm->parent, "Failed to get hypervisor resources for VM: %d\n", ret);
+ goto err;
+ }
+
+ for (i = 0, n = le32_to_cpu(resources->n_entries); i < n; i++) {
+ ghrsc = gh_rm_alloc_resource(ghvm->rm, &resources->entries[i]);
+ if (!ghrsc) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ gh_vm_add_resource(ghvm, ghrsc);
+ }
+
ret = gh_rm_vm_start(ghvm->rm, ghvm->vmid);
if (ret) {
dev_warn(ghvm->parent, "Failed to start VM: %d\n", ret);
@@ -457,6 +571,7 @@ static void gh_vm_free(struct work_struct *work)
gh_vm_stop(ghvm);

gh_vm_remove_functions(ghvm);
+ gh_vm_clean_resources(ghvm);

if (ghvm->vm_status != GH_RM_VM_STATUS_NO_STATE &&
ghvm->vm_status != GH_RM_VM_STATUS_LOAD &&
diff --git a/drivers/virt/gunyah/vm_mgr.h b/drivers/virt/gunyah/vm_mgr.h
index c4bec1469ae8c..e5e0c92d4cb12 100644
--- a/drivers/virt/gunyah/vm_mgr.h
+++ b/drivers/virt/gunyah/vm_mgr.h
@@ -7,6 +7,7 @@
#define _GH_VM_MGR_H

#include <linux/gunyah_rsc_mgr.h>
+#include <linux/gunyah_vm_mgr.h>
#include <linux/list.h>
#include <linux/kref.h>
#include <linux/miscdevice.h>
@@ -52,6 +53,9 @@ struct gh_vm {
struct list_head memory_mappings;
struct mutex fn_lock;
struct list_head functions;
+ struct mutex resources_lock;
+ struct list_head resources;
+ struct list_head resource_tickets;
};

int gh_vm_mem_alloc(struct gh_vm *ghvm, struct gh_userspace_memory_region *region);
diff --git a/include/linux/gunyah_vm_mgr.h b/include/linux/gunyah_vm_mgr.h
index 6e4dd6fa5f96d..af97fec9e2ef5 100644
--- a/include/linux/gunyah_vm_mgr.h
+++ b/include/linux/gunyah_vm_mgr.h
@@ -94,4 +94,35 @@ void gh_vm_function_unregister(struct gh_vm_function *f);
module_gh_vm_function(_name); \
MODULE_ALIAS_GH_VM_FUNCTION(_type, _idx)

+/**
+ * struct gh_vm_resource_ticket - Represents a ticket to reserve exclusive access to VM resource(s)
+ * @vm_list: for @gh_vm->resource_tickets
+ * @resources: List of resource(s) associated with this ticket(members are from @gh_resource->list)
+ * @resource_type: Type of resource this ticket reserves
+ * @label: Label of the resource from resource manager this ticket reserves.
+ * @owner: owner of the ticket
+ * @populate: callback provided by the ticket owner and called when a resource is found that
+ * matches @resource_type and @label. Note that this callback could be called
+ * multiple times if userspace created mutliple resources with the same type/label.
+ * This callback may also have significant delay after gh_vm_add_resource_ticket()
+ * since gh_vm_add_resource_ticket() could be called before the VM starts.
+ * @unpopulate: callback provided by the ticket owner and called when the ticket owner should no
+ * no longer use the resource provided in the argument. When unpopulate() returns,
+ * the ticket owner should not be able to use the resource any more as the resource
+ * might being freed.
+ */
+struct gh_vm_resource_ticket {
+ struct list_head vm_list;
+ struct list_head resources;
+ enum gh_resource_type resource_type;
+ u32 label;
+
+ struct module *owner;
+ bool (*populate)(struct gh_vm_resource_ticket *ticket, struct gh_resource *ghrsc);
+ void (*unpopulate)(struct gh_vm_resource_ticket *ticket, struct gh_resource *ghrsc);
+};
+
+int gh_vm_add_resource_ticket(struct gh_vm *ghvm, struct gh_vm_resource_ticket *ticket);
+void gh_vm_remove_resource_ticket(struct gh_vm *ghvm, struct gh_vm_resource_ticket *ticket);
+
#endif
--
2.40.0


2023-06-13 17:33:47

by Elliot Berman

[permalink] [raw]
Subject: [PATCH v14 07/25] gunyah: rsc_mgr: Add resource manager RPC core

The resource manager is a special virtual machine which is always
running on a Gunyah system. It provides APIs for creating and destroying
VMs, secure memory management, sharing/lending of memory between VMs,
and setup of inter-VM communication. Calls to the resource manager are
made via message queues.

This patch implements the basic probing and RPC mechanism to make those
API calls. Request/response calls can be made with gh_rm_call.
Drivers can also register to notifications pushed by RM via
gh_rm_register_notifier

Specific API calls that resource manager supports will be implemented in
subsequent patches.

Reviewed-by: Alex Elder <[email protected]>
Reviewed-by: Srinivas Kandagatla <[email protected]>
Signed-off-by: Elliot Berman <[email protected]>
---
drivers/virt/Makefile | 1 +
drivers/virt/gunyah/Makefile | 4 +
drivers/virt/gunyah/rsc_mgr.c | 700 +++++++++++++++++++++++++++++++++
drivers/virt/gunyah/rsc_mgr.h | 16 +
include/linux/gunyah_rsc_mgr.h | 21 +
5 files changed, 742 insertions(+)
create mode 100644 drivers/virt/gunyah/Makefile
create mode 100644 drivers/virt/gunyah/rsc_mgr.c
create mode 100644 drivers/virt/gunyah/rsc_mgr.h
create mode 100644 include/linux/gunyah_rsc_mgr.h

diff --git a/drivers/virt/Makefile b/drivers/virt/Makefile
index e9aa6fc96fab7..a5817e2d7d718 100644
--- a/drivers/virt/Makefile
+++ b/drivers/virt/Makefile
@@ -12,3 +12,4 @@ obj-$(CONFIG_ACRN_HSM) += acrn/
obj-$(CONFIG_EFI_SECRET) += coco/efi_secret/
obj-$(CONFIG_SEV_GUEST) += coco/sev-guest/
obj-$(CONFIG_INTEL_TDX_GUEST) += coco/tdx-guest/
+obj-y += gunyah/
diff --git a/drivers/virt/gunyah/Makefile b/drivers/virt/gunyah/Makefile
new file mode 100644
index 0000000000000..0f5aec8346988
--- /dev/null
+++ b/drivers/virt/gunyah/Makefile
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
+
+gunyah-y += rsc_mgr.o
+obj-$(CONFIG_GUNYAH) += gunyah.o
diff --git a/drivers/virt/gunyah/rsc_mgr.c b/drivers/virt/gunyah/rsc_mgr.c
new file mode 100644
index 0000000000000..04c8e131d259f
--- /dev/null
+++ b/drivers/virt/gunyah/rsc_mgr.c
@@ -0,0 +1,700 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/mutex.h>
+#include <linux/sched.h>
+#include <linux/gunyah.h>
+#include <linux/module.h>
+#include <linux/of_irq.h>
+#include <linux/notifier.h>
+#include <linux/workqueue.h>
+#include <linux/completion.h>
+#include <linux/gunyah_rsc_mgr.h>
+#include <linux/platform_device.h>
+
+#include "rsc_mgr.h"
+
+#define RM_RPC_API_VERSION_MASK GENMASK(3, 0)
+#define RM_RPC_HEADER_WORDS_MASK GENMASK(7, 4)
+#define RM_RPC_API_VERSION FIELD_PREP(RM_RPC_API_VERSION_MASK, 1)
+#define RM_RPC_HEADER_WORDS FIELD_PREP(RM_RPC_HEADER_WORDS_MASK, \
+ (sizeof(struct gh_rm_rpc_hdr) / sizeof(u32)))
+#define RM_RPC_API (RM_RPC_API_VERSION | RM_RPC_HEADER_WORDS)
+
+#define RM_RPC_TYPE_CONTINUATION 0x0
+#define RM_RPC_TYPE_REQUEST 0x1
+#define RM_RPC_TYPE_REPLY 0x2
+#define RM_RPC_TYPE_NOTIF 0x3
+#define RM_RPC_TYPE_MASK GENMASK(1, 0)
+
+#define GH_RM_MAX_NUM_FRAGMENTS 62
+#define RM_RPC_FRAGMENTS_MASK GENMASK(7, 2)
+
+struct gh_rm_rpc_hdr {
+ u8 api;
+ u8 type;
+ __le16 seq;
+ __le32 msg_id;
+} __packed;
+
+struct gh_rm_rpc_reply_hdr {
+ struct gh_rm_rpc_hdr hdr;
+ __le32 err_code; /* GH_RM_ERROR_* */
+} __packed;
+
+#define GH_RM_MAX_MSG_SIZE (GH_MSGQ_MAX_MSG_SIZE - sizeof(struct gh_rm_rpc_hdr))
+
+/* RM Error codes */
+enum gh_rm_error {
+ GH_RM_ERROR_OK = 0x0,
+ GH_RM_ERROR_UNIMPLEMENTED = 0xFFFFFFFF,
+ GH_RM_ERROR_NOMEM = 0x1,
+ GH_RM_ERROR_NORESOURCE = 0x2,
+ GH_RM_ERROR_DENIED = 0x3,
+ GH_RM_ERROR_INVALID = 0x4,
+ GH_RM_ERROR_BUSY = 0x5,
+ GH_RM_ERROR_ARGUMENT_INVALID = 0x6,
+ GH_RM_ERROR_HANDLE_INVALID = 0x7,
+ GH_RM_ERROR_VALIDATE_FAILED = 0x8,
+ GH_RM_ERROR_MAP_FAILED = 0x9,
+ GH_RM_ERROR_MEM_INVALID = 0xA,
+ GH_RM_ERROR_MEM_INUSE = 0xB,
+ GH_RM_ERROR_MEM_RELEASED = 0xC,
+ GH_RM_ERROR_VMID_INVALID = 0xD,
+ GH_RM_ERROR_LOOKUP_FAILED = 0xE,
+ GH_RM_ERROR_IRQ_INVALID = 0xF,
+ GH_RM_ERROR_IRQ_INUSE = 0x10,
+ GH_RM_ERROR_IRQ_RELEASED = 0x11,
+};
+
+/**
+ * struct gh_rm_connection - Represents a complete message from resource manager
+ * @payload: Combined payload of all the fragments (msg headers stripped off).
+ * @size: Size of the payload received so far.
+ * @msg_id: Message ID from the header.
+ * @type: RM_RPC_TYPE_REPLY or RM_RPC_TYPE_NOTIF.
+ * @num_fragments: total number of fragments expected to be received.
+ * @fragments_received: fragments received so far.
+ * @reply: Fields used for request/reply sequences
+ * @notification: Fields used for notifiations
+ */
+struct gh_rm_connection {
+ void *payload;
+ size_t size;
+ __le32 msg_id;
+ u8 type;
+
+ u8 num_fragments;
+ u8 fragments_received;
+
+ union {
+ /**
+ * @ret: Linux return code, there was an error processing connection
+ * @seq: Sequence ID for the main message.
+ * @rm_error: For request/reply sequences with standard replies
+ * @seq_done: Signals caller that the RM reply has been received
+ */
+ struct {
+ int ret;
+ u16 seq;
+ enum gh_rm_error rm_error;
+ struct completion seq_done;
+ } reply;
+
+ /**
+ * @rm: Pointer to the RM that launched the connection
+ * @work: Triggered when all fragments of a notification received
+ */
+ struct {
+ struct gh_rm *rm;
+ struct work_struct work;
+ } notification;
+ };
+};
+
+/**
+ * struct gh_rm - private data for communicating w/Gunyah resource manager
+ * @dev: pointer to RM platform device
+ * @tx_ghrsc: message queue resource to TX to RM
+ * @rx_ghrsc: message queue resource to RX from RM
+ * @msgq: mailbox instance of TX/RX resources above
+ * @msgq_client: mailbox client of above msgq
+ * @active_rx_connection: ongoing gh_rm_connection for which we're receiving fragments
+ * @last_tx_ret: return value of last mailbox tx
+ * @call_xarray: xarray to allocate & lookup sequence IDs for Request/Response flows
+ * @next_seq: next ID to allocate (for xa_alloc_cyclic)
+ * @cache: cache for allocating Tx messages
+ * @send_lock: synchronization to allow only one request to be sent at a time
+ * @nh: notifier chain for clients interested in RM notification messages
+ */
+struct gh_rm {
+ struct device *dev;
+ struct gh_resource tx_ghrsc;
+ struct gh_resource rx_ghrsc;
+ struct gh_msgq msgq;
+ struct mbox_client msgq_client;
+ struct gh_rm_connection *active_rx_connection;
+ int last_tx_ret;
+
+ struct xarray call_xarray;
+ u32 next_seq;
+
+ struct kmem_cache *cache;
+ struct mutex send_lock;
+ struct blocking_notifier_head nh;
+};
+
+/**
+ * gh_rm_error_remap() - Remap Gunyah resource manager errors into a Linux error code
+ * @rm_error: "Standard" return value from Gunyah resource manager
+ */
+static inline int gh_rm_error_remap(enum gh_rm_error rm_error)
+{
+ switch (rm_error) {
+ case GH_RM_ERROR_OK:
+ return 0;
+ case GH_RM_ERROR_UNIMPLEMENTED:
+ return -EOPNOTSUPP;
+ case GH_RM_ERROR_NOMEM:
+ return -ENOMEM;
+ case GH_RM_ERROR_NORESOURCE:
+ return -ENODEV;
+ case GH_RM_ERROR_DENIED:
+ return -EPERM;
+ case GH_RM_ERROR_BUSY:
+ return -EBUSY;
+ case GH_RM_ERROR_INVALID:
+ case GH_RM_ERROR_ARGUMENT_INVALID:
+ case GH_RM_ERROR_HANDLE_INVALID:
+ case GH_RM_ERROR_VALIDATE_FAILED:
+ case GH_RM_ERROR_MAP_FAILED:
+ case GH_RM_ERROR_MEM_INVALID:
+ case GH_RM_ERROR_MEM_INUSE:
+ case GH_RM_ERROR_MEM_RELEASED:
+ case GH_RM_ERROR_VMID_INVALID:
+ case GH_RM_ERROR_LOOKUP_FAILED:
+ case GH_RM_ERROR_IRQ_INVALID:
+ case GH_RM_ERROR_IRQ_INUSE:
+ case GH_RM_ERROR_IRQ_RELEASED:
+ return -EINVAL;
+ default:
+ return -EBADMSG;
+ }
+}
+
+static int gh_rm_init_connection_payload(struct gh_rm_connection *connection, void *msg,
+ size_t hdr_size, size_t msg_size)
+{
+ size_t max_buf_size, payload_size;
+ struct gh_rm_rpc_hdr *hdr = msg;
+
+ if (msg_size < hdr_size)
+ return -EINVAL;
+
+ payload_size = msg_size - hdr_size;
+
+ connection->num_fragments = FIELD_GET(RM_RPC_FRAGMENTS_MASK, hdr->type);
+ connection->fragments_received = 0;
+
+ /* There's not going to be any payload, no need to allocate buffer. */
+ if (!payload_size && !connection->num_fragments)
+ return 0;
+
+ if (connection->num_fragments > GH_RM_MAX_NUM_FRAGMENTS)
+ return -EINVAL;
+
+ max_buf_size = payload_size + (connection->num_fragments * GH_RM_MAX_MSG_SIZE);
+
+ connection->payload = kzalloc(max_buf_size, GFP_KERNEL);
+ if (!connection->payload)
+ return -ENOMEM;
+
+ memcpy(connection->payload, msg + hdr_size, payload_size);
+ connection->size = payload_size;
+ return 0;
+}
+
+static void gh_rm_abort_connection(struct gh_rm *rm)
+{
+ switch (rm->active_rx_connection->type) {
+ case RM_RPC_TYPE_REPLY:
+ rm->active_rx_connection->reply.ret = -EIO;
+ complete(&rm->active_rx_connection->reply.seq_done);
+ break;
+ case RM_RPC_TYPE_NOTIF:
+ fallthrough;
+ default:
+ kfree(rm->active_rx_connection->payload);
+ kfree(rm->active_rx_connection);
+ }
+
+ rm->active_rx_connection = NULL;
+}
+
+static void gh_rm_notif_work(struct work_struct *work)
+{
+ struct gh_rm_connection *connection = container_of(work, struct gh_rm_connection,
+ notification.work);
+ struct gh_rm *rm = connection->notification.rm;
+
+ blocking_notifier_call_chain(&rm->nh, le32_to_cpu(connection->msg_id), connection->payload);
+
+ put_device(rm->dev);
+ kfree(connection->payload);
+ kfree(connection);
+}
+
+static void gh_rm_process_notif(struct gh_rm *rm, void *msg, size_t msg_size)
+{
+ struct gh_rm_connection *connection;
+ struct gh_rm_rpc_hdr *hdr = msg;
+ int ret;
+
+ if (rm->active_rx_connection)
+ gh_rm_abort_connection(rm);
+
+ connection = kzalloc(sizeof(*connection), GFP_KERNEL);
+ if (!connection)
+ return;
+
+ connection->type = RM_RPC_TYPE_NOTIF;
+ connection->msg_id = hdr->msg_id;
+
+ get_device(rm->dev);
+ connection->notification.rm = rm;
+ INIT_WORK(&connection->notification.work, gh_rm_notif_work);
+
+ ret = gh_rm_init_connection_payload(connection, msg, sizeof(*hdr), msg_size);
+ if (ret) {
+ dev_err(rm->dev, "Failed to initialize connection for notification: %d\n", ret);
+ put_device(rm->dev);
+ kfree(connection);
+ return;
+ }
+
+ rm->active_rx_connection = connection;
+}
+
+static void gh_rm_process_reply(struct gh_rm *rm, void *msg, size_t msg_size)
+{
+ struct gh_rm_rpc_reply_hdr *reply_hdr = msg;
+ struct gh_rm_connection *connection;
+ u16 seq_id;
+
+ seq_id = le16_to_cpu(reply_hdr->hdr.seq);
+ connection = xa_load(&rm->call_xarray, seq_id);
+
+ if (!connection || connection->msg_id != reply_hdr->hdr.msg_id)
+ return;
+
+ if (rm->active_rx_connection)
+ gh_rm_abort_connection(rm);
+
+ if (gh_rm_init_connection_payload(connection, msg, sizeof(*reply_hdr), msg_size)) {
+ dev_err(rm->dev, "Failed to alloc connection buffer for sequence %d\n", seq_id);
+ /* Send connection complete and error the client. */
+ connection->reply.ret = -ENOMEM;
+ complete(&connection->reply.seq_done);
+ return;
+ }
+
+ connection->reply.rm_error = le32_to_cpu(reply_hdr->err_code);
+ rm->active_rx_connection = connection;
+}
+
+static void gh_rm_process_cont(struct gh_rm *rm, struct gh_rm_connection *connection,
+ void *msg, size_t msg_size)
+{
+ struct gh_rm_rpc_hdr *hdr = msg;
+ size_t payload_size = msg_size - sizeof(*hdr);
+
+ if (!rm->active_rx_connection)
+ return;
+
+ /*
+ * hdr->fragments and hdr->msg_id preserves the value from first reply
+ * or notif message. To detect mishandling, check it's still intact.
+ */
+ if (connection->msg_id != hdr->msg_id ||
+ connection->num_fragments != FIELD_GET(RM_RPC_FRAGMENTS_MASK, hdr->type)) {
+ gh_rm_abort_connection(rm);
+ return;
+ }
+
+ memcpy(connection->payload + connection->size, msg + sizeof(*hdr), payload_size);
+ connection->size += payload_size;
+ connection->fragments_received++;
+}
+
+static void gh_rm_try_complete_connection(struct gh_rm *rm)
+{
+ struct gh_rm_connection *connection = rm->active_rx_connection;
+
+ if (!connection || connection->fragments_received != connection->num_fragments)
+ return;
+
+ switch (connection->type) {
+ case RM_RPC_TYPE_REPLY:
+ complete(&connection->reply.seq_done);
+ break;
+ case RM_RPC_TYPE_NOTIF:
+ schedule_work(&connection->notification.work);
+ break;
+ default:
+ dev_err_ratelimited(rm->dev, "Invalid message type (%u) received\n",
+ connection->type);
+ gh_rm_abort_connection(rm);
+ break;
+ }
+
+ rm->active_rx_connection = NULL;
+}
+
+static void gh_rm_msgq_rx_data(struct mbox_client *cl, void *mssg)
+{
+ struct gh_rm *rm = container_of(cl, struct gh_rm, msgq_client);
+ struct gh_msgq_rx_data *rx_data = mssg;
+ size_t msg_size = rx_data->length;
+ void *msg = rx_data->data;
+ struct gh_rm_rpc_hdr *hdr;
+
+ if (msg_size < sizeof(*hdr) || msg_size > GH_MSGQ_MAX_MSG_SIZE)
+ return;
+
+ hdr = msg;
+ if (hdr->api != RM_RPC_API) {
+ dev_err(rm->dev, "Unknown RM RPC API version: %x\n", hdr->api);
+ return;
+ }
+
+ switch (FIELD_GET(RM_RPC_TYPE_MASK, hdr->type)) {
+ case RM_RPC_TYPE_NOTIF:
+ gh_rm_process_notif(rm, msg, msg_size);
+ break;
+ case RM_RPC_TYPE_REPLY:
+ gh_rm_process_reply(rm, msg, msg_size);
+ break;
+ case RM_RPC_TYPE_CONTINUATION:
+ gh_rm_process_cont(rm, rm->active_rx_connection, msg, msg_size);
+ break;
+ default:
+ dev_err(rm->dev, "Invalid message type (%lu) received\n",
+ FIELD_GET(RM_RPC_TYPE_MASK, hdr->type));
+ return;
+ }
+
+ gh_rm_try_complete_connection(rm);
+}
+
+static void gh_rm_msgq_tx_done(struct mbox_client *cl, void *mssg, int r)
+{
+ struct gh_rm *rm = container_of(cl, struct gh_rm, msgq_client);
+
+ kmem_cache_free(rm->cache, mssg);
+ rm->last_tx_ret = r;
+}
+
+static int gh_rm_send_request(struct gh_rm *rm, u32 message_id,
+ const void *req_buf, size_t req_buf_size,
+ struct gh_rm_connection *connection)
+{
+ size_t buf_size_remaining = req_buf_size;
+ const void *req_buf_curr = req_buf;
+ struct gh_msgq_tx_data *msg;
+ struct gh_rm_rpc_hdr *hdr, hdr_template;
+ u32 cont_fragments = 0;
+ size_t payload_size;
+ void *payload;
+ int ret;
+
+ if (req_buf_size > GH_RM_MAX_NUM_FRAGMENTS * GH_RM_MAX_MSG_SIZE) {
+ dev_warn(rm->dev, "Limit (%lu bytes) exceeded for the maximum message size: %lu\n",
+ GH_RM_MAX_NUM_FRAGMENTS * GH_RM_MAX_MSG_SIZE, req_buf_size);
+ dump_stack();
+ return -E2BIG;
+ }
+
+ if (req_buf_size)
+ cont_fragments = (req_buf_size - 1) / GH_RM_MAX_MSG_SIZE;
+
+ hdr_template.api = RM_RPC_API;
+ hdr_template.type = FIELD_PREP(RM_RPC_TYPE_MASK, RM_RPC_TYPE_REQUEST) |
+ FIELD_PREP(RM_RPC_FRAGMENTS_MASK, cont_fragments);
+ hdr_template.seq = cpu_to_le16(connection->reply.seq);
+ hdr_template.msg_id = cpu_to_le32(message_id);
+
+ ret = mutex_lock_interruptible(&rm->send_lock);
+ if (ret)
+ return ret;
+
+ do {
+ msg = kmem_cache_zalloc(rm->cache, GFP_KERNEL);
+ if (!msg) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ /* Fill header */
+ hdr = (struct gh_rm_rpc_hdr *)&msg->data[0];
+ *hdr = hdr_template;
+
+ /* Copy payload */
+ payload = &msg->data[0] + sizeof(*hdr);
+ payload_size = min(buf_size_remaining, GH_RM_MAX_MSG_SIZE);
+ memcpy(payload, req_buf_curr, payload_size);
+ req_buf_curr += payload_size;
+ buf_size_remaining -= payload_size;
+
+ /* Force the last fragment to immediately alert the receiver */
+ msg->push = !buf_size_remaining;
+ msg->length = sizeof(*hdr) + payload_size;
+
+ ret = mbox_send_message(gh_msgq_chan(&rm->msgq), msg);
+ if (ret < 0) {
+ kmem_cache_free(rm->cache, msg);
+ break;
+ }
+
+ if (rm->last_tx_ret) {
+ ret = rm->last_tx_ret;
+ break;
+ }
+
+ hdr_template.type = FIELD_PREP(RM_RPC_TYPE_MASK, RM_RPC_TYPE_CONTINUATION) |
+ FIELD_PREP(RM_RPC_FRAGMENTS_MASK, cont_fragments);
+ } while (buf_size_remaining);
+
+out:
+ mutex_unlock(&rm->send_lock);
+ return ret < 0 ? ret : 0;
+}
+
+/**
+ * gh_rm_call: Achieve request-response type communication with RPC
+ * @rm: Pointer to Gunyah resource manager internal data
+ * @message_id: The RM RPC message-id
+ * @req_buf: Request buffer that contains the payload
+ * @req_buf_size: Total size of the payload
+ * @resp_buf: Pointer to a response buffer
+ * @resp_buf_size: Size of the response buffer
+ *
+ * Make a request to the Resource Manager and wait for reply back. For a successful
+ * response, the function returns the payload. The size of the payload is set in
+ * resp_buf_size. The resp_buf must be freed by the caller when 0 is returned
+ * and resp_buf_size != 0.
+ *
+ * req_buf should be not NULL for req_buf_size >0. If req_buf_size == 0,
+ * req_buf *can* be NULL and no additional payload is sent.
+ *
+ * Context: Process context. Will sleep waiting for reply.
+ * Return: 0 on success. <0 if error.
+ */
+int gh_rm_call(struct gh_rm *rm, u32 message_id, const void *req_buf, size_t req_buf_size,
+ void **resp_buf, size_t *resp_buf_size)
+{
+ struct gh_rm_connection *connection;
+ u32 seq_id;
+ int ret;
+
+ /* message_id 0 is reserved. req_buf_size implies req_buf is not NULL */
+ if (!rm || !message_id || (!req_buf && req_buf_size))
+ return -EINVAL;
+
+
+ connection = kzalloc(sizeof(*connection), GFP_KERNEL);
+ if (!connection)
+ return -ENOMEM;
+
+ connection->type = RM_RPC_TYPE_REPLY;
+ connection->msg_id = cpu_to_le32(message_id);
+
+ init_completion(&connection->reply.seq_done);
+
+ /* Allocate a new seq number for this connection */
+ ret = xa_alloc_cyclic(&rm->call_xarray, &seq_id, connection, xa_limit_16b, &rm->next_seq,
+ GFP_KERNEL);
+ if (ret < 0)
+ goto free;
+ connection->reply.seq = lower_16_bits(seq_id);
+
+ /* Send the request to the Resource Manager */
+ ret = gh_rm_send_request(rm, message_id, req_buf, req_buf_size, connection);
+ if (ret < 0)
+ goto out;
+
+ /* Wait for response. Uninterruptible because rollback based on what RM did to VM
+ * requires us to know how RM handled the call.
+ */
+ wait_for_completion(&connection->reply.seq_done);
+
+ /* Check for internal (kernel) error waiting for the response */
+ if (connection->reply.ret) {
+ ret = connection->reply.ret;
+ if (ret != -ENOMEM)
+ kfree(connection->payload);
+ goto out;
+ }
+
+ /* Got a response, did resource manager give us an error? */
+ if (connection->reply.rm_error != GH_RM_ERROR_OK) {
+ dev_warn(rm->dev, "RM rejected message %08x. Error: %d\n", message_id,
+ connection->reply.rm_error);
+ ret = gh_rm_error_remap(connection->reply.rm_error);
+ kfree(connection->payload);
+ goto out;
+ }
+
+ /* Everything looks good, return the payload */
+ if (resp_buf_size)
+ *resp_buf_size = connection->size;
+ if (connection->size && resp_buf)
+ *resp_buf = connection->payload;
+ else {
+ /* kfree in case RM sent us multiple fragments but never any data in
+ * those fragments. We would've allocated memory for it, but connection->size == 0
+ */
+ kfree(connection->payload);
+ }
+
+out:
+ xa_erase(&rm->call_xarray, connection->reply.seq);
+free:
+ kfree(connection);
+ return ret;
+}
+
+
+int gh_rm_notifier_register(struct gh_rm *rm, struct notifier_block *nb)
+{
+ return blocking_notifier_chain_register(&rm->nh, nb);
+}
+EXPORT_SYMBOL_GPL(gh_rm_notifier_register);
+
+int gh_rm_notifier_unregister(struct gh_rm *rm, struct notifier_block *nb)
+{
+ return blocking_notifier_chain_unregister(&rm->nh, nb);
+}
+EXPORT_SYMBOL_GPL(gh_rm_notifier_unregister);
+
+static int gh_msgq_platform_probe_direction(struct platform_device *pdev, bool tx,
+ struct gh_resource *ghrsc)
+{
+ struct device_node *node = pdev->dev.of_node;
+ int ret;
+ int idx = tx ? 0 : 1;
+
+ ghrsc->type = tx ? GH_RESOURCE_TYPE_MSGQ_TX : GH_RESOURCE_TYPE_MSGQ_RX;
+
+ ghrsc->irq = platform_get_irq(pdev, idx);
+ if (ghrsc->irq < 0) {
+ dev_err(&pdev->dev, "Failed to get irq%d: %d\n", idx, ghrsc->irq);
+ return ghrsc->irq;
+ }
+
+ ret = of_property_read_u64_index(node, "reg", idx, &ghrsc->capid);
+ if (ret) {
+ dev_err(&pdev->dev, "Failed to get capid%d: %d\n", idx, ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int gh_identify(void)
+{
+ struct gh_hypercall_hyp_identify_resp gh_api;
+
+ if (!arch_is_gh_guest())
+ return -ENODEV;
+
+ gh_hypercall_hyp_identify(&gh_api);
+
+ pr_info("Running under Gunyah hypervisor %llx/v%u\n",
+ FIELD_GET(GH_API_INFO_VARIANT_MASK, gh_api.api_info),
+ gh_api_version(&gh_api));
+
+ /* We might move this out to individual drivers if there's ever an API version bump */
+ if (gh_api_version(&gh_api) != GH_API_V1) {
+ pr_info("Unsupported Gunyah version: %u\n", gh_api_version(&gh_api));
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+static int gh_rm_drv_probe(struct platform_device *pdev)
+{
+ struct gh_msgq_tx_data *msg;
+ struct gh_rm *rm;
+ int ret;
+
+ ret = gh_identify();
+ if (ret)
+ return ret;
+
+ rm = devm_kzalloc(&pdev->dev, sizeof(*rm), GFP_KERNEL);
+ if (!rm)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, rm);
+ rm->dev = &pdev->dev;
+
+ mutex_init(&rm->send_lock);
+ BLOCKING_INIT_NOTIFIER_HEAD(&rm->nh);
+ xa_init_flags(&rm->call_xarray, XA_FLAGS_ALLOC);
+ rm->cache = kmem_cache_create("gh_rm", struct_size(msg, data, GH_MSGQ_MAX_MSG_SIZE), 0,
+ SLAB_HWCACHE_ALIGN, NULL);
+ if (!rm->cache)
+ return -ENOMEM;
+
+ ret = gh_msgq_platform_probe_direction(pdev, true, &rm->tx_ghrsc);
+ if (ret)
+ goto err_cache;
+
+ ret = gh_msgq_platform_probe_direction(pdev, false, &rm->rx_ghrsc);
+ if (ret)
+ goto err_cache;
+
+ rm->msgq_client.dev = &pdev->dev;
+ rm->msgq_client.tx_block = true;
+ rm->msgq_client.rx_callback = gh_rm_msgq_rx_data;
+ rm->msgq_client.tx_done = gh_rm_msgq_tx_done;
+
+ return gh_msgq_init(&pdev->dev, &rm->msgq, &rm->msgq_client, &rm->tx_ghrsc, &rm->rx_ghrsc);
+err_cache:
+ kmem_cache_destroy(rm->cache);
+ return ret;
+}
+
+static int gh_rm_drv_remove(struct platform_device *pdev)
+{
+ struct gh_rm *rm = platform_get_drvdata(pdev);
+
+ gh_msgq_remove(&rm->msgq);
+ kmem_cache_destroy(rm->cache);
+
+ return 0;
+}
+
+static const struct of_device_id gh_rm_of_match[] = {
+ { .compatible = "gunyah-resource-manager" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, gh_rm_of_match);
+
+static struct platform_driver gh_rm_driver = {
+ .probe = gh_rm_drv_probe,
+ .remove = gh_rm_drv_remove,
+ .driver = {
+ .name = "gh_rsc_mgr",
+ .of_match_table = gh_rm_of_match,
+ },
+};
+module_platform_driver(gh_rm_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Gunyah Resource Manager Driver");
diff --git a/drivers/virt/gunyah/rsc_mgr.h b/drivers/virt/gunyah/rsc_mgr.h
new file mode 100644
index 0000000000000..8309b7bf46683
--- /dev/null
+++ b/drivers/virt/gunyah/rsc_mgr.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+#ifndef __GH_RSC_MGR_PRIV_H
+#define __GH_RSC_MGR_PRIV_H
+
+#include <linux/gunyah.h>
+#include <linux/gunyah_rsc_mgr.h>
+#include <linux/types.h>
+
+struct gh_rm;
+int gh_rm_call(struct gh_rm *rsc_mgr, u32 message_id, const void *req_buf, size_t req_buf_size,
+ void **resp_buf, size_t *resp_buf_size);
+
+#endif
diff --git a/include/linux/gunyah_rsc_mgr.h b/include/linux/gunyah_rsc_mgr.h
new file mode 100644
index 0000000000000..f2a312e80af52
--- /dev/null
+++ b/include/linux/gunyah_rsc_mgr.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#ifndef _GUNYAH_RSC_MGR_H
+#define _GUNYAH_RSC_MGR_H
+
+#include <linux/list.h>
+#include <linux/notifier.h>
+#include <linux/gunyah.h>
+
+#define GH_VMID_INVAL U16_MAX
+
+struct gh_rm;
+int gh_rm_notifier_register(struct gh_rm *rm, struct notifier_block *nb);
+int gh_rm_notifier_unregister(struct gh_rm *rm, struct notifier_block *nb);
+struct device *gh_rm_get(struct gh_rm *rm);
+void gh_rm_put(struct gh_rm *rm);
+
+#endif
--
2.40.0


2023-06-13 17:33:51

by Elliot Berman

[permalink] [raw]
Subject: [PATCH v14 10/25] gunyah: rsc_mgr: Add RPC for sharing memory

Gunyah resource manager provides API to manipulate stage 2 page tables.
Manipulations are represented as a memory parcel. Memory parcels
describe a list of memory regions (intermediate physical address--IPA--and
size), a list of new permissions for VMs, and the memory type (DDR or
MMIO). Each memory parcel is uniquely identified by a handle allocated by
Gunyah. There are a few types of memory parcel sharing which Gunyah
supports:

- Sharing: the guest and host VM both have access
- Lending: only the guest has access; host VM loses access
- Donating: Permanently lent (not reclaimed even if guest shuts down)

Memory parcels that have been shared or lent can be reclaimed by the
host via an additional call. The reclaim operation restores the original
access the host VM had to the memory parcel and removes the access to
other VM.

One point to note that memory parcels don't describe where in the guest
VM the memory parcel should reside. The guest VM must accept the memory
parcel either explicitly via a "gh_rm_mem_accept" call (not introduced
here) or be configured to accept it automatically at boot. When the guest
VM accepts the memory parcel, it also mentions the IPA it wants to place
memory parcel. Although the region might be discontiguous on the host,
the memory parcel is place contiguously in the guest memory at the
specified IPA.

Reviewed-by: Alex Elder <[email protected]>
Reviewed-by: Srinivas Kandagatla <[email protected]>
Co-developed-by: Prakruthi Deepak Heragu <[email protected]>
Signed-off-by: Prakruthi Deepak Heragu <[email protected]>
Signed-off-by: Elliot Berman <[email protected]>
---
drivers/virt/gunyah/rsc_mgr_rpc.c | 227 ++++++++++++++++++++++++++++++
include/linux/gunyah_rsc_mgr.h | 48 +++++++
2 files changed, 275 insertions(+)

diff --git a/drivers/virt/gunyah/rsc_mgr_rpc.c b/drivers/virt/gunyah/rsc_mgr_rpc.c
index a4a9f0ba4e1fc..25064123a31c3 100644
--- a/drivers/virt/gunyah/rsc_mgr_rpc.c
+++ b/drivers/virt/gunyah/rsc_mgr_rpc.c
@@ -6,6 +6,12 @@
#include <linux/gunyah_rsc_mgr.h>
#include "rsc_mgr.h"

+/* Message IDs: Memory Management */
+#define GH_RM_RPC_MEM_LEND 0x51000012
+#define GH_RM_RPC_MEM_SHARE 0x51000013
+#define GH_RM_RPC_MEM_RECLAIM 0x51000015
+#define GH_RM_RPC_MEM_APPEND 0x51000018
+
/* Message IDs: VM Management */
#define GH_RM_RPC_VM_ALLOC_VMID 0x56000001
#define GH_RM_RPC_VM_DEALLOC_VMID 0x56000002
@@ -22,6 +28,46 @@ struct gh_rm_vm_common_vmid_req {
__le16 _padding;
} __packed;

+/* Call: MEM_LEND, MEM_SHARE */
+#define GH_MEM_SHARE_REQ_FLAGS_APPEND BIT(1)
+
+struct gh_rm_mem_share_req_header {
+ u8 mem_type;
+ u8 _padding0;
+ u8 flags;
+ u8 _padding1;
+ __le32 label;
+} __packed;
+
+struct gh_rm_mem_share_req_acl_section {
+ __le32 n_entries;
+ struct gh_rm_mem_acl_entry entries[];
+};
+
+struct gh_rm_mem_share_req_mem_section {
+ __le16 n_entries;
+ __le16 _padding;
+ struct gh_rm_mem_entry entries[];
+};
+
+/* Call: MEM_RELEASE */
+struct gh_rm_mem_release_req {
+ __le32 mem_handle;
+ u8 flags; /* currently not used */
+ u8 _padding0;
+ __le16 _padding1;
+} __packed;
+
+/* Call: MEM_APPEND */
+#define GH_MEM_APPEND_REQ_FLAGS_END BIT(0)
+
+struct gh_rm_mem_append_req_header {
+ __le32 mem_handle;
+ u8 flags;
+ u8 _padding0;
+ __le16 _padding1;
+} __packed;
+
/* Call: VM_ALLOC */
struct gh_rm_vm_alloc_vmid_resp {
__le16 vmid;
@@ -51,6 +97,8 @@ struct gh_rm_vm_config_image_req {
__le64 dtb_size;
} __packed;

+#define GH_RM_MAX_MEM_ENTRIES 512
+
/*
* Several RM calls take only a VMID as a parameter and give only standard
* response back. Deduplicate boilerplate code by using this common call.
@@ -64,6 +112,185 @@ static int gh_rm_common_vmid_call(struct gh_rm *rm, u32 message_id, u16 vmid)
return gh_rm_call(rm, message_id, &req_payload, sizeof(req_payload), NULL, NULL);
}

+static int _gh_rm_mem_append(struct gh_rm *rm, u32 mem_handle, bool end_append,
+ struct gh_rm_mem_entry *mem_entries, size_t n_mem_entries)
+{
+ struct gh_rm_mem_share_req_mem_section *mem_section;
+ struct gh_rm_mem_append_req_header *req_header;
+ size_t msg_size = 0;
+ void *msg;
+ int ret;
+
+ msg_size += sizeof(struct gh_rm_mem_append_req_header);
+ msg_size += struct_size(mem_section, entries, n_mem_entries);
+
+ msg = kzalloc(msg_size, GFP_KERNEL);
+ if (!msg)
+ return -ENOMEM;
+
+ req_header = msg;
+ mem_section = (void *)(req_header + 1);
+
+ req_header->mem_handle = cpu_to_le32(mem_handle);
+ if (end_append)
+ req_header->flags |= GH_MEM_APPEND_REQ_FLAGS_END;
+
+ mem_section->n_entries = cpu_to_le16(n_mem_entries);
+ memcpy(mem_section->entries, mem_entries, sizeof(*mem_entries) * n_mem_entries);
+
+ ret = gh_rm_call(rm, GH_RM_RPC_MEM_APPEND, msg, msg_size, NULL, NULL);
+ kfree(msg);
+
+ return ret;
+}
+
+static int gh_rm_mem_append(struct gh_rm *rm, u32 mem_handle,
+ struct gh_rm_mem_entry *mem_entries, size_t n_mem_entries)
+{
+ bool end_append;
+ int ret = 0;
+ size_t n;
+
+ while (n_mem_entries) {
+ if (n_mem_entries > GH_RM_MAX_MEM_ENTRIES) {
+ end_append = false;
+ n = GH_RM_MAX_MEM_ENTRIES;
+ } else {
+ end_append = true;
+ n = n_mem_entries;
+ }
+
+ ret = _gh_rm_mem_append(rm, mem_handle, end_append, mem_entries, n);
+ if (ret)
+ break;
+
+ mem_entries += n;
+ n_mem_entries -= n;
+ }
+
+ return ret;
+}
+
+static int gh_rm_mem_lend_common(struct gh_rm *rm, u32 message_id, struct gh_rm_mem_parcel *p)
+{
+ size_t msg_size = 0, initial_mem_entries = p->n_mem_entries, resp_size;
+ size_t acl_section_size, mem_section_size;
+ struct gh_rm_mem_share_req_acl_section *acl_section;
+ struct gh_rm_mem_share_req_mem_section *mem_section;
+ struct gh_rm_mem_share_req_header *req_header;
+ u32 *attr_section;
+ __le32 *resp;
+ void *msg;
+ int ret;
+
+ if (!p->acl_entries || !p->n_acl_entries || !p->mem_entries || !p->n_mem_entries ||
+ p->n_acl_entries > U8_MAX || p->mem_handle != GH_MEM_HANDLE_INVAL)
+ return -EINVAL;
+
+ if (initial_mem_entries > GH_RM_MAX_MEM_ENTRIES)
+ initial_mem_entries = GH_RM_MAX_MEM_ENTRIES;
+
+ acl_section_size = struct_size(acl_section, entries, p->n_acl_entries);
+ mem_section_size = struct_size(mem_section, entries, initial_mem_entries);
+ /* The format of the message goes:
+ * request header
+ * ACL entries (which VMs get what kind of access to this memory parcel)
+ * Memory entries (list of memory regions to share)
+ * Memory attributes (currently unused, we'll hard-code the size to 0)
+ */
+ msg_size += sizeof(struct gh_rm_mem_share_req_header);
+ msg_size += acl_section_size;
+ msg_size += mem_section_size;
+ msg_size += sizeof(u32); /* for memory attributes, currently unused */
+
+ msg = kzalloc(msg_size, GFP_KERNEL);
+ if (!msg)
+ return -ENOMEM;
+
+ req_header = msg;
+ acl_section = (void *)req_header + sizeof(*req_header);
+ mem_section = (void *)acl_section + acl_section_size;
+ attr_section = (void *)mem_section + mem_section_size;
+
+ req_header->mem_type = p->mem_type;
+ if (initial_mem_entries != p->n_mem_entries)
+ req_header->flags |= GH_MEM_SHARE_REQ_FLAGS_APPEND;
+ req_header->label = cpu_to_le32(p->label);
+
+ acl_section->n_entries = cpu_to_le32(p->n_acl_entries);
+ memcpy(acl_section->entries, p->acl_entries,
+ flex_array_size(acl_section, entries, p->n_acl_entries));
+
+ mem_section->n_entries = cpu_to_le16(initial_mem_entries);
+ memcpy(mem_section->entries, p->mem_entries,
+ flex_array_size(mem_section, entries, initial_mem_entries));
+
+ /* Set n_entries for memory attribute section to 0 */
+ *attr_section = 0;
+
+ ret = gh_rm_call(rm, message_id, msg, msg_size, (void **)&resp, &resp_size);
+ kfree(msg);
+
+ if (ret)
+ return ret;
+
+ p->mem_handle = le32_to_cpu(*resp);
+ kfree(resp);
+
+ if (initial_mem_entries != p->n_mem_entries) {
+ ret = gh_rm_mem_append(rm, p->mem_handle,
+ &p->mem_entries[initial_mem_entries],
+ p->n_mem_entries - initial_mem_entries);
+ if (ret) {
+ gh_rm_mem_reclaim(rm, p);
+ p->mem_handle = GH_MEM_HANDLE_INVAL;
+ }
+ }
+
+ return ret;
+}
+
+/**
+ * gh_rm_mem_lend() - Lend memory to other virtual machines.
+ * @rm: Handle to a Gunyah resource manager
+ * @parcel: Information about the memory to be lent.
+ *
+ * Lending removes Linux's access to the memory while the memory parcel is lent.
+ */
+int gh_rm_mem_lend(struct gh_rm *rm, struct gh_rm_mem_parcel *parcel)
+{
+ return gh_rm_mem_lend_common(rm, GH_RM_RPC_MEM_LEND, parcel);
+}
+
+
+/**
+ * gh_rm_mem_share() - Share memory with other virtual machines.
+ * @rm: Handle to a Gunyah resource manager
+ * @parcel: Information about the memory to be shared.
+ *
+ * Sharing keeps Linux's access to the memory while the memory parcel is shared.
+ */
+int gh_rm_mem_share(struct gh_rm *rm, struct gh_rm_mem_parcel *parcel)
+{
+ return gh_rm_mem_lend_common(rm, GH_RM_RPC_MEM_SHARE, parcel);
+}
+
+/**
+ * gh_rm_mem_reclaim() - Reclaim a memory parcel
+ * @rm: Handle to a Gunyah resource manager
+ * @parcel: Information about the memory to be reclaimed.
+ *
+ * RM maps the associated memory back into the stage-2 page tables of the owner VM.
+ */
+int gh_rm_mem_reclaim(struct gh_rm *rm, struct gh_rm_mem_parcel *parcel)
+{
+ struct gh_rm_mem_release_req req = {
+ .mem_handle = cpu_to_le32(parcel->mem_handle),
+ };
+
+ return gh_rm_call(rm, GH_RM_RPC_MEM_RECLAIM, &req, sizeof(req), NULL, NULL);
+}
+
/**
* gh_rm_alloc_vmid() - Allocate a new VM in Gunyah. Returns the VM identifier.
* @rm: Handle to a Gunyah resource manager
diff --git a/include/linux/gunyah_rsc_mgr.h b/include/linux/gunyah_rsc_mgr.h
index 1ac66d9004d2b..dfac088420bda 100644
--- a/include/linux/gunyah_rsc_mgr.h
+++ b/include/linux/gunyah_rsc_mgr.h
@@ -11,6 +11,7 @@
#include <linux/gunyah.h>

#define GH_VMID_INVAL U16_MAX
+#define GH_MEM_HANDLE_INVAL U32_MAX

struct gh_rm;
int gh_rm_notifier_register(struct gh_rm *rm, struct notifier_block *nb);
@@ -51,7 +52,54 @@ struct gh_rm_vm_status_payload {

#define GH_RM_NOTIFICATION_VM_STATUS 0x56100008

+#define GH_RM_ACL_X BIT(0)
+#define GH_RM_ACL_W BIT(1)
+#define GH_RM_ACL_R BIT(2)
+
+struct gh_rm_mem_acl_entry {
+ __le16 vmid;
+ u8 perms;
+ u8 reserved;
+} __packed;
+
+struct gh_rm_mem_entry {
+ __le64 phys_addr;
+ __le64 size;
+} __packed;
+
+enum gh_rm_mem_type {
+ GH_RM_MEM_TYPE_NORMAL = 0,
+ GH_RM_MEM_TYPE_IO = 1,
+};
+
+/*
+ * struct gh_rm_mem_parcel - Info about memory to be lent/shared/donated/reclaimed
+ * @mem_type: The type of memory: normal (DDR) or IO
+ * @label: An client-specified identifier which can be used by the other VMs to identify the purpose
+ * of the memory parcel.
+ * @n_acl_entries: Count of the number of entries in the @acl_entries array.
+ * @acl_entries: An array of access control entries. Each entry specifies a VM and what access
+ * is allowed for the memory parcel.
+ * @n_mem_entries: Count of the number of entries in the @mem_entries array.
+ * @mem_entries: An array of regions to be associated with the memory parcel. Addresses should be
+ * (intermediate) physical addresses from Linux's perspective.
+ * @mem_handle: On success, filled with memory handle that RM allocates for this memory parcel
+ */
+struct gh_rm_mem_parcel {
+ enum gh_rm_mem_type mem_type;
+ u32 label;
+ size_t n_acl_entries;
+ struct gh_rm_mem_acl_entry *acl_entries;
+ size_t n_mem_entries;
+ struct gh_rm_mem_entry *mem_entries;
+ u32 mem_handle;
+};
+
/* RPC Calls */
+int gh_rm_mem_lend(struct gh_rm *rm, struct gh_rm_mem_parcel *parcel);
+int gh_rm_mem_share(struct gh_rm *rm, struct gh_rm_mem_parcel *parcel);
+int gh_rm_mem_reclaim(struct gh_rm *rm, struct gh_rm_mem_parcel *parcel);
+
int gh_rm_alloc_vmid(struct gh_rm *rm, u16 vmid);
int gh_rm_dealloc_vmid(struct gh_rm *rm, u16 vmid);
int gh_rm_vm_reset(struct gh_rm *rm, u16 vmid);
--
2.40.0


2023-06-13 17:33:51

by Elliot Berman

[permalink] [raw]
Subject: [PATCH v14 18/25] gunyah: vm_mgr: Add framework for VM Functions

Introduce a framework for Gunyah userspace to install VM functions. VM
functions are optional interfaces to the virtual machine. vCPUs,
ioeventfs, and irqfds are examples of such VM functions and are
implemented in subsequent patches.

A generic framework is implemented instead of individual ioctls to
create vCPUs, irqfds, etc., in order to simplify the VM manager core
implementation and allow dynamic loading of VM function modules.

Signed-off-by: Elliot Berman <[email protected]>
---
Documentation/virt/gunyah/vm-manager.rst | 18 ++
drivers/virt/gunyah/vm_mgr.c | 213 ++++++++++++++++++++++-
drivers/virt/gunyah/vm_mgr.h | 4 +
include/linux/gunyah_vm_mgr.h | 97 +++++++++++
include/uapi/linux/gunyah.h | 18 ++
5 files changed, 347 insertions(+), 3 deletions(-)
create mode 100644 include/linux/gunyah_vm_mgr.h

diff --git a/Documentation/virt/gunyah/vm-manager.rst b/Documentation/virt/gunyah/vm-manager.rst
index df0e1a8279bf5..cbc79bd8749b4 100644
--- a/Documentation/virt/gunyah/vm-manager.rst
+++ b/Documentation/virt/gunyah/vm-manager.rst
@@ -15,6 +15,24 @@ such as vCPUs for the VM. Memory can be shared with the VM with
`GH_VM_SET_USER_MEM_REGION`_. Userspace can interact with the resources in Linux
by adding "functions" to the VM.

+Gunyah Functions
+================
+
+Components of a Gunyah VM's configuration that need kernel configuration are
+called "functions" and are built on top of a framework. Functions are identified
+by a string and have some argument(s) to configure them. They are typically
+created by the `GH_VM_ADD_FUNCTION`_ ioctl.
+
+Functions typically will always do at least one of these operations:
+
+1. Create resource ticket(s). Resource tickets allow a function to register
+ itself as the client for a Gunyah resource (e.g. doorbell or vCPU) and
+ the function is given the pointer to the &struct gh_resource when the
+ VM is starting.
+
+2. Register IO handler(s). IO handlers allow a function to handle stage-2 faults
+ from the virtual machine.
+
Sample Userspace VMM
====================

diff --git a/drivers/virt/gunyah/vm_mgr.c b/drivers/virt/gunyah/vm_mgr.c
index 562ae6ed4a5f1..cfd79bc9900fd 100644
--- a/drivers/virt/gunyah/vm_mgr.c
+++ b/drivers/virt/gunyah/vm_mgr.c
@@ -6,10 +6,13 @@
#define pr_fmt(fmt) "gh_vm_mgr: " fmt

#include <linux/anon_inodes.h>
+#include <linux/compat.h>
#include <linux/file.h>
#include <linux/gunyah_rsc_mgr.h>
+#include <linux/gunyah_vm_mgr.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
+#include <linux/xarray.h>

#include <uapi/linux/gunyah.h>

@@ -17,6 +20,169 @@

static void gh_vm_free(struct work_struct *work);

+static DEFINE_XARRAY(gh_vm_functions);
+
+static void gh_vm_put_function(struct gh_vm_function *fn)
+{
+ module_put(fn->mod);
+}
+
+static struct gh_vm_function *gh_vm_get_function(u32 type)
+{
+ struct gh_vm_function *fn;
+
+ fn = xa_load(&gh_vm_functions, type);
+ if (!fn) {
+ request_module("ghfunc:%d", type);
+
+ fn = xa_load(&gh_vm_functions, type);
+ }
+
+ if (!fn || !try_module_get(fn->mod))
+ fn = ERR_PTR(-ENOENT);
+
+ return fn;
+}
+
+static void gh_vm_remove_function_instance(struct gh_vm_function_instance *inst)
+ __must_hold(&inst->ghvm->fn_lock)
+{
+ inst->fn->unbind(inst);
+ list_del(&inst->vm_list);
+ gh_vm_put_function(inst->fn);
+ kfree(inst->argp);
+ kfree(inst);
+}
+
+static void gh_vm_remove_functions(struct gh_vm *ghvm)
+{
+ struct gh_vm_function_instance *inst, *iiter;
+
+ mutex_lock(&ghvm->fn_lock);
+ list_for_each_entry_safe(inst, iiter, &ghvm->functions, vm_list) {
+ gh_vm_remove_function_instance(inst);
+ }
+ mutex_unlock(&ghvm->fn_lock);
+}
+
+static long gh_vm_add_function_instance(struct gh_vm *ghvm, struct gh_fn_desc *f)
+{
+ struct gh_vm_function_instance *inst;
+ void __user *argp;
+ long r = 0;
+
+ if (f->arg_size > GH_FN_MAX_ARG_SIZE) {
+ dev_err_ratelimited(ghvm->parent, "%s: arg_size > %d\n",
+ __func__, GH_FN_MAX_ARG_SIZE);
+ return -EINVAL;
+ }
+
+ inst = kzalloc(sizeof(*inst), GFP_KERNEL);
+ if (!inst)
+ return -ENOMEM;
+
+ inst->arg_size = f->arg_size;
+ if (inst->arg_size) {
+ inst->argp = kzalloc(inst->arg_size, GFP_KERNEL);
+ if (!inst->argp) {
+ r = -ENOMEM;
+ goto free;
+ }
+
+ argp = u64_to_user_ptr(f->arg);
+ if (copy_from_user(inst->argp, argp, f->arg_size)) {
+ r = -EFAULT;
+ goto free_arg;
+ }
+ }
+
+ inst->fn = gh_vm_get_function(f->type);
+ if (IS_ERR(inst->fn)) {
+ r = PTR_ERR(inst->fn);
+ goto free_arg;
+ }
+
+ inst->ghvm = ghvm;
+ inst->rm = ghvm->rm;
+
+ mutex_lock(&ghvm->fn_lock);
+ r = inst->fn->bind(inst);
+ if (r < 0) {
+ mutex_unlock(&ghvm->fn_lock);
+ gh_vm_put_function(inst->fn);
+ goto free_arg;
+ }
+
+ list_add(&inst->vm_list, &ghvm->functions);
+ mutex_unlock(&ghvm->fn_lock);
+
+ return r;
+free_arg:
+ kfree(inst->argp);
+free:
+ kfree(inst);
+ return r;
+}
+
+static long gh_vm_rm_function_instance(struct gh_vm *ghvm, struct gh_fn_desc *f)
+{
+ struct gh_vm_function_instance *inst, *iter;
+ void __user *user_argp;
+ void *argp;
+ long r = 0;
+
+ r = mutex_lock_interruptible(&ghvm->fn_lock);
+ if (r)
+ return r;
+
+ if (f->arg_size) {
+ argp = kzalloc(f->arg_size, GFP_KERNEL);
+ if (!argp) {
+ r = -ENOMEM;
+ goto out;
+ }
+
+ user_argp = u64_to_user_ptr(f->arg);
+ if (copy_from_user(argp, user_argp, f->arg_size)) {
+ r = -EFAULT;
+ kfree(argp);
+ goto out;
+ }
+
+ r = -ENOENT;
+ list_for_each_entry_safe(inst, iter, &ghvm->functions, vm_list) {
+ if (inst->fn->type == f->type &&
+ inst->fn->compare(inst, argp, f->arg_size)) {
+ gh_vm_remove_function_instance(inst);
+ r = 0;
+ }
+ }
+
+ kfree(argp);
+ }
+
+out:
+ mutex_unlock(&ghvm->fn_lock);
+ return r;
+}
+
+int gh_vm_function_register(struct gh_vm_function *fn)
+{
+ if (!fn->bind || !fn->unbind)
+ return -EINVAL;
+
+ return xa_err(xa_store(&gh_vm_functions, fn->type, fn, GFP_KERNEL));
+}
+EXPORT_SYMBOL_GPL(gh_vm_function_register);
+
+void gh_vm_function_unregister(struct gh_vm_function *fn)
+{
+ /* Expecting unregister to only come when unloading a module */
+ WARN_ON(fn->mod && module_refcount(fn->mod));
+ xa_erase(&gh_vm_functions, fn->type);
+}
+EXPORT_SYMBOL_GPL(gh_vm_function_unregister);
+
static int gh_vm_rm_notification_status(struct gh_vm *ghvm, void *data)
{
struct gh_rm_vm_status_payload *payload = data;
@@ -98,6 +264,8 @@ static __must_check struct gh_vm *gh_vm_alloc(struct gh_rm *rm)
init_rwsem(&ghvm->status_lock);
init_waitqueue_head(&ghvm->vm_status_wait);
INIT_WORK(&ghvm->free_work, gh_vm_free);
+ kref_init(&ghvm->kref);
+ INIT_LIST_HEAD(&ghvm->functions);
ghvm->vm_status = GH_RM_VM_STATUS_NO_STATE;

return ghvm;
@@ -254,6 +422,24 @@ static long gh_vm_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
r = gh_vm_ensure_started(ghvm);
break;
}
+ case GH_VM_ADD_FUNCTION: {
+ struct gh_fn_desc f;
+
+ if (copy_from_user(&f, argp, sizeof(f)))
+ return -EFAULT;
+
+ r = gh_vm_add_function_instance(ghvm, &f);
+ break;
+ }
+ case GH_VM_REMOVE_FUNCTION: {
+ struct gh_fn_desc f;
+
+ if (copy_from_user(&f, argp, sizeof(f)))
+ return -EFAULT;
+
+ r = gh_vm_rm_function_instance(ghvm, &f);
+ break;
+ }
default:
r = -ENOTTY;
break;
@@ -270,6 +456,8 @@ static void gh_vm_free(struct work_struct *work)
if (ghvm->vm_status == GH_RM_VM_STATUS_RUNNING)
gh_vm_stop(ghvm);

+ gh_vm_remove_functions(ghvm);
+
if (ghvm->vm_status != GH_RM_VM_STATUS_NO_STATE &&
ghvm->vm_status != GH_RM_VM_STATUS_LOAD &&
ghvm->vm_status != GH_RM_VM_STATUS_RESET) {
@@ -294,14 +482,33 @@ static void gh_vm_free(struct work_struct *work)
kfree(ghvm);
}

-static int gh_vm_release(struct inode *inode, struct file *filp)
+int __must_check gh_vm_get(struct gh_vm *ghvm)
{
- struct gh_vm *ghvm = filp->private_data;
+ return kref_get_unless_zero(&ghvm->kref);
+}
+EXPORT_SYMBOL_GPL(gh_vm_get);
+
+static void _gh_vm_put(struct kref *kref)
+{
+ struct gh_vm *ghvm = container_of(kref, struct gh_vm, kref);

/* VM will be reset and make RM calls which can interruptible sleep.
* Defer to a work so this thread can receive signal.
*/
schedule_work(&ghvm->free_work);
+}
+
+void gh_vm_put(struct gh_vm *ghvm)
+{
+ kref_put(&ghvm->kref, _gh_vm_put);
+}
+EXPORT_SYMBOL_GPL(gh_vm_put);
+
+static int gh_vm_release(struct inode *inode, struct file *filp)
+{
+ struct gh_vm *ghvm = filp->private_data;
+
+ gh_vm_put(ghvm);
return 0;
}

@@ -346,7 +553,7 @@ static long gh_dev_ioctl_create_vm(struct gh_rm *rm, unsigned long arg)
err_put_fd:
put_unused_fd(fd);
err_destroy_vm:
- gh_vm_free(&ghvm->free_work);
+ gh_vm_put(ghvm);
return err;
}

diff --git a/drivers/virt/gunyah/vm_mgr.h b/drivers/virt/gunyah/vm_mgr.h
index 4173bd51f83fe..c4bec1469ae8c 100644
--- a/drivers/virt/gunyah/vm_mgr.h
+++ b/drivers/virt/gunyah/vm_mgr.h
@@ -8,6 +8,7 @@

#include <linux/gunyah_rsc_mgr.h>
#include <linux/list.h>
+#include <linux/kref.h>
#include <linux/miscdevice.h>
#include <linux/mutex.h>
#include <linux/rwsem.h>
@@ -45,9 +46,12 @@ struct gh_vm {
struct rw_semaphore status_lock;

struct work_struct free_work;
+ struct kref kref;
struct mm_struct *mm; /* userspace tied to this vm */
struct mutex mm_lock;
struct list_head memory_mappings;
+ struct mutex fn_lock;
+ struct list_head functions;
};

int gh_vm_mem_alloc(struct gh_vm *ghvm, struct gh_userspace_memory_region *region);
diff --git a/include/linux/gunyah_vm_mgr.h b/include/linux/gunyah_vm_mgr.h
new file mode 100644
index 0000000000000..6e4dd6fa5f96d
--- /dev/null
+++ b/include/linux/gunyah_vm_mgr.h
@@ -0,0 +1,97 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#ifndef _GUNYAH_VM_MGR_H
+#define _GUNYAH_VM_MGR_H
+
+#include <linux/compiler_types.h>
+#include <linux/gunyah.h>
+#include <linux/gunyah_rsc_mgr.h>
+#include <linux/list.h>
+#include <linux/mod_devicetable.h>
+#include <linux/notifier.h>
+
+#include <uapi/linux/gunyah.h>
+
+struct gh_vm;
+
+int __must_check gh_vm_get(struct gh_vm *ghvm);
+void gh_vm_put(struct gh_vm *ghvm);
+
+struct gh_vm_function_instance;
+/**
+ * struct gh_vm_function - Represents a function type
+ * @type: value from &enum gh_fn_type
+ * @name: friendly name for debug purposes
+ * @mod: owner of the function type
+ * @bind: Called when a new function of this type has been allocated.
+ * @unbind: Called when the function instance is being destroyed.
+ * @compare: Compare function instance @f's argument to the provided arg.
+ * Return true if they are equivalent. Used on GH_VM_REMOVE_FUNCTION.
+ */
+struct gh_vm_function {
+ u32 type;
+ const char *name;
+ struct module *mod;
+ long (*bind)(struct gh_vm_function_instance *f);
+ void (*unbind)(struct gh_vm_function_instance *f);
+ bool (*compare)(const struct gh_vm_function_instance *f, const void *arg, size_t size);
+};
+
+/**
+ * struct gh_vm_function_instance - Represents one function instance
+ * @arg_size: size of user argument
+ * @argp: pointer to user argument
+ * @ghvm: Pointer to VM instance
+ * @rm: Pointer to resource manager for the VM instance
+ * @fn: The ops for the function
+ * @data: Private data for function
+ * @vm_list: for gh_vm's functions list
+ * @fn_list: for gh_vm_function's instances list
+ */
+struct gh_vm_function_instance {
+ size_t arg_size;
+ void *argp;
+ struct gh_vm *ghvm;
+ struct gh_rm *rm;
+ struct gh_vm_function *fn;
+ void *data;
+ struct list_head vm_list;
+};
+
+int gh_vm_function_register(struct gh_vm_function *f);
+void gh_vm_function_unregister(struct gh_vm_function *f);
+
+/* Since the function identifiers were setup in a uapi header as an
+ * enum and we do no want to change that, the user must supply the expanded
+ * constant as well and the compiler checks they are the same.
+ * See also MODULE_ALIAS_RDMA_NETLINK.
+ */
+#define MODULE_ALIAS_GH_VM_FUNCTION(_type, _idx) \
+ static inline void __maybe_unused __chk##_idx(void) \
+ { \
+ BUILD_BUG_ON(_type != _idx); \
+ } \
+ MODULE_ALIAS("ghfunc:" __stringify(_idx))
+
+#define DECLARE_GH_VM_FUNCTION(_name, _type, _bind, _unbind, _compare) \
+ static struct gh_vm_function _name = { \
+ .type = _type, \
+ .name = __stringify(_name), \
+ .mod = THIS_MODULE, \
+ .bind = _bind, \
+ .unbind = _unbind, \
+ .compare = _compare, \
+ }
+
+#define module_gh_vm_function(__gf) \
+ module_driver(__gf, gh_vm_function_register, gh_vm_function_unregister)
+
+#define DECLARE_GH_VM_FUNCTION_INIT(_name, _type, _idx, _bind, _unbind, _compare) \
+ DECLARE_GH_VM_FUNCTION(_name, _type, _bind, _unbind, _compare); \
+ module_gh_vm_function(_name); \
+ MODULE_ALIAS_GH_VM_FUNCTION(_type, _idx)
+
+#endif
diff --git a/include/uapi/linux/gunyah.h b/include/uapi/linux/gunyah.h
index 4b63d0b9b8ba7..bb07118a351fd 100644
--- a/include/uapi/linux/gunyah.h
+++ b/include/uapi/linux/gunyah.h
@@ -72,4 +72,22 @@ struct gh_vm_dtb_config {

#define GH_VM_START _IO(GH_IOCTL_TYPE, 0x3)

+#define GH_FN_MAX_ARG_SIZE 256
+
+/**
+ * struct gh_fn_desc - Arguments to create a VM function
+ * @type: Type of the function. See &enum gh_fn_type.
+ * @arg_size: Size of argument to pass to the function. arg_size <= GH_FN_MAX_ARG_SIZE
+ * @arg: Pointer to argument given to the function. See &enum gh_fn_type for expected
+ * arguments for a function type.
+ */
+struct gh_fn_desc {
+ __u32 type;
+ __u32 arg_size;
+ __u64 arg;
+};
+
+#define GH_VM_ADD_FUNCTION _IOW(GH_IOCTL_TYPE, 0x4, struct gh_fn_desc)
+#define GH_VM_REMOVE_FUNCTION _IOW(GH_IOCTL_TYPE, 0x7, struct gh_fn_desc)
+
#endif
--
2.40.0


2023-06-13 17:33:57

by Elliot Berman

[permalink] [raw]
Subject: [PATCH v14 23/25] virt: gunyah: Add irqfd interface

Enable support for creating irqfds which can raise an interrupt on a
Gunyah virtual machine. irqfds are exposed to userspace as a Gunyah VM
function with the name "irqfd". If the VM devicetree is not configured
to create a doorbell with the corresponding label, userspace will still
be able to assert the eventfd but no interrupt will be raised on the
guest.

Acked-by: Alex Elder <[email protected]>
Co-developed-by: Prakruthi Deepak Heragu <[email protected]>
Signed-off-by: Prakruthi Deepak Heragu <[email protected]>
Signed-off-by: Elliot Berman <[email protected]>
---
Documentation/virt/gunyah/vm-manager.rst | 2 +-
drivers/virt/gunyah/Kconfig | 9 ++
drivers/virt/gunyah/Makefile | 1 +
drivers/virt/gunyah/gunyah_irqfd.c | 180 +++++++++++++++++++++++
include/uapi/linux/gunyah.h | 35 +++++
5 files changed, 226 insertions(+), 1 deletion(-)
create mode 100644 drivers/virt/gunyah/gunyah_irqfd.c

diff --git a/Documentation/virt/gunyah/vm-manager.rst b/Documentation/virt/gunyah/vm-manager.rst
index b0c3bde105ae9..57a254827be26 100644
--- a/Documentation/virt/gunyah/vm-manager.rst
+++ b/Documentation/virt/gunyah/vm-manager.rst
@@ -116,7 +116,7 @@ the VM *before* the VM starts.
The argument types are documented below:

.. kernel-doc:: include/uapi/linux/gunyah.h
- :identifiers: gh_fn_vcpu_arg
+ :identifiers: gh_fn_vcpu_arg gh_fn_irqfd_arg gh_irqfd_flags

Gunyah VCPU API Descriptions
----------------------------
diff --git a/drivers/virt/gunyah/Kconfig b/drivers/virt/gunyah/Kconfig
index 0a58395f7d2c5..bc2c46d9df946 100644
--- a/drivers/virt/gunyah/Kconfig
+++ b/drivers/virt/gunyah/Kconfig
@@ -39,3 +39,12 @@ config GUNYAH_VCPU
VMMs can also handle stage 2 faults of the vCPUs.

Say Y/M here if unsure and you want to support Gunyah VMMs.
+
+config GUNYAH_IRQFD
+ tristate "Gunyah irqfd interface"
+ depends on GUNYAH
+ help
+ Enable kernel support for creating irqfds which can raise an interrupt
+ on Gunyah virtual machine.
+
+ Say Y/M here if unsure and you want to support Gunyah VMMs.
diff --git a/drivers/virt/gunyah/Makefile b/drivers/virt/gunyah/Makefile
index cc16b6c19db92..ad212a1cf9671 100644
--- a/drivers/virt/gunyah/Makefile
+++ b/drivers/virt/gunyah/Makefile
@@ -7,3 +7,4 @@ gunyah-y += rsc_mgr.o rsc_mgr_rpc.o vm_mgr.o vm_mgr_mm.o
obj-$(CONFIG_GUNYAH) += gunyah.o

obj-$(CONFIG_GUNYAH_VCPU) += gunyah_vcpu.o
+obj-$(CONFIG_GUNYAH_IRQFD) += gunyah_irqfd.o
diff --git a/drivers/virt/gunyah/gunyah_irqfd.c b/drivers/virt/gunyah/gunyah_irqfd.c
new file mode 100644
index 0000000000000..3e954ebd20297
--- /dev/null
+++ b/drivers/virt/gunyah/gunyah_irqfd.c
@@ -0,0 +1,180 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <linux/eventfd.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/gunyah.h>
+#include <linux/gunyah_vm_mgr.h>
+#include <linux/module.h>
+#include <linux/poll.h>
+#include <linux/printk.h>
+
+#include <uapi/linux/gunyah.h>
+
+struct gh_irqfd {
+ struct gh_resource *ghrsc;
+ struct gh_vm_resource_ticket ticket;
+ struct gh_vm_function_instance *f;
+
+ bool level;
+
+ struct eventfd_ctx *ctx;
+ wait_queue_entry_t wait;
+ poll_table pt;
+};
+
+static int irqfd_wakeup(wait_queue_entry_t *wait, unsigned int mode, int sync, void *key)
+{
+ struct gh_irqfd *irqfd = container_of(wait, struct gh_irqfd, wait);
+ __poll_t flags = key_to_poll(key);
+ int ret = 0;
+
+ if (flags & EPOLLIN) {
+ if (irqfd->ghrsc) {
+ ret = gh_hypercall_bell_send(irqfd->ghrsc->capid, 1, NULL);
+ if (ret)
+ pr_err_ratelimited("Failed to inject interrupt %d: %d\n",
+ irqfd->ticket.label, ret);
+ } else
+ pr_err_ratelimited("Premature injection of interrupt\n");
+ }
+
+ return 0;
+}
+
+static void irqfd_ptable_queue_proc(struct file *file, wait_queue_head_t *wqh, poll_table *pt)
+{
+ struct gh_irqfd *irq_ctx = container_of(pt, struct gh_irqfd, pt);
+
+ add_wait_queue(wqh, &irq_ctx->wait);
+}
+
+static bool gh_irqfd_populate(struct gh_vm_resource_ticket *ticket, struct gh_resource *ghrsc)
+{
+ struct gh_irqfd *irqfd = container_of(ticket, struct gh_irqfd, ticket);
+ int ret;
+
+ if (irqfd->ghrsc) {
+ pr_warn("irqfd%d already got a Gunyah resource. Check if multiple resources with same label were configured.\n",
+ irqfd->ticket.label);
+ return false;
+ }
+
+ irqfd->ghrsc = ghrsc;
+ if (irqfd->level) {
+ /* Configure the bell to trigger when bit 0 is asserted (see
+ * irq_wakeup) and for bell to automatically clear bit 0 once
+ * received by the VM (ack_mask). need to make sure bit 0 is cleared right away,
+ * otherwise the line will never be deasserted. Emulating edge
+ * trigger interrupt does not need to set either mask
+ * because irq is listed only once per gh_hypercall_bell_send
+ */
+ ret = gh_hypercall_bell_set_mask(irqfd->ghrsc->capid, 1, 1);
+ if (ret)
+ pr_warn("irq %d couldn't be set as level triggered. Might cause IRQ storm if asserted\n",
+ irqfd->ticket.label);
+ }
+
+ return true;
+}
+
+static void gh_irqfd_unpopulate(struct gh_vm_resource_ticket *ticket, struct gh_resource *ghrsc)
+{
+ struct gh_irqfd *irqfd = container_of(ticket, struct gh_irqfd, ticket);
+ u64 cnt;
+
+ eventfd_ctx_remove_wait_queue(irqfd->ctx, &irqfd->wait, &cnt);
+}
+
+static long gh_irqfd_bind(struct gh_vm_function_instance *f)
+{
+ struct gh_fn_irqfd_arg *args = f->argp;
+ struct gh_irqfd *irqfd;
+ __poll_t events;
+ struct fd fd;
+ long r;
+
+ if (f->arg_size != sizeof(*args))
+ return -EINVAL;
+
+ /* All other flag bits are reserved for future use */
+ if (args->flags & ~GH_IRQFD_FLAGS_LEVEL)
+ return -EINVAL;
+
+ irqfd = kzalloc(sizeof(*irqfd), GFP_KERNEL);
+ if (!irqfd)
+ return -ENOMEM;
+
+ irqfd->f = f;
+ f->data = irqfd;
+
+ fd = fdget(args->fd);
+ if (!fd.file) {
+ kfree(irqfd);
+ return -EBADF;
+ }
+
+ irqfd->ctx = eventfd_ctx_fileget(fd.file);
+ if (IS_ERR(irqfd->ctx)) {
+ r = PTR_ERR(irqfd->ctx);
+ goto err_fdput;
+ }
+
+ if (args->flags & GH_IRQFD_FLAGS_LEVEL)
+ irqfd->level = true;
+
+ init_waitqueue_func_entry(&irqfd->wait, irqfd_wakeup);
+ init_poll_funcptr(&irqfd->pt, irqfd_ptable_queue_proc);
+
+ irqfd->ticket.resource_type = GH_RESOURCE_TYPE_BELL_TX;
+ irqfd->ticket.label = args->label;
+ irqfd->ticket.owner = THIS_MODULE;
+ irqfd->ticket.populate = gh_irqfd_populate;
+ irqfd->ticket.unpopulate = gh_irqfd_unpopulate;
+
+ r = gh_vm_add_resource_ticket(f->ghvm, &irqfd->ticket);
+ if (r)
+ goto err_ctx;
+
+ events = vfs_poll(fd.file, &irqfd->pt);
+ if (events & EPOLLIN)
+ pr_warn("Premature injection of interrupt\n");
+ fdput(fd);
+
+ return 0;
+err_ctx:
+ eventfd_ctx_put(irqfd->ctx);
+err_fdput:
+ fdput(fd);
+ kfree(irqfd);
+ return r;
+}
+
+static void gh_irqfd_unbind(struct gh_vm_function_instance *f)
+{
+ struct gh_irqfd *irqfd = f->data;
+
+ gh_vm_remove_resource_ticket(irqfd->f->ghvm, &irqfd->ticket);
+ eventfd_ctx_put(irqfd->ctx);
+ kfree(irqfd);
+}
+
+static bool gh_irqfd_compare(const struct gh_vm_function_instance *f,
+ const void *arg, size_t size)
+{
+ const struct gh_fn_irqfd_arg *instance = f->argp,
+ *other = arg;
+
+ if (sizeof(*other) != size)
+ return false;
+
+ return instance->label == other->label;
+}
+
+DECLARE_GH_VM_FUNCTION_INIT(irqfd, GH_FN_IRQFD, 2, gh_irqfd_bind, gh_irqfd_unbind,
+ gh_irqfd_compare);
+MODULE_DESCRIPTION("Gunyah irqfd VM Function");
+MODULE_LICENSE("GPL");
diff --git a/include/uapi/linux/gunyah.h b/include/uapi/linux/gunyah.h
index 434ffa8ffc783..0c480c622686a 100644
--- a/include/uapi/linux/gunyah.h
+++ b/include/uapi/linux/gunyah.h
@@ -77,9 +77,12 @@ struct gh_vm_dtb_config {
* @GH_FN_VCPU: create a vCPU instance to control a vCPU
* &struct gh_fn_desc.arg is a pointer to &struct gh_fn_vcpu_arg
* Return: file descriptor to manipulate the vcpu.
+ * @GH_FN_IRQFD: register eventfd to assert a Gunyah doorbell
+ * &struct gh_fn_desc.arg is a pointer to &struct gh_fn_irqfd_arg
*/
enum gh_fn_type {
GH_FN_VCPU = 1,
+ GH_FN_IRQFD,
};

#define GH_FN_MAX_ARG_SIZE 256
@@ -99,6 +102,38 @@ struct gh_fn_vcpu_arg {
__u32 id;
};

+/**
+ * enum gh_irqfd_flags - flags for use in gh_fn_irqfd_arg
+ * @GH_IRQFD_FLAGS_LEVEL: make the interrupt operate like a level triggered
+ * interrupt on guest side. Triggering IRQFD before
+ * guest handles the interrupt causes interrupt to
+ * stay asserted.
+ */
+enum gh_irqfd_flags {
+ GH_IRQFD_FLAGS_LEVEL = 1UL << 0,
+};
+
+/**
+ * struct gh_fn_irqfd_arg - Arguments to create an irqfd function.
+ *
+ * Create this function with &GH_VM_ADD_FUNCTION using type &GH_FN_IRQFD.
+ *
+ * Allows setting an eventfd to directly trigger a guest interrupt.
+ * irqfd.fd specifies the file descriptor to use as the eventfd.
+ * irqfd.label corresponds to the doorbell label used in the guest VM's devicetree.
+ *
+ * @fd: an eventfd which when written to will raise a doorbell
+ * @label: Label of the doorbell created on the guest VM
+ * @flags: see &enum gh_irqfd_flags
+ * @padding: padding bytes
+ */
+struct gh_fn_irqfd_arg {
+ __u32 fd;
+ __u32 label;
+ __u32 flags;
+ __u32 padding;
+};
+
/**
* struct gh_fn_desc - Arguments to create a VM function
* @type: Type of the function. See &enum gh_fn_type.
--
2.40.0


2023-06-13 17:34:13

by Elliot Berman

[permalink] [raw]
Subject: [PATCH v14 15/25] virt: gunyah: Add Qualcomm Gunyah platform ops

Qualcomm platforms have a firmware entity which performs access control
to physical pages. Dynamically started Gunyah virtual machines use the
QCOM_SCM_RM_MANAGED_VMID for access. Linux thus needs to assign access
to the memory used by guest VMs. Gunyah doesn't do this operation for us
since it is the current VM (typically VMID_HLOS) delegating the access
and not Gunyah itself. Use the Gunyah platform ops to achieve this so
that only Qualcomm platforms attempt to make the needed SCM calls.

Reviewed-by: Alex Elder <[email protected]>
Co-developed-by: Prakruthi Deepak Heragu <[email protected]>
Signed-off-by: Prakruthi Deepak Heragu <[email protected]>
Signed-off-by: Elliot Berman <[email protected]>
---
drivers/virt/gunyah/Kconfig | 13 +++
drivers/virt/gunyah/Makefile | 1 +
drivers/virt/gunyah/gunyah_qcom.c | 153 ++++++++++++++++++++++++++++++
3 files changed, 167 insertions(+)
create mode 100644 drivers/virt/gunyah/gunyah_qcom.c

diff --git a/drivers/virt/gunyah/Kconfig b/drivers/virt/gunyah/Kconfig
index de815189dab6c..0421b751aad4f 100644
--- a/drivers/virt/gunyah/Kconfig
+++ b/drivers/virt/gunyah/Kconfig
@@ -5,6 +5,7 @@ config GUNYAH
depends on ARM64
depends on MAILBOX
select GUNYAH_PLATFORM_HOOKS
+ imply GUNYAH_QCOM_PLATFORM if ARCH_QCOM
help
The Gunyah drivers are the helper interfaces that run in a guest VM
such as basic inter-VM IPC and signaling mechanisms, and higher level
@@ -15,3 +16,15 @@ config GUNYAH

config GUNYAH_PLATFORM_HOOKS
tristate
+
+config GUNYAH_QCOM_PLATFORM
+ tristate "Support for Gunyah on Qualcomm platforms"
+ depends on GUNYAH
+ select GUNYAH_PLATFORM_HOOKS
+ select QCOM_SCM
+ help
+ Enable support for interacting with Gunyah on Qualcomm
+ platforms. Interaction with Qualcomm firmware requires
+ extra platform-specific support.
+
+ Say Y/M here to use Gunyah on Qualcomm platforms.
diff --git a/drivers/virt/gunyah/Makefile b/drivers/virt/gunyah/Makefile
index 4fbeee521d60a..2aa9ff038ed02 100644
--- a/drivers/virt/gunyah/Makefile
+++ b/drivers/virt/gunyah/Makefile
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: GPL-2.0

obj-$(CONFIG_GUNYAH_PLATFORM_HOOKS) += gunyah_platform_hooks.o
+obj-$(CONFIG_GUNYAH_QCOM_PLATFORM) += gunyah_qcom.o

gunyah-y += rsc_mgr.o rsc_mgr_rpc.o vm_mgr.o vm_mgr_mm.o
obj-$(CONFIG_GUNYAH) += gunyah.o
diff --git a/drivers/virt/gunyah/gunyah_qcom.c b/drivers/virt/gunyah/gunyah_qcom.c
new file mode 100644
index 0000000000000..f06a598f2e1b3
--- /dev/null
+++ b/drivers/virt/gunyah/gunyah_qcom.c
@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <linux/arm-smccc.h>
+#include <linux/gunyah_rsc_mgr.h>
+#include <linux/module.h>
+#include <linux/firmware/qcom/qcom_scm.h>
+#include <linux/types.h>
+#include <linux/uuid.h>
+
+#define QCOM_SCM_RM_MANAGED_VMID 0x3A
+#define QCOM_SCM_MAX_MANAGED_VMID 0x3F
+
+static int qcom_scm_gh_rm_pre_mem_share(struct gh_rm *rm, struct gh_rm_mem_parcel *mem_parcel)
+{
+ struct qcom_scm_vmperm *new_perms;
+ u64 src, src_cpy;
+ int ret = 0, i, n;
+ u16 vmid;
+
+ new_perms = kcalloc(mem_parcel->n_acl_entries, sizeof(*new_perms), GFP_KERNEL);
+ if (!new_perms)
+ return -ENOMEM;
+
+ for (n = 0; n < mem_parcel->n_acl_entries; n++) {
+ vmid = le16_to_cpu(mem_parcel->acl_entries[n].vmid);
+ if (vmid <= QCOM_SCM_MAX_MANAGED_VMID)
+ new_perms[n].vmid = vmid;
+ else
+ new_perms[n].vmid = QCOM_SCM_RM_MANAGED_VMID;
+ if (mem_parcel->acl_entries[n].perms & GH_RM_ACL_X)
+ new_perms[n].perm |= QCOM_SCM_PERM_EXEC;
+ if (mem_parcel->acl_entries[n].perms & GH_RM_ACL_W)
+ new_perms[n].perm |= QCOM_SCM_PERM_WRITE;
+ if (mem_parcel->acl_entries[n].perms & GH_RM_ACL_R)
+ new_perms[n].perm |= QCOM_SCM_PERM_READ;
+ }
+
+ src = BIT_ULL(QCOM_SCM_VMID_HLOS);
+
+ for (i = 0; i < mem_parcel->n_mem_entries; i++) {
+ src_cpy = src;
+ ret = qcom_scm_assign_mem(le64_to_cpu(mem_parcel->mem_entries[i].phys_addr),
+ le64_to_cpu(mem_parcel->mem_entries[i].size),
+ &src_cpy, new_perms, mem_parcel->n_acl_entries);
+ if (ret)
+ break;
+ }
+
+ if (!ret)
+ goto out;
+
+ src = 0;
+ for (n = 0; n < mem_parcel->n_acl_entries; n++) {
+ vmid = le16_to_cpu(mem_parcel->acl_entries[n].vmid);
+ if (vmid <= QCOM_SCM_MAX_MANAGED_VMID)
+ src |= BIT_ULL(vmid);
+ else
+ src |= BIT_ULL(QCOM_SCM_RM_MANAGED_VMID);
+ }
+
+ new_perms[0].vmid = QCOM_SCM_VMID_HLOS;
+
+ for (i--; i >= 0; i--) {
+ src_cpy = src;
+ WARN_ON_ONCE(qcom_scm_assign_mem(
+ le64_to_cpu(mem_parcel->mem_entries[i].phys_addr),
+ le64_to_cpu(mem_parcel->mem_entries[i].size),
+ &src_cpy, new_perms, 1));
+ }
+
+out:
+ kfree(new_perms);
+ return ret;
+}
+
+static int qcom_scm_gh_rm_post_mem_reclaim(struct gh_rm *rm, struct gh_rm_mem_parcel *mem_parcel)
+{
+ struct qcom_scm_vmperm new_perms;
+ u64 src = 0, src_cpy;
+ int ret = 0, i, n;
+ u16 vmid;
+
+ new_perms.vmid = QCOM_SCM_VMID_HLOS;
+ new_perms.perm = QCOM_SCM_PERM_EXEC | QCOM_SCM_PERM_WRITE | QCOM_SCM_PERM_READ;
+
+ for (n = 0; n < mem_parcel->n_acl_entries; n++) {
+ vmid = le16_to_cpu(mem_parcel->acl_entries[n].vmid);
+ if (vmid <= QCOM_SCM_MAX_MANAGED_VMID)
+ src |= (1ull << vmid);
+ else
+ src |= (1ull << QCOM_SCM_RM_MANAGED_VMID);
+ }
+
+ for (i = 0; i < mem_parcel->n_mem_entries; i++) {
+ src_cpy = src;
+ ret = qcom_scm_assign_mem(le64_to_cpu(mem_parcel->mem_entries[i].phys_addr),
+ le64_to_cpu(mem_parcel->mem_entries[i].size),
+ &src_cpy, &new_perms, 1);
+ WARN_ON_ONCE(ret);
+ }
+
+ return ret;
+}
+
+static struct gh_rm_platform_ops qcom_scm_gh_rm_platform_ops = {
+ .pre_mem_share = qcom_scm_gh_rm_pre_mem_share,
+ .post_mem_reclaim = qcom_scm_gh_rm_post_mem_reclaim,
+};
+
+/* {19bd54bd-0b37-571b-946f-609b54539de6} */
+static const uuid_t QCOM_EXT_UUID =
+ UUID_INIT(0x19bd54bd, 0x0b37, 0x571b, 0x94, 0x6f, 0x60, 0x9b, 0x54, 0x53, 0x9d, 0xe6);
+
+#define GH_QCOM_EXT_CALL_UUID_ID ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, ARM_SMCCC_SMC_32, \
+ ARM_SMCCC_OWNER_VENDOR_HYP, 0x3f01)
+
+static bool gh_has_qcom_extensions(void)
+{
+ struct arm_smccc_res res;
+ uuid_t uuid;
+ u32 *up;
+
+ arm_smccc_1_1_smc(GH_QCOM_EXT_CALL_UUID_ID, &res);
+
+ up = (u32 *)&uuid.b[0];
+ up[0] = lower_32_bits(res.a0);
+ up[1] = lower_32_bits(res.a1);
+ up[2] = lower_32_bits(res.a2);
+ up[3] = lower_32_bits(res.a3);
+
+ return uuid_equal(&uuid, &QCOM_EXT_UUID);
+}
+
+static int __init qcom_gh_platform_hooks_register(void)
+{
+ if (!gh_has_qcom_extensions())
+ return -ENODEV;
+
+ return gh_rm_register_platform_ops(&qcom_scm_gh_rm_platform_ops);
+}
+
+static void __exit qcom_gh_platform_hooks_unregister(void)
+{
+ gh_rm_unregister_platform_ops(&qcom_scm_gh_rm_platform_ops);
+}
+
+module_init(qcom_gh_platform_hooks_register);
+module_exit(qcom_gh_platform_hooks_unregister);
+MODULE_DESCRIPTION("Qualcomm Technologies, Inc. Platform Hooks for Gunyah");
+MODULE_LICENSE("GPL");
--
2.40.0


2023-06-13 17:35:50

by Elliot Berman

[permalink] [raw]
Subject: [PATCH v14 21/25] virt: gunyah: Add proxy-scheduled vCPUs

Gunyah allows host virtual machines to schedule guest virtual machines
and handle their MMIO accesses. vCPUs are presented to the host as a
Gunyah resource and represented to userspace as a Gunyah VM function.

Creating the vcpu VM function will create a file descriptor that:
- can run an ioctl: GH_VCPU_RUN to schedule the guest vCPU until the
next interrupt occurs on the host or when the guest vCPU can no
longer be run.
- can be mmap'd to share a gh_vcpu_run structure which can look up the
reason why GH_VCPU_RUN returned and provide return values for MMIO
access.

Acked-by: Alex Elder <[email protected]>
Co-developed-by: Prakruthi Deepak Heragu <[email protected]>
Signed-off-by: Prakruthi Deepak Heragu <[email protected]>
Signed-off-by: Elliot Berman <[email protected]>
---
Documentation/virt/gunyah/vm-manager.rst | 46 ++-
arch/arm64/gunyah/gunyah_hypercall.c | 28 ++
drivers/virt/gunyah/Kconfig | 11 +
drivers/virt/gunyah/Makefile | 2 +
drivers/virt/gunyah/gunyah_vcpu.c | 470 +++++++++++++++++++++++
drivers/virt/gunyah/vm_mgr.c | 4 +
drivers/virt/gunyah/vm_mgr.h | 1 +
include/linux/gunyah.h | 24 ++
include/uapi/linux/gunyah.h | 128 ++++++
9 files changed, 712 insertions(+), 2 deletions(-)
create mode 100644 drivers/virt/gunyah/gunyah_vcpu.c

diff --git a/Documentation/virt/gunyah/vm-manager.rst b/Documentation/virt/gunyah/vm-manager.rst
index cbc79bd8749b4..b0c3bde105ae9 100644
--- a/Documentation/virt/gunyah/vm-manager.rst
+++ b/Documentation/virt/gunyah/vm-manager.rst
@@ -5,8 +5,7 @@ Virtual Machine Manager
=======================

The Gunyah Virtual Machine Manager is a Linux driver to support launching
-virtual machines using Gunyah. It presently supports launching virtual machines
-scheduled by Gunyah's scheduler.
+virtual machines using Gunyah.

Configuration of a Gunyah virtual machine is done via a devicetree. When the VM
is launched, memory is provided by the host VM which contains the devictree.
@@ -99,3 +98,46 @@ GH_VM_START
~~~~~~~~~~~

This ioctl starts the VM.
+
+GH_VM_ADD_FUNCTION
+~~~~~~~~~~~~~~~~~~
+
+This ioctl registers a Gunyah VM function with the VM manager. The VM function
+is described with a &struct gh_fn_desc.type and some arguments for that type.
+Typically, the function is added before the VM starts, but the function doesn't
+"operate" until the VM starts with `GH_VM_START`_. For example, vCPU ioctls will
+all return an error until the VM starts because the vCPUs don't exist until the
+VM is started. This allows the VMM to set up all the kernel functions needed for
+the VM *before* the VM starts.
+
+.. kernel-doc:: include/uapi/linux/gunyah.h
+ :identifiers: gh_fn_desc gh_fn_type
+
+The argument types are documented below:
+
+.. kernel-doc:: include/uapi/linux/gunyah.h
+ :identifiers: gh_fn_vcpu_arg
+
+Gunyah VCPU API Descriptions
+----------------------------
+
+A vCPU file descriptor is created after calling `GH_VM_ADD_FUNCTION` with the type `GH_FN_VCPU`.
+
+GH_VCPU_RUN
+~~~~~~~~~~~
+
+This ioctl is used to run a guest virtual cpu. While there are no
+explicit parameters, there is an implicit parameter block that can be
+obtained by mmap()ing the vcpu fd at offset 0, with the size given by
+`GH_VCPU_MMAP_SIZE`_. The parameter block is formatted as a 'struct
+gh_vcpu_run' (see below).
+
+GH_VCPU_MMAP_SIZE
+~~~~~~~~~~~~~~~~~
+
+The `GH_VCPU_RUN`_ ioctl communicates with userspace via a shared
+memory region. This ioctl returns the size of that region. See the
+`GH_VCPU_RUN`_ documentation for details.
+
+.. kernel-doc:: include/uapi/linux/gunyah.h
+ :identifiers: gh_vcpu_exit gh_vcpu_run gh_vm_status gh_vm_exit_info
diff --git a/arch/arm64/gunyah/gunyah_hypercall.c b/arch/arm64/gunyah/gunyah_hypercall.c
index c5bf0dd468ec9..7d96491f84e00 100644
--- a/arch/arm64/gunyah/gunyah_hypercall.c
+++ b/arch/arm64/gunyah/gunyah_hypercall.c
@@ -37,6 +37,7 @@ EXPORT_SYMBOL_GPL(arch_is_gh_guest);
#define GH_HYPERCALL_HYP_IDENTIFY GH_HYPERCALL(0x8000)
#define GH_HYPERCALL_MSGQ_SEND GH_HYPERCALL(0x801B)
#define GH_HYPERCALL_MSGQ_RECV GH_HYPERCALL(0x801C)
+#define GH_HYPERCALL_VCPU_RUN GH_HYPERCALL(0x8065)

/**
* gh_hypercall_hyp_identify() - Returns build information and feature flags
@@ -85,5 +86,32 @@ enum gh_error gh_hypercall_msgq_recv(u64 capid, void *buff, size_t size, size_t
}
EXPORT_SYMBOL_GPL(gh_hypercall_msgq_recv);

+enum gh_error gh_hypercall_vcpu_run(u64 capid, u64 *resume_data,
+ struct gh_hypercall_vcpu_run_resp *resp)
+{
+ struct arm_smccc_1_2_regs args = {
+ .a0 = GH_HYPERCALL_VCPU_RUN,
+ .a1 = capid,
+ .a2 = resume_data[0],
+ .a3 = resume_data[1],
+ .a4 = resume_data[2],
+ /* C language says this will be implictly zero. Gunyah requires 0, so be explicit */
+ .a5 = 0,
+ };
+ struct arm_smccc_1_2_regs res;
+
+ arm_smccc_1_2_hvc(&args, &res);
+
+ if (res.a0 == GH_ERROR_OK) {
+ resp->sized_state = res.a1;
+ resp->state_data[0] = res.a2;
+ resp->state_data[1] = res.a3;
+ resp->state_data[2] = res.a4;
+ }
+
+ return res.a0;
+}
+EXPORT_SYMBOL_GPL(gh_hypercall_vcpu_run);
+
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Gunyah Hypervisor Hypercalls");
diff --git a/drivers/virt/gunyah/Kconfig b/drivers/virt/gunyah/Kconfig
index 0421b751aad4f..0a58395f7d2c5 100644
--- a/drivers/virt/gunyah/Kconfig
+++ b/drivers/virt/gunyah/Kconfig
@@ -28,3 +28,14 @@ config GUNYAH_QCOM_PLATFORM
extra platform-specific support.

Say Y/M here to use Gunyah on Qualcomm platforms.
+
+config GUNYAH_VCPU
+ tristate "Runnable Gunyah vCPUs"
+ depends on GUNYAH
+ help
+ Enable kernel support for host-scheduled vCPUs running under Gunyah.
+ When selecting this option, userspace virtual machine managers (VMM)
+ can schedule the guest VM's vCPUs instead of using Gunyah's scheduler.
+ VMMs can also handle stage 2 faults of the vCPUs.
+
+ Say Y/M here if unsure and you want to support Gunyah VMMs.
diff --git a/drivers/virt/gunyah/Makefile b/drivers/virt/gunyah/Makefile
index 2aa9ff038ed02..cc16b6c19db92 100644
--- a/drivers/virt/gunyah/Makefile
+++ b/drivers/virt/gunyah/Makefile
@@ -5,3 +5,5 @@ obj-$(CONFIG_GUNYAH_QCOM_PLATFORM) += gunyah_qcom.o

gunyah-y += rsc_mgr.o rsc_mgr_rpc.o vm_mgr.o vm_mgr_mm.o
obj-$(CONFIG_GUNYAH) += gunyah.o
+
+obj-$(CONFIG_GUNYAH_VCPU) += gunyah_vcpu.o
diff --git a/drivers/virt/gunyah/gunyah_vcpu.c b/drivers/virt/gunyah/gunyah_vcpu.c
new file mode 100644
index 0000000000000..82a0cbf55caf6
--- /dev/null
+++ b/drivers/virt/gunyah/gunyah_vcpu.c
@@ -0,0 +1,470 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <linux/anon_inodes.h>
+#include <linux/file.h>
+#include <linux/gunyah.h>
+#include <linux/gunyah_vm_mgr.h>
+#include <linux/interrupt.h>
+#include <linux/kref.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/wait.h>
+
+#include "vm_mgr.h"
+
+#include <uapi/linux/gunyah.h>
+
+#define MAX_VCPU_NAME 20 /* gh-vcpu:u32_max+NUL */
+
+struct gh_vcpu {
+ struct gh_vm_function_instance *f;
+ struct gh_resource *rsc;
+ struct mutex run_lock;
+ /* Track why vcpu_run left last time around. */
+ enum {
+ GH_VCPU_UNKNOWN = 0,
+ GH_VCPU_READY,
+ GH_VCPU_MMIO_READ,
+ GH_VCPU_SYSTEM_DOWN,
+ } state;
+ u8 mmio_read_len;
+ struct gh_vcpu_run *vcpu_run;
+ struct completion ready;
+ struct gh_vm *ghvm;
+
+ struct notifier_block nb;
+ struct gh_vm_resource_ticket ticket;
+ struct kref kref;
+};
+
+static void vcpu_release(struct kref *kref)
+{
+ struct gh_vcpu *vcpu = container_of(kref, struct gh_vcpu, kref);
+
+ free_page((unsigned long)vcpu->vcpu_run);
+ kfree(vcpu);
+}
+
+/*
+ * When hypervisor allows us to schedule vCPU again, it gives us an interrupt
+ */
+static irqreturn_t gh_vcpu_irq_handler(int irq, void *data)
+{
+ struct gh_vcpu *vcpu = data;
+
+ complete(&vcpu->ready);
+ return IRQ_HANDLED;
+}
+
+static bool gh_handle_mmio(struct gh_vcpu *vcpu,
+ struct gh_hypercall_vcpu_run_resp *vcpu_run_resp)
+{
+ int ret = 0;
+ u64 addr = vcpu_run_resp->state_data[0],
+ len = vcpu_run_resp->state_data[1],
+ data = vcpu_run_resp->state_data[2];
+
+ if (WARN_ON(len > sizeof(u64)))
+ len = sizeof(u64);
+
+ if (vcpu_run_resp->state == GH_VCPU_ADDRSPACE_VMMIO_READ) {
+ vcpu->vcpu_run->mmio.is_write = 0;
+ /* Record that we need to give vCPU user's supplied value next gh_vcpu_run() */
+ vcpu->state = GH_VCPU_MMIO_READ;
+ vcpu->mmio_read_len = len;
+ } else { /* GH_VCPU_ADDRSPACE_VMMIO_WRITE */
+ /* Try internal handlers first */
+ ret = gh_vm_mmio_write(vcpu->f->ghvm, addr, len, data);
+ if (!ret)
+ return true;
+
+ /* Give userspace the info */
+ vcpu->vcpu_run->mmio.is_write = 1;
+ memcpy(vcpu->vcpu_run->mmio.data, &data, len);
+ }
+
+ vcpu->vcpu_run->mmio.phys_addr = addr;
+ vcpu->vcpu_run->mmio.len = len;
+ vcpu->vcpu_run->exit_reason = GH_VCPU_EXIT_MMIO;
+
+ return false;
+}
+
+static int gh_vcpu_rm_notification(struct notifier_block *nb, unsigned long action, void *data)
+{
+ struct gh_vcpu *vcpu = container_of(nb, struct gh_vcpu, nb);
+ struct gh_rm_vm_exited_payload *exit_payload = data;
+
+ if (action == GH_RM_NOTIFICATION_VM_EXITED &&
+ le16_to_cpu(exit_payload->vmid) == vcpu->ghvm->vmid)
+ complete(&vcpu->ready);
+
+ return NOTIFY_OK;
+}
+
+static inline enum gh_vm_status remap_vm_status(enum gh_rm_vm_status rm_status)
+{
+ switch (rm_status) {
+ case GH_RM_VM_STATUS_INIT_FAILED:
+ return GH_VM_STATUS_LOAD_FAILED;
+ case GH_RM_VM_STATUS_EXITED:
+ return GH_VM_STATUS_EXITED;
+ default:
+ return GH_VM_STATUS_CRASHED;
+ }
+}
+
+/**
+ * gh_vcpu_check_system() - Check whether VM as a whole is running
+ * @vcpu: Pointer to gh_vcpu
+ *
+ * Returns true if the VM is alive.
+ * Returns false if the vCPU is the VM is not alive (can only be that VM is shutting down).
+ */
+static bool gh_vcpu_check_system(struct gh_vcpu *vcpu)
+ __must_hold(&vcpu->run_lock)
+{
+ bool ret = true;
+
+ down_read(&vcpu->ghvm->status_lock);
+ if (likely(vcpu->ghvm->vm_status == GH_RM_VM_STATUS_RUNNING))
+ goto out;
+
+ vcpu->vcpu_run->status.status = remap_vm_status(vcpu->ghvm->vm_status);
+ vcpu->vcpu_run->status.exit_info = vcpu->ghvm->exit_info;
+ vcpu->vcpu_run->exit_reason = GH_VCPU_EXIT_STATUS;
+ vcpu->state = GH_VCPU_SYSTEM_DOWN;
+ ret = false;
+out:
+ up_read(&vcpu->ghvm->status_lock);
+ return ret;
+}
+
+/**
+ * gh_vcpu_run() - Request Gunyah to begin scheduling this vCPU.
+ * @vcpu: The client descriptor that was obtained via gh_vcpu_alloc()
+ */
+static int gh_vcpu_run(struct gh_vcpu *vcpu)
+{
+ struct gh_hypercall_vcpu_run_resp vcpu_run_resp;
+ u64 state_data[3] = { 0 };
+ enum gh_error gh_error;
+ int ret = 0;
+
+ if (!vcpu->f)
+ return -ENODEV;
+
+ if (mutex_lock_interruptible(&vcpu->run_lock))
+ return -ERESTARTSYS;
+
+ if (!vcpu->rsc) {
+ ret = -ENODEV;
+ goto out;
+ }
+
+ switch (vcpu->state) {
+ case GH_VCPU_UNKNOWN:
+ if (vcpu->ghvm->vm_status != GH_RM_VM_STATUS_RUNNING) {
+ /* Check if VM is up. If VM is starting, will block until VM is fully up
+ * since that thread does down_write.
+ */
+ if (!gh_vcpu_check_system(vcpu))
+ goto out;
+ }
+ vcpu->state = GH_VCPU_READY;
+ break;
+ case GH_VCPU_MMIO_READ:
+ if (unlikely(vcpu->mmio_read_len > sizeof(state_data[0])))
+ vcpu->mmio_read_len = sizeof(state_data[0]);
+ memcpy(&state_data[0], vcpu->vcpu_run->mmio.data, vcpu->mmio_read_len);
+ vcpu->state = GH_VCPU_READY;
+ break;
+ case GH_VCPU_SYSTEM_DOWN:
+ goto out;
+ default:
+ break;
+ }
+
+ while (!ret && !signal_pending(current)) {
+ if (vcpu->vcpu_run->immediate_exit) {
+ ret = -EINTR;
+ goto out;
+ }
+
+ gh_error = gh_hypercall_vcpu_run(vcpu->rsc->capid, state_data, &vcpu_run_resp);
+ if (gh_error == GH_ERROR_OK) {
+ switch (vcpu_run_resp.state) {
+ case GH_VCPU_STATE_READY:
+ if (need_resched())
+ schedule();
+ break;
+ case GH_VCPU_STATE_POWERED_OFF:
+ /* vcpu might be off because the VM is shut down.
+ * If so, it won't ever run again: exit back to user
+ */
+ if (!gh_vcpu_check_system(vcpu))
+ goto out;
+ /* Otherwise, another vcpu will turn it on (e.g. by PSCI)
+ * and hyp sends an interrupt to wake Linux up.
+ */
+ fallthrough;
+ case GH_VCPU_STATE_EXPECTS_WAKEUP:
+ ret = wait_for_completion_interruptible(&vcpu->ready);
+ /* reinitialize completion before next hypercall. If we reinitialize
+ * after the hypercall, interrupt may have already come before
+ * re-initializing the completion and then end up waiting for
+ * event that already happened.
+ */
+ reinit_completion(&vcpu->ready);
+ /* Check system status again. Completion might've
+ * come from gh_vcpu_rm_notification
+ */
+ if (!ret && !gh_vcpu_check_system(vcpu))
+ goto out;
+ break;
+ case GH_VCPU_STATE_BLOCKED:
+ schedule();
+ break;
+ case GH_VCPU_ADDRSPACE_VMMIO_READ:
+ case GH_VCPU_ADDRSPACE_VMMIO_WRITE:
+ if (!gh_handle_mmio(vcpu, &vcpu_run_resp))
+ goto out;
+ break;
+ default:
+ pr_warn_ratelimited("Unknown vCPU state: %llx\n",
+ vcpu_run_resp.sized_state);
+ schedule();
+ break;
+ }
+ } else if (gh_error == GH_ERROR_RETRY) {
+ schedule();
+ } else {
+ ret = gh_error_remap(gh_error);
+ }
+ }
+
+out:
+ mutex_unlock(&vcpu->run_lock);
+
+ if (signal_pending(current))
+ return -ERESTARTSYS;
+
+ return ret;
+}
+
+static long gh_vcpu_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+ struct gh_vcpu *vcpu = filp->private_data;
+ long ret = -EINVAL;
+
+ switch (cmd) {
+ case GH_VCPU_RUN:
+ ret = gh_vcpu_run(vcpu);
+ break;
+ case GH_VCPU_MMAP_SIZE:
+ ret = PAGE_SIZE;
+ break;
+ default:
+ break;
+ }
+ return ret;
+}
+
+static int gh_vcpu_release(struct inode *inode, struct file *filp)
+{
+ struct gh_vcpu *vcpu = filp->private_data;
+
+ gh_vm_put(vcpu->ghvm);
+ kref_put(&vcpu->kref, vcpu_release);
+ return 0;
+}
+
+static vm_fault_t gh_vcpu_fault(struct vm_fault *vmf)
+{
+ struct gh_vcpu *vcpu = vmf->vma->vm_file->private_data;
+ struct page *page = NULL;
+
+ if (vmf->pgoff == 0)
+ page = virt_to_page(vcpu->vcpu_run);
+
+ get_page(page);
+ vmf->page = page;
+ return 0;
+}
+
+static const struct vm_operations_struct gh_vcpu_ops = {
+ .fault = gh_vcpu_fault,
+};
+
+static int gh_vcpu_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ vma->vm_ops = &gh_vcpu_ops;
+ return 0;
+}
+
+static const struct file_operations gh_vcpu_fops = {
+ .owner = THIS_MODULE,
+ .unlocked_ioctl = gh_vcpu_ioctl,
+ .release = gh_vcpu_release,
+ .llseek = noop_llseek,
+ .mmap = gh_vcpu_mmap,
+};
+
+static bool gh_vcpu_populate(struct gh_vm_resource_ticket *ticket, struct gh_resource *ghrsc)
+{
+ struct gh_vcpu *vcpu = container_of(ticket, struct gh_vcpu, ticket);
+ int ret;
+
+ mutex_lock(&vcpu->run_lock);
+ if (vcpu->rsc) {
+ pr_warn("vcpu%d already got a Gunyah resource. Check if multiple resources with same label were configured.\n",
+ vcpu->ticket.label);
+ ret = -EEXIST;
+ goto out;
+ }
+
+ vcpu->rsc = ghrsc;
+ init_completion(&vcpu->ready);
+
+ ret = request_irq(vcpu->rsc->irq, gh_vcpu_irq_handler, IRQF_TRIGGER_RISING, "gh_vcpu",
+ vcpu);
+ if (ret)
+ pr_warn("Failed to request vcpu irq %d: %d", vcpu->rsc->irq, ret);
+
+ enable_irq_wake(vcpu->rsc->irq);
+
+out:
+ mutex_unlock(&vcpu->run_lock);
+ return !ret;
+}
+
+static void gh_vcpu_unpopulate(struct gh_vm_resource_ticket *ticket,
+ struct gh_resource *ghrsc)
+{
+ struct gh_vcpu *vcpu = container_of(ticket, struct gh_vcpu, ticket);
+
+ vcpu->vcpu_run->immediate_exit = true;
+ complete_all(&vcpu->ready);
+ mutex_lock(&vcpu->run_lock);
+ free_irq(vcpu->rsc->irq, vcpu);
+ vcpu->rsc = NULL;
+ mutex_unlock(&vcpu->run_lock);
+}
+
+static long gh_vcpu_bind(struct gh_vm_function_instance *f)
+{
+ struct gh_fn_vcpu_arg *arg = f->argp;
+ struct gh_vcpu *vcpu;
+ char name[MAX_VCPU_NAME];
+ struct file *file;
+ struct page *page;
+ int fd;
+ long r;
+
+ if (f->arg_size != sizeof(*arg))
+ return -EINVAL;
+
+ vcpu = kzalloc(sizeof(*vcpu), GFP_KERNEL);
+ if (!vcpu)
+ return -ENOMEM;
+
+ vcpu->f = f;
+ f->data = vcpu;
+ mutex_init(&vcpu->run_lock);
+ kref_init(&vcpu->kref);
+
+ page = alloc_page(GFP_KERNEL | __GFP_ZERO);
+ if (!page) {
+ r = -ENOMEM;
+ goto err_destroy_vcpu;
+ }
+ vcpu->vcpu_run = page_address(page);
+
+ vcpu->ticket.resource_type = GH_RESOURCE_TYPE_VCPU;
+ vcpu->ticket.label = arg->id;
+ vcpu->ticket.owner = THIS_MODULE;
+ vcpu->ticket.populate = gh_vcpu_populate;
+ vcpu->ticket.unpopulate = gh_vcpu_unpopulate;
+
+ r = gh_vm_add_resource_ticket(f->ghvm, &vcpu->ticket);
+ if (r)
+ goto err_destroy_page;
+
+ if (!gh_vm_get(f->ghvm)) {
+ r = -ENODEV;
+ goto err_remove_resource_ticket;
+ }
+ vcpu->ghvm = f->ghvm;
+
+ vcpu->nb.notifier_call = gh_vcpu_rm_notification;
+ /* Ensure we run after the vm_mgr handles the notification and does
+ * any necessary state changes. We wake up to check the new state.
+ */
+ vcpu->nb.priority = -1;
+ r = gh_rm_notifier_register(f->rm, &vcpu->nb);
+ if (r)
+ goto err_put_gh_vm;
+
+ kref_get(&vcpu->kref);
+
+ fd = get_unused_fd_flags(O_CLOEXEC);
+ if (fd < 0) {
+ r = fd;
+ goto err_notifier;
+ }
+
+ snprintf(name, sizeof(name), "gh-vcpu:%u", vcpu->ticket.label);
+ file = anon_inode_getfile(name, &gh_vcpu_fops, vcpu, O_RDWR);
+ if (IS_ERR(file)) {
+ r = PTR_ERR(file);
+ goto err_put_fd;
+ }
+
+ fd_install(fd, file);
+
+ return fd;
+err_put_fd:
+ put_unused_fd(fd);
+err_notifier:
+ gh_rm_notifier_unregister(f->rm, &vcpu->nb);
+err_put_gh_vm:
+ gh_vm_put(vcpu->ghvm);
+err_remove_resource_ticket:
+ gh_vm_remove_resource_ticket(f->ghvm, &vcpu->ticket);
+err_destroy_page:
+ free_page((unsigned long)vcpu->vcpu_run);
+err_destroy_vcpu:
+ kfree(vcpu);
+ return r;
+}
+
+static void gh_vcpu_unbind(struct gh_vm_function_instance *f)
+{
+ struct gh_vcpu *vcpu = f->data;
+
+ gh_rm_notifier_unregister(f->rm, &vcpu->nb);
+ gh_vm_remove_resource_ticket(vcpu->f->ghvm, &vcpu->ticket);
+ vcpu->f = NULL;
+
+ kref_put(&vcpu->kref, vcpu_release);
+}
+
+static bool gh_vcpu_compare(const struct gh_vm_function_instance *f,
+ const void *arg, size_t size)
+{
+ const struct gh_fn_vcpu_arg *instance = f->argp,
+ *other = arg;
+
+ if (sizeof(*other) != size)
+ return false;
+
+ return instance->id == other->id;
+}
+
+DECLARE_GH_VM_FUNCTION_INIT(vcpu, GH_FN_VCPU, 1, gh_vcpu_bind, gh_vcpu_unbind, gh_vcpu_compare);
+MODULE_DESCRIPTION("Gunyah vCPU Function");
+MODULE_LICENSE("GPL");
diff --git a/drivers/virt/gunyah/vm_mgr.c b/drivers/virt/gunyah/vm_mgr.c
index 28da1f95e49ec..afea4923847f1 100644
--- a/drivers/virt/gunyah/vm_mgr.c
+++ b/drivers/virt/gunyah/vm_mgr.c
@@ -405,6 +405,10 @@ static int gh_vm_rm_notification_exited(struct gh_vm *ghvm, void *data)

down_write(&ghvm->status_lock);
ghvm->vm_status = GH_RM_VM_STATUS_EXITED;
+ ghvm->exit_info.type = le16_to_cpu(payload->exit_type);
+ ghvm->exit_info.reason_size = le32_to_cpu(payload->exit_reason_size);
+ memcpy(&ghvm->exit_info.reason, payload->exit_reason,
+ min(GH_VM_MAX_EXIT_REASON_SIZE, ghvm->exit_info.reason_size));
up_write(&ghvm->status_lock);
wake_up(&ghvm->vm_status_wait);

diff --git a/drivers/virt/gunyah/vm_mgr.h b/drivers/virt/gunyah/vm_mgr.h
index 3fc0f91dfd1a9..fa2a61e10b57a 100644
--- a/drivers/virt/gunyah/vm_mgr.h
+++ b/drivers/virt/gunyah/vm_mgr.h
@@ -45,6 +45,7 @@ struct gh_vm {
enum gh_rm_vm_status vm_status;
wait_queue_head_t vm_status_wait;
struct rw_semaphore status_lock;
+ struct gh_vm_exit_info exit_info;

struct work_struct free_work;
struct kref kref;
diff --git a/include/linux/gunyah.h b/include/linux/gunyah.h
index 4b398b59c2c5a..cd5704a82c6a5 100644
--- a/include/linux/gunyah.h
+++ b/include/linux/gunyah.h
@@ -177,4 +177,28 @@ enum gh_error gh_hypercall_msgq_send(u64 capid, size_t size, void *buff, u64 tx_
enum gh_error gh_hypercall_msgq_recv(u64 capid, void *buff, size_t size, size_t *recv_size,
bool *ready);

+struct gh_hypercall_vcpu_run_resp {
+ union {
+ enum {
+ /* VCPU is ready to run */
+ GH_VCPU_STATE_READY = 0,
+ /* VCPU is sleeping until an interrupt arrives */
+ GH_VCPU_STATE_EXPECTS_WAKEUP = 1,
+ /* VCPU is powered off */
+ GH_VCPU_STATE_POWERED_OFF = 2,
+ /* VCPU is blocked in EL2 for unspecified reason */
+ GH_VCPU_STATE_BLOCKED = 3,
+ /* VCPU has returned for MMIO READ */
+ GH_VCPU_ADDRSPACE_VMMIO_READ = 4,
+ /* VCPU has returned for MMIO WRITE */
+ GH_VCPU_ADDRSPACE_VMMIO_WRITE = 5,
+ } state;
+ u64 sized_state;
+ };
+ u64 state_data[3];
+};
+
+enum gh_error gh_hypercall_vcpu_run(u64 capid, u64 *resume_data,
+ struct gh_hypercall_vcpu_run_resp *resp);
+
#endif
diff --git a/include/uapi/linux/gunyah.h b/include/uapi/linux/gunyah.h
index bb07118a351fd..434ffa8ffc783 100644
--- a/include/uapi/linux/gunyah.h
+++ b/include/uapi/linux/gunyah.h
@@ -72,8 +72,33 @@ struct gh_vm_dtb_config {

#define GH_VM_START _IO(GH_IOCTL_TYPE, 0x3)

+/**
+ * enum gh_fn_type - Valid types of Gunyah VM functions
+ * @GH_FN_VCPU: create a vCPU instance to control a vCPU
+ * &struct gh_fn_desc.arg is a pointer to &struct gh_fn_vcpu_arg
+ * Return: file descriptor to manipulate the vcpu.
+ */
+enum gh_fn_type {
+ GH_FN_VCPU = 1,
+};
+
#define GH_FN_MAX_ARG_SIZE 256

+/**
+ * struct gh_fn_vcpu_arg - Arguments to create a vCPU.
+ * @id: vcpu id
+ *
+ * Create this function with &GH_VM_ADD_FUNCTION using type &GH_FN_VCPU.
+ *
+ * The vcpu type will register with the VM Manager to expect to control
+ * vCPU number `vcpu_id`. It returns a file descriptor allowing interaction with
+ * the vCPU. See the Gunyah vCPU API description sections for interacting with
+ * the Gunyah vCPU file descriptors.
+ */
+struct gh_fn_vcpu_arg {
+ __u32 id;
+};
+
/**
* struct gh_fn_desc - Arguments to create a VM function
* @type: Type of the function. See &enum gh_fn_type.
@@ -90,4 +115,107 @@ struct gh_fn_desc {
#define GH_VM_ADD_FUNCTION _IOW(GH_IOCTL_TYPE, 0x4, struct gh_fn_desc)
#define GH_VM_REMOVE_FUNCTION _IOW(GH_IOCTL_TYPE, 0x7, struct gh_fn_desc)

+/*
+ * ioctls for vCPU fds
+ */
+
+/**
+ * enum gh_vm_status - Stores status reason why VM is not runnable (exited).
+ * @GH_VM_STATUS_LOAD_FAILED: VM didn't start because it couldn't be loaded.
+ * @GH_VM_STATUS_EXITED: VM requested shutdown/reboot.
+ * Use &struct gh_vm_exit_info.reason for further details.
+ * @GH_VM_STATUS_CRASHED: VM state is unknown and has crashed.
+ */
+enum gh_vm_status {
+ GH_VM_STATUS_LOAD_FAILED = 1,
+ GH_VM_STATUS_EXITED = 2,
+ GH_VM_STATUS_CRASHED = 3,
+};
+
+/*
+ * Gunyah presently sends max 4 bytes of exit_reason.
+ * If that changes, this macro can be safely increased without breaking
+ * userspace so long as struct gh_vcpu_run < PAGE_SIZE.
+ */
+#define GH_VM_MAX_EXIT_REASON_SIZE 8u
+
+/**
+ * struct gh_vm_exit_info - Reason for VM exit as reported by Gunyah
+ * See Gunyah documentation for values.
+ * @type: Describes how VM exited
+ * @padding: padding bytes
+ * @reason_size: Number of bytes valid for `reason`
+ * @reason: See Gunyah documentation for interpretation. Note: these values are
+ * not interpreted by Linux and need to be converted from little-endian
+ * as applicable.
+ */
+struct gh_vm_exit_info {
+ __u16 type;
+ __u16 padding;
+ __u32 reason_size;
+ __u8 reason[GH_VM_MAX_EXIT_REASON_SIZE];
+};
+
+/**
+ * enum gh_vcpu_exit - Stores reason why &GH_VCPU_RUN ioctl recently exited with status 0
+ * @GH_VCPU_EXIT_UNKNOWN: Not used, status != 0
+ * @GH_VCPU_EXIT_MMIO: vCPU performed a read or write that could not be handled
+ * by hypervisor or Linux. Use @struct gh_vcpu_run.mmio for
+ * details of the read/write.
+ * @GH_VCPU_EXIT_STATUS: vCPU not able to run because the VM has exited.
+ * Use @struct gh_vcpu_run.status for why VM has exited.
+ */
+enum gh_vcpu_exit {
+ GH_VCPU_EXIT_UNKNOWN,
+ GH_VCPU_EXIT_MMIO,
+ GH_VCPU_EXIT_STATUS,
+};
+
+/**
+ * struct gh_vcpu_run - Application code obtains a pointer to the gh_vcpu_run
+ * structure by mmap()ing a vcpu fd.
+ * @immediate_exit: polled when scheduling the vcpu. If set, immediately returns -EINTR.
+ * @padding: padding bytes
+ * @exit_reason: Set when GH_VCPU_RUN returns successfully and gives reason why
+ * GH_VCPU_RUN has stopped running the vCPU. See &enum gh_vcpu_exit.
+ * @mmio: Used when exit_reason == GH_VCPU_EXIT_MMIO
+ * The guest has faulted on an memory-mapped I/O instruction that
+ * couldn't be satisfied by gunyah.
+ * @mmio.phys_addr: Address guest tried to access
+ * @mmio.data: the value that was written if `is_write == 1`. Filled by
+ * user for reads (`is_write == 0`).
+ * @mmio.len: Length of write. Only the first `len` bytes of `data`
+ * are considered by Gunyah.
+ * @mmio.is_write: 1 if VM tried to perform a write, 0 for a read
+ * @status: Used when exit_reason == GH_VCPU_EXIT_STATUS.
+ * The guest VM is no longer runnable. This struct informs why.
+ * @status.status: See &enum gh_vm_status for possible values
+ * @status.exit_info: Used when status == GH_VM_STATUS_EXITED
+ */
+struct gh_vcpu_run {
+ /* in */
+ __u8 immediate_exit;
+ __u8 padding[7];
+
+ /* out */
+ __u32 exit_reason;
+
+ union {
+ struct {
+ __u64 phys_addr;
+ __u8 data[8];
+ __u32 len;
+ __u8 is_write;
+ } mmio;
+
+ struct {
+ enum gh_vm_status status;
+ struct gh_vm_exit_info exit_info;
+ } status;
+ };
+};
+
+#define GH_VCPU_RUN _IO(GH_IOCTL_TYPE, 0x5)
+#define GH_VCPU_MMAP_SIZE _IO(GH_IOCTL_TYPE, 0x6)
+
#endif
--
2.40.0


2023-06-13 17:38:13

by Elliot Berman

[permalink] [raw]
Subject: [PATCH v14 03/25] gunyah: Common types and error codes for Gunyah hypercalls

Add architecture-independent standard error codes, types, and macros for
Gunyah hypercalls.

Reviewed-by: Dmitry Baryshkov <[email protected]>
Reviewed-by: Srinivas Kandagatla <[email protected]>
Reviewed-by: Alex Elder <[email protected]>
Signed-off-by: Elliot Berman <[email protected]>
---
include/linux/gunyah.h | 83 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 83 insertions(+)
create mode 100644 include/linux/gunyah.h

diff --git a/include/linux/gunyah.h b/include/linux/gunyah.h
new file mode 100644
index 0000000000000..a4e8ec91961d1
--- /dev/null
+++ b/include/linux/gunyah.h
@@ -0,0 +1,83 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#ifndef _LINUX_GUNYAH_H
+#define _LINUX_GUNYAH_H
+
+#include <linux/errno.h>
+#include <linux/limits.h>
+
+/******************************************************************************/
+/* Common arch-independent definitions for Gunyah hypercalls */
+#define GH_CAPID_INVAL U64_MAX
+#define GH_VMID_ROOT_VM 0xff
+
+enum gh_error {
+ GH_ERROR_OK = 0,
+ GH_ERROR_UNIMPLEMENTED = -1,
+ GH_ERROR_RETRY = -2,
+
+ GH_ERROR_ARG_INVAL = 1,
+ GH_ERROR_ARG_SIZE = 2,
+ GH_ERROR_ARG_ALIGN = 3,
+
+ GH_ERROR_NOMEM = 10,
+
+ GH_ERROR_ADDR_OVFL = 20,
+ GH_ERROR_ADDR_UNFL = 21,
+ GH_ERROR_ADDR_INVAL = 22,
+
+ GH_ERROR_DENIED = 30,
+ GH_ERROR_BUSY = 31,
+ GH_ERROR_IDLE = 32,
+
+ GH_ERROR_IRQ_BOUND = 40,
+ GH_ERROR_IRQ_UNBOUND = 41,
+
+ GH_ERROR_CSPACE_CAP_NULL = 50,
+ GH_ERROR_CSPACE_CAP_REVOKED = 51,
+ GH_ERROR_CSPACE_WRONG_OBJ_TYPE = 52,
+ GH_ERROR_CSPACE_INSUF_RIGHTS = 53,
+ GH_ERROR_CSPACE_FULL = 54,
+
+ GH_ERROR_MSGQUEUE_EMPTY = 60,
+ GH_ERROR_MSGQUEUE_FULL = 61,
+};
+
+/**
+ * gh_error_remap() - Remap Gunyah hypervisor errors into a Linux error code
+ * @gh_error: Gunyah hypercall return value
+ */
+static inline int gh_error_remap(enum gh_error gh_error)
+{
+ switch (gh_error) {
+ case GH_ERROR_OK:
+ return 0;
+ case GH_ERROR_NOMEM:
+ return -ENOMEM;
+ case GH_ERROR_DENIED:
+ case GH_ERROR_CSPACE_CAP_NULL:
+ case GH_ERROR_CSPACE_CAP_REVOKED:
+ case GH_ERROR_CSPACE_WRONG_OBJ_TYPE:
+ case GH_ERROR_CSPACE_INSUF_RIGHTS:
+ case GH_ERROR_CSPACE_FULL:
+ return -EACCES;
+ case GH_ERROR_BUSY:
+ case GH_ERROR_IDLE:
+ return -EBUSY;
+ case GH_ERROR_IRQ_BOUND:
+ case GH_ERROR_IRQ_UNBOUND:
+ case GH_ERROR_MSGQUEUE_FULL:
+ case GH_ERROR_MSGQUEUE_EMPTY:
+ return -EIO;
+ case GH_ERROR_UNIMPLEMENTED:
+ case GH_ERROR_RETRY:
+ return -EOPNOTSUPP;
+ default:
+ return -EINVAL;
+ }
+}
+
+#endif
--
2.40.0


2023-06-13 17:40:55

by Elliot Berman

[permalink] [raw]
Subject: [PATCH v14 13/25] samples: Add sample userspace Gunyah VM Manager

Add a sample Gunyah VMM capable of launching a non-proxy scheduled VM.

Reviewed-by: Alex Elder <[email protected]>
Signed-off-by: Elliot Berman <[email protected]>
---
samples/Kconfig | 10 ++
samples/Makefile | 1 +
samples/gunyah/.gitignore | 2 +
samples/gunyah/Makefile | 6 +
samples/gunyah/gunyah_vmm.c | 266 +++++++++++++++++++++++++++++++++++
samples/gunyah/sample_vm.dts | 68 +++++++++
6 files changed, 353 insertions(+)
create mode 100644 samples/gunyah/.gitignore
create mode 100644 samples/gunyah/Makefile
create mode 100644 samples/gunyah/gunyah_vmm.c
create mode 100644 samples/gunyah/sample_vm.dts

diff --git a/samples/Kconfig b/samples/Kconfig
index b2db430bd3ff3..567c7a706c010 100644
--- a/samples/Kconfig
+++ b/samples/Kconfig
@@ -280,6 +280,16 @@ config SAMPLE_KMEMLEAK
Build a sample program which have explicitly leaks memory to test
kmemleak

+config SAMPLE_GUNYAH
+ bool "Build example Gunyah Virtual Machine Manager"
+ depends on CC_CAN_LINK && HEADERS_INSTALL
+ depends on GUNYAH
+ help
+ Build an example Gunyah VMM userspace program capable of launching
+ a basic virtual machine under the Gunyah hypervisor.
+ This demonstrates how to create a virtual machine under the Gunyah
+ hypervisor.
+
source "samples/rust/Kconfig"

endif # SAMPLES
diff --git a/samples/Makefile b/samples/Makefile
index 7727f1a0d6d15..e1b92dec169f3 100644
--- a/samples/Makefile
+++ b/samples/Makefile
@@ -37,3 +37,4 @@ obj-$(CONFIG_SAMPLE_KMEMLEAK) += kmemleak/
obj-$(CONFIG_SAMPLE_CORESIGHT_SYSCFG) += coresight/
obj-$(CONFIG_SAMPLE_FPROBE) += fprobe/
obj-$(CONFIG_SAMPLES_RUST) += rust/
+obj-$(CONFIG_SAMPLE_GUNYAH) += gunyah/
diff --git a/samples/gunyah/.gitignore b/samples/gunyah/.gitignore
new file mode 100644
index 0000000000000..adc7d1589fde6
--- /dev/null
+++ b/samples/gunyah/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0
+/gunyah_vmm
diff --git a/samples/gunyah/Makefile b/samples/gunyah/Makefile
new file mode 100644
index 0000000000000..faf14f9bb3374
--- /dev/null
+++ b/samples/gunyah/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+userprogs-always-y += gunyah_vmm
+dtb-y += sample_vm.dtb
+
+userccflags += -I usr/include
diff --git a/samples/gunyah/gunyah_vmm.c b/samples/gunyah/gunyah_vmm.c
new file mode 100644
index 0000000000000..6f636ac227c69
--- /dev/null
+++ b/samples/gunyah/gunyah_vmm.c
@@ -0,0 +1,266 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <getopt.h>
+#include <limits.h>
+#include <stdint.h>
+#include <fcntl.h>
+#include <string.h>
+#include <sys/sysmacros.h>
+#define __USE_GNU
+#include <sys/mman.h>
+
+#include <linux/gunyah.h>
+
+#define DEFAULT_GUEST_BASE 0x80000000
+#define DEFAULT_GUEST_SIZE 0x6400000 /* 100 MiB */
+#define DEFAULT_DTB_OFFSET 0x45f0000 /* 70MiB - 64 KiB */
+#define DEFAULT_RAMDISK_OFFSET 0x4600000 /* 70MiB */
+
+struct vm_config {
+ int image_fd;
+ int dtb_fd;
+ int ramdisk_fd;
+
+ uint64_t guest_base;
+ uint64_t guest_size;
+
+ off_t image_size;
+ uint64_t dtb_offset;
+ off_t dtb_size;
+ uint64_t ramdisk_offset;
+ off_t ramdisk_size;
+};
+
+static struct option options[] = {
+ { "help", no_argument, NULL, 'h' },
+ { "image", required_argument, NULL, 'i' },
+ { "dtb", required_argument, NULL, 'd' },
+ { "ramdisk", optional_argument, NULL, 'r' },
+ { "base", optional_argument, NULL, 'B' },
+ { "size", optional_argument, NULL, 'S' },
+ { "dtb_offset", optional_argument, NULL, 'D' },
+ { "ramdisk_offset", optional_argument, NULL, 'R' },
+ { }
+};
+
+static void print_help(char *cmd)
+{
+ printf("gunyah_vmm, a sample tool to launch Gunyah VMs\n"
+ "Usage: %s <options>\n"
+ " --help, -h this menu\n"
+ " --image, -i <image> VM image file to load (e.g. a kernel Image) [Required]\n"
+ " --dtb, -d <dtb> Devicetree file to load [Required]\n"
+ " --ramdisk, -r <ramdisk> Ramdisk file to load\n"
+ " --base, -B <address> Set the base address of guest's memory [Default: 0x%08x]\n"
+ " --size, -S <number> The number of bytes large to make the guest's memory [Default: 0x%08x]\n"
+ " --dtb_offset, -D <number> Offset into guest memory to load the DTB [Default: 0x%08x]\n"
+ " --ramdisk_offset, -R <number> Offset into guest memory to load a ramdisk [Default: 0x%08x]\n"
+ , cmd, DEFAULT_GUEST_BASE, DEFAULT_GUEST_SIZE,
+ DEFAULT_DTB_OFFSET, DEFAULT_RAMDISK_OFFSET);
+}
+
+int main(int argc, char **argv)
+{
+ int gunyah_fd, vm_fd, guest_fd;
+ struct gh_userspace_memory_region guest_mem_desc = { 0 };
+ struct gh_vm_dtb_config dtb_config = { 0 };
+ char *guest_mem;
+ struct vm_config config = {
+ /* Defaults good enough to boot static kernel and a basic ramdisk */
+ .image_fd = -1,
+ .dtb_fd = -1,
+ .ramdisk_fd = -1,
+ .guest_base = DEFAULT_GUEST_BASE,
+ .guest_size = DEFAULT_GUEST_SIZE,
+ .dtb_offset = DEFAULT_DTB_OFFSET,
+ .ramdisk_offset = DEFAULT_RAMDISK_OFFSET,
+ };
+ struct stat st;
+ int opt, optidx, ret = 0;
+ long l;
+
+ while ((opt = getopt_long(argc, argv, "hi:d:r:B:S:D:R:c:", options, &optidx)) != -1) {
+ switch (opt) {
+ case 'i':
+ config.image_fd = open(optarg, O_RDONLY | O_CLOEXEC);
+ if (config.image_fd < 0) {
+ perror("Failed to open image");
+ return -1;
+ }
+ if (stat(optarg, &st) < 0) {
+ perror("Failed to stat image");
+ return -1;
+ }
+ config.image_size = st.st_size;
+ break;
+ case 'd':
+ config.dtb_fd = open(optarg, O_RDONLY | O_CLOEXEC);
+ if (config.dtb_fd < 0) {
+ perror("Failed to open dtb");
+ return -1;
+ }
+ if (stat(optarg, &st) < 0) {
+ perror("Failed to stat dtb");
+ return -1;
+ }
+ config.dtb_size = st.st_size;
+ break;
+ case 'r':
+ config.ramdisk_fd = open(optarg, O_RDONLY | O_CLOEXEC);
+ if (config.ramdisk_fd < 0) {
+ perror("Failed to open ramdisk");
+ return -1;
+ }
+ if (stat(optarg, &st) < 0) {
+ perror("Failed to stat ramdisk");
+ return -1;
+ }
+ config.ramdisk_size = st.st_size;
+ break;
+ case 'B':
+ l = strtol(optarg, NULL, 0);
+ if (l == LONG_MIN) {
+ perror("Failed to parse base address");
+ return -1;
+ }
+ config.guest_base = l;
+ break;
+ case 'S':
+ l = strtol(optarg, NULL, 0);
+ if (l == LONG_MIN) {
+ perror("Failed to parse memory size");
+ return -1;
+ }
+ config.guest_size = l;
+ break;
+ case 'D':
+ l = strtol(optarg, NULL, 0);
+ if (l == LONG_MIN) {
+ perror("Failed to parse dtb offset");
+ return -1;
+ }
+ config.dtb_offset = l;
+ break;
+ case 'R':
+ l = strtol(optarg, NULL, 0);
+ if (l == LONG_MIN) {
+ perror("Failed to parse ramdisk offset");
+ return -1;
+ }
+ config.ramdisk_offset = l;
+ break;
+ case 'h':
+ print_help(argv[0]);
+ return 0;
+ default:
+ print_help(argv[0]);
+ return -1;
+ }
+ }
+
+ if (config.image_fd == -1 || config.dtb_fd == -1) {
+ print_help(argv[0]);
+ return -1;
+ }
+
+ if (config.image_size > config.guest_size) {
+ fprintf(stderr, "Image size puts it outside guest memory. Make image smaller or increase guest memory size.\n");
+ return -1;
+ }
+
+ if (config.dtb_offset + config.dtb_size > config.guest_size) {
+ fprintf(stderr, "DTB offset and size puts it outside guest memory. Make dtb smaller or increase guest memory size.\n");
+ return -1;
+ }
+
+ if (config.ramdisk_fd == -1 &&
+ config.ramdisk_offset + config.ramdisk_size > config.guest_size) {
+ fprintf(stderr, "Ramdisk offset and size puts it outside guest memory. Make ramdisk smaller or increase guest memory size.\n");
+ return -1;
+ }
+
+ gunyah_fd = open("/dev/gunyah", O_RDWR | O_CLOEXEC);
+ if (gunyah_fd < 0) {
+ perror("Failed to open /dev/gunyah");
+ return -1;
+ }
+
+ vm_fd = ioctl(gunyah_fd, GH_CREATE_VM, 0);
+ if (vm_fd < 0) {
+ perror("Failed to create vm");
+ return -1;
+ }
+
+ guest_fd = memfd_create("guest_memory", MFD_CLOEXEC);
+ if (guest_fd < 0) {
+ perror("Failed to create guest memfd");
+ return -1;
+ }
+
+ if (ftruncate(guest_fd, config.guest_size) < 0) {
+ perror("Failed to grow guest memory");
+ return -1;
+ }
+
+ guest_mem = mmap(NULL, config.guest_size, PROT_READ | PROT_WRITE, MAP_SHARED, guest_fd, 0);
+ if (guest_mem == MAP_FAILED) {
+ perror("Not enough memory");
+ return -1;
+ }
+
+ if (read(config.image_fd, guest_mem, config.image_size) < 0) {
+ perror("Failed to read image into guest memory");
+ return -1;
+ }
+
+ if (read(config.dtb_fd, guest_mem + config.dtb_offset, config.dtb_size) < 0) {
+ perror("Failed to read dtb into guest memory");
+ return -1;
+ }
+
+ if (config.ramdisk_fd > 0 &&
+ read(config.ramdisk_fd, guest_mem + config.ramdisk_offset,
+ config.ramdisk_size) < 0) {
+ perror("Failed to read ramdisk into guest memory");
+ return -1;
+ }
+
+ guest_mem_desc.label = 0;
+ guest_mem_desc.flags = GH_MEM_ALLOW_READ | GH_MEM_ALLOW_WRITE | GH_MEM_ALLOW_EXEC;
+ guest_mem_desc.guest_phys_addr = config.guest_base;
+ guest_mem_desc.memory_size = config.guest_size;
+ guest_mem_desc.userspace_addr = (__u64)guest_mem;
+
+ if (ioctl(vm_fd, GH_VM_SET_USER_MEM_REGION, &guest_mem_desc) < 0) {
+ perror("Failed to register guest memory with VM");
+ return -1;
+ }
+
+ dtb_config.guest_phys_addr = config.guest_base + config.dtb_offset;
+ dtb_config.size = config.dtb_size;
+ if (ioctl(vm_fd, GH_VM_SET_DTB_CONFIG, &dtb_config) < 0) {
+ perror("Failed to set DTB configuration for VM");
+ return -1;
+ }
+
+ ret = ioctl(vm_fd, GH_VM_START);
+ if (ret) {
+ perror("GH_VM_START failed");
+ return -1;
+ }
+
+ while (1)
+ pause();
+
+ return 0;
+}
diff --git a/samples/gunyah/sample_vm.dts b/samples/gunyah/sample_vm.dts
new file mode 100644
index 0000000000000..293bbc0469c8f
--- /dev/null
+++ b/samples/gunyah/sample_vm.dts
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: BSD-3-Clause
+/*
+ * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+/dts-v1/;
+
+/ {
+ #address-cells = <2>;
+ #size-cells = <2>;
+ interrupt-parent = <&intc>;
+
+ chosen {
+ bootargs = "nokaslr";
+ };
+
+ cpus {
+ #address-cells = <0x2>;
+ #size-cells = <0>;
+
+ cpu@0 {
+ device_type = "cpu";
+ compatible = "arm,armv8";
+ reg = <0 0>;
+ };
+ };
+
+ intc: interrupt-controller@3FFF0000 {
+ compatible = "arm,gic-v3";
+ #interrupt-cells = <3>;
+ #address-cells = <2>;
+ #size-cells = <2>;
+ interrupt-controller;
+ reg = <0 0x3FFF0000 0 0x10000>,
+ <0 0x3FFD0000 0 0x20000>;
+ };
+
+ timer {
+ compatible = "arm,armv8-timer";
+ always-on;
+ interrupts = <1 13 0x108>,
+ <1 14 0x108>,
+ <1 11 0x108>,
+ <1 10 0x108>;
+ clock-frequency = <19200000>;
+ };
+
+ gunyah-vm-config {
+ image-name = "linux_vm_0";
+
+ memory {
+ #address-cells = <2>;
+ #size-cells = <2>;
+
+ base-address = <0 0x80000000>;
+ };
+
+ interrupts {
+ config = <&intc>;
+ };
+
+ vcpus {
+ affinity-map = < 0 >;
+ sched-priority = < (-1) >;
+ sched-timeslice = < 2000 >;
+ };
+ };
+};
--
2.40.0


2023-06-13 17:43:15

by Elliot Berman

[permalink] [raw]
Subject: [PATCH v14 08/25] gunyah: rsc_mgr: Add VM lifecycle RPC

Add Gunyah Resource Manager RPC to launch an unauthenticated VM.

Reviewed-by: Alex Elder <[email protected]>
Reviewed-by: Srinivas Kandagatla <[email protected]>
Signed-off-by: Elliot Berman <[email protected]>
---
drivers/virt/gunyah/Makefile | 2 +-
drivers/virt/gunyah/rsc_mgr_rpc.c | 259 ++++++++++++++++++++++++++++++
include/linux/gunyah_rsc_mgr.h | 73 +++++++++
3 files changed, 333 insertions(+), 1 deletion(-)
create mode 100644 drivers/virt/gunyah/rsc_mgr_rpc.c

diff --git a/drivers/virt/gunyah/Makefile b/drivers/virt/gunyah/Makefile
index 0f5aec8346988..241bab357b86c 100644
--- a/drivers/virt/gunyah/Makefile
+++ b/drivers/virt/gunyah/Makefile
@@ -1,4 +1,4 @@
# SPDX-License-Identifier: GPL-2.0

-gunyah-y += rsc_mgr.o
+gunyah-y += rsc_mgr.o rsc_mgr_rpc.o
obj-$(CONFIG_GUNYAH) += gunyah.o
diff --git a/drivers/virt/gunyah/rsc_mgr_rpc.c b/drivers/virt/gunyah/rsc_mgr_rpc.c
new file mode 100644
index 0000000000000..a4a9f0ba4e1fc
--- /dev/null
+++ b/drivers/virt/gunyah/rsc_mgr_rpc.c
@@ -0,0 +1,259 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <linux/gunyah_rsc_mgr.h>
+#include "rsc_mgr.h"
+
+/* Message IDs: VM Management */
+#define GH_RM_RPC_VM_ALLOC_VMID 0x56000001
+#define GH_RM_RPC_VM_DEALLOC_VMID 0x56000002
+#define GH_RM_RPC_VM_START 0x56000004
+#define GH_RM_RPC_VM_STOP 0x56000005
+#define GH_RM_RPC_VM_RESET 0x56000006
+#define GH_RM_RPC_VM_CONFIG_IMAGE 0x56000009
+#define GH_RM_RPC_VM_INIT 0x5600000B
+#define GH_RM_RPC_VM_GET_HYP_RESOURCES 0x56000020
+#define GH_RM_RPC_VM_GET_VMID 0x56000024
+
+struct gh_rm_vm_common_vmid_req {
+ __le16 vmid;
+ __le16 _padding;
+} __packed;
+
+/* Call: VM_ALLOC */
+struct gh_rm_vm_alloc_vmid_resp {
+ __le16 vmid;
+ __le16 _padding;
+} __packed;
+
+/* Call: VM_STOP */
+#define GH_RM_VM_STOP_FLAG_FORCE_STOP BIT(0)
+
+#define GH_RM_VM_STOP_REASON_FORCE_STOP 3
+
+struct gh_rm_vm_stop_req {
+ __le16 vmid;
+ u8 flags;
+ u8 _padding;
+ __le32 stop_reason;
+} __packed;
+
+/* Call: VM_CONFIG_IMAGE */
+struct gh_rm_vm_config_image_req {
+ __le16 vmid;
+ __le16 auth_mech;
+ __le32 mem_handle;
+ __le64 image_offset;
+ __le64 image_size;
+ __le64 dtb_offset;
+ __le64 dtb_size;
+} __packed;
+
+/*
+ * Several RM calls take only a VMID as a parameter and give only standard
+ * response back. Deduplicate boilerplate code by using this common call.
+ */
+static int gh_rm_common_vmid_call(struct gh_rm *rm, u32 message_id, u16 vmid)
+{
+ struct gh_rm_vm_common_vmid_req req_payload = {
+ .vmid = cpu_to_le16(vmid),
+ };
+
+ return gh_rm_call(rm, message_id, &req_payload, sizeof(req_payload), NULL, NULL);
+}
+
+/**
+ * gh_rm_alloc_vmid() - Allocate a new VM in Gunyah. Returns the VM identifier.
+ * @rm: Handle to a Gunyah resource manager
+ * @vmid: Use 0 to dynamically allocate a VM. A reserved VMID can be supplied
+ * to request allocation of a platform-defined VM.
+ *
+ * Returns - the allocated VMID or negative value on error
+ */
+int gh_rm_alloc_vmid(struct gh_rm *rm, u16 vmid)
+{
+ struct gh_rm_vm_common_vmid_req req_payload = {
+ .vmid = cpu_to_le16(vmid),
+ };
+ struct gh_rm_vm_alloc_vmid_resp *resp_payload;
+ size_t resp_size;
+ void *resp;
+ int ret;
+
+ ret = gh_rm_call(rm, GH_RM_RPC_VM_ALLOC_VMID, &req_payload, sizeof(req_payload), &resp,
+ &resp_size);
+ if (ret)
+ return ret;
+
+ if (!vmid) {
+ resp_payload = resp;
+ ret = le16_to_cpu(resp_payload->vmid);
+ kfree(resp);
+ }
+
+ return ret;
+}
+
+/**
+ * gh_rm_dealloc_vmid() - Dispose of a VMID
+ * @rm: Handle to a Gunyah resource manager
+ * @vmid: VM identifier allocated with gh_rm_alloc_vmid
+ */
+int gh_rm_dealloc_vmid(struct gh_rm *rm, u16 vmid)
+{
+ return gh_rm_common_vmid_call(rm, GH_RM_RPC_VM_DEALLOC_VMID, vmid);
+}
+
+/**
+ * gh_rm_vm_reset() - Reset a VM's resources
+ * @rm: Handle to a Gunyah resource manager
+ * @vmid: VM identifier allocated with gh_rm_alloc_vmid
+ *
+ * As part of tearing down the VM, request RM to clean up all the VM resources
+ * associated with the VM. Only after this, Linux can clean up all the
+ * references it maintains to resources.
+ */
+int gh_rm_vm_reset(struct gh_rm *rm, u16 vmid)
+{
+ return gh_rm_common_vmid_call(rm, GH_RM_RPC_VM_RESET, vmid);
+}
+
+/**
+ * gh_rm_vm_start() - Move a VM into "ready to run" state
+ * @rm: Handle to a Gunyah resource manager
+ * @vmid: VM identifier allocated with gh_rm_alloc_vmid
+ *
+ * On VMs which use proxy scheduling, vcpu_run is needed to actually run the VM.
+ * On VMs which use Gunyah's scheduling, the vCPUs start executing in accordance with Gunyah
+ * scheduling policies.
+ */
+int gh_rm_vm_start(struct gh_rm *rm, u16 vmid)
+{
+ return gh_rm_common_vmid_call(rm, GH_RM_RPC_VM_START, vmid);
+}
+
+/**
+ * gh_rm_vm_stop() - Send a request to Resource Manager VM to forcibly stop a VM.
+ * @rm: Handle to a Gunyah resource manager
+ * @vmid: VM identifier allocated with gh_rm_alloc_vmid
+ */
+int gh_rm_vm_stop(struct gh_rm *rm, u16 vmid)
+{
+ struct gh_rm_vm_stop_req req_payload = {
+ .vmid = cpu_to_le16(vmid),
+ .flags = GH_RM_VM_STOP_FLAG_FORCE_STOP,
+ .stop_reason = cpu_to_le32(GH_RM_VM_STOP_REASON_FORCE_STOP),
+ };
+
+ return gh_rm_call(rm, GH_RM_RPC_VM_STOP, &req_payload, sizeof(req_payload), NULL, NULL);
+}
+
+/**
+ * gh_rm_vm_configure() - Prepare a VM to start and provide the common
+ * configuration needed by RM to configure a VM
+ * @rm: Handle to a Gunyah resource manager
+ * @vmid: VM identifier allocated with gh_rm_alloc_vmid
+ * @auth_mechanism: Authentication mechanism used by resource manager to verify
+ * the virtual machine
+ * @mem_handle: Handle to a previously shared memparcel that contains all parts
+ * of the VM image subject to authentication.
+ * @image_offset: Start address of VM image, relative to the start of memparcel
+ * @image_size: Size of the VM image
+ * @dtb_offset: Start address of the devicetree binary with VM configuration,
+ * relative to start of memparcel.
+ * @dtb_size: Maximum size of devicetree binary.
+ */
+int gh_rm_vm_configure(struct gh_rm *rm, u16 vmid, enum gh_rm_vm_auth_mechanism auth_mechanism,
+ u32 mem_handle, u64 image_offset, u64 image_size, u64 dtb_offset, u64 dtb_size)
+{
+ struct gh_rm_vm_config_image_req req_payload = {
+ .vmid = cpu_to_le16(vmid),
+ .auth_mech = cpu_to_le16(auth_mechanism),
+ .mem_handle = cpu_to_le32(mem_handle),
+ .image_offset = cpu_to_le64(image_offset),
+ .image_size = cpu_to_le64(image_size),
+ .dtb_offset = cpu_to_le64(dtb_offset),
+ .dtb_size = cpu_to_le64(dtb_size),
+ };
+
+ return gh_rm_call(rm, GH_RM_RPC_VM_CONFIG_IMAGE, &req_payload, sizeof(req_payload),
+ NULL, NULL);
+}
+
+/**
+ * gh_rm_vm_init() - Move the VM to initialized state.
+ * @rm: Handle to a Gunyah resource manager
+ * @vmid: VM identifier
+ *
+ * RM will allocate needed resources for the VM.
+ */
+int gh_rm_vm_init(struct gh_rm *rm, u16 vmid)
+{
+ return gh_rm_common_vmid_call(rm, GH_RM_RPC_VM_INIT, vmid);
+}
+
+/**
+ * gh_rm_get_hyp_resources() - Retrieve hypervisor resources (capabilities) associated with a VM
+ * @rm: Handle to a Gunyah resource manager
+ * @vmid: VMID of the other VM to get the resources of
+ * @resources: Set by gh_rm_get_hyp_resources and contains the returned hypervisor resources.
+ * Caller must free the resources pointer if successful.
+ */
+int gh_rm_get_hyp_resources(struct gh_rm *rm, u16 vmid,
+ struct gh_rm_hyp_resources **resources)
+{
+ struct gh_rm_vm_common_vmid_req req_payload = {
+ .vmid = cpu_to_le16(vmid),
+ };
+ struct gh_rm_hyp_resources *resp;
+ size_t resp_size;
+ int ret;
+
+ ret = gh_rm_call(rm, GH_RM_RPC_VM_GET_HYP_RESOURCES,
+ &req_payload, sizeof(req_payload),
+ (void **)&resp, &resp_size);
+ if (ret)
+ return ret;
+
+ if (!resp_size)
+ return -EBADMSG;
+
+ if (resp_size < struct_size(resp, entries, 0) ||
+ resp_size != struct_size(resp, entries, le32_to_cpu(resp->n_entries))) {
+ kfree(resp);
+ return -EBADMSG;
+ }
+
+ *resources = resp;
+ return 0;
+}
+
+/**
+ * gh_rm_get_vmid() - Retrieve VMID of this virtual machine
+ * @rm: Handle to a Gunyah resource manager
+ * @vmid: Filled with the VMID of this VM
+ */
+int gh_rm_get_vmid(struct gh_rm *rm, u16 *vmid)
+{
+ static u16 cached_vmid = GH_VMID_INVAL;
+ size_t resp_size;
+ __le32 *resp;
+ int ret;
+
+ if (cached_vmid != GH_VMID_INVAL) {
+ *vmid = cached_vmid;
+ return 0;
+ }
+
+ ret = gh_rm_call(rm, GH_RM_RPC_VM_GET_VMID, NULL, 0, (void **)&resp, &resp_size);
+ if (ret)
+ return ret;
+
+ *vmid = cached_vmid = lower_16_bits(le32_to_cpu(*resp));
+ kfree(resp);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(gh_rm_get_vmid);
diff --git a/include/linux/gunyah_rsc_mgr.h b/include/linux/gunyah_rsc_mgr.h
index f2a312e80af52..1ac66d9004d2b 100644
--- a/include/linux/gunyah_rsc_mgr.h
+++ b/include/linux/gunyah_rsc_mgr.h
@@ -18,4 +18,77 @@ int gh_rm_notifier_unregister(struct gh_rm *rm, struct notifier_block *nb);
struct device *gh_rm_get(struct gh_rm *rm);
void gh_rm_put(struct gh_rm *rm);

+struct gh_rm_vm_exited_payload {
+ __le16 vmid;
+ __le16 exit_type;
+ __le32 exit_reason_size;
+ u8 exit_reason[];
+} __packed;
+
+#define GH_RM_NOTIFICATION_VM_EXITED 0x56100001
+
+enum gh_rm_vm_status {
+ GH_RM_VM_STATUS_NO_STATE = 0,
+ GH_RM_VM_STATUS_INIT = 1,
+ GH_RM_VM_STATUS_READY = 2,
+ GH_RM_VM_STATUS_RUNNING = 3,
+ GH_RM_VM_STATUS_PAUSED = 4,
+ GH_RM_VM_STATUS_LOAD = 5,
+ GH_RM_VM_STATUS_AUTH = 6,
+ GH_RM_VM_STATUS_INIT_FAILED = 8,
+ GH_RM_VM_STATUS_EXITED = 9,
+ GH_RM_VM_STATUS_RESETTING = 10,
+ GH_RM_VM_STATUS_RESET = 11,
+};
+
+struct gh_rm_vm_status_payload {
+ __le16 vmid;
+ u16 reserved;
+ u8 vm_status;
+ u8 os_status;
+ __le16 app_status;
+} __packed;
+
+#define GH_RM_NOTIFICATION_VM_STATUS 0x56100008
+
+/* RPC Calls */
+int gh_rm_alloc_vmid(struct gh_rm *rm, u16 vmid);
+int gh_rm_dealloc_vmid(struct gh_rm *rm, u16 vmid);
+int gh_rm_vm_reset(struct gh_rm *rm, u16 vmid);
+int gh_rm_vm_start(struct gh_rm *rm, u16 vmid);
+int gh_rm_vm_stop(struct gh_rm *rm, u16 vmid);
+
+enum gh_rm_vm_auth_mechanism {
+ GH_RM_VM_AUTH_NONE = 0,
+ GH_RM_VM_AUTH_QCOM_PIL_ELF = 1,
+ GH_RM_VM_AUTH_QCOM_ANDROID_PVM = 2,
+};
+
+int gh_rm_vm_configure(struct gh_rm *rm, u16 vmid, enum gh_rm_vm_auth_mechanism auth_mechanism,
+ u32 mem_handle, u64 image_offset, u64 image_size,
+ u64 dtb_offset, u64 dtb_size);
+int gh_rm_vm_init(struct gh_rm *rm, u16 vmid);
+
+struct gh_rm_hyp_resource {
+ u8 type;
+ u8 reserved;
+ __le16 partner_vmid;
+ __le32 resource_handle;
+ __le32 resource_label;
+ __le64 cap_id;
+ __le32 virq_handle;
+ __le32 virq;
+ __le64 base;
+ __le64 size;
+} __packed;
+
+struct gh_rm_hyp_resources {
+ __le32 n_entries;
+ struct gh_rm_hyp_resource entries[];
+} __packed;
+
+int gh_rm_get_hyp_resources(struct gh_rm *rm, u16 vmid,
+ struct gh_rm_hyp_resources **resources);
+int gh_rm_get_vmid(struct gh_rm *rm, u16 *vmid);
+
#endif
--
2.40.0


2023-06-13 17:45:58

by Elliot Berman

[permalink] [raw]
Subject: [PATCH v14 11/25] gunyah: vm_mgr: Add/remove user memory regions

When launching a virtual machine, Gunyah userspace allocates memory for
the guest and informs Gunyah about these memory regions through
SET_USER_MEMORY_REGION ioctl.

Co-developed-by: Prakruthi Deepak Heragu <[email protected]>
Signed-off-by: Prakruthi Deepak Heragu <[email protected]>
Signed-off-by: Elliot Berman <[email protected]>
---
drivers/virt/gunyah/Makefile | 2 +-
drivers/virt/gunyah/vm_mgr.c | 59 +++++++-
drivers/virt/gunyah/vm_mgr.h | 26 ++++
drivers/virt/gunyah/vm_mgr_mm.c | 232 ++++++++++++++++++++++++++++++++
include/uapi/linux/gunyah.h | 37 +++++
5 files changed, 352 insertions(+), 4 deletions(-)
create mode 100644 drivers/virt/gunyah/vm_mgr_mm.c

diff --git a/drivers/virt/gunyah/Makefile b/drivers/virt/gunyah/Makefile
index e47e25895299c..bacf78b8fa337 100644
--- a/drivers/virt/gunyah/Makefile
+++ b/drivers/virt/gunyah/Makefile
@@ -1,4 +1,4 @@
# SPDX-License-Identifier: GPL-2.0

-gunyah-y += rsc_mgr.o rsc_mgr_rpc.o vm_mgr.o
+gunyah-y += rsc_mgr.o rsc_mgr_rpc.o vm_mgr.o vm_mgr_mm.o
obj-$(CONFIG_GUNYAH) += gunyah.o
diff --git a/drivers/virt/gunyah/vm_mgr.c b/drivers/virt/gunyah/vm_mgr.c
index a43401cb34f7d..297427952b8c7 100644
--- a/drivers/virt/gunyah/vm_mgr.c
+++ b/drivers/virt/gunyah/vm_mgr.c
@@ -15,6 +15,8 @@

#include "vm_mgr.h"

+static void gh_vm_free(struct work_struct *work);
+
static __must_check struct gh_vm *gh_vm_alloc(struct gh_rm *rm)
{
struct gh_vm *ghvm;
@@ -26,20 +28,72 @@ static __must_check struct gh_vm *gh_vm_alloc(struct gh_rm *rm)
ghvm->parent = gh_rm_get(rm);
ghvm->rm = rm;

+ mmgrab(current->mm);
+ ghvm->mm = current->mm;
+ mutex_init(&ghvm->mm_lock);
+ INIT_LIST_HEAD(&ghvm->memory_mappings);
+ INIT_WORK(&ghvm->free_work, gh_vm_free);
+
return ghvm;
}

-static int gh_vm_release(struct inode *inode, struct file *filp)
+static long gh_vm_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct gh_vm *ghvm = filp->private_data;
+ void __user *argp = (void __user *)arg;
+ long r;
+
+ switch (cmd) {
+ case GH_VM_SET_USER_MEM_REGION: {
+ struct gh_userspace_memory_region region;
+
+ /* only allow owner task to add memory */
+ if (ghvm->mm != current->mm)
+ return -EPERM;
+
+ if (copy_from_user(&region, argp, sizeof(region)))
+ return -EFAULT;
+
+ /* All other flag bits are reserved for future use */
+ if (region.flags & ~(GH_MEM_ALLOW_READ | GH_MEM_ALLOW_WRITE | GH_MEM_ALLOW_EXEC))
+ return -EINVAL;
+
+ r = gh_vm_mem_alloc(ghvm, &region);
+ break;
+ }
+ default:
+ r = -ENOTTY;
+ break;
+ }

+ return r;
+}
+
+static void gh_vm_free(struct work_struct *work)
+{
+ struct gh_vm *ghvm = container_of(work, struct gh_vm, free_work);
+
+ gh_vm_mem_reclaim(ghvm);
gh_rm_put(ghvm->rm);
+ mmdrop(ghvm->mm);
kfree(ghvm);
+}
+
+static int gh_vm_release(struct inode *inode, struct file *filp)
+{
+ struct gh_vm *ghvm = filp->private_data;
+
+ /* VM will be reset and make RM calls which can interruptible sleep.
+ * Defer to a work so this thread can receive signal.
+ */
+ schedule_work(&ghvm->free_work);
return 0;
}

static const struct file_operations gh_vm_fops = {
.owner = THIS_MODULE,
+ .unlocked_ioctl = gh_vm_ioctl,
+ .compat_ioctl = compat_ptr_ioctl,
.release = gh_vm_release,
.llseek = noop_llseek,
};
@@ -77,8 +131,7 @@ static long gh_dev_ioctl_create_vm(struct gh_rm *rm, unsigned long arg)
err_put_fd:
put_unused_fd(fd);
err_destroy_vm:
- gh_rm_put(ghvm->rm);
- kfree(ghvm);
+ gh_vm_free(&ghvm->free_work);
return err;
}

diff --git a/drivers/virt/gunyah/vm_mgr.h b/drivers/virt/gunyah/vm_mgr.h
index 1e94b58d7d34d..434ef9f662a7a 100644
--- a/drivers/virt/gunyah/vm_mgr.h
+++ b/drivers/virt/gunyah/vm_mgr.h
@@ -7,14 +7,40 @@
#define _GH_VM_MGR_H

#include <linux/gunyah_rsc_mgr.h>
+#include <linux/list.h>
+#include <linux/miscdevice.h>
+#include <linux/mutex.h>

#include <uapi/linux/gunyah.h>

long gh_dev_vm_mgr_ioctl(struct gh_rm *rm, unsigned int cmd, unsigned long arg);

+enum gh_vm_mem_share_type {
+ VM_MEM_SHARE,
+ VM_MEM_LEND,
+};
+
+struct gh_vm_mem {
+ struct list_head list;
+ enum gh_vm_mem_share_type share_type;
+ struct gh_rm_mem_parcel parcel;
+
+ __u64 guest_phys_addr;
+ struct page **pages;
+ unsigned long npages;
+};
+
struct gh_vm {
struct gh_rm *rm;
struct device *parent;
+
+ struct work_struct free_work;
+ struct mm_struct *mm; /* userspace tied to this vm */
+ struct mutex mm_lock;
+ struct list_head memory_mappings;
};

+int gh_vm_mem_alloc(struct gh_vm *ghvm, struct gh_userspace_memory_region *region);
+void gh_vm_mem_reclaim(struct gh_vm *ghvm);
+
#endif
diff --git a/drivers/virt/gunyah/vm_mgr_mm.c b/drivers/virt/gunyah/vm_mgr_mm.c
new file mode 100644
index 0000000000000..6974607f02edd
--- /dev/null
+++ b/drivers/virt/gunyah/vm_mgr_mm.c
@@ -0,0 +1,232 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#define pr_fmt(fmt) "gh_vm_mgr: " fmt
+
+#include <linux/gunyah_rsc_mgr.h>
+#include <linux/mm.h>
+
+#include <uapi/linux/gunyah.h>
+
+#include "vm_mgr.h"
+
+static bool pages_are_mergeable(struct page *a, struct page *b)
+{
+ return page_to_pfn(a) + 1 == page_to_pfn(b);
+}
+
+static bool gh_vm_mem_overlap(struct gh_vm_mem *a, u64 addr, u64 size)
+{
+ u64 a_end = a->guest_phys_addr + (a->npages << PAGE_SHIFT);
+ u64 end = addr + size;
+
+ return a->guest_phys_addr < end && addr < a_end;
+}
+
+static struct gh_vm_mem *__gh_vm_mem_find_by_label(struct gh_vm *ghvm, u32 label)
+ __must_hold(&ghvm->mm_lock)
+{
+ struct gh_vm_mem *mapping;
+
+ list_for_each_entry(mapping, &ghvm->memory_mappings, list)
+ if (mapping->parcel.label == label)
+ return mapping;
+
+ return NULL;
+}
+
+static void gh_vm_mem_reclaim_mapping(struct gh_vm *ghvm, struct gh_vm_mem *mapping)
+ __must_hold(&ghvm->mm_lock)
+{
+ int ret = 0;
+
+ if (mapping->parcel.mem_handle != GH_MEM_HANDLE_INVAL) {
+ ret = gh_rm_mem_reclaim(ghvm->rm, &mapping->parcel);
+ if (ret)
+ pr_warn("Failed to reclaim memory parcel for label %d: %d\n",
+ mapping->parcel.label, ret);
+ }
+
+ if (!ret) {
+ unpin_user_pages(mapping->pages, mapping->npages);
+ account_locked_vm(ghvm->mm, mapping->npages, false);
+ }
+
+ kfree(mapping->pages);
+ kfree(mapping->parcel.acl_entries);
+ kfree(mapping->parcel.mem_entries);
+
+ list_del(&mapping->list);
+}
+
+void gh_vm_mem_reclaim(struct gh_vm *ghvm)
+{
+ struct gh_vm_mem *mapping, *tmp;
+
+ mutex_lock(&ghvm->mm_lock);
+
+ list_for_each_entry_safe(mapping, tmp, &ghvm->memory_mappings, list) {
+ gh_vm_mem_reclaim_mapping(ghvm, mapping);
+ kfree(mapping);
+ }
+
+ mutex_unlock(&ghvm->mm_lock);
+}
+
+int gh_vm_mem_alloc(struct gh_vm *ghvm, struct gh_userspace_memory_region *region)
+{
+ struct gh_vm_mem *mapping, *tmp_mapping;
+ struct page *curr_page, *prev_page;
+ struct gh_rm_mem_parcel *parcel;
+ int i, j, pinned, ret = 0;
+ unsigned int gup_flags;
+ size_t entry_size;
+ u16 vmid;
+
+ if (!region->memory_size || !PAGE_ALIGNED(region->memory_size) ||
+ !PAGE_ALIGNED(region->userspace_addr) ||
+ !PAGE_ALIGNED(region->guest_phys_addr))
+ return -EINVAL;
+
+ if (overflows_type(region->guest_phys_addr + region->memory_size, u64))
+ return -EOVERFLOW;
+
+ ret = mutex_lock_interruptible(&ghvm->mm_lock);
+ if (ret)
+ return ret;
+
+ mapping = __gh_vm_mem_find_by_label(ghvm, region->label);
+ if (mapping) {
+ ret = -EEXIST;
+ goto unlock;
+ }
+
+ list_for_each_entry(tmp_mapping, &ghvm->memory_mappings, list) {
+ if (gh_vm_mem_overlap(tmp_mapping, region->guest_phys_addr,
+ region->memory_size)) {
+ ret = -EEXIST;
+ goto unlock;
+ }
+ }
+
+ mapping = kzalloc(sizeof(*mapping), GFP_KERNEL_ACCOUNT);
+ if (!mapping) {
+ ret = -ENOMEM;
+ goto unlock;
+ }
+
+ mapping->guest_phys_addr = region->guest_phys_addr;
+ mapping->npages = region->memory_size >> PAGE_SHIFT;
+ parcel = &mapping->parcel;
+ parcel->label = region->label;
+ parcel->mem_handle = GH_MEM_HANDLE_INVAL; /* to be filled later by mem_share/mem_lend */
+ parcel->mem_type = GH_RM_MEM_TYPE_NORMAL;
+
+ ret = account_locked_vm(ghvm->mm, mapping->npages, true);
+ if (ret)
+ goto free_mapping;
+
+ mapping->pages = kcalloc(mapping->npages, sizeof(*mapping->pages), GFP_KERNEL_ACCOUNT);
+ if (!mapping->pages) {
+ ret = -ENOMEM;
+ mapping->npages = 0; /* update npages for reclaim */
+ goto unlock_pages;
+ }
+
+ gup_flags = FOLL_LONGTERM;
+ if (region->flags & GH_MEM_ALLOW_WRITE)
+ gup_flags |= FOLL_WRITE;
+
+ pinned = pin_user_pages_fast(region->userspace_addr, mapping->npages,
+ gup_flags, mapping->pages);
+ if (pinned < 0) {
+ ret = pinned;
+ goto free_pages;
+ } else if (pinned != mapping->npages) {
+ ret = -EFAULT;
+ mapping->npages = pinned; /* update npages for reclaim */
+ goto unpin_pages;
+ }
+
+ parcel->n_acl_entries = 2;
+ mapping->share_type = VM_MEM_SHARE;
+ parcel->acl_entries = kcalloc(parcel->n_acl_entries, sizeof(*parcel->acl_entries),
+ GFP_KERNEL);
+ if (!parcel->acl_entries) {
+ ret = -ENOMEM;
+ goto unpin_pages;
+ }
+
+ /* acl_entries[0].vmid will be this VM's vmid. We'll fill it when the
+ * VM is starting and we know the VM's vmid.
+ */
+ if (region->flags & GH_MEM_ALLOW_READ)
+ parcel->acl_entries[0].perms |= GH_RM_ACL_R;
+ if (region->flags & GH_MEM_ALLOW_WRITE)
+ parcel->acl_entries[0].perms |= GH_RM_ACL_W;
+ if (region->flags & GH_MEM_ALLOW_EXEC)
+ parcel->acl_entries[0].perms |= GH_RM_ACL_X;
+
+ ret = gh_rm_get_vmid(ghvm->rm, &vmid);
+ if (ret)
+ goto free_acl;
+
+ parcel->acl_entries[1].vmid = cpu_to_le16(vmid);
+ /* Host assumed to have all these permissions. Gunyah will not
+ * grant new permissions if host actually had less than RWX
+ */
+ parcel->acl_entries[1].perms = GH_RM_ACL_R | GH_RM_ACL_W | GH_RM_ACL_X;
+
+ parcel->n_mem_entries = 1;
+ for (i = 1; i < mapping->npages; i++) {
+ if (!pages_are_mergeable(mapping->pages[i - 1], mapping->pages[i]))
+ parcel->n_mem_entries++;
+ }
+
+ parcel->mem_entries = kcalloc(parcel->n_mem_entries,
+ sizeof(parcel->mem_entries[0]),
+ GFP_KERNEL_ACCOUNT);
+ if (!parcel->mem_entries) {
+ ret = -ENOMEM;
+ goto free_acl;
+ }
+
+ /* reduce number of entries by combining contiguous pages into single memory entry */
+ prev_page = mapping->pages[0];
+ parcel->mem_entries[0].phys_addr = cpu_to_le64(page_to_phys(prev_page));
+ entry_size = PAGE_SIZE;
+ for (i = 1, j = 0; i < mapping->npages; i++) {
+ curr_page = mapping->pages[i];
+ if (pages_are_mergeable(prev_page, curr_page)) {
+ entry_size += PAGE_SIZE;
+ } else {
+ parcel->mem_entries[j].size = cpu_to_le64(entry_size);
+ j++;
+ parcel->mem_entries[j].phys_addr =
+ cpu_to_le64(page_to_phys(curr_page));
+ entry_size = PAGE_SIZE;
+ }
+
+ prev_page = curr_page;
+ }
+ parcel->mem_entries[j].size = cpu_to_le64(entry_size);
+
+ list_add(&mapping->list, &ghvm->memory_mappings);
+ mutex_unlock(&ghvm->mm_lock);
+ return 0;
+free_acl:
+ kfree(parcel->acl_entries);
+unpin_pages:
+ unpin_user_pages(mapping->pages, pinned);
+free_pages:
+ kfree(mapping->pages);
+unlock_pages:
+ account_locked_vm(ghvm->mm, mapping->npages, false);
+free_mapping:
+ kfree(mapping);
+unlock:
+ mutex_unlock(&ghvm->mm_lock);
+ return ret;
+}
diff --git a/include/uapi/linux/gunyah.h b/include/uapi/linux/gunyah.h
index 86b9cb60118dd..91d6dd26fcc89 100644
--- a/include/uapi/linux/gunyah.h
+++ b/include/uapi/linux/gunyah.h
@@ -20,4 +20,41 @@
*/
#define GH_CREATE_VM _IO(GH_IOCTL_TYPE, 0x0) /* Returns a Gunyah VM fd */

+/*
+ * ioctls for VM fds
+ */
+
+/**
+ * enum gh_mem_flags - Possible flags on &struct gh_userspace_memory_region
+ * @GH_MEM_ALLOW_READ: Allow guest to read the memory
+ * @GH_MEM_ALLOW_WRITE: Allow guest to write to the memory
+ * @GH_MEM_ALLOW_EXEC: Allow guest to execute instructions in the memory
+ */
+enum gh_mem_flags {
+ GH_MEM_ALLOW_READ = 1UL << 0,
+ GH_MEM_ALLOW_WRITE = 1UL << 1,
+ GH_MEM_ALLOW_EXEC = 1UL << 2,
+};
+
+/**
+ * struct gh_userspace_memory_region - Userspace memory descripion for GH_VM_SET_USER_MEM_REGION
+ * @label: Identifer to the region which is unique to the VM.
+ * @flags: Flags for memory parcel behavior. See &enum gh_mem_flags.
+ * @guest_phys_addr: Location of the memory region in guest's memory space (page-aligned)
+ * @memory_size: Size of the region (page-aligned)
+ * @userspace_addr: Location of the memory region in caller (userspace)'s memory
+ *
+ * See Documentation/virt/gunyah/vm-manager.rst for further details.
+ */
+struct gh_userspace_memory_region {
+ __u32 label;
+ __u32 flags;
+ __u64 guest_phys_addr;
+ __u64 memory_size;
+ __u64 userspace_addr;
+};
+
+#define GH_VM_SET_USER_MEM_REGION _IOW(GH_IOCTL_TYPE, 0x1, \
+ struct gh_userspace_memory_region)
+
#endif
--
2.40.0


2023-06-13 17:47:43

by Elliot Berman

[permalink] [raw]
Subject: [PATCH v14 16/25] docs: gunyah: Document Gunyah VM Manager

Document the ioctls and usage of Gunyah VM Manager driver.

Signed-off-by: Elliot Berman <[email protected]>
---
Documentation/virt/gunyah/index.rst | 1 +
Documentation/virt/gunyah/vm-manager.rst | 83 ++++++++++++++++++++++++
2 files changed, 84 insertions(+)
create mode 100644 Documentation/virt/gunyah/vm-manager.rst

diff --git a/Documentation/virt/gunyah/index.rst b/Documentation/virt/gunyah/index.rst
index 74aa345e0a144..7058249825b16 100644
--- a/Documentation/virt/gunyah/index.rst
+++ b/Documentation/virt/gunyah/index.rst
@@ -7,6 +7,7 @@ Gunyah Hypervisor
.. toctree::
:maxdepth: 1

+ vm-manager
message-queue

Gunyah is a Type-1 hypervisor which is independent of any OS kernel, and runs in
diff --git a/Documentation/virt/gunyah/vm-manager.rst b/Documentation/virt/gunyah/vm-manager.rst
new file mode 100644
index 0000000000000..df0e1a8279bf5
--- /dev/null
+++ b/Documentation/virt/gunyah/vm-manager.rst
@@ -0,0 +1,83 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=======================
+Virtual Machine Manager
+=======================
+
+The Gunyah Virtual Machine Manager is a Linux driver to support launching
+virtual machines using Gunyah. It presently supports launching virtual machines
+scheduled by Gunyah's scheduler.
+
+Configuration of a Gunyah virtual machine is done via a devicetree. When the VM
+is launched, memory is provided by the host VM which contains the devictree.
+Gunyah reads the devicetree to configure the memory map and create resources
+such as vCPUs for the VM. Memory can be shared with the VM with
+`GH_VM_SET_USER_MEM_REGION`_. Userspace can interact with the resources in Linux
+by adding "functions" to the VM.
+
+Sample Userspace VMM
+====================
+
+A sample userspace VMM is included in samples/gunyah/ along with a minimal
+devicetree that can be used to launch a VM. To build this sample, enable
+CONFIG_SAMPLE_GUNYAH.
+
+IOCTLs and userspace VMM flows
+==============================
+
+The kernel exposes a char device interface at /dev/gunyah.
+
+To create a VM, use the `GH_CREATE_VM`_ ioctl. A successful call will return a
+"Gunyah VM" file descriptor.
+
+/dev/gunyah API Descriptions
+----------------------------
+
+GH_CREATE_VM
+~~~~~~~~~~~~
+
+Creates a Gunyah VM. The argument is reserved for future use and must be 0.
+A successful call will return a Gunyah VM file descriptor. See
+`Gunyah VM API Descriptions`_ for list of IOCTLs that can be made on this file
+file descriptor.
+
+Gunyah VM API Descriptions
+--------------------------
+
+GH_VM_SET_USER_MEM_REGION
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+This ioctl allows the user to create or delete a memory parcel for a guest
+virtual machine. Each memory region is uniquely identified by a label;
+attempting to create two regions with the same label is not allowed. Labels are
+unique per virtual machine.
+
+While VMM is guest-agnostic and allows runtime addition of memory regions,
+Linux guest virtual machines do not support accepting memory regions at runtime.
+Thus, for Linux guests, memory regions should be provided before starting the VM
+and the VM must be configured via the devicetree to accept these at boot-up.
+
+The guest physical address is used by Linux kernel to check that the requested
+user regions do not overlap and to help find the corresponding memory region
+for calls like `GH_VM_SET_DTB_CONFIG`_. It must be page aligned.
+
+To add a memory region, call `GH_VM_SET_USER_MEM_REGION`_ with fields set as
+described above.
+
+.. kernel-doc:: include/uapi/linux/gunyah.h
+ :identifiers: gh_userspace_memory_region gh_mem_flags
+
+GH_VM_SET_DTB_CONFIG
+~~~~~~~~~~~~~~~~~~~~
+
+This ioctl sets the location of the VM's devicetree blob and is used by Gunyah
+Resource Manager to allocate resources. The guest physical memory must be part
+of the primary memory parcel provided to the VM prior to GH_VM_START.
+
+.. kernel-doc:: include/uapi/linux/gunyah.h
+ :identifiers: gh_vm_dtb_config
+
+GH_VM_START
+~~~~~~~~~~~
+
+This ioctl starts the VM.
--
2.40.0


2023-06-13 17:48:35

by Elliot Berman

[permalink] [raw]
Subject: [PATCH v14 24/25] virt: gunyah: Add ioeventfd

Allow userspace to attach an ioeventfd to an mmio address within the guest.

Reviewed-by: Alex Elder <[email protected]>
Co-developed-by: Prakruthi Deepak Heragu <[email protected]>
Signed-off-by: Prakruthi Deepak Heragu <[email protected]>
Signed-off-by: Elliot Berman <[email protected]>
---
Documentation/virt/gunyah/vm-manager.rst | 2 +-
drivers/virt/gunyah/Kconfig | 9 ++
drivers/virt/gunyah/Makefile | 1 +
drivers/virt/gunyah/gunyah_ioeventfd.c | 130 +++++++++++++++++++++++
include/uapi/linux/gunyah.h | 37 +++++++
5 files changed, 178 insertions(+), 1 deletion(-)
create mode 100644 drivers/virt/gunyah/gunyah_ioeventfd.c

diff --git a/Documentation/virt/gunyah/vm-manager.rst b/Documentation/virt/gunyah/vm-manager.rst
index 57a254827be26..415b11248e00b 100644
--- a/Documentation/virt/gunyah/vm-manager.rst
+++ b/Documentation/virt/gunyah/vm-manager.rst
@@ -116,7 +116,7 @@ the VM *before* the VM starts.
The argument types are documented below:

.. kernel-doc:: include/uapi/linux/gunyah.h
- :identifiers: gh_fn_vcpu_arg gh_fn_irqfd_arg gh_irqfd_flags
+ :identifiers: gh_fn_vcpu_arg gh_fn_irqfd_arg gh_irqfd_flags gh_fn_ioeventfd_arg gh_ioeventfd_flags

Gunyah VCPU API Descriptions
----------------------------
diff --git a/drivers/virt/gunyah/Kconfig b/drivers/virt/gunyah/Kconfig
index bc2c46d9df946..63bebc5b9f825 100644
--- a/drivers/virt/gunyah/Kconfig
+++ b/drivers/virt/gunyah/Kconfig
@@ -48,3 +48,12 @@ config GUNYAH_IRQFD
on Gunyah virtual machine.

Say Y/M here if unsure and you want to support Gunyah VMMs.
+
+config GUNYAH_IOEVENTFD
+ tristate "Gunyah ioeventfd interface"
+ depends on GUNYAH
+ help
+ Enable kernel support for creating ioeventfds which can alert userspace
+ when a Gunyah virtual machine accesses a memory address.
+
+ Say Y/M here if unsure and you want to support Gunyah VMMs.
diff --git a/drivers/virt/gunyah/Makefile b/drivers/virt/gunyah/Makefile
index ad212a1cf9671..63ca11e747961 100644
--- a/drivers/virt/gunyah/Makefile
+++ b/drivers/virt/gunyah/Makefile
@@ -8,3 +8,4 @@ obj-$(CONFIG_GUNYAH) += gunyah.o

obj-$(CONFIG_GUNYAH_VCPU) += gunyah_vcpu.o
obj-$(CONFIG_GUNYAH_IRQFD) += gunyah_irqfd.o
+obj-$(CONFIG_GUNYAH_IOEVENTFD) += gunyah_ioeventfd.o
diff --git a/drivers/virt/gunyah/gunyah_ioeventfd.c b/drivers/virt/gunyah/gunyah_ioeventfd.c
new file mode 100644
index 0000000000000..5b1b9fd9ac3aa
--- /dev/null
+++ b/drivers/virt/gunyah/gunyah_ioeventfd.c
@@ -0,0 +1,130 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <linux/eventfd.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/gunyah.h>
+#include <linux/gunyah_vm_mgr.h>
+#include <linux/module.h>
+#include <linux/printk.h>
+
+#include <uapi/linux/gunyah.h>
+
+struct gh_ioeventfd {
+ struct gh_vm_function_instance *f;
+ struct gh_vm_io_handler io_handler;
+
+ struct eventfd_ctx *ctx;
+};
+
+static int gh_write_ioeventfd(struct gh_vm_io_handler *io_dev, u64 addr, u32 len, u64 data)
+{
+ struct gh_ioeventfd *iofd = container_of(io_dev, struct gh_ioeventfd, io_handler);
+
+ eventfd_signal(iofd->ctx, 1);
+ return 0;
+}
+
+static struct gh_vm_io_handler_ops io_ops = {
+ .write = gh_write_ioeventfd,
+};
+
+static long gh_ioeventfd_bind(struct gh_vm_function_instance *f)
+{
+ const struct gh_fn_ioeventfd_arg *args = f->argp;
+ struct gh_ioeventfd *iofd;
+ struct eventfd_ctx *ctx;
+ int ret;
+
+ if (f->arg_size != sizeof(*args))
+ return -EINVAL;
+
+ /* All other flag bits are reserved for future use */
+ if (args->flags & ~GH_IOEVENTFD_FLAGS_DATAMATCH)
+ return -EINVAL;
+
+ /* must be natural-word sized, or 0 to ignore length */
+ switch (args->len) {
+ case 0:
+ case 1:
+ case 2:
+ case 4:
+ case 8:
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /* check for range overflow */
+ if (overflows_type(args->addr + args->len, u64))
+ return -EINVAL;
+
+ /* ioeventfd with no length can't be combined with DATAMATCH */
+ if (!args->len && (args->flags & GH_IOEVENTFD_FLAGS_DATAMATCH))
+ return -EINVAL;
+
+ ctx = eventfd_ctx_fdget(args->fd);
+ if (IS_ERR(ctx))
+ return PTR_ERR(ctx);
+
+ iofd = kzalloc(sizeof(*iofd), GFP_KERNEL);
+ if (!iofd) {
+ ret = -ENOMEM;
+ goto err_eventfd;
+ }
+
+ f->data = iofd;
+ iofd->f = f;
+
+ iofd->ctx = ctx;
+
+ if (args->flags & GH_IOEVENTFD_FLAGS_DATAMATCH) {
+ iofd->io_handler.datamatch = true;
+ iofd->io_handler.len = args->len;
+ iofd->io_handler.data = args->datamatch;
+ }
+ iofd->io_handler.addr = args->addr;
+ iofd->io_handler.ops = &io_ops;
+
+ ret = gh_vm_add_io_handler(f->ghvm, &iofd->io_handler);
+ if (ret)
+ goto err_io_dev_add;
+
+ return 0;
+
+err_io_dev_add:
+ kfree(iofd);
+err_eventfd:
+ eventfd_ctx_put(ctx);
+ return ret;
+}
+
+static void gh_ioevent_unbind(struct gh_vm_function_instance *f)
+{
+ struct gh_ioeventfd *iofd = f->data;
+
+ eventfd_ctx_put(iofd->ctx);
+ gh_vm_remove_io_handler(iofd->f->ghvm, &iofd->io_handler);
+ kfree(iofd);
+}
+
+static bool gh_ioevent_compare(const struct gh_vm_function_instance *f,
+ const void *arg, size_t size)
+{
+ const struct gh_fn_ioeventfd_arg *instance = f->argp,
+ *other = arg;
+
+ if (sizeof(*other) != size)
+ return false;
+
+ return instance->addr == other->addr;
+}
+
+DECLARE_GH_VM_FUNCTION_INIT(ioeventfd, GH_FN_IOEVENTFD, 3,
+ gh_ioeventfd_bind, gh_ioevent_unbind,
+ gh_ioevent_compare);
+MODULE_DESCRIPTION("Gunyah ioeventfd VM Function");
+MODULE_LICENSE("GPL");
diff --git a/include/uapi/linux/gunyah.h b/include/uapi/linux/gunyah.h
index 0c480c622686a..fa1cae7419d2b 100644
--- a/include/uapi/linux/gunyah.h
+++ b/include/uapi/linux/gunyah.h
@@ -79,10 +79,13 @@ struct gh_vm_dtb_config {
* Return: file descriptor to manipulate the vcpu.
* @GH_FN_IRQFD: register eventfd to assert a Gunyah doorbell
* &struct gh_fn_desc.arg is a pointer to &struct gh_fn_irqfd_arg
+ * @GH_FN_IOEVENTFD: register ioeventfd to trigger when VM faults on parameter
+ * &struct gh_fn_desc.arg is a pointer to &struct gh_fn_ioeventfd_arg
*/
enum gh_fn_type {
GH_FN_VCPU = 1,
GH_FN_IRQFD,
+ GH_FN_IOEVENTFD,
};

#define GH_FN_MAX_ARG_SIZE 256
@@ -134,6 +137,40 @@ struct gh_fn_irqfd_arg {
__u32 padding;
};

+/**
+ * enum gh_ioeventfd_flags - flags for use in gh_fn_ioeventfd_arg
+ * @GH_IOEVENTFD_FLAGS_DATAMATCH: the event will be signaled only if the
+ * written value to the registered address is
+ * equal to &struct gh_fn_ioeventfd_arg.datamatch
+ */
+enum gh_ioeventfd_flags {
+ GH_IOEVENTFD_FLAGS_DATAMATCH = 1UL << 0,
+};
+
+/**
+ * struct gh_fn_ioeventfd_arg - Arguments to create an ioeventfd function
+ * @datamatch: data used when GH_IOEVENTFD_DATAMATCH is set
+ * @addr: Address in guest memory
+ * @len: Length of access
+ * @fd: When ioeventfd is matched, this eventfd is written
+ * @flags: See &enum gh_ioeventfd_flags
+ * @padding: padding bytes
+ *
+ * Create this function with &GH_VM_ADD_FUNCTION using type &GH_FN_IOEVENTFD.
+ *
+ * Attaches an ioeventfd to a legal mmio address within the guest. A guest write
+ * in the registered address will signal the provided event instead of triggering
+ * an exit on the GH_VCPU_RUN ioctl.
+ */
+struct gh_fn_ioeventfd_arg {
+ __u64 datamatch;
+ __u64 addr; /* legal mmio address */
+ __u32 len; /* 1, 2, 4, or 8 bytes; or 0 to ignore length */
+ __s32 fd;
+ __u32 flags;
+ __u32 padding;
+};
+
/**
* struct gh_fn_desc - Arguments to create a VM function
* @type: Type of the function. See &enum gh_fn_type.
--
2.40.0


2023-06-16 16:45:53

by Alex Elder

[permalink] [raw]
Subject: Re: [PATCH v14 16/25] docs: gunyah: Document Gunyah VM Manager

On 6/13/23 12:20 PM, Elliot Berman wrote:
> Document the ioctls and usage of Gunyah VM Manager driver.
>
> Signed-off-by: Elliot Berman <[email protected]>

A few minor comments below, but regardless:

Reviewed-by: Alex Elder <[email protected]>

> ---
> Documentation/virt/gunyah/index.rst | 1 +
> Documentation/virt/gunyah/vm-manager.rst | 83 ++++++++++++++++++++++++
> 2 files changed, 84 insertions(+)
> create mode 100644 Documentation/virt/gunyah/vm-manager.rst
>
> diff --git a/Documentation/virt/gunyah/index.rst b/Documentation/virt/gunyah/index.rst
> index 74aa345e0a144..7058249825b16 100644
> --- a/Documentation/virt/gunyah/index.rst
> +++ b/Documentation/virt/gunyah/index.rst
> @@ -7,6 +7,7 @@ Gunyah Hypervisor
> .. toctree::
> :maxdepth: 1
>
> + vm-manager
> message-queue
>
> Gunyah is a Type-1 hypervisor which is independent of any OS kernel, and runs in
> diff --git a/Documentation/virt/gunyah/vm-manager.rst b/Documentation/virt/gunyah/vm-manager.rst
> new file mode 100644
> index 0000000000000..df0e1a8279bf5
> --- /dev/null
> +++ b/Documentation/virt/gunyah/vm-manager.rst
> @@ -0,0 +1,83 @@
> +.. SPDX-License-Identifier: GPL-2.0
> +
> +=======================
> +Virtual Machine Manager
> +=======================
> +
> +The Gunyah Virtual Machine Manager is a Linux driver to support launching
> +virtual machines using Gunyah. It presently supports launching virtual machines
> +scheduled by Gunyah's scheduler.

You referred to this as "behind-the-back" scheduling in patch 1.
(I don't know if this terminology is important to use.)

> +
> +Configuration of a Gunyah virtual machine is done via a devicetree. When the VM
> +is launched, memory is provided by the host VM which contains the devictree.
> +Gunyah reads the devicetree to configure the memory map and create resources
> +such as vCPUs for the VM. Memory can be shared with the VM with
> +`GH_VM_SET_USER_MEM_REGION`_. Userspace can interact with the resources in Linux
> +by adding "functions" to the VM.
> +
> +Sample Userspace VMM
> +====================
> +
> +A sample userspace VMM is included in samples/gunyah/ along with a minimal
> +devicetree that can be used to launch a VM. To build this sample, enable
> +CONFIG_SAMPLE_GUNYAH.
> +
> +IOCTLs and userspace VMM flows
> +==============================
> +
> +The kernel exposes a char device interface at /dev/gunyah.
> +
> +To create a VM, use the `GH_CREATE_VM`_ ioctl. A successful call will return a
> +"Gunyah VM" file descriptor.

Maybe reword this a bit so it's clearer that the IOCTL calls
are performed on the file descriptor resulting from opening
/dev/gunyah?

> +
> +/dev/gunyah API Descriptions
> +----------------------------
> +
> +GH_CREATE_VM
> +~~~~~~~~~~~~
> +
> +Creates a Gunyah VM. The argument is reserved for future use and must be 0.
> +A successful call will return a Gunyah VM file descriptor. See
> +`Gunyah VM API Descriptions`_ for list of IOCTLs that can be made on this file

Maybe "the next section" rather than an explicit reference.
But it's fine as-is.

Also (because you duplicate "file"):

s/on this file/on this/

> +file descriptor.
> +
> +Gunyah VM API Descriptions
> +--------------------------
> +
> +GH_VM_SET_USER_MEM_REGION
> +~~~~~~~~~~~~~~~~~~~~~~~~~
> +
> +This ioctl allows the user to create or delete a memory parcel for a guest

How are memory parcels deleted? (Maybe add a sentence at the end
of this section.)

> +virtual machine. Each memory region is uniquely identified by a label;
> +attempting to create two regions with the same label is not allowed. Labels are
> +unique per virtual machine.
> +
> +While VMM is guest-agnostic and allows runtime addition of memory regions,
> +Linux guest virtual machines do not support accepting memory regions at runtime.
> +Thus, for Linux guests, memory regions should be provided before starting the VM
> +and the VM must be configured via the devicetree to accept these at boot-up.
> +
> +The guest physical address is used by Linux kernel to check that the requested
> +user regions do not overlap and to help find the corresponding memory region
> +for calls like `GH_VM_SET_DTB_CONFIG`_. It must be page aligned.
> +
> +To add a memory region, call `GH_VM_SET_USER_MEM_REGION`_ with fields set as
> +described above.
> +
> +.. kernel-doc:: include/uapi/linux/gunyah.h
> + :identifiers: gh_userspace_memory_region gh_mem_flags
> +
> +GH_VM_SET_DTB_CONFIG
> +~~~~~~~~~~~~~~~~~~~~
> +
> +This ioctl sets the location of the VM's devicetree blob and is used by Gunyah
> +Resource Manager to allocate resources. The guest physical memory must be part
> +of the primary memory parcel provided to the VM prior to GH_VM_START.
> +
> +.. kernel-doc:: include/uapi/linux/gunyah.h
> + :identifiers: gh_vm_dtb_config
> +
> +GH_VM_START
> +~~~~~~~~~~~
> +
> +This ioctl starts the VM.


2023-06-16 16:48:44

by Alex Elder

[permalink] [raw]
Subject: Re: [PATCH v14 11/25] gunyah: vm_mgr: Add/remove user memory regions

On 6/13/23 12:20 PM, Elliot Berman wrote:
> When launching a virtual machine, Gunyah userspace allocates memory for
> the guest and informs Gunyah about these memory regions through
> SET_USER_MEMORY_REGION ioctl.
>
> Co-developed-by: Prakruthi Deepak Heragu <[email protected]>
> Signed-off-by: Prakruthi Deepak Heragu <[email protected]>
> Signed-off-by: Elliot Berman <[email protected]>

I have one trivial comment below. This patch adds some complexity
but this time around I'm going to assume I checked those things
in some detail previously. This time I'm doing more of a scan
through the patch and I find it looks good. (If you want me to
spend more time on this, say so.)

Reviewed-by: Alex Elder <[email protected]>

> ---
> drivers/virt/gunyah/Makefile | 2 +-
> drivers/virt/gunyah/vm_mgr.c | 59 +++++++-
> drivers/virt/gunyah/vm_mgr.h | 26 ++++
> drivers/virt/gunyah/vm_mgr_mm.c | 232 ++++++++++++++++++++++++++++++++
> include/uapi/linux/gunyah.h | 37 +++++
> 5 files changed, 352 insertions(+), 4 deletions(-)
> create mode 100644 drivers/virt/gunyah/vm_mgr_mm.c
>
> diff --git a/drivers/virt/gunyah/Makefile b/drivers/virt/gunyah/Makefile
> index e47e25895299c..bacf78b8fa337 100644
> --- a/drivers/virt/gunyah/Makefile
> +++ b/drivers/virt/gunyah/Makefile
> @@ -1,4 +1,4 @@
> # SPDX-License-Identifier: GPL-2.0
>
> -gunyah-y += rsc_mgr.o rsc_mgr_rpc.o vm_mgr.o
> +gunyah-y += rsc_mgr.o rsc_mgr_rpc.o vm_mgr.o vm_mgr_mm.o
> obj-$(CONFIG_GUNYAH) += gunyah.o
> diff --git a/drivers/virt/gunyah/vm_mgr.c b/drivers/virt/gunyah/vm_mgr.c
> index a43401cb34f7d..297427952b8c7 100644
> --- a/drivers/virt/gunyah/vm_mgr.c
> +++ b/drivers/virt/gunyah/vm_mgr.c
> @@ -15,6 +15,8 @@
>
> #include "vm_mgr.h"
>
> +static void gh_vm_free(struct work_struct *work);
> +
> static __must_check struct gh_vm *gh_vm_alloc(struct gh_rm *rm)
> {
> struct gh_vm *ghvm;
> @@ -26,20 +28,72 @@ static __must_check struct gh_vm *gh_vm_alloc(struct gh_rm *rm)
> ghvm->parent = gh_rm_get(rm);
> ghvm->rm = rm;
>
> + mmgrab(current->mm);
> + ghvm->mm = current->mm;
> + mutex_init(&ghvm->mm_lock);
> + INIT_LIST_HEAD(&ghvm->memory_mappings);
> + INIT_WORK(&ghvm->free_work, gh_vm_free);
> +
> return ghvm;
> }
>
> -static int gh_vm_release(struct inode *inode, struct file *filp)
> +static long gh_vm_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
> {
> struct gh_vm *ghvm = filp->private_data;
> + void __user *argp = (void __user *)arg;
> + long r;

Don't you use "ret" for return values most of the time?
(Not a big deal, maybe there's another reason you used
"r" here.)

> +
> + switch (cmd) {
> + case GH_VM_SET_USER_MEM_REGION: {
> + struct gh_userspace_memory_region region;
> +
> + /* only allow owner task to add memory */
> + if (ghvm->mm != current->mm)
> + return -EPERM;
> +
> + if (copy_from_user(&region, argp, sizeof(region)))
> + return -EFAULT;
> +
> + /* All other flag bits are reserved for future use */
> + if (region.flags & ~(GH_MEM_ALLOW_READ | GH_MEM_ALLOW_WRITE | GH_MEM_ALLOW_EXEC))
> + return -EINVAL;
> +
> + r = gh_vm_mem_alloc(ghvm, &region);
> + break;
> + }
> + default:
> + r = -ENOTTY;
> + break;
> + }
>
> + return r;
> +}
> +
> +static void gh_vm_free(struct work_struct *work)
> +{
> + struct gh_vm *ghvm = container_of(work, struct gh_vm, free_work);
> +
> + gh_vm_mem_reclaim(ghvm);
> gh_rm_put(ghvm->rm);
> + mmdrop(ghvm->mm);
> kfree(ghvm);
> +}
> +
> +static int gh_vm_release(struct inode *inode, struct file *filp)
> +{
> + struct gh_vm *ghvm = filp->private_data;
> +
> + /* VM will be reset and make RM calls which can interruptible sleep.
> + * Defer to a work so this thread can receive signal.
> + */
> + schedule_work(&ghvm->free_work);
> return 0;
> }
>
> static const struct file_operations gh_vm_fops = {
> .owner = THIS_MODULE,
> + .unlocked_ioctl = gh_vm_ioctl,
> + .compat_ioctl = compat_ptr_ioctl,
> .release = gh_vm_release,
> .llseek = noop_llseek,
> };
> @@ -77,8 +131,7 @@ static long gh_dev_ioctl_create_vm(struct gh_rm *rm, unsigned long arg)
> err_put_fd:
> put_unused_fd(fd);
> err_destroy_vm:
> - gh_rm_put(ghvm->rm);
> - kfree(ghvm);
> + gh_vm_free(&ghvm->free_work);
> return err;
> }
>
> diff --git a/drivers/virt/gunyah/vm_mgr.h b/drivers/virt/gunyah/vm_mgr.h
> index 1e94b58d7d34d..434ef9f662a7a 100644
> --- a/drivers/virt/gunyah/vm_mgr.h
> +++ b/drivers/virt/gunyah/vm_mgr.h
> @@ -7,14 +7,40 @@
> #define _GH_VM_MGR_H
>
> #include <linux/gunyah_rsc_mgr.h>
> +#include <linux/list.h>
> +#include <linux/miscdevice.h>
> +#include <linux/mutex.h>
>
> #include <uapi/linux/gunyah.h>
>
> long gh_dev_vm_mgr_ioctl(struct gh_rm *rm, unsigned int cmd, unsigned long arg);
>
> +enum gh_vm_mem_share_type {
> + VM_MEM_SHARE,
> + VM_MEM_LEND,
> +};
> +
> +struct gh_vm_mem {
> + struct list_head list;
> + enum gh_vm_mem_share_type share_type;
> + struct gh_rm_mem_parcel parcel;
> +
> + __u64 guest_phys_addr;
> + struct page **pages;
> + unsigned long npages;
> +};
> +
> struct gh_vm {
> struct gh_rm *rm;
> struct device *parent;
> +
> + struct work_struct free_work;
> + struct mm_struct *mm; /* userspace tied to this vm */
> + struct mutex mm_lock;
> + struct list_head memory_mappings;
> };
>
> +int gh_vm_mem_alloc(struct gh_vm *ghvm, struct gh_userspace_memory_region *region);
> +void gh_vm_mem_reclaim(struct gh_vm *ghvm);
> +
> #endif
> diff --git a/drivers/virt/gunyah/vm_mgr_mm.c b/drivers/virt/gunyah/vm_mgr_mm.c
> new file mode 100644
> index 0000000000000..6974607f02edd
> --- /dev/null
> +++ b/drivers/virt/gunyah/vm_mgr_mm.c
> @@ -0,0 +1,232 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#define pr_fmt(fmt) "gh_vm_mgr: " fmt
> +
> +#include <linux/gunyah_rsc_mgr.h>
> +#include <linux/mm.h>
> +
> +#include <uapi/linux/gunyah.h>
> +
> +#include "vm_mgr.h"
> +
> +static bool pages_are_mergeable(struct page *a, struct page *b)
> +{
> + return page_to_pfn(a) + 1 == page_to_pfn(b);
> +}
> +
> +static bool gh_vm_mem_overlap(struct gh_vm_mem *a, u64 addr, u64 size)
> +{
> + u64 a_end = a->guest_phys_addr + (a->npages << PAGE_SHIFT);
> + u64 end = addr + size;
> +
> + return a->guest_phys_addr < end && addr < a_end;
> +}
> +
> +static struct gh_vm_mem *__gh_vm_mem_find_by_label(struct gh_vm *ghvm, u32 label)
> + __must_hold(&ghvm->mm_lock)
> +{
> + struct gh_vm_mem *mapping;
> +
> + list_for_each_entry(mapping, &ghvm->memory_mappings, list)
> + if (mapping->parcel.label == label)
> + return mapping;
> +
> + return NULL;
> +}
> +
> +static void gh_vm_mem_reclaim_mapping(struct gh_vm *ghvm, struct gh_vm_mem *mapping)
> + __must_hold(&ghvm->mm_lock)
> +{
> + int ret = 0;
> +
> + if (mapping->parcel.mem_handle != GH_MEM_HANDLE_INVAL) {
> + ret = gh_rm_mem_reclaim(ghvm->rm, &mapping->parcel);
> + if (ret)
> + pr_warn("Failed to reclaim memory parcel for label %d: %d\n",
> + mapping->parcel.label, ret);
> + }
> +
> + if (!ret) {
> + unpin_user_pages(mapping->pages, mapping->npages);
> + account_locked_vm(ghvm->mm, mapping->npages, false);
> + }
> +
> + kfree(mapping->pages);
> + kfree(mapping->parcel.acl_entries);
> + kfree(mapping->parcel.mem_entries);
> +
> + list_del(&mapping->list);
> +}
> +
> +void gh_vm_mem_reclaim(struct gh_vm *ghvm)
> +{
> + struct gh_vm_mem *mapping, *tmp;
> +
> + mutex_lock(&ghvm->mm_lock);
> +
> + list_for_each_entry_safe(mapping, tmp, &ghvm->memory_mappings, list) {
> + gh_vm_mem_reclaim_mapping(ghvm, mapping);
> + kfree(mapping);
> + }
> +
> + mutex_unlock(&ghvm->mm_lock);
> +}
> +
> +int gh_vm_mem_alloc(struct gh_vm *ghvm, struct gh_userspace_memory_region *region)
> +{
> + struct gh_vm_mem *mapping, *tmp_mapping;
> + struct page *curr_page, *prev_page;
> + struct gh_rm_mem_parcel *parcel;
> + int i, j, pinned, ret = 0;
> + unsigned int gup_flags;
> + size_t entry_size;
> + u16 vmid;
> +
> + if (!region->memory_size || !PAGE_ALIGNED(region->memory_size) ||
> + !PAGE_ALIGNED(region->userspace_addr) ||
> + !PAGE_ALIGNED(region->guest_phys_addr))
> + return -EINVAL;
> +
> + if (overflows_type(region->guest_phys_addr + region->memory_size, u64))
> + return -EOVERFLOW;
> +
> + ret = mutex_lock_interruptible(&ghvm->mm_lock);
> + if (ret)
> + return ret;
> +
> + mapping = __gh_vm_mem_find_by_label(ghvm, region->label);
> + if (mapping) {
> + ret = -EEXIST;
> + goto unlock;
> + }
> +
> + list_for_each_entry(tmp_mapping, &ghvm->memory_mappings, list) {
> + if (gh_vm_mem_overlap(tmp_mapping, region->guest_phys_addr,
> + region->memory_size)) {
> + ret = -EEXIST;
> + goto unlock;
> + }
> + }
> +
> + mapping = kzalloc(sizeof(*mapping), GFP_KERNEL_ACCOUNT);
> + if (!mapping) {
> + ret = -ENOMEM;
> + goto unlock;
> + }
> +
> + mapping->guest_phys_addr = region->guest_phys_addr;
> + mapping->npages = region->memory_size >> PAGE_SHIFT;
> + parcel = &mapping->parcel;
> + parcel->label = region->label;
> + parcel->mem_handle = GH_MEM_HANDLE_INVAL; /* to be filled later by mem_share/mem_lend */
> + parcel->mem_type = GH_RM_MEM_TYPE_NORMAL;
> +
> + ret = account_locked_vm(ghvm->mm, mapping->npages, true);
> + if (ret)
> + goto free_mapping;
> +
> + mapping->pages = kcalloc(mapping->npages, sizeof(*mapping->pages), GFP_KERNEL_ACCOUNT);
> + if (!mapping->pages) {
> + ret = -ENOMEM;
> + mapping->npages = 0; /* update npages for reclaim */
> + goto unlock_pages;
> + }
> +
> + gup_flags = FOLL_LONGTERM;
> + if (region->flags & GH_MEM_ALLOW_WRITE)
> + gup_flags |= FOLL_WRITE;
> +
> + pinned = pin_user_pages_fast(region->userspace_addr, mapping->npages,
> + gup_flags, mapping->pages);
> + if (pinned < 0) {
> + ret = pinned;
> + goto free_pages;
> + } else if (pinned != mapping->npages) {
> + ret = -EFAULT;
> + mapping->npages = pinned; /* update npages for reclaim */
> + goto unpin_pages;
> + }
> +
> + parcel->n_acl_entries = 2;
> + mapping->share_type = VM_MEM_SHARE;
> + parcel->acl_entries = kcalloc(parcel->n_acl_entries, sizeof(*parcel->acl_entries),
> + GFP_KERNEL);
> + if (!parcel->acl_entries) {
> + ret = -ENOMEM;
> + goto unpin_pages;
> + }
> +
> + /* acl_entries[0].vmid will be this VM's vmid. We'll fill it when the
> + * VM is starting and we know the VM's vmid.
> + */
> + if (region->flags & GH_MEM_ALLOW_READ)
> + parcel->acl_entries[0].perms |= GH_RM_ACL_R;
> + if (region->flags & GH_MEM_ALLOW_WRITE)
> + parcel->acl_entries[0].perms |= GH_RM_ACL_W;
> + if (region->flags & GH_MEM_ALLOW_EXEC)
> + parcel->acl_entries[0].perms |= GH_RM_ACL_X;
> +
> + ret = gh_rm_get_vmid(ghvm->rm, &vmid);
> + if (ret)
> + goto free_acl;
> +
> + parcel->acl_entries[1].vmid = cpu_to_le16(vmid);
> + /* Host assumed to have all these permissions. Gunyah will not
> + * grant new permissions if host actually had less than RWX
> + */
> + parcel->acl_entries[1].perms = GH_RM_ACL_R | GH_RM_ACL_W | GH_RM_ACL_X;
> +
> + parcel->n_mem_entries = 1;
> + for (i = 1; i < mapping->npages; i++) {
> + if (!pages_are_mergeable(mapping->pages[i - 1], mapping->pages[i]))
> + parcel->n_mem_entries++;
> + }
> +
> + parcel->mem_entries = kcalloc(parcel->n_mem_entries,
> + sizeof(parcel->mem_entries[0]),
> + GFP_KERNEL_ACCOUNT);
> + if (!parcel->mem_entries) {
> + ret = -ENOMEM;
> + goto free_acl;
> + }
> +
> + /* reduce number of entries by combining contiguous pages into single memory entry */
> + prev_page = mapping->pages[0];
> + parcel->mem_entries[0].phys_addr = cpu_to_le64(page_to_phys(prev_page));
> + entry_size = PAGE_SIZE;
> + for (i = 1, j = 0; i < mapping->npages; i++) {
> + curr_page = mapping->pages[i];
> + if (pages_are_mergeable(prev_page, curr_page)) {
> + entry_size += PAGE_SIZE;
> + } else {
> + parcel->mem_entries[j].size = cpu_to_le64(entry_size);
> + j++;
> + parcel->mem_entries[j].phys_addr =
> + cpu_to_le64(page_to_phys(curr_page));
> + entry_size = PAGE_SIZE;
> + }
> +
> + prev_page = curr_page;
> + }
> + parcel->mem_entries[j].size = cpu_to_le64(entry_size);
> +
> + list_add(&mapping->list, &ghvm->memory_mappings);
> + mutex_unlock(&ghvm->mm_lock);
> + return 0;
> +free_acl:
> + kfree(parcel->acl_entries);
> +unpin_pages:
> + unpin_user_pages(mapping->pages, pinned);
> +free_pages:
> + kfree(mapping->pages);
> +unlock_pages:
> + account_locked_vm(ghvm->mm, mapping->npages, false);
> +free_mapping:
> + kfree(mapping);
> +unlock:
> + mutex_unlock(&ghvm->mm_lock);
> + return ret;
> +}
> diff --git a/include/uapi/linux/gunyah.h b/include/uapi/linux/gunyah.h
> index 86b9cb60118dd..91d6dd26fcc89 100644
> --- a/include/uapi/linux/gunyah.h
> +++ b/include/uapi/linux/gunyah.h
> @@ -20,4 +20,41 @@
> */
> #define GH_CREATE_VM _IO(GH_IOCTL_TYPE, 0x0) /* Returns a Gunyah VM fd */
>
> +/*
> + * ioctls for VM fds
> + */
> +
> +/**
> + * enum gh_mem_flags - Possible flags on &struct gh_userspace_memory_region
> + * @GH_MEM_ALLOW_READ: Allow guest to read the memory
> + * @GH_MEM_ALLOW_WRITE: Allow guest to write to the memory
> + * @GH_MEM_ALLOW_EXEC: Allow guest to execute instructions in the memory
> + */
> +enum gh_mem_flags {
> + GH_MEM_ALLOW_READ = 1UL << 0,
> + GH_MEM_ALLOW_WRITE = 1UL << 1,
> + GH_MEM_ALLOW_EXEC = 1UL << 2,
> +};
> +
> +/**
> + * struct gh_userspace_memory_region - Userspace memory descripion for GH_VM_SET_USER_MEM_REGION
> + * @label: Identifer to the region which is unique to the VM.
> + * @flags: Flags for memory parcel behavior. See &enum gh_mem_flags.
> + * @guest_phys_addr: Location of the memory region in guest's memory space (page-aligned)
> + * @memory_size: Size of the region (page-aligned)
> + * @userspace_addr: Location of the memory region in caller (userspace)'s memory
> + *
> + * See Documentation/virt/gunyah/vm-manager.rst for further details.
> + */
> +struct gh_userspace_memory_region {
> + __u32 label;
> + __u32 flags;
> + __u64 guest_phys_addr;
> + __u64 memory_size;
> + __u64 userspace_addr;
> +};
> +
> +#define GH_VM_SET_USER_MEM_REGION _IOW(GH_IOCTL_TYPE, 0x1, \
> + struct gh_userspace_memory_region)
> +
> #endif


2023-06-16 16:51:27

by Alex Elder

[permalink] [raw]
Subject: Re: [PATCH v14 18/25] gunyah: vm_mgr: Add framework for VM Functions

On 6/13/23 12:20 PM, Elliot Berman wrote:
> Introduce a framework for Gunyah userspace to install VM functions. VM
> functions are optional interfaces to the virtual machine. vCPUs,
> ioeventfs, and irqfds are examples of such VM functions and are

s/ioventfs/ioeventfds/

> implemented in subsequent patches.
>
> A generic framework is implemented instead of individual ioctls to
> create vCPUs, irqfds, etc., in order to simplify the VM manager core
> implementation and allow dynamic loading of VM function modules.

I have some comments, and one question about the user space
argument passed during function instance removal. Assuming
you explain/address that:

Reviewed-by: Alex Elder <[email protected]>

>
> Signed-off-by: Elliot Berman <[email protected]>
> ---
> Documentation/virt/gunyah/vm-manager.rst | 18 ++
> drivers/virt/gunyah/vm_mgr.c | 213 ++++++++++++++++++++++-
> drivers/virt/gunyah/vm_mgr.h | 4 +
> include/linux/gunyah_vm_mgr.h | 97 +++++++++++
> include/uapi/linux/gunyah.h | 18 ++
> 5 files changed, 347 insertions(+), 3 deletions(-)
> create mode 100644 include/linux/gunyah_vm_mgr.h
>
> diff --git a/Documentation/virt/gunyah/vm-manager.rst b/Documentation/virt/gunyah/vm-manager.rst
> index df0e1a8279bf5..cbc79bd8749b4 100644
> --- a/Documentation/virt/gunyah/vm-manager.rst
> +++ b/Documentation/virt/gunyah/vm-manager.rst
> @@ -15,6 +15,24 @@ such as vCPUs for the VM. Memory can be shared with the VM with
> `GH_VM_SET_USER_MEM_REGION`_. Userspace can interact with the resources in Linux
> by adding "functions" to the VM.
>
> +Gunyah Functions
> +================
> +
> +Components of a Gunyah VM's configuration that need kernel configuration are
> +called "functions" and are built on top of a framework. Functions are identified
> +by a string and have some argument(s) to configure them. They are typically
> +created by the `GH_VM_ADD_FUNCTION`_ ioctl.

Regarding "typically": when are they not aded by this IOCTL?

> +
> +Functions typically will always do at least one of these operations:

Again, "typically" or "always"? I just find using both of those
in the same sentence a little odd.

> +
> +1. Create resource ticket(s). Resource tickets allow a function to register
> + itself as the client for a Gunyah resource (e.g. doorbell or vCPU) and
> + the function is given the pointer to the &struct gh_resource when the

s/when the/when a/

> + VM is starting.
> +
> +2. Register IO handler(s). IO handlers allow a function to handle stage-2 faults
> + from the virtual machine.
> +
> Sample Userspace VMM
> ====================
>
> diff --git a/drivers/virt/gunyah/vm_mgr.c b/drivers/virt/gunyah/vm_mgr.c
> index 562ae6ed4a5f1..cfd79bc9900fd 100644
> --- a/drivers/virt/gunyah/vm_mgr.c
> +++ b/drivers/virt/gunyah/vm_mgr.c
> @@ -6,10 +6,13 @@
> #define pr_fmt(fmt) "gh_vm_mgr: " fmt
>
> #include <linux/anon_inodes.h>
> +#include <linux/compat.h>
> #include <linux/file.h>
> #include <linux/gunyah_rsc_mgr.h>
> +#include <linux/gunyah_vm_mgr.h>
> #include <linux/miscdevice.h>
> #include <linux/module.h>
> +#include <linux/xarray.h>
>
> #include <uapi/linux/gunyah.h>
>
> @@ -17,6 +20,169 @@
>
> static void gh_vm_free(struct work_struct *work);
>
> +static DEFINE_XARRAY(gh_vm_functions);
> +
> +static void gh_vm_put_function(struct gh_vm_function *fn)
> +{
> + module_put(fn->mod);
> +}
> +
> +static struct gh_vm_function *gh_vm_get_function(u32 type)
> +{
> + struct gh_vm_function *fn;
> +
> + fn = xa_load(&gh_vm_functions, type);
> + if (!fn) {
> + request_module("ghfunc:%d", type);
> +
> + fn = xa_load(&gh_vm_functions, type);
> + }
> +
> + if (!fn || !try_module_get(fn->mod))
> + fn = ERR_PTR(-ENOENT);
> +
> + return fn;
> +}
> +
> +static void gh_vm_remove_function_instance(struct gh_vm_function_instance *inst)
> + __must_hold(&inst->ghvm->fn_lock)
> +{
> + inst->fn->unbind(inst);
> + list_del(&inst->vm_list);
> + gh_vm_put_function(inst->fn);
> + kfree(inst->argp);
> + kfree(inst);
> +}
> +
> +static void gh_vm_remove_functions(struct gh_vm *ghvm)
> +{
> + struct gh_vm_function_instance *inst, *iiter;
> +
> + mutex_lock(&ghvm->fn_lock);
> + list_for_each_entry_safe(inst, iiter, &ghvm->functions, vm_list) {
> + gh_vm_remove_function_instance(inst);
> + }
> + mutex_unlock(&ghvm->fn_lock);
> +}
> +
> +static long gh_vm_add_function_instance(struct gh_vm *ghvm, struct gh_fn_desc *f)
> +{
> + struct gh_vm_function_instance *inst;
> + void __user *argp;
> + long r = 0;
> +
> + if (f->arg_size > GH_FN_MAX_ARG_SIZE) {
> + dev_err_ratelimited(ghvm->parent, "%s: arg_size > %d\n",
> + __func__, GH_FN_MAX_ARG_SIZE);
> + return -EINVAL;
> + }
> +
> + inst = kzalloc(sizeof(*inst), GFP_KERNEL);
> + if (!inst)
> + return -ENOMEM;
> +
> + inst->arg_size = f->arg_size;
> + if (inst->arg_size) {
> + inst->argp = kzalloc(inst->arg_size, GFP_KERNEL);
> + if (!inst->argp) {
> + r = -ENOMEM;
> + goto free;
> + }
> +
> + argp = u64_to_user_ptr(f->arg);
> + if (copy_from_user(inst->argp, argp, f->arg_size)) {
> + r = -EFAULT;
> + goto free_arg;
> + }
> + }
> +
> + inst->fn = gh_vm_get_function(f->type);
> + if (IS_ERR(inst->fn)) {
> + r = PTR_ERR(inst->fn);
> + goto free_arg;
> + }
> +
> + inst->ghvm = ghvm;
> + inst->rm = ghvm->rm;
> +
> + mutex_lock(&ghvm->fn_lock);
> + r = inst->fn->bind(inst);
> + if (r < 0) {
> + mutex_unlock(&ghvm->fn_lock);
> + gh_vm_put_function(inst->fn);
> + goto free_arg;
> + }
> +
> + list_add(&inst->vm_list, &ghvm->functions);
> + mutex_unlock(&ghvm->fn_lock);
> +
> + return r;
> +free_arg:
> + kfree(inst->argp);
> +free:
> + kfree(inst);
> + return r;
> +}
> +
> +static long gh_vm_rm_function_instance(struct gh_vm *ghvm, struct gh_fn_desc *f)
> +{
> + struct gh_vm_function_instance *inst, *iter;
> + void __user *user_argp;
> + void *argp;
> + long r = 0;
> +
> + r = mutex_lock_interruptible(&ghvm->fn_lock);
> + if (r)
> + return r;
> +
> + if (f->arg_size) {
> + argp = kzalloc(f->arg_size, GFP_KERNEL);
> + if (!argp) {
> + r = -ENOMEM;
> + goto out;
> + }
> +
> + user_argp = u64_to_user_ptr(f->arg);

What is the user pointer even needed for here? What
is the purpose of copying it into the local buffer?
You never reference it after this point.

I could envision it being usable (and so it makes
some sense being part of the user space API), but
at least at this time it serves no purpose.

> + if (copy_from_user(argp, user_argp, f->arg_size)) {
> + r = -EFAULT;
> + kfree(argp);
> + goto out;
> + }
> +
> + r = -ENOENT;
> + list_for_each_entry_safe(inst, iter, &ghvm->functions, vm_list) {
> + if (inst->fn->type == f->type &&
> + inst->fn->compare(inst, argp, f->arg_size)) {
> + gh_vm_remove_function_instance(inst);
> + r = 0;
> + }
> + }
> +
> + kfree(argp);
> + }
> +
> +out:
> + mutex_unlock(&ghvm->fn_lock);
> + return r;
> +}
> +
> +int gh_vm_function_register(struct gh_vm_function *fn)
> +{
> + if (!fn->bind || !fn->unbind)
> + return -EINVAL;
> +
> + return xa_err(xa_store(&gh_vm_functions, fn->type, fn, GFP_KERNEL));
> +}
> +EXPORT_SYMBOL_GPL(gh_vm_function_register);
> +
> +void gh_vm_function_unregister(struct gh_vm_function *fn)
> +{
> + /* Expecting unregister to only come when unloading a module */
> + WARN_ON(fn->mod && module_refcount(fn->mod));
> + xa_erase(&gh_vm_functions, fn->type);
> +}
> +EXPORT_SYMBOL_GPL(gh_vm_function_unregister);
> +
> static int gh_vm_rm_notification_status(struct gh_vm *ghvm, void *data)
> {
> struct gh_rm_vm_status_payload *payload = data;
> @@ -98,6 +264,8 @@ static __must_check struct gh_vm *gh_vm_alloc(struct gh_rm *rm)
> init_rwsem(&ghvm->status_lock);
> init_waitqueue_head(&ghvm->vm_status_wait);
> INIT_WORK(&ghvm->free_work, gh_vm_free);
> + kref_init(&ghvm->kref);
> + INIT_LIST_HEAD(&ghvm->functions);
> ghvm->vm_status = GH_RM_VM_STATUS_NO_STATE;
>
> return ghvm;
> @@ -254,6 +422,24 @@ static long gh_vm_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
> r = gh_vm_ensure_started(ghvm);
> break;
> }
> + case GH_VM_ADD_FUNCTION: {
> + struct gh_fn_desc f;
> +
> + if (copy_from_user(&f, argp, sizeof(f)))
> + return -EFAULT;
> +
> + r = gh_vm_add_function_instance(ghvm, &f);
> + break;
> + }
> + case GH_VM_REMOVE_FUNCTION: {
> + struct gh_fn_desc f;
> +
> + if (copy_from_user(&f, argp, sizeof(f)))
> + return -EFAULT;
> +
> + r = gh_vm_rm_function_instance(ghvm, &f);
> + break;
> + }
> default:
> r = -ENOTTY;
> break;
> @@ -270,6 +456,8 @@ static void gh_vm_free(struct work_struct *work)
> if (ghvm->vm_status == GH_RM_VM_STATUS_RUNNING)
> gh_vm_stop(ghvm);
>
> + gh_vm_remove_functions(ghvm);
> +
> if (ghvm->vm_status != GH_RM_VM_STATUS_NO_STATE &&
> ghvm->vm_status != GH_RM_VM_STATUS_LOAD &&
> ghvm->vm_status != GH_RM_VM_STATUS_RESET) {
> @@ -294,14 +482,33 @@ static void gh_vm_free(struct work_struct *work)
> kfree(ghvm);
> }
>
> -static int gh_vm_release(struct inode *inode, struct file *filp)
> +int __must_check gh_vm_get(struct gh_vm *ghvm)
> {
> - struct gh_vm *ghvm = filp->private_data;
> + return kref_get_unless_zero(&ghvm->kref);
> +}
> +EXPORT_SYMBOL_GPL(gh_vm_get);
> +
> +static void _gh_vm_put(struct kref *kref)
> +{
> + struct gh_vm *ghvm = container_of(kref, struct gh_vm, kref);
>
> /* VM will be reset and make RM calls which can interruptible sleep.
> * Defer to a work so this thread can receive signal.
> */
> schedule_work(&ghvm->free_work);
> +}
> +
> +void gh_vm_put(struct gh_vm *ghvm)
> +{
> + kref_put(&ghvm->kref, _gh_vm_put);
> +}
> +EXPORT_SYMBOL_GPL(gh_vm_put);
> +
> +static int gh_vm_release(struct inode *inode, struct file *filp)
> +{
> + struct gh_vm *ghvm = filp->private_data;
> +
> + gh_vm_put(ghvm);
> return 0;
> }
>
> @@ -346,7 +553,7 @@ static long gh_dev_ioctl_create_vm(struct gh_rm *rm, unsigned long arg)
> err_put_fd:
> put_unused_fd(fd);
> err_destroy_vm:
> - gh_vm_free(&ghvm->free_work);
> + gh_vm_put(ghvm);
> return err;
> }
>
> diff --git a/drivers/virt/gunyah/vm_mgr.h b/drivers/virt/gunyah/vm_mgr.h
> index 4173bd51f83fe..c4bec1469ae8c 100644
> --- a/drivers/virt/gunyah/vm_mgr.h
> +++ b/drivers/virt/gunyah/vm_mgr.h
> @@ -8,6 +8,7 @@
>
> #include <linux/gunyah_rsc_mgr.h>
> #include <linux/list.h>
> +#include <linux/kref.h>
> #include <linux/miscdevice.h>
> #include <linux/mutex.h>
> #include <linux/rwsem.h>
> @@ -45,9 +46,12 @@ struct gh_vm {
> struct rw_semaphore status_lock;
>
> struct work_struct free_work;
> + struct kref kref;
> struct mm_struct *mm; /* userspace tied to this vm */
> struct mutex mm_lock;
> struct list_head memory_mappings;
> + struct mutex fn_lock;
> + struct list_head functions;
> };
>
> int gh_vm_mem_alloc(struct gh_vm *ghvm, struct gh_userspace_memory_region *region);
> diff --git a/include/linux/gunyah_vm_mgr.h b/include/linux/gunyah_vm_mgr.h
> new file mode 100644
> index 0000000000000..6e4dd6fa5f96d
> --- /dev/null
> +++ b/include/linux/gunyah_vm_mgr.h
> @@ -0,0 +1,97 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#ifndef _GUNYAH_VM_MGR_H
> +#define _GUNYAH_VM_MGR_H
> +
> +#include <linux/compiler_types.h>
> +#include <linux/gunyah.h>
> +#include <linux/gunyah_rsc_mgr.h>
> +#include <linux/list.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/notifier.h>
> +
> +#include <uapi/linux/gunyah.h>
> +
> +struct gh_vm;
> +
> +int __must_check gh_vm_get(struct gh_vm *ghvm);
> +void gh_vm_put(struct gh_vm *ghvm);
> +
> +struct gh_vm_function_instance;
> +/**
> + * struct gh_vm_function - Represents a function type
> + * @type: value from &enum gh_fn_type
> + * @name: friendly name for debug purposes
> + * @mod: owner of the function type
> + * @bind: Called when a new function of this type has been allocated.
> + * @unbind: Called when the function instance is being destroyed.
> + * @compare: Compare function instance @f's argument to the provided arg.
> + * Return true if they are equivalent. Used on GH_VM_REMOVE_FUNCTION.
> + */
> +struct gh_vm_function {
> + u32 type;
> + const char *name;
> + struct module *mod;
> + long (*bind)(struct gh_vm_function_instance *f);
> + void (*unbind)(struct gh_vm_function_instance *f);
> + bool (*compare)(const struct gh_vm_function_instance *f, const void *arg, size_t size);
> +};
> +
> +/**
> + * struct gh_vm_function_instance - Represents one function instance
> + * @arg_size: size of user argument
> + * @argp: pointer to user argument
> + * @ghvm: Pointer to VM instance
> + * @rm: Pointer to resource manager for the VM instance
> + * @fn: The ops for the function
> + * @data: Private data for function
> + * @vm_list: for gh_vm's functions list
> + * @fn_list: for gh_vm_function's instances list
> + */
> +struct gh_vm_function_instance {
> + size_t arg_size;
> + void *argp;
> + struct gh_vm *ghvm;
> + struct gh_rm *rm;
> + struct gh_vm_function *fn;
> + void *data;
> + struct list_head vm_list;
> +};
> +
> +int gh_vm_function_register(struct gh_vm_function *f);
> +void gh_vm_function_unregister(struct gh_vm_function *f);
> +
> +/* Since the function identifiers were setup in a uapi header as an
> + * enum and we do no want to change that, the user must supply the expanded
> + * constant as well and the compiler checks they are the same.
> + * See also MODULE_ALIAS_RDMA_NETLINK.
> + */
> +#define MODULE_ALIAS_GH_VM_FUNCTION(_type, _idx) \
> + static inline void __maybe_unused __chk##_idx(void) \
> + { \
> + BUILD_BUG_ON(_type != _idx); \
> + } \
> + MODULE_ALIAS("ghfunc:" __stringify(_idx))
> +
> +#define DECLARE_GH_VM_FUNCTION(_name, _type, _bind, _unbind, _compare) \
> + static struct gh_vm_function _name = { \
> + .type = _type, \
> + .name = __stringify(_name), \
> + .mod = THIS_MODULE, \
> + .bind = _bind, \
> + .unbind = _unbind, \
> + .compare = _compare, \
> + }
> +
> +#define module_gh_vm_function(__gf) \
> + module_driver(__gf, gh_vm_function_register, gh_vm_function_unregister)
> +
> +#define DECLARE_GH_VM_FUNCTION_INIT(_name, _type, _idx, _bind, _unbind, _compare) \
> + DECLARE_GH_VM_FUNCTION(_name, _type, _bind, _unbind, _compare); \
> + module_gh_vm_function(_name); \
> + MODULE_ALIAS_GH_VM_FUNCTION(_type, _idx)
> +
> +#endif
> diff --git a/include/uapi/linux/gunyah.h b/include/uapi/linux/gunyah.h
> index 4b63d0b9b8ba7..bb07118a351fd 100644
> --- a/include/uapi/linux/gunyah.h
> +++ b/include/uapi/linux/gunyah.h
> @@ -72,4 +72,22 @@ struct gh_vm_dtb_config {
>
> #define GH_VM_START _IO(GH_IOCTL_TYPE, 0x3)
>
> +#define GH_FN_MAX_ARG_SIZE 256
> +
> +/**
> + * struct gh_fn_desc - Arguments to create a VM function
> + * @type: Type of the function. See &enum gh_fn_type.
> + * @arg_size: Size of argument to pass to the function. arg_size <= GH_FN_MAX_ARG_SIZE
> + * @arg: Pointer to argument given to the function. See &enum gh_fn_type for expected
> + * arguments for a function type.
> + */
> +struct gh_fn_desc {
> + __u32 type;
> + __u32 arg_size;
> + __u64 arg;
> +};
> +
> +#define GH_VM_ADD_FUNCTION _IOW(GH_IOCTL_TYPE, 0x4, struct gh_fn_desc)
> +#define GH_VM_REMOVE_FUNCTION _IOW(GH_IOCTL_TYPE, 0x7, struct gh_fn_desc)
> +
> #endif


2023-06-16 16:51:36

by Alex Elder

[permalink] [raw]
Subject: Re: [PATCH v14 23/25] virt: gunyah: Add irqfd interface

On 6/13/23 12:20 PM, Elliot Berman wrote:
> Enable support for creating irqfds which can raise an interrupt on a
> Gunyah virtual machine. irqfds are exposed to userspace as a Gunyah VM
> function with the name "irqfd". If the VM devicetree is not configured
> to create a doorbell with the corresponding label, userspace will still
> be able to assert the eventfd but no interrupt will be raised on the
> guest.
>
> Acked-by: Alex Elder <[email protected]>

I guess I don't mind upgrading this. It looks good to me.

Reviewed-by: Alex Elder <[email protected]>

> Co-developed-by: Prakruthi Deepak Heragu <[email protected]>
> Signed-off-by: Prakruthi Deepak Heragu <[email protected]>
> Signed-off-by: Elliot Berman <[email protected]>
> ---
> Documentation/virt/gunyah/vm-manager.rst | 2 +-
> drivers/virt/gunyah/Kconfig | 9 ++
> drivers/virt/gunyah/Makefile | 1 +
> drivers/virt/gunyah/gunyah_irqfd.c | 180 +++++++++++++++++++++++
> include/uapi/linux/gunyah.h | 35 +++++
> 5 files changed, 226 insertions(+), 1 deletion(-)
> create mode 100644 drivers/virt/gunyah/gunyah_irqfd.c
>
> diff --git a/Documentation/virt/gunyah/vm-manager.rst b/Documentation/virt/gunyah/vm-manager.rst
> index b0c3bde105ae9..57a254827be26 100644
> --- a/Documentation/virt/gunyah/vm-manager.rst
> +++ b/Documentation/virt/gunyah/vm-manager.rst
> @@ -116,7 +116,7 @@ the VM *before* the VM starts.
> The argument types are documented below:
>
> .. kernel-doc:: include/uapi/linux/gunyah.h
> - :identifiers: gh_fn_vcpu_arg
> + :identifiers: gh_fn_vcpu_arg gh_fn_irqfd_arg gh_irqfd_flags
>
> Gunyah VCPU API Descriptions
> ----------------------------
> diff --git a/drivers/virt/gunyah/Kconfig b/drivers/virt/gunyah/Kconfig
> index 0a58395f7d2c5..bc2c46d9df946 100644
> --- a/drivers/virt/gunyah/Kconfig
> +++ b/drivers/virt/gunyah/Kconfig
> @@ -39,3 +39,12 @@ config GUNYAH_VCPU
> VMMs can also handle stage 2 faults of the vCPUs.
>
> Say Y/M here if unsure and you want to support Gunyah VMMs.
> +
> +config GUNYAH_IRQFD
> + tristate "Gunyah irqfd interface"
> + depends on GUNYAH
> + help
> + Enable kernel support for creating irqfds which can raise an interrupt
> + on Gunyah virtual machine.
> +
> + Say Y/M here if unsure and you want to support Gunyah VMMs.
> diff --git a/drivers/virt/gunyah/Makefile b/drivers/virt/gunyah/Makefile
> index cc16b6c19db92..ad212a1cf9671 100644
> --- a/drivers/virt/gunyah/Makefile
> +++ b/drivers/virt/gunyah/Makefile
> @@ -7,3 +7,4 @@ gunyah-y += rsc_mgr.o rsc_mgr_rpc.o vm_mgr.o vm_mgr_mm.o
> obj-$(CONFIG_GUNYAH) += gunyah.o
>
> obj-$(CONFIG_GUNYAH_VCPU) += gunyah_vcpu.o
> +obj-$(CONFIG_GUNYAH_IRQFD) += gunyah_irqfd.o
> diff --git a/drivers/virt/gunyah/gunyah_irqfd.c b/drivers/virt/gunyah/gunyah_irqfd.c
> new file mode 100644
> index 0000000000000..3e954ebd20297
> --- /dev/null
> +++ b/drivers/virt/gunyah/gunyah_irqfd.c
> @@ -0,0 +1,180 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#include <linux/eventfd.h>
> +#include <linux/file.h>
> +#include <linux/fs.h>
> +#include <linux/gunyah.h>
> +#include <linux/gunyah_vm_mgr.h>
> +#include <linux/module.h>
> +#include <linux/poll.h>
> +#include <linux/printk.h>
> +
> +#include <uapi/linux/gunyah.h>
> +
> +struct gh_irqfd {
> + struct gh_resource *ghrsc;
> + struct gh_vm_resource_ticket ticket;
> + struct gh_vm_function_instance *f;
> +
> + bool level;
> +
> + struct eventfd_ctx *ctx;
> + wait_queue_entry_t wait;
> + poll_table pt;
> +};
> +
> +static int irqfd_wakeup(wait_queue_entry_t *wait, unsigned int mode, int sync, void *key)
> +{
> + struct gh_irqfd *irqfd = container_of(wait, struct gh_irqfd, wait);
> + __poll_t flags = key_to_poll(key);
> + int ret = 0;
> +
> + if (flags & EPOLLIN) {
> + if (irqfd->ghrsc) {
> + ret = gh_hypercall_bell_send(irqfd->ghrsc->capid, 1, NULL);
> + if (ret)
> + pr_err_ratelimited("Failed to inject interrupt %d: %d\n",
> + irqfd->ticket.label, ret);
> + } else
> + pr_err_ratelimited("Premature injection of interrupt\n");
> + }
> +
> + return 0;
> +}
> +
> +static void irqfd_ptable_queue_proc(struct file *file, wait_queue_head_t *wqh, poll_table *pt)
> +{
> + struct gh_irqfd *irq_ctx = container_of(pt, struct gh_irqfd, pt);
> +
> + add_wait_queue(wqh, &irq_ctx->wait);
> +}
> +
> +static bool gh_irqfd_populate(struct gh_vm_resource_ticket *ticket, struct gh_resource *ghrsc)
> +{
> + struct gh_irqfd *irqfd = container_of(ticket, struct gh_irqfd, ticket);
> + int ret;
> +
> + if (irqfd->ghrsc) {
> + pr_warn("irqfd%d already got a Gunyah resource. Check if multiple resources with same label were configured.\n",
> + irqfd->ticket.label);
> + return false;
> + }
> +
> + irqfd->ghrsc = ghrsc;
> + if (irqfd->level) {
> + /* Configure the bell to trigger when bit 0 is asserted (see
> + * irq_wakeup) and for bell to automatically clear bit 0 once
> + * received by the VM (ack_mask). need to make sure bit 0 is cleared right away,
> + * otherwise the line will never be deasserted. Emulating edge
> + * trigger interrupt does not need to set either mask
> + * because irq is listed only once per gh_hypercall_bell_send
> + */
> + ret = gh_hypercall_bell_set_mask(irqfd->ghrsc->capid, 1, 1);
> + if (ret)
> + pr_warn("irq %d couldn't be set as level triggered. Might cause IRQ storm if asserted\n",
> + irqfd->ticket.label);
> + }
> +
> + return true;
> +}
> +
> +static void gh_irqfd_unpopulate(struct gh_vm_resource_ticket *ticket, struct gh_resource *ghrsc)
> +{
> + struct gh_irqfd *irqfd = container_of(ticket, struct gh_irqfd, ticket);
> + u64 cnt;
> +
> + eventfd_ctx_remove_wait_queue(irqfd->ctx, &irqfd->wait, &cnt);
> +}
> +
> +static long gh_irqfd_bind(struct gh_vm_function_instance *f)
> +{
> + struct gh_fn_irqfd_arg *args = f->argp;
> + struct gh_irqfd *irqfd;
> + __poll_t events;
> + struct fd fd;
> + long r;
> +
> + if (f->arg_size != sizeof(*args))
> + return -EINVAL;
> +
> + /* All other flag bits are reserved for future use */
> + if (args->flags & ~GH_IRQFD_FLAGS_LEVEL)
> + return -EINVAL;
> +
> + irqfd = kzalloc(sizeof(*irqfd), GFP_KERNEL);
> + if (!irqfd)
> + return -ENOMEM;
> +
> + irqfd->f = f;
> + f->data = irqfd;
> +
> + fd = fdget(args->fd);
> + if (!fd.file) {
> + kfree(irqfd);
> + return -EBADF;
> + }
> +
> + irqfd->ctx = eventfd_ctx_fileget(fd.file);
> + if (IS_ERR(irqfd->ctx)) {
> + r = PTR_ERR(irqfd->ctx);
> + goto err_fdput;
> + }
> +
> + if (args->flags & GH_IRQFD_FLAGS_LEVEL)
> + irqfd->level = true;
> +
> + init_waitqueue_func_entry(&irqfd->wait, irqfd_wakeup);
> + init_poll_funcptr(&irqfd->pt, irqfd_ptable_queue_proc);
> +
> + irqfd->ticket.resource_type = GH_RESOURCE_TYPE_BELL_TX;
> + irqfd->ticket.label = args->label;
> + irqfd->ticket.owner = THIS_MODULE;
> + irqfd->ticket.populate = gh_irqfd_populate;
> + irqfd->ticket.unpopulate = gh_irqfd_unpopulate;
> +
> + r = gh_vm_add_resource_ticket(f->ghvm, &irqfd->ticket);
> + if (r)
> + goto err_ctx;
> +
> + events = vfs_poll(fd.file, &irqfd->pt);
> + if (events & EPOLLIN)
> + pr_warn("Premature injection of interrupt\n");
> + fdput(fd);
> +
> + return 0;
> +err_ctx:
> + eventfd_ctx_put(irqfd->ctx);
> +err_fdput:
> + fdput(fd);
> + kfree(irqfd);
> + return r;
> +}
> +
> +static void gh_irqfd_unbind(struct gh_vm_function_instance *f)
> +{
> + struct gh_irqfd *irqfd = f->data;
> +
> + gh_vm_remove_resource_ticket(irqfd->f->ghvm, &irqfd->ticket);
> + eventfd_ctx_put(irqfd->ctx);
> + kfree(irqfd);
> +}
> +
> +static bool gh_irqfd_compare(const struct gh_vm_function_instance *f,
> + const void *arg, size_t size)
> +{
> + const struct gh_fn_irqfd_arg *instance = f->argp,
> + *other = arg;
> +
> + if (sizeof(*other) != size)
> + return false;
> +
> + return instance->label == other->label;
> +}
> +
> +DECLARE_GH_VM_FUNCTION_INIT(irqfd, GH_FN_IRQFD, 2, gh_irqfd_bind, gh_irqfd_unbind,
> + gh_irqfd_compare);
> +MODULE_DESCRIPTION("Gunyah irqfd VM Function");
> +MODULE_LICENSE("GPL");
> diff --git a/include/uapi/linux/gunyah.h b/include/uapi/linux/gunyah.h
> index 434ffa8ffc783..0c480c622686a 100644
> --- a/include/uapi/linux/gunyah.h
> +++ b/include/uapi/linux/gunyah.h
> @@ -77,9 +77,12 @@ struct gh_vm_dtb_config {
> * @GH_FN_VCPU: create a vCPU instance to control a vCPU
> * &struct gh_fn_desc.arg is a pointer to &struct gh_fn_vcpu_arg
> * Return: file descriptor to manipulate the vcpu.
> + * @GH_FN_IRQFD: register eventfd to assert a Gunyah doorbell
> + * &struct gh_fn_desc.arg is a pointer to &struct gh_fn_irqfd_arg
> */
> enum gh_fn_type {
> GH_FN_VCPU = 1,
> + GH_FN_IRQFD,
> };
>
> #define GH_FN_MAX_ARG_SIZE 256
> @@ -99,6 +102,38 @@ struct gh_fn_vcpu_arg {
> __u32 id;
> };
>
> +/**
> + * enum gh_irqfd_flags - flags for use in gh_fn_irqfd_arg
> + * @GH_IRQFD_FLAGS_LEVEL: make the interrupt operate like a level triggered
> + * interrupt on guest side. Triggering IRQFD before
> + * guest handles the interrupt causes interrupt to
> + * stay asserted.
> + */
> +enum gh_irqfd_flags {
> + GH_IRQFD_FLAGS_LEVEL = 1UL << 0,
> +};
> +
> +/**
> + * struct gh_fn_irqfd_arg - Arguments to create an irqfd function.
> + *
> + * Create this function with &GH_VM_ADD_FUNCTION using type &GH_FN_IRQFD.
> + *
> + * Allows setting an eventfd to directly trigger a guest interrupt.
> + * irqfd.fd specifies the file descriptor to use as the eventfd.
> + * irqfd.label corresponds to the doorbell label used in the guest VM's devicetree.
> + *
> + * @fd: an eventfd which when written to will raise a doorbell
> + * @label: Label of the doorbell created on the guest VM
> + * @flags: see &enum gh_irqfd_flags
> + * @padding: padding bytes
> + */
> +struct gh_fn_irqfd_arg {
> + __u32 fd;
> + __u32 label;
> + __u32 flags;
> + __u32 padding;
> +};
> +
> /**
> * struct gh_fn_desc - Arguments to create a VM function
> * @type: Type of the function. See &enum gh_fn_type.


2023-06-16 17:02:14

by Alex Elder

[permalink] [raw]
Subject: Re: [PATCH v14 00/25] Drivers for Gunyah hypervisor

On 6/13/23 12:20 PM, Elliot Berman wrote:
> Gunyah is a Type-1 hypervisor independent of any
> high-level OS kernel, and runs in a higher CPU privilege level. It does
> not depend on any lower-privileged OS kernel/code for its core
> functionality. This increases its security and can support a much smaller
> trusted computing base than a Type-2 hypervisor.

I believe I have marked "Reviewed-by" on this entire series
now. If I'm mistaken about that, or if you make a change
that you think warrants me taking another look, please call
that to my attention.

Thanks for being very responsive to my review comments. My
greatest hope is that we've prevented some bugs from getting
accepted, but I also hope you have found my feedback helpful.

-Alex

> Gunyah is an open source hypervisor. The source repo is available at
> https://github.com/quic/gunyah-hypervisor.
>
> The diagram below shows the architecture.
>
> ::
>
> VM A VM B
> +-----+ +-----+ | +-----+ +-----+ +-----+
> | | | | | | | | | | |
> EL0 | APP | | APP | | | APP | | APP | | APP |
> | | | | | | | | | | |
> +-----+ +-----+ | +-----+ +-----+ +-----+
> ---------------------|-------------------------
> +--------------+ | +----------------------+
> | | | | |
> EL1 | Linux Kernel | | |Linux kernel/Other OS | ...
> | | | | |
> +--------------+ | +----------------------+
> --------hvc/smc------|------hvc/smc------------
> +----------------------------------------+
> | |
> EL2 | Gunyah Hypervisor |
> | |
> +----------------------------------------+
>
> Gunyah provides these following features.
>
> - Threads and Scheduling: The scheduler schedules virtual CPUs (VCPUs) on
> physical CPUs and enables time-sharing of the CPUs.
> - Memory Management: Gunyah tracks memory ownership and use of all memory
> under its control. Memory partitioning between VMs is a fundamental
> security feature.
> - Interrupt Virtualization: All interrupts are handled in the hypervisor
> and routed to the assigned VM.
> - Inter-VM Communication: There are several different mechanisms provided
> for communicating between VMs.
> - Device Virtualization: Para-virtualization of devices is supported using
> inter-VM communication. Low level system features and devices such as
> interrupt controllers are supported with emulation where required.
>
> This series adds the basic framework for detecting that Linux is running
> under Gunyah as a virtual machine, communication with the Gunyah Resource
> Manager, and a sample virtual machine manager capable of launching virtual machines.
>
> The series relies on two other patches posted separately:
> - https://lore.kernel.org/all/[email protected]/
> - https://lore.kernel.org/all/[email protected]/
>
>
> Changes in v14:
> - Coding/cosmetic tweaks suggested by Alex
> - Mark IRQs as wake-up capable
>
> Changes in v13: https://lore.kernel.org/all/[email protected]/
> - Tweaks to message queue driver to address race condition between IRQ and mailbox registration
> - Allow removal of VM functions by function-specific comparison -- specifically to allow
> removing irqfd by label only and not requiring original FD to be provided.
>
> Changes in v12: https://lore.kernel.org/all/[email protected]/
> - Stylistic/cosmetic tweaks suggested by Alex
> - Remove patch "virt: gunyah: Identify hypervisor version" and squash the
> check that we're running under a reasonable Gunyah hypervisor into RM driver
> - Refactor platform hooks into a separate module per suggestion from Srini
> - GFP_KERNEL_ACCOUNT and account_locked_vm() for page pinning
> - enum-ify related constants
>
> Changes in v11: https://lore.kernel.org/all/[email protected]/
> - Rename struct gh_vm_dtb_config:gpa -> guest_phys_addr & overflow checks for this
> - More docstrings throughout
> - Make resp_buf and resp_buf_size optional
> - Replace deprecated idr with xarray
> - Refconting on misc device instead of RM's platform device
> - Renaming variables, structs, etc. from gunyah_ -> gh_
> - Drop removal of user mem regions
> - Drop mem_lend functionality; to converge with restricted_memfd later
>
> Changes in v10: https://lore.kernel.org/all/[email protected]/
> - Fix bisectability (end result of series is same, --fixups applied to wrong commits)
> - Convert GH_ERROR_* and GH_RM_ERROR_* to enums
> - Correct race condition between allocating/freeing user memory
> - Replace offsetof with struct_size
> - Series-wide renaming of functions to be more consistent
> - VM shutdown & restart support added in vCPU and VM Manager patches
> - Convert VM function name (string) to type (number)
> - Convert VM function argument to value (which could be a pointer) to remove memory wastage for arguments
> - Remove defensive checks of hypervisor correctness
> - Clean ups to ioeventfd as suggested by Srivatsa
>
> Changes in v9: https://lore.kernel.org/all/[email protected]/
> - Refactor Gunyah API flags to be exposed as feature flags at kernel level
> - Move mbox client cleanup into gunyah_msgq_remove()
> - Simplify gh_rm_call return value and response payload
> - Missing clean-up/error handling/little endian fixes as suggested by Srivatsa and Alex in v8 series
>
> Changes in v8: https://lore.kernel.org/all/[email protected]/
> - Treat VM manager as a library of RM
> - Add patches 21-28 as RFC to support proxy-scheduled vCPUs and necessary bits to support virtio
> from Gunyah userspace
>
> Changes in v7: https://lore.kernel.org/all/[email protected]/
> - Refactor to remove gunyah RM bus
> - Refactor allow multiple RM device instances
> - Bump UAPI to start at 0x0
> - Refactor QCOM SCM's platform hooks to allow CONFIG_QCOM_SCM=Y/CONFIG_GUNYAH=M combinations
>
> Changes in v6: https://lore.kernel.org/all/[email protected]/
> - *Replace gunyah-console with gunyah VM Manager*
> - Move include/asm-generic/gunyah.h into include/linux/gunyah.h
> - s/gunyah_msgq/gh_msgq/
> - Minor tweaks and documentation tidying based on comments from Jiri, Greg, Arnd, Dmitry, and Bagas.
>
> Changes in v5: https://lore.kernel.org/all/[email protected]/
> - Dropped sysfs nodes
> - Switch from aux bus to Gunyah RM bus for the subdevices
> - Cleaning up RM console
>
> Changes in v4: https://lore.kernel.org/all/[email protected]/
> - Tidied up documentation throughout based on questions/feedback received
> - Switched message queue implementation to use mailboxes
> - Renamed "gunyah_device" as "gunyah_resource"
>
> Changes in v3: https://lore.kernel.org/all/[email protected]/
> - /Maintained/Supported/ in MAINTAINERS
> - Tidied up documentation throughout based on questions/feedback received
> - Moved hypercalls into arch/arm64/gunyah/; following hyper-v's implementation
> - Drop opaque typedefs
> - Move sysfs nodes under /sys/hypervisor/gunyah/
> - Moved Gunyah console driver to drivers/tty/
> - Reworked gh_device design to drop the Gunyah bus.
>
> Changes in v2: https://lore.kernel.org/all/[email protected]/
> - DT bindings clean up
> - Switch hypercalls to follow SMCCC
>
> v1: https://lore.kernel.org/all/[email protected]/
>
> Elliot Berman (25):
> docs: gunyah: Introduce Gunyah Hypervisor
> dt-bindings: Add binding for gunyah hypervisor
> gunyah: Common types and error codes for Gunyah hypercalls
> virt: gunyah: Add hypercalls to identify Gunyah
> virt: gunyah: msgq: Add hypercalls to send and receive messages
> mailbox: Add Gunyah message queue mailbox
> gunyah: rsc_mgr: Add resource manager RPC core
> gunyah: rsc_mgr: Add VM lifecycle RPC
> gunyah: vm_mgr: Introduce basic VM Manager
> gunyah: rsc_mgr: Add RPC for sharing memory
> gunyah: vm_mgr: Add/remove user memory regions
> gunyah: vm_mgr: Add ioctls to support basic non-proxy VM boot
> samples: Add sample userspace Gunyah VM Manager
> gunyah: rsc_mgr: Add platform ops on mem_lend/mem_reclaim
> virt: gunyah: Add Qualcomm Gunyah platform ops
> docs: gunyah: Document Gunyah VM Manager
> virt: gunyah: Translate gh_rm_hyp_resource into gunyah_resource
> gunyah: vm_mgr: Add framework for VM Functions
> virt: gunyah: Add resource tickets
> virt: gunyah: Add IO handlers
> virt: gunyah: Add proxy-scheduled vCPUs
> virt: gunyah: Add hypercalls for sending doorbell
> virt: gunyah: Add irqfd interface
> virt: gunyah: Add ioeventfd
> MAINTAINERS: Add Gunyah hypervisor drivers section
>
> .../bindings/firmware/gunyah-hypervisor.yaml | 82 ++
> .../userspace-api/ioctl/ioctl-number.rst | 1 +
> Documentation/virt/gunyah/index.rst | 114 +++
> Documentation/virt/gunyah/message-queue.rst | 71 ++
> Documentation/virt/gunyah/vm-manager.rst | 143 +++
> Documentation/virt/index.rst | 1 +
> MAINTAINERS | 13 +
> arch/arm64/Kbuild | 1 +
> arch/arm64/gunyah/Makefile | 3 +
> arch/arm64/gunyah/gunyah_hypercall.c | 142 +++
> arch/arm64/include/asm/gunyah.h | 24 +
> drivers/mailbox/Makefile | 2 +
> drivers/mailbox/gunyah-msgq.c | 219 +++++
> drivers/virt/Kconfig | 2 +
> drivers/virt/Makefile | 1 +
> drivers/virt/gunyah/Kconfig | 59 ++
> drivers/virt/gunyah/Makefile | 11 +
> drivers/virt/gunyah/gunyah_ioeventfd.c | 130 +++
> drivers/virt/gunyah/gunyah_irqfd.c | 180 ++++
> drivers/virt/gunyah/gunyah_platform_hooks.c | 80 ++
> drivers/virt/gunyah/gunyah_qcom.c | 153 +++
> drivers/virt/gunyah/gunyah_vcpu.c | 470 +++++++++
> drivers/virt/gunyah/rsc_mgr.c | 909 ++++++++++++++++++
> drivers/virt/gunyah/rsc_mgr.h | 19 +
> drivers/virt/gunyah/rsc_mgr_rpc.c | 500 ++++++++++
> drivers/virt/gunyah/vm_mgr.c | 791 +++++++++++++++
> drivers/virt/gunyah/vm_mgr.h | 70 ++
> drivers/virt/gunyah/vm_mgr_mm.c | 252 +++++
> include/linux/gunyah.h | 207 ++++
> include/linux/gunyah_rsc_mgr.h | 162 ++++
> include/linux/gunyah_vm_mgr.h | 153 +++
> include/uapi/linux/gunyah.h | 293 ++++++
> samples/Kconfig | 10 +
> samples/Makefile | 1 +
> samples/gunyah/.gitignore | 2 +
> samples/gunyah/Makefile | 6 +
> samples/gunyah/gunyah_vmm.c | 266 +++++
> samples/gunyah/sample_vm.dts | 68 ++
> 38 files changed, 5611 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/firmware/gunyah-hypervisor.yaml
> create mode 100644 Documentation/virt/gunyah/index.rst
> create mode 100644 Documentation/virt/gunyah/message-queue.rst
> create mode 100644 Documentation/virt/gunyah/vm-manager.rst
> create mode 100644 arch/arm64/gunyah/Makefile
> create mode 100644 arch/arm64/gunyah/gunyah_hypercall.c
> create mode 100644 arch/arm64/include/asm/gunyah.h
> create mode 100644 drivers/mailbox/gunyah-msgq.c
> create mode 100644 drivers/virt/gunyah/Kconfig
> create mode 100644 drivers/virt/gunyah/Makefile
> create mode 100644 drivers/virt/gunyah/gunyah_ioeventfd.c
> create mode 100644 drivers/virt/gunyah/gunyah_irqfd.c
> create mode 100644 drivers/virt/gunyah/gunyah_platform_hooks.c
> create mode 100644 drivers/virt/gunyah/gunyah_qcom.c
> create mode 100644 drivers/virt/gunyah/gunyah_vcpu.c
> create mode 100644 drivers/virt/gunyah/rsc_mgr.c
> create mode 100644 drivers/virt/gunyah/rsc_mgr.h
> create mode 100644 drivers/virt/gunyah/rsc_mgr_rpc.c
> create mode 100644 drivers/virt/gunyah/vm_mgr.c
> create mode 100644 drivers/virt/gunyah/vm_mgr.h
> create mode 100644 drivers/virt/gunyah/vm_mgr_mm.c
> create mode 100644 include/linux/gunyah.h
> create mode 100644 include/linux/gunyah_rsc_mgr.h
> create mode 100644 include/linux/gunyah_vm_mgr.h
> create mode 100644 include/uapi/linux/gunyah.h
> create mode 100644 samples/gunyah/.gitignore
> create mode 100644 samples/gunyah/Makefile
> create mode 100644 samples/gunyah/gunyah_vmm.c
> create mode 100644 samples/gunyah/sample_vm.dts
>
>
> base-commit: 858fd168a95c5b9669aac8db6c14a9aeab446375


2023-08-05 04:08:25

by Bjorn Andersson

[permalink] [raw]
Subject: Re: [PATCH v14 03/25] gunyah: Common types and error codes for Gunyah hypercalls

On Tue, Jun 13, 2023 at 10:20:31AM -0700, Elliot Berman wrote:
> diff --git a/include/linux/gunyah.h b/include/linux/gunyah.h
[..]
> +/******************************************************************************/
> +/* Common arch-independent definitions for Gunyah hypercalls */
> +#define GH_CAPID_INVAL U64_MAX
> +#define GH_VMID_ROOT_VM 0xff
> +
> +enum gh_error {

"gh_" happens to be an unused prefix in the Linux kernel, but I find it
to be an unnatural abbreviation of "gunyah".

I would therefor prefer to have it expanded to "gunyah" for all
functions, macros and data types throughout the implementation.

Regards,
Bjorn

2023-08-05 06:11:36

by Bjorn Andersson

[permalink] [raw]
Subject: Re: [PATCH v14 07/25] gunyah: rsc_mgr: Add resource manager RPC core

On Tue, Jun 13, 2023 at 10:20:35AM -0700, Elliot Berman wrote:
> The resource manager is a special virtual machine which is always
> running on a Gunyah system. It provides APIs for creating and destroying
> VMs, secure memory management, sharing/lending of memory between VMs,
> and setup of inter-VM communication. Calls to the resource manager are
> made via message queues.
>
> This patch implements the basic probing and RPC mechanism to make those
> API calls. Request/response calls can be made with gh_rm_call.
> Drivers can also register to notifications pushed by RM via
> gh_rm_register_notifier
>
> Specific API calls that resource manager supports will be implemented in
> subsequent patches.
>
> Reviewed-by: Alex Elder <[email protected]>
> Reviewed-by: Srinivas Kandagatla <[email protected]>
> Signed-off-by: Elliot Berman <[email protected]>
> ---
> drivers/virt/Makefile | 1 +
> drivers/virt/gunyah/Makefile | 4 +
> drivers/virt/gunyah/rsc_mgr.c | 700 +++++++++++++++++++++++++++++++++
> drivers/virt/gunyah/rsc_mgr.h | 16 +
> include/linux/gunyah_rsc_mgr.h | 21 +
> 5 files changed, 742 insertions(+)
> create mode 100644 drivers/virt/gunyah/Makefile
> create mode 100644 drivers/virt/gunyah/rsc_mgr.c
> create mode 100644 drivers/virt/gunyah/rsc_mgr.h
> create mode 100644 include/linux/gunyah_rsc_mgr.h
>
> diff --git a/drivers/virt/Makefile b/drivers/virt/Makefile
> index e9aa6fc96fab7..a5817e2d7d718 100644
> --- a/drivers/virt/Makefile
> +++ b/drivers/virt/Makefile
> @@ -12,3 +12,4 @@ obj-$(CONFIG_ACRN_HSM) += acrn/
> obj-$(CONFIG_EFI_SECRET) += coco/efi_secret/
> obj-$(CONFIG_SEV_GUEST) += coco/sev-guest/
> obj-$(CONFIG_INTEL_TDX_GUEST) += coco/tdx-guest/
> +obj-y += gunyah/
> diff --git a/drivers/virt/gunyah/Makefile b/drivers/virt/gunyah/Makefile
> new file mode 100644
> index 0000000000000..0f5aec8346988
> --- /dev/null
> +++ b/drivers/virt/gunyah/Makefile
> @@ -0,0 +1,4 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +gunyah-y += rsc_mgr.o
> +obj-$(CONFIG_GUNYAH) += gunyah.o
> diff --git a/drivers/virt/gunyah/rsc_mgr.c b/drivers/virt/gunyah/rsc_mgr.c
> new file mode 100644
> index 0000000000000..04c8e131d259f
> --- /dev/null
> +++ b/drivers/virt/gunyah/rsc_mgr.c
> @@ -0,0 +1,700 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#include <linux/of.h>
> +#include <linux/slab.h>
> +#include <linux/mutex.h>
> +#include <linux/sched.h>
> +#include <linux/gunyah.h>
> +#include <linux/module.h>
> +#include <linux/of_irq.h>
> +#include <linux/notifier.h>
> +#include <linux/workqueue.h>
> +#include <linux/completion.h>
> +#include <linux/gunyah_rsc_mgr.h>
> +#include <linux/platform_device.h>
> +
> +#include "rsc_mgr.h"
> +
> +#define RM_RPC_API_VERSION_MASK GENMASK(3, 0)
> +#define RM_RPC_HEADER_WORDS_MASK GENMASK(7, 4)
> +#define RM_RPC_API_VERSION FIELD_PREP(RM_RPC_API_VERSION_MASK, 1)
> +#define RM_RPC_HEADER_WORDS FIELD_PREP(RM_RPC_HEADER_WORDS_MASK, \
> + (sizeof(struct gh_rm_rpc_hdr) / sizeof(u32)))
> +#define RM_RPC_API (RM_RPC_API_VERSION | RM_RPC_HEADER_WORDS)
> +
> +#define RM_RPC_TYPE_CONTINUATION 0x0
> +#define RM_RPC_TYPE_REQUEST 0x1
> +#define RM_RPC_TYPE_REPLY 0x2
> +#define RM_RPC_TYPE_NOTIF 0x3
> +#define RM_RPC_TYPE_MASK GENMASK(1, 0)
> +
> +#define GH_RM_MAX_NUM_FRAGMENTS 62
> +#define RM_RPC_FRAGMENTS_MASK GENMASK(7, 2)
> +
> +struct gh_rm_rpc_hdr {
> + u8 api;
> + u8 type;
> + __le16 seq;
> + __le32 msg_id;
> +} __packed;
> +
> +struct gh_rm_rpc_reply_hdr {
> + struct gh_rm_rpc_hdr hdr;
> + __le32 err_code; /* GH_RM_ERROR_* */
> +} __packed;
> +
> +#define GH_RM_MAX_MSG_SIZE (GH_MSGQ_MAX_MSG_SIZE - sizeof(struct gh_rm_rpc_hdr))
> +
> +/* RM Error codes */
> +enum gh_rm_error {
> + GH_RM_ERROR_OK = 0x0,
> + GH_RM_ERROR_UNIMPLEMENTED = 0xFFFFFFFF,
> + GH_RM_ERROR_NOMEM = 0x1,
> + GH_RM_ERROR_NORESOURCE = 0x2,
> + GH_RM_ERROR_DENIED = 0x3,
> + GH_RM_ERROR_INVALID = 0x4,
> + GH_RM_ERROR_BUSY = 0x5,
> + GH_RM_ERROR_ARGUMENT_INVALID = 0x6,
> + GH_RM_ERROR_HANDLE_INVALID = 0x7,
> + GH_RM_ERROR_VALIDATE_FAILED = 0x8,
> + GH_RM_ERROR_MAP_FAILED = 0x9,
> + GH_RM_ERROR_MEM_INVALID = 0xA,
> + GH_RM_ERROR_MEM_INUSE = 0xB,
> + GH_RM_ERROR_MEM_RELEASED = 0xC,
> + GH_RM_ERROR_VMID_INVALID = 0xD,
> + GH_RM_ERROR_LOOKUP_FAILED = 0xE,
> + GH_RM_ERROR_IRQ_INVALID = 0xF,
> + GH_RM_ERROR_IRQ_INUSE = 0x10,
> + GH_RM_ERROR_IRQ_RELEASED = 0x11,
> +};
> +
> +/**
> + * struct gh_rm_connection - Represents a complete message from resource manager
> + * @payload: Combined payload of all the fragments (msg headers stripped off).
> + * @size: Size of the payload received so far.
> + * @msg_id: Message ID from the header.
> + * @type: RM_RPC_TYPE_REPLY or RM_RPC_TYPE_NOTIF.
> + * @num_fragments: total number of fragments expected to be received.
> + * @fragments_received: fragments received so far.
> + * @reply: Fields used for request/reply sequences
> + * @notification: Fields used for notifiations
> + */
> +struct gh_rm_connection {

Is there a good reason why this is called a connection, when it's
actually a message (specifically a response or notification)?

> + void *payload;
> + size_t size;
> + __le32 msg_id;

Everything else in this struct is native endian, I don't think you loose
much from keeping this native and moving your
cpu_to_le32()/le32_to_cpu() calls around the implementation.

> + u8 type;
> +
> + u8 num_fragments;
> + u8 fragments_received;
> +
> + union {
> + /**
> + * @ret: Linux return code, there was an error processing connection
> + * @seq: Sequence ID for the main message.
> + * @rm_error: For request/reply sequences with standard replies
> + * @seq_done: Signals caller that the RM reply has been received
> + */
> + struct {
> + int ret;
> + u16 seq;
> + enum gh_rm_error rm_error;
> + struct completion seq_done;
> + } reply;
> +
> + /**
> + * @rm: Pointer to the RM that launched the connection
> + * @work: Triggered when all fragments of a notification received
> + */
> + struct {
> + struct gh_rm *rm;
> + struct work_struct work;
> + } notification;
> + };
> +};
> +
> +/**
> + * struct gh_rm - private data for communicating w/Gunyah resource manager
> + * @dev: pointer to RM platform device
> + * @tx_ghrsc: message queue resource to TX to RM
> + * @rx_ghrsc: message queue resource to RX from RM
> + * @msgq: mailbox instance of TX/RX resources above
> + * @msgq_client: mailbox client of above msgq
> + * @active_rx_connection: ongoing gh_rm_connection for which we're receiving fragments
> + * @last_tx_ret: return value of last mailbox tx
> + * @call_xarray: xarray to allocate & lookup sequence IDs for Request/Response flows
> + * @next_seq: next ID to allocate (for xa_alloc_cyclic)
> + * @cache: cache for allocating Tx messages
> + * @send_lock: synchronization to allow only one request to be sent at a time
> + * @nh: notifier chain for clients interested in RM notification messages
> + */
> +struct gh_rm {
> + struct device *dev;
> + struct gh_resource tx_ghrsc;
> + struct gh_resource rx_ghrsc;
> + struct gh_msgq msgq;
> + struct mbox_client msgq_client;
> + struct gh_rm_connection *active_rx_connection;
> + int last_tx_ret;
> +
> + struct xarray call_xarray;
> + u32 next_seq;
> +
> + struct kmem_cache *cache;
> + struct mutex send_lock;
> + struct blocking_notifier_head nh;
> +};
> +
> +/**
> + * gh_rm_error_remap() - Remap Gunyah resource manager errors into a Linux error code
> + * @rm_error: "Standard" return value from Gunyah resource manager
> + */
> +static inline int gh_rm_error_remap(enum gh_rm_error rm_error)
> +{
> + switch (rm_error) {
> + case GH_RM_ERROR_OK:
> + return 0;
> + case GH_RM_ERROR_UNIMPLEMENTED:
> + return -EOPNOTSUPP;
> + case GH_RM_ERROR_NOMEM:
> + return -ENOMEM;
> + case GH_RM_ERROR_NORESOURCE:
> + return -ENODEV;
> + case GH_RM_ERROR_DENIED:
> + return -EPERM;
> + case GH_RM_ERROR_BUSY:
> + return -EBUSY;
> + case GH_RM_ERROR_INVALID:
> + case GH_RM_ERROR_ARGUMENT_INVALID:
> + case GH_RM_ERROR_HANDLE_INVALID:
> + case GH_RM_ERROR_VALIDATE_FAILED:
> + case GH_RM_ERROR_MAP_FAILED:
> + case GH_RM_ERROR_MEM_INVALID:
> + case GH_RM_ERROR_MEM_INUSE:
> + case GH_RM_ERROR_MEM_RELEASED:
> + case GH_RM_ERROR_VMID_INVALID:
> + case GH_RM_ERROR_LOOKUP_FAILED:
> + case GH_RM_ERROR_IRQ_INVALID:
> + case GH_RM_ERROR_IRQ_INUSE:
> + case GH_RM_ERROR_IRQ_RELEASED:
> + return -EINVAL;
> + default:
> + return -EBADMSG;
> + }
> +}
> +
> +static int gh_rm_init_connection_payload(struct gh_rm_connection *connection, void *msg,
> + size_t hdr_size, size_t msg_size)
> +{
> + size_t max_buf_size, payload_size;
> + struct gh_rm_rpc_hdr *hdr = msg;
> +
> + if (msg_size < hdr_size)
> + return -EINVAL;
> +
> + payload_size = msg_size - hdr_size;
> +
> + connection->num_fragments = FIELD_GET(RM_RPC_FRAGMENTS_MASK, hdr->type);
> + connection->fragments_received = 0;
> +
> + /* There's not going to be any payload, no need to allocate buffer. */
> + if (!payload_size && !connection->num_fragments)
> + return 0;
> +
> + if (connection->num_fragments > GH_RM_MAX_NUM_FRAGMENTS)
> + return -EINVAL;
> +
> + max_buf_size = payload_size + (connection->num_fragments * GH_RM_MAX_MSG_SIZE);
> +
> + connection->payload = kzalloc(max_buf_size, GFP_KERNEL);
> + if (!connection->payload)
> + return -ENOMEM;
> +
> + memcpy(connection->payload, msg + hdr_size, payload_size);
> + connection->size = payload_size;
> + return 0;
> +}
> +
> +static void gh_rm_abort_connection(struct gh_rm *rm)
> +{
> + switch (rm->active_rx_connection->type) {
> + case RM_RPC_TYPE_REPLY:
> + rm->active_rx_connection->reply.ret = -EIO;
> + complete(&rm->active_rx_connection->reply.seq_done);
> + break;
> + case RM_RPC_TYPE_NOTIF:
> + fallthrough;

Don't you need to cancel the work here as well?

> + default:
> + kfree(rm->active_rx_connection->payload);
> + kfree(rm->active_rx_connection);
> + }
> +
> + rm->active_rx_connection = NULL;
> +}
> +
> +static void gh_rm_notif_work(struct work_struct *work)
> +{
> + struct gh_rm_connection *connection = container_of(work, struct gh_rm_connection,
> + notification.work);
> + struct gh_rm *rm = connection->notification.rm;
> +
> + blocking_notifier_call_chain(&rm->nh, le32_to_cpu(connection->msg_id), connection->payload);
> +
> + put_device(rm->dev);
> + kfree(connection->payload);
> + kfree(connection);
> +}
> +
> +static void gh_rm_process_notif(struct gh_rm *rm, void *msg, size_t msg_size)
> +{
> + struct gh_rm_connection *connection;
> + struct gh_rm_rpc_hdr *hdr = msg;
> + int ret;
> +
> + if (rm->active_rx_connection)
> + gh_rm_abort_connection(rm);

So every notification or reply is always expected to be sent in full, or
it should be thrown away?

I do find this logic a little bit odd, can you confirm that this is
defined by the hypervisor?

> +
> + connection = kzalloc(sizeof(*connection), GFP_KERNEL);
> + if (!connection)
> + return;
> +
> + connection->type = RM_RPC_TYPE_NOTIF;
> + connection->msg_id = hdr->msg_id;
> +
> + get_device(rm->dev);
> + connection->notification.rm = rm;
> + INIT_WORK(&connection->notification.work, gh_rm_notif_work);

I tend to dislike work in allocated objects, in particularly when they
are scheduled on the global work queues...

I'd prefer a list of outstanding notifications associated with the rm
and a worker that traverses that list. That saves you from carrying the
rm back-pointer in the "connection" and you don't need to refcount the
rm->dev.

> +
> + ret = gh_rm_init_connection_payload(connection, msg, sizeof(*hdr), msg_size);
> + if (ret) {
> + dev_err(rm->dev, "Failed to initialize connection for notification: %d\n", ret);
> + put_device(rm->dev);
> + kfree(connection);
> + return;
> + }
> +
> + rm->active_rx_connection = connection;
> +}
> +
> +static void gh_rm_process_reply(struct gh_rm *rm, void *msg, size_t msg_size)
> +{
> + struct gh_rm_rpc_reply_hdr *reply_hdr = msg;
> + struct gh_rm_connection *connection;
> + u16 seq_id;
> +
> + seq_id = le16_to_cpu(reply_hdr->hdr.seq);
> + connection = xa_load(&rm->call_xarray, seq_id);
> +
> + if (!connection || connection->msg_id != reply_hdr->hdr.msg_id)

Wouldn't it be bad if a response is received with the wrong msg_id?
Please confirm that this should be silently ignored.

> + return;
> +
> + if (rm->active_rx_connection)
> + gh_rm_abort_connection(rm);
> +
> + if (gh_rm_init_connection_payload(connection, msg, sizeof(*reply_hdr), msg_size)) {
> + dev_err(rm->dev, "Failed to alloc connection buffer for sequence %d\n", seq_id);
> + /* Send connection complete and error the client. */
> + connection->reply.ret = -ENOMEM;
> + complete(&connection->reply.seq_done);
> + return;
> + }
> +
> + connection->reply.rm_error = le32_to_cpu(reply_hdr->err_code);
> + rm->active_rx_connection = connection;
> +}
> +
> +static void gh_rm_process_cont(struct gh_rm *rm, struct gh_rm_connection *connection,
> + void *msg, size_t msg_size)
> +{
> + struct gh_rm_rpc_hdr *hdr = msg;
> + size_t payload_size = msg_size - sizeof(*hdr);
> +
> + if (!rm->active_rx_connection)

Perhaps reasonable to be consistent and complain if the hypervisor gives
you a continuation when you have no active response? Seems like this
would result in a silent hang...

> + return;
> +
> + /*
> + * hdr->fragments and hdr->msg_id preserves the value from first reply
> + * or notif message. To detect mishandling, check it's still intact.
> + */
> + if (connection->msg_id != hdr->msg_id ||
> + connection->num_fragments != FIELD_GET(RM_RPC_FRAGMENTS_MASK, hdr->type)) {

When breaking an expression, align all lines under each other. Here it
looks like connection->num_fragments.. is part of the conditional block,
rather than the expression.

> + gh_rm_abort_connection(rm);
> + return;
> + }
> +
> + memcpy(connection->payload + connection->size, msg + sizeof(*hdr), payload_size);
> + connection->size += payload_size;
> + connection->fragments_received++;
> +}
> +
> +static void gh_rm_try_complete_connection(struct gh_rm *rm)
> +{
> + struct gh_rm_connection *connection = rm->active_rx_connection;
> +
> + if (!connection || connection->fragments_received != connection->num_fragments)
> + return;
> +
> + switch (connection->type) {
> + case RM_RPC_TYPE_REPLY:
> + complete(&connection->reply.seq_done);
> + break;
> + case RM_RPC_TYPE_NOTIF:
> + schedule_work(&connection->notification.work);
> + break;
> + default:
> + dev_err_ratelimited(rm->dev, "Invalid message type (%u) received\n",
> + connection->type);
> + gh_rm_abort_connection(rm);
> + break;
> + }
> +
> + rm->active_rx_connection = NULL;
> +}
> +
> +static void gh_rm_msgq_rx_data(struct mbox_client *cl, void *mssg)
> +{
> + struct gh_rm *rm = container_of(cl, struct gh_rm, msgq_client);
> + struct gh_msgq_rx_data *rx_data = mssg;
> + size_t msg_size = rx_data->length;
> + void *msg = rx_data->data;
> + struct gh_rm_rpc_hdr *hdr;
> +
> + if (msg_size < sizeof(*hdr) || msg_size > GH_MSGQ_MAX_MSG_SIZE)
> + return;
> +
> + hdr = msg;
> + if (hdr->api != RM_RPC_API) {
> + dev_err(rm->dev, "Unknown RM RPC API version: %x\n", hdr->api);
> + return;
> + }
> +
> + switch (FIELD_GET(RM_RPC_TYPE_MASK, hdr->type)) {
> + case RM_RPC_TYPE_NOTIF:
> + gh_rm_process_notif(rm, msg, msg_size);
> + break;
> + case RM_RPC_TYPE_REPLY:
> + gh_rm_process_reply(rm, msg, msg_size);
> + break;
> + case RM_RPC_TYPE_CONTINUATION:
> + gh_rm_process_cont(rm, rm->active_rx_connection, msg, msg_size);
> + break;
> + default:
> + dev_err(rm->dev, "Invalid message type (%lu) received\n",
> + FIELD_GET(RM_RPC_TYPE_MASK, hdr->type));
> + return;
> + }
> +
> + gh_rm_try_complete_connection(rm);

I stared at this logic for quite a while, I think it would be clearer if
you moved the "now check if we did get all the data and if so handle it"
to each f the process functions.

> +}
> +
> +static void gh_rm_msgq_tx_done(struct mbox_client *cl, void *mssg, int r)
> +{
> + struct gh_rm *rm = container_of(cl, struct gh_rm, msgq_client);
> +
> + kmem_cache_free(rm->cache, mssg);
> + rm->last_tx_ret = r;
> +}
> +
> +static int gh_rm_send_request(struct gh_rm *rm, u32 message_id,
> + const void *req_buf, size_t req_buf_size,
> + struct gh_rm_connection *connection)
> +{
> + size_t buf_size_remaining = req_buf_size;
> + const void *req_buf_curr = req_buf;
> + struct gh_msgq_tx_data *msg;
> + struct gh_rm_rpc_hdr *hdr, hdr_template;
> + u32 cont_fragments = 0;
> + size_t payload_size;
> + void *payload;
> + int ret;
> +
> + if (req_buf_size > GH_RM_MAX_NUM_FRAGMENTS * GH_RM_MAX_MSG_SIZE) {
> + dev_warn(rm->dev, "Limit (%lu bytes) exceeded for the maximum message size: %lu\n",
> + GH_RM_MAX_NUM_FRAGMENTS * GH_RM_MAX_MSG_SIZE, req_buf_size);
> + dump_stack();
> + return -E2BIG;
> + }
> +
> + if (req_buf_size)
> + cont_fragments = (req_buf_size - 1) / GH_RM_MAX_MSG_SIZE;
> +
> + hdr_template.api = RM_RPC_API;
> + hdr_template.type = FIELD_PREP(RM_RPC_TYPE_MASK, RM_RPC_TYPE_REQUEST) |
> + FIELD_PREP(RM_RPC_FRAGMENTS_MASK, cont_fragments);
> + hdr_template.seq = cpu_to_le16(connection->reply.seq);
> + hdr_template.msg_id = cpu_to_le32(message_id);
> +
> + ret = mutex_lock_interruptible(&rm->send_lock);
> + if (ret)
> + return ret;
> +
> + do {
> + msg = kmem_cache_zalloc(rm->cache, GFP_KERNEL);

Per the rm->send_lock() we can only have one msg outstanding at any
point in time. So you should be able to allocate one of those at probe
time and be done with it.

> + if (!msg) {
> + ret = -ENOMEM;
> + goto out;
> + }
> +
> + /* Fill header */
> + hdr = (struct gh_rm_rpc_hdr *)&msg->data[0];
> + *hdr = hdr_template;
> +
> + /* Copy payload */
> + payload = &msg->data[0] + sizeof(*hdr);
> + payload_size = min(buf_size_remaining, GH_RM_MAX_MSG_SIZE);
> + memcpy(payload, req_buf_curr, payload_size);
> + req_buf_curr += payload_size;
> + buf_size_remaining -= payload_size;
> +
> + /* Force the last fragment to immediately alert the receiver */
> + msg->push = !buf_size_remaining;
> + msg->length = sizeof(*hdr) + payload_size;
> +
> + ret = mbox_send_message(gh_msgq_chan(&rm->msgq), msg);

This would be much cleaner if it was just an optional wait for pending
tx irq and a synchronous call to gh_hypercall_msgq_send().

> + if (ret < 0) {
> + kmem_cache_free(rm->cache, msg);
> + break;
> + }
> +
> + if (rm->last_tx_ret) {
> + ret = rm->last_tx_ret;
> + break;
> + }
> +
> + hdr_template.type = FIELD_PREP(RM_RPC_TYPE_MASK, RM_RPC_TYPE_CONTINUATION) |
> + FIELD_PREP(RM_RPC_FRAGMENTS_MASK, cont_fragments);
> + } while (buf_size_remaining);
> +
> +out:
> + mutex_unlock(&rm->send_lock);
> + return ret < 0 ? ret : 0;
> +}
> +
> +/**
> + * gh_rm_call: Achieve request-response type communication with RPC
> + * @rm: Pointer to Gunyah resource manager internal data
> + * @message_id: The RM RPC message-id
> + * @req_buf: Request buffer that contains the payload
> + * @req_buf_size: Total size of the payload
> + * @resp_buf: Pointer to a response buffer
> + * @resp_buf_size: Size of the response buffer
> + *
> + * Make a request to the Resource Manager and wait for reply back. For a successful
> + * response, the function returns the payload. The size of the payload is set in
> + * resp_buf_size. The resp_buf must be freed by the caller when 0 is returned
> + * and resp_buf_size != 0.
> + *
> + * req_buf should be not NULL for req_buf_size >0. If req_buf_size == 0,
> + * req_buf *can* be NULL and no additional payload is sent.
> + *
> + * Context: Process context. Will sleep waiting for reply.
> + * Return: 0 on success. <0 if error.
> + */
> +int gh_rm_call(struct gh_rm *rm, u32 message_id, const void *req_buf, size_t req_buf_size,
> + void **resp_buf, size_t *resp_buf_size)
> +{
> + struct gh_rm_connection *connection;
> + u32 seq_id;
> + int ret;
> +
> + /* message_id 0 is reserved. req_buf_size implies req_buf is not NULL */
> + if (!rm || !message_id || (!req_buf && req_buf_size))
> + return -EINVAL;
> +
> +
> + connection = kzalloc(sizeof(*connection), GFP_KERNEL);

No matter how many times I read this code, this isn't "a connection" it
is the response message.

sizeof(*connection) doesn't seem too bad either, so you should be able
to just store it on the stack.

> + if (!connection)
> + return -ENOMEM;
> +
> + connection->type = RM_RPC_TYPE_REPLY;
> + connection->msg_id = cpu_to_le32(message_id);
> +
> + init_completion(&connection->reply.seq_done);
> +
> + /* Allocate a new seq number for this connection */
> + ret = xa_alloc_cyclic(&rm->call_xarray, &seq_id, connection, xa_limit_16b, &rm->next_seq,
> + GFP_KERNEL);
> + if (ret < 0)
> + goto free;
> + connection->reply.seq = lower_16_bits(seq_id);

You use connection->reply.seq for two things; 1) as a local variable, 2)
to pass the sequence id as an argument to gh_rm_send_request().

Further more, reply.seq is the only thing extracted from "connection" in
gh_rm_send_request(), so if you passed that directly instead of the
"connection" #2 is gone and you're down to duplicating the variable
already on the stack...

So you can remove "seq" from struct gh_rm_connection...

> +
> + /* Send the request to the Resource Manager */
> + ret = gh_rm_send_request(rm, message_id, req_buf, req_buf_size, connection);
> + if (ret < 0)
> + goto out;
> +
> + /* Wait for response. Uninterruptible because rollback based on what RM did to VM

/*
* Multi-line comments should generally be started on the second line.
*/

> + * requires us to know how RM handled the call.
> + */
> + wait_for_completion(&connection->reply.seq_done);
> +
> + /* Check for internal (kernel) error waiting for the response */
> + if (connection->reply.ret) {
> + ret = connection->reply.ret;
> + if (ret != -ENOMEM)
> + kfree(connection->payload);
> + goto out;
> + }
> +
> + /* Got a response, did resource manager give us an error? */
> + if (connection->reply.rm_error != GH_RM_ERROR_OK) {
> + dev_warn(rm->dev, "RM rejected message %08x. Error: %d\n", message_id,
> + connection->reply.rm_error);
> + ret = gh_rm_error_remap(connection->reply.rm_error);
> + kfree(connection->payload);
> + goto out;
> + }
> +
> + /* Everything looks good, return the payload */
> + if (resp_buf_size)
> + *resp_buf_size = connection->size;
> + if (connection->size && resp_buf)

Keep {} around all blocks if anyone of them need it.

> + *resp_buf = connection->payload;
> + else {
> + /* kfree in case RM sent us multiple fragments but never any data in
> + * those fragments. We would've allocated memory for it, but connection->size == 0
> + */
> + kfree(connection->payload);
> + }
> +
> +out:
> + xa_erase(&rm->call_xarray, connection->reply.seq);
> +free:
> + kfree(connection);
> + return ret;
> +}
> +
> +
> +int gh_rm_notifier_register(struct gh_rm *rm, struct notifier_block *nb)
> +{
> + return blocking_notifier_chain_register(&rm->nh, nb);
> +}
> +EXPORT_SYMBOL_GPL(gh_rm_notifier_register);
> +
> +int gh_rm_notifier_unregister(struct gh_rm *rm, struct notifier_block *nb)
> +{
> + return blocking_notifier_chain_unregister(&rm->nh, nb);
> +}
> +EXPORT_SYMBOL_GPL(gh_rm_notifier_unregister);
> +
> +static int gh_msgq_platform_probe_direction(struct platform_device *pdev, bool tx,
> + struct gh_resource *ghrsc)
> +{
> + struct device_node *node = pdev->dev.of_node;
> + int ret;
> + int idx = tx ? 0 : 1;
> +
> + ghrsc->type = tx ? GH_RESOURCE_TYPE_MSGQ_TX : GH_RESOURCE_TYPE_MSGQ_RX;
> +
> + ghrsc->irq = platform_get_irq(pdev, idx);
> + if (ghrsc->irq < 0) {
> + dev_err(&pdev->dev, "Failed to get irq%d: %d\n", idx, ghrsc->irq);

"irq0"/"irq1" won't help the reader much.

... "Failed to get %s irq: %d\n", tx ? "tx" : "rx", ghrsc->irq);

> + return ghrsc->irq;
> + }
> +
> + ret = of_property_read_u64_index(node, "reg", idx, &ghrsc->capid);
> + if (ret) {
> + dev_err(&pdev->dev, "Failed to get capid%d: %d\n", idx, ret);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int gh_identify(void)
> +{
> + struct gh_hypercall_hyp_identify_resp gh_api;
> +
> + if (!arch_is_gh_guest())
> + return -ENODEV;
> +
> + gh_hypercall_hyp_identify(&gh_api);
> +
> + pr_info("Running under Gunyah hypervisor %llx/v%u\n",
> + FIELD_GET(GH_API_INFO_VARIANT_MASK, gh_api.api_info),
> + gh_api_version(&gh_api));
> +
> + /* We might move this out to individual drivers if there's ever an API version bump */
> + if (gh_api_version(&gh_api) != GH_API_V1) {
> + pr_info("Unsupported Gunyah version: %u\n", gh_api_version(&gh_api));

Is this just an informational statement?

> + return -ENODEV;
> + }
> +
> + return 0;
> +}
> +
> +static int gh_rm_drv_probe(struct platform_device *pdev)

Does "_drv_" add value to this function name?

> +{
> + struct gh_msgq_tx_data *msg;
> + struct gh_rm *rm;
> + int ret;
> +
> + ret = gh_identify();
> + if (ret)
> + return ret;
> +
> + rm = devm_kzalloc(&pdev->dev, sizeof(*rm), GFP_KERNEL);
> + if (!rm)
> + return -ENOMEM;
> +
> + platform_set_drvdata(pdev, rm);
> + rm->dev = &pdev->dev;
> +
> + mutex_init(&rm->send_lock);
> + BLOCKING_INIT_NOTIFIER_HEAD(&rm->nh);
> + xa_init_flags(&rm->call_xarray, XA_FLAGS_ALLOC);
> + rm->cache = kmem_cache_create("gh_rm", struct_size(msg, data, GH_MSGQ_MAX_MSG_SIZE), 0,
> + SLAB_HWCACHE_ALIGN, NULL);
> + if (!rm->cache)
> + return -ENOMEM;
> +
> + ret = gh_msgq_platform_probe_direction(pdev, true, &rm->tx_ghrsc);
> + if (ret)
> + goto err_cache;
> +
> + ret = gh_msgq_platform_probe_direction(pdev, false, &rm->rx_ghrsc);
> + if (ret)
> + goto err_cache;
> +
> + rm->msgq_client.dev = &pdev->dev;
> + rm->msgq_client.tx_block = true;
> + rm->msgq_client.rx_callback = gh_rm_msgq_rx_data;
> + rm->msgq_client.tx_done = gh_rm_msgq_tx_done;
> +
> + return gh_msgq_init(&pdev->dev, &rm->msgq, &rm->msgq_client, &rm->tx_ghrsc, &rm->rx_ghrsc);
> +err_cache:
> + kmem_cache_destroy(rm->cache);
> + return ret;
> +}
> +
> +static int gh_rm_drv_remove(struct platform_device *pdev)
> +{
> + struct gh_rm *rm = platform_get_drvdata(pdev);
> +
> + gh_msgq_remove(&rm->msgq);
> + kmem_cache_destroy(rm->cache);
> +

As soon as you return here, "rm" will be freed by devres (it's not tied
to the refcount of the struct device). If you have any outstanding
notification work, that will result in a use-after-free.

> + return 0;
> +}
> +
> +static const struct of_device_id gh_rm_of_match[] = {
> + { .compatible = "gunyah-resource-manager" },
> + {}
> +};
> +MODULE_DEVICE_TABLE(of, gh_rm_of_match);
> +
> +static struct platform_driver gh_rm_driver = {
> + .probe = gh_rm_drv_probe,
> + .remove = gh_rm_drv_remove,
> + .driver = {
> + .name = "gh_rsc_mgr",
> + .of_match_table = gh_rm_of_match,
> + },
> +};
> +module_platform_driver(gh_rm_driver);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("Gunyah Resource Manager Driver");
> diff --git a/drivers/virt/gunyah/rsc_mgr.h b/drivers/virt/gunyah/rsc_mgr.h
> new file mode 100644
> index 0000000000000..8309b7bf46683
> --- /dev/null
> +++ b/drivers/virt/gunyah/rsc_mgr.h
> @@ -0,0 +1,16 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +#ifndef __GH_RSC_MGR_PRIV_H
> +#define __GH_RSC_MGR_PRIV_H
> +
> +#include <linux/gunyah.h>
> +#include <linux/gunyah_rsc_mgr.h>

You declare struct gh_rm below, so do you really need these two
includes?

> +#include <linux/types.h>
> +
> +struct gh_rm;

Would be nice with an empty line here.

> +int gh_rm_call(struct gh_rm *rsc_mgr, u32 message_id, const void *req_buf, size_t req_buf_size,
> + void **resp_buf, size_t *resp_buf_size);
> +
> +#endif
> diff --git a/include/linux/gunyah_rsc_mgr.h b/include/linux/gunyah_rsc_mgr.h
> new file mode 100644
> index 0000000000000..f2a312e80af52
> --- /dev/null
> +++ b/include/linux/gunyah_rsc_mgr.h
> @@ -0,0 +1,21 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#ifndef _GUNYAH_RSC_MGR_H
> +#define _GUNYAH_RSC_MGR_H
> +
> +#include <linux/list.h>

Unused?

> +#include <linux/notifier.h>
> +#include <linux/gunyah.h>
> +
> +#define GH_VMID_INVAL U16_MAX

Unused in this patch.

> +
> +struct gh_rm;

Would be nice with an empty line here.

> +int gh_rm_notifier_register(struct gh_rm *rm, struct notifier_block *nb);
> +int gh_rm_notifier_unregister(struct gh_rm *rm, struct notifier_block *nb);
> +struct device *gh_rm_get(struct gh_rm *rm);
> +void gh_rm_put(struct gh_rm *rm);
> +

Regards,
Bjorn

2023-08-05 17:23:36

by Bjorn Andersson

[permalink] [raw]
Subject: Re: [PATCH v14 08/25] gunyah: rsc_mgr: Add VM lifecycle RPC

On Tue, Jun 13, 2023 at 10:20:36AM -0700, Elliot Berman wrote:
> diff --git a/drivers/virt/gunyah/rsc_mgr_rpc.c b/drivers/virt/gunyah/rsc_mgr_rpc.c
[..]
> +/**
> + * gh_rm_alloc_vmid() - Allocate a new VM in Gunyah. Returns the VM identifier.
> + * @rm: Handle to a Gunyah resource manager
> + * @vmid: Use 0 to dynamically allocate a VM. A reserved VMID can be supplied
> + * to request allocation of a platform-defined VM.
> + *
> + * Returns - the allocated VMID or negative value on error

kernel-doc Return:

> + */
> +int gh_rm_alloc_vmid(struct gh_rm *rm, u16 vmid)
> +{
> + struct gh_rm_vm_common_vmid_req req_payload = {
> + .vmid = cpu_to_le16(vmid),
> + };
> + struct gh_rm_vm_alloc_vmid_resp *resp_payload;
> + size_t resp_size;
> + void *resp;
> + int ret;
> +
> + ret = gh_rm_call(rm, GH_RM_RPC_VM_ALLOC_VMID, &req_payload, sizeof(req_payload), &resp,

Wrap lines at 80 characters, unless it improves readability, which is
doesn't here as you wrap it later anyways.

(The gh_rm_call() in gh_rm_common_vmid_call() above is a good example of
where going above 80 characters looks good)

> + &resp_size);
> + if (ret)
> + return ret;
> +
> + if (!vmid) {
> + resp_payload = resp;
> + ret = le16_to_cpu(resp_payload->vmid);
> + kfree(resp);
> + }

With vmid specified, will the call somehow not return a response buffer?
If this is the case please document it here with a comment.

Otherwise, you're leaking resp.

> +
> + return ret;
> +}
> +
> +/**
> + * gh_rm_dealloc_vmid() - Dispose of a VMID
> + * @rm: Handle to a Gunyah resource manager
> + * @vmid: VM identifier allocated with gh_rm_alloc_vmid

Doesn't hurt to define the return value of all these apis.

> + */
> +int gh_rm_dealloc_vmid(struct gh_rm *rm, u16 vmid)
> +{
> + return gh_rm_common_vmid_call(rm, GH_RM_RPC_VM_DEALLOC_VMID, vmid);
> +}
> +
> +/**
> + * gh_rm_vm_reset() - Reset a VM's resources
> + * @rm: Handle to a Gunyah resource manager
> + * @vmid: VM identifier allocated with gh_rm_alloc_vmid
> + *
> + * As part of tearing down the VM, request RM to clean up all the VM resources
> + * associated with the VM. Only after this, Linux can clean up all the

s/, Linux can/can Linux/

> + * references it maintains to resources.
> + */
> +int gh_rm_vm_reset(struct gh_rm *rm, u16 vmid)
> +{
> + return gh_rm_common_vmid_call(rm, GH_RM_RPC_VM_RESET, vmid);
> +}
[..]
> +int gh_rm_get_hyp_resources(struct gh_rm *rm, u16 vmid,
> + struct gh_rm_hyp_resources **resources)
> +{
> + struct gh_rm_vm_common_vmid_req req_payload = {
> + .vmid = cpu_to_le16(vmid),
> + };
> + struct gh_rm_hyp_resources *resp;
> + size_t resp_size;
> + int ret;
> +
> + ret = gh_rm_call(rm, GH_RM_RPC_VM_GET_HYP_RESOURCES,
> + &req_payload, sizeof(req_payload),
> + (void **)&resp, &resp_size);
> + if (ret)
> + return ret;
> +
> + if (!resp_size)
> + return -EBADMSG;
> +
> + if (resp_size < struct_size(resp, entries, 0) ||
> + resp_size != struct_size(resp, entries, le32_to_cpu(resp->n_entries))) {

Indent wrapped expressions to match the previous start of that
expression.

> + kfree(resp);
> + return -EBADMSG;
> + }
> +
> + *resources = resp;
> + return 0;
> +}
> +
> +/**
> + * gh_rm_get_vmid() - Retrieve VMID of this virtual machine
> + * @rm: Handle to a Gunyah resource manager
> + * @vmid: Filled with the VMID of this VM

In gh_rm_alloc_vmid() you return the vmid (or a errno), here you return
the value by reference. Pick one please. (Preferably return vmid)

> + */
> +int gh_rm_get_vmid(struct gh_rm *rm, u16 *vmid)
> +{
> + static u16 cached_vmid = GH_VMID_INVAL;
> + size_t resp_size;
> + __le32 *resp;
> + int ret;
> +
> + if (cached_vmid != GH_VMID_INVAL) {
> + *vmid = cached_vmid;
> + return 0;
> + }

Regards,
Bjorn

2023-08-05 18:33:23

by Bjorn Andersson

[permalink] [raw]
Subject: Re: [PATCH v14 13/25] samples: Add sample userspace Gunyah VM Manager

On Tue, Jun 13, 2023 at 10:20:41AM -0700, Elliot Berman wrote:
> diff --git a/samples/gunyah/gunyah_vmm.c b/samples/gunyah/gunyah_vmm.c
> new file mode 100644
> index 0000000000000..6f636ac227c69
> --- /dev/null
> +++ b/samples/gunyah/gunyah_vmm.c
> @@ -0,0 +1,266 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#include <stdlib.h>
> +#include <stdio.h>
> +#include <unistd.h>
> +#include <sys/types.h>
> +#include <sys/stat.h>
> +#include <fcntl.h>
> +#include <sys/ioctl.h>
> +#include <getopt.h>
> +#include <limits.h>
> +#include <stdint.h>
> +#include <fcntl.h>
> +#include <string.h>
> +#include <sys/sysmacros.h>
> +#define __USE_GNU
> +#include <sys/mman.h>
> +
> +#include <linux/gunyah.h>
> +
> +#define DEFAULT_GUEST_BASE 0x80000000
> +#define DEFAULT_GUEST_SIZE 0x6400000 /* 100 MiB */
> +#define DEFAULT_DTB_OFFSET 0x45f0000 /* 70MiB - 64 KiB */
> +#define DEFAULT_RAMDISK_OFFSET 0x4600000 /* 70MiB */

Would be nice if the default ramdisk offset was close to accounting for
the kernel modules produced in an upstream defconfig build... Perhaps
just bumping the default guest size to facilitate this?

[..]
> diff --git a/samples/gunyah/sample_vm.dts b/samples/gunyah/sample_vm.dts
> new file mode 100644
> index 0000000000000..293bbc0469c8f
> --- /dev/null
> +++ b/samples/gunyah/sample_vm.dts
> @@ -0,0 +1,68 @@
> +// SPDX-License-Identifier: BSD-3-Clause
> +/*
> + * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +/dts-v1/;
> +
> +/ {
> + #address-cells = <2>;
> + #size-cells = <2>;
> + interrupt-parent = <&intc>;
> +
> + chosen {
> + bootargs = "nokaslr";

Is this required?

> + };
> +
> + cpus {
> + #address-cells = <0x2>;
> + #size-cells = <0>;
> +
> + cpu@0 {
> + device_type = "cpu";
> + compatible = "arm,armv8";
> + reg = <0 0>;
> + };
> + };
> +
> + intc: interrupt-controller@3FFF0000 {
> + compatible = "arm,gic-v3";
> + #interrupt-cells = <3>;
> + #address-cells = <2>;
> + #size-cells = <2>;
> + interrupt-controller;
> + reg = <0 0x3FFF0000 0 0x10000>,
> + <0 0x3FFD0000 0 0x20000>;

Lowercase hex digits please.

> + };
> +
> + timer {
> + compatible = "arm,armv8-timer";
> + always-on;
> + interrupts = <1 13 0x108>,
> + <1 14 0x108>,
> + <1 11 0x108>,
> + <1 10 0x108>;
> + clock-frequency = <19200000>;
> + };
> +
> + gunyah-vm-config {

Is this node documented somewhere?

Regards,
Bjorn

> + image-name = "linux_vm_0";
> +
> + memory {
> + #address-cells = <2>;
> + #size-cells = <2>;
> +
> + base-address = <0 0x80000000>;
> + };
> +
> + interrupts {
> + config = <&intc>;
> + };
> +
> + vcpus {
> + affinity-map = < 0 >;
> + sched-priority = < (-1) >;
> + sched-timeslice = < 2000 >;
> + };
> + };
> +};
> --
> 2.40.0
>

2023-08-05 18:45:42

by Bjorn Andersson

[permalink] [raw]
Subject: Re: [PATCH v14 10/25] gunyah: rsc_mgr: Add RPC for sharing memory

On Tue, Jun 13, 2023 at 10:20:38AM -0700, Elliot Berman wrote:
> Gunyah resource manager provides API to manipulate stage 2 page tables.
> Manipulations are represented as a memory parcel. Memory parcels
> describe a list of memory regions (intermediate physical address--IPA--and
> size), a list of new permissions for VMs, and the memory type (DDR or
> MMIO). Each memory parcel is uniquely identified by a handle allocated by
> Gunyah. There are a few types of memory parcel sharing which Gunyah
> supports:
>
> - Sharing: the guest and host VM both have access
> - Lending: only the guest has access; host VM loses access
> - Donating: Permanently lent (not reclaimed even if guest shuts down)
>
> Memory parcels that have been shared or lent can be reclaimed by the
> host via an additional call. The reclaim operation restores the original
> access the host VM had to the memory parcel and removes the access to
> other VM.
>
> One point to note that memory parcels don't describe where in the guest
> VM the memory parcel should reside. The guest VM must accept the memory
> parcel either explicitly via a "gh_rm_mem_accept" call (not introduced
> here) or be configured to accept it automatically at boot. When the guest
> VM accepts the memory parcel, it also mentions the IPA it wants to place
> memory parcel. Although the region might be discontiguous on the host,
> the memory parcel is place contiguously in the guest memory at the
> specified IPA.
>
> Reviewed-by: Alex Elder <[email protected]>
> Reviewed-by: Srinivas Kandagatla <[email protected]>
> Co-developed-by: Prakruthi Deepak Heragu <[email protected]>
> Signed-off-by: Prakruthi Deepak Heragu <[email protected]>
> Signed-off-by: Elliot Berman <[email protected]>
> ---
> drivers/virt/gunyah/rsc_mgr_rpc.c | 227 ++++++++++++++++++++++++++++++
> include/linux/gunyah_rsc_mgr.h | 48 +++++++
> 2 files changed, 275 insertions(+)
>
> diff --git a/drivers/virt/gunyah/rsc_mgr_rpc.c b/drivers/virt/gunyah/rsc_mgr_rpc.c
> index a4a9f0ba4e1fc..25064123a31c3 100644
> --- a/drivers/virt/gunyah/rsc_mgr_rpc.c
> +++ b/drivers/virt/gunyah/rsc_mgr_rpc.c
> @@ -6,6 +6,12 @@
> #include <linux/gunyah_rsc_mgr.h>
> #include "rsc_mgr.h"
>
> +/* Message IDs: Memory Management */
> +#define GH_RM_RPC_MEM_LEND 0x51000012
> +#define GH_RM_RPC_MEM_SHARE 0x51000013
> +#define GH_RM_RPC_MEM_RECLAIM 0x51000015
> +#define GH_RM_RPC_MEM_APPEND 0x51000018
> +
> /* Message IDs: VM Management */
> #define GH_RM_RPC_VM_ALLOC_VMID 0x56000001
> #define GH_RM_RPC_VM_DEALLOC_VMID 0x56000002
> @@ -22,6 +28,46 @@ struct gh_rm_vm_common_vmid_req {
> __le16 _padding;
> } __packed;
>
> +/* Call: MEM_LEND, MEM_SHARE */
> +#define GH_MEM_SHARE_REQ_FLAGS_APPEND BIT(1)
> +
> +struct gh_rm_mem_share_req_header {
> + u8 mem_type;
> + u8 _padding0;
> + u8 flags;
> + u8 _padding1;
> + __le32 label;
> +} __packed;
> +
> +struct gh_rm_mem_share_req_acl_section {
> + __le32 n_entries;
> + struct gh_rm_mem_acl_entry entries[];
> +};
> +
> +struct gh_rm_mem_share_req_mem_section {
> + __le16 n_entries;
> + __le16 _padding;
> + struct gh_rm_mem_entry entries[];
> +};

Any reason why these two are not explicitly packed?

> +
> +/* Call: MEM_RELEASE */
> +struct gh_rm_mem_release_req {
> + __le32 mem_handle;
> + u8 flags; /* currently not used */
> + u8 _padding0;
> + __le16 _padding1;
> +} __packed;
> +
> +/* Call: MEM_APPEND */
> +#define GH_MEM_APPEND_REQ_FLAGS_END BIT(0)
> +
> +struct gh_rm_mem_append_req_header {
> + __le32 mem_handle;
> + u8 flags;
> + u8 _padding0;
> + __le16 _padding1;
> +} __packed;
> +
> /* Call: VM_ALLOC */
> struct gh_rm_vm_alloc_vmid_resp {
> __le16 vmid;
> @@ -51,6 +97,8 @@ struct gh_rm_vm_config_image_req {
> __le64 dtb_size;
> } __packed;
>
> +#define GH_RM_MAX_MEM_ENTRIES 512
> +
> /*
> * Several RM calls take only a VMID as a parameter and give only standard
> * response back. Deduplicate boilerplate code by using this common call.
> @@ -64,6 +112,185 @@ static int gh_rm_common_vmid_call(struct gh_rm *rm, u32 message_id, u16 vmid)
> return gh_rm_call(rm, message_id, &req_payload, sizeof(req_payload), NULL, NULL);
> }
>
> +static int _gh_rm_mem_append(struct gh_rm *rm, u32 mem_handle, bool end_append,
> + struct gh_rm_mem_entry *mem_entries, size_t n_mem_entries)
> +{
> + struct gh_rm_mem_share_req_mem_section *mem_section;

"sections" is sufficient.

> + struct gh_rm_mem_append_req_header *req_header;
> + size_t msg_size = 0;
> + void *msg;
> + int ret;
> +
> + msg_size += sizeof(struct gh_rm_mem_append_req_header);

msg_size is sizeof(header) + sizeof(sections), but written this way you
state that it's:

msg_size is X + sizeof(header),
and msg_size is also sizeof(sections)


It's the same thing, but you're forcing the reader to look for the
initial value of msg_size.

> + msg_size += struct_size(mem_section, entries, n_mem_entries);
> +
> + msg = kzalloc(msg_size, GFP_KERNEL);
> + if (!msg)
> + return -ENOMEM;
> +
> + req_header = msg;

Can't you just make msg a strcut gh_rm_mem_append_req_header?

> + mem_section = (void *)(req_header + 1);
> +
> + req_header->mem_handle = cpu_to_le32(mem_handle);
> + if (end_append)
> + req_header->flags |= GH_MEM_APPEND_REQ_FLAGS_END;
> +
> + mem_section->n_entries = cpu_to_le16(n_mem_entries);
> + memcpy(mem_section->entries, mem_entries, sizeof(*mem_entries) * n_mem_entries);
> +
> + ret = gh_rm_call(rm, GH_RM_RPC_MEM_APPEND, msg, msg_size, NULL, NULL);
> + kfree(msg);
> +
> + return ret;
> +}
> +
> +static int gh_rm_mem_append(struct gh_rm *rm, u32 mem_handle,
> + struct gh_rm_mem_entry *mem_entries, size_t n_mem_entries)

You can name these arguments "entries" and "n_entries" (or num_entries)
without loosing any infromation, but saving a whole bunch of characters
that people have to read.

> +{
> + bool end_append;

Iiuc this means "is this the last entry", perhaps calling it "last"
would make its purpose immediately obvious.

> + int ret = 0;
> + size_t n;
> +
> + while (n_mem_entries) {
> + if (n_mem_entries > GH_RM_MAX_MEM_ENTRIES) {
> + end_append = false;
> + n = GH_RM_MAX_MEM_ENTRIES;
> + } else {
> + end_append = true;
> + n = n_mem_entries;
> + }
> +
> + ret = _gh_rm_mem_append(rm, mem_handle, end_append, mem_entries, n);

Every loop here you kzallc() and kfree() the same chunk of scratch
memory. If you inline _gh_rm_mem_append() here and do the allocation
once based on GH_RM_MAX_MEM_ENTRIES this would be faster and seemingly
easier to read/follow.

> + if (ret)
> + break;
> +
> + mem_entries += n;
> + n_mem_entries -= n;
> + }
> +
> + return ret;
> +}
> +
> +static int gh_rm_mem_lend_common(struct gh_rm *rm, u32 message_id, struct gh_rm_mem_parcel *p)
> +{
> + size_t msg_size = 0, initial_mem_entries = p->n_mem_entries, resp_size;
> + size_t acl_section_size, mem_section_size;

You keep all other variables one per line, and in reverse x-mas style.
Please do the same for this.

Naming these acl_size and mem_size would be beneficial.

> + struct gh_rm_mem_share_req_acl_section *acl_section;
> + struct gh_rm_mem_share_req_mem_section *mem_section;

Naming these acl and mem will make below easier to read.

> + struct gh_rm_mem_share_req_header *req_header;
> + u32 *attr_section;
> + __le32 *resp;
> + void *msg;
> + int ret;
> +
> + if (!p->acl_entries || !p->n_acl_entries || !p->mem_entries || !p->n_mem_entries ||
> + p->n_acl_entries > U8_MAX || p->mem_handle != GH_MEM_HANDLE_INVAL)
> + return -EINVAL;
> +
> + if (initial_mem_entries > GH_RM_MAX_MEM_ENTRIES)
> + initial_mem_entries = GH_RM_MAX_MEM_ENTRIES;
> +
> + acl_section_size = struct_size(acl_section, entries, p->n_acl_entries);
> + mem_section_size = struct_size(mem_section, entries, initial_mem_entries);

An empty line here seems reasonable.

> + /* The format of the message goes:
> + * request header
> + * ACL entries (which VMs get what kind of access to this memory parcel)
> + * Memory entries (list of memory regions to share)
> + * Memory attributes (currently unused, we'll hard-code the size to 0)
> + */
> + msg_size += sizeof(struct gh_rm_mem_share_req_header);

Hidden above is the confirmation that msg_size was initialized to 0,
drop the '+' here to make it clear.

> + msg_size += acl_section_size;
> + msg_size += mem_section_size;
> + msg_size += sizeof(u32); /* for memory attributes, currently unused */
> +
> + msg = kzalloc(msg_size, GFP_KERNEL);
> + if (!msg)
> + return -ENOMEM;
> +
> + req_header = msg;

I don't think you need to keep req_header and msg separately.

> + acl_section = (void *)req_header + sizeof(*req_header);
> + mem_section = (void *)acl_section + acl_section_size;
> + attr_section = (void *)mem_section + mem_section_size;
> +
> + req_header->mem_type = p->mem_type;
> + if (initial_mem_entries != p->n_mem_entries)

I think this will only happen if p->n_mem_entries >
GH_RM_MAX_MEM_ENTRIES, for which you already have a condition earlier.
Set the flag in that condition rather than spreading it over two (three)
code paths.

> + req_header->flags |= GH_MEM_SHARE_REQ_FLAGS_APPEND;
> + req_header->label = cpu_to_le32(p->label);
> +
> + acl_section->n_entries = cpu_to_le32(p->n_acl_entries);
> + memcpy(acl_section->entries, p->acl_entries,
> + flex_array_size(acl_section, entries, p->n_acl_entries));
> +
> + mem_section->n_entries = cpu_to_le16(initial_mem_entries);
> + memcpy(mem_section->entries, p->mem_entries,
> + flex_array_size(mem_section, entries, initial_mem_entries));
> +
> + /* Set n_entries for memory attribute section to 0 */
> + *attr_section = 0;
> +
> + ret = gh_rm_call(rm, message_id, msg, msg_size, (void **)&resp, &resp_size);
> + kfree(msg);
> +
> + if (ret)
> + return ret;
> +
> + p->mem_handle = le32_to_cpu(*resp);
> + kfree(resp);
> +
> + if (initial_mem_entries != p->n_mem_entries) {

Another "we took that conditional path above", please make it obvious.


Can you please also write a comment describing that this operation is
split in a main one, followed by one of more appended operations as
necessary. This took me too long time to realize...

In particular I was wondering why "initial" didn't mean "the original
value", but now I see that it probably means "the value relevant for the
initial request".

> + ret = gh_rm_mem_append(rm, p->mem_handle,
> + &p->mem_entries[initial_mem_entries],
> + p->n_mem_entries - initial_mem_entries);
> + if (ret) {
> + gh_rm_mem_reclaim(rm, p);
> + p->mem_handle = GH_MEM_HANDLE_INVAL;

What happens to the entries that was already lended or shared?

Regards,
Bjorn

2023-08-05 19:38:16

by Bjorn Andersson

[permalink] [raw]
Subject: Re: [PATCH v14 15/25] virt: gunyah: Add Qualcomm Gunyah platform ops

On Tue, Jun 13, 2023 at 10:20:43AM -0700, Elliot Berman wrote:
> Qualcomm platforms have a firmware entity which performs access control
> to physical pages. Dynamically started Gunyah virtual machines use the
> QCOM_SCM_RM_MANAGED_VMID for access. Linux thus needs to assign access
> to the memory used by guest VMs. Gunyah doesn't do this operation for us
> since it is the current VM (typically VMID_HLOS) delegating the access
> and not Gunyah itself. Use the Gunyah platform ops to achieve this so
> that only Qualcomm platforms attempt to make the needed SCM calls.
>
> Reviewed-by: Alex Elder <[email protected]>
> Co-developed-by: Prakruthi Deepak Heragu <[email protected]>
> Signed-off-by: Prakruthi Deepak Heragu <[email protected]>
> Signed-off-by: Elliot Berman <[email protected]>
> ---
> drivers/virt/gunyah/Kconfig | 13 +++
> drivers/virt/gunyah/Makefile | 1 +
> drivers/virt/gunyah/gunyah_qcom.c | 153 ++++++++++++++++++++++++++++++
> 3 files changed, 167 insertions(+)
> create mode 100644 drivers/virt/gunyah/gunyah_qcom.c
>
> diff --git a/drivers/virt/gunyah/Kconfig b/drivers/virt/gunyah/Kconfig
> index de815189dab6c..0421b751aad4f 100644
> --- a/drivers/virt/gunyah/Kconfig
> +++ b/drivers/virt/gunyah/Kconfig
> @@ -5,6 +5,7 @@ config GUNYAH
> depends on ARM64
> depends on MAILBOX
> select GUNYAH_PLATFORM_HOOKS
> + imply GUNYAH_QCOM_PLATFORM if ARCH_QCOM
> help
> The Gunyah drivers are the helper interfaces that run in a guest VM
> such as basic inter-VM IPC and signaling mechanisms, and higher level
> @@ -15,3 +16,15 @@ config GUNYAH
>
> config GUNYAH_PLATFORM_HOOKS
> tristate
> +
> +config GUNYAH_QCOM_PLATFORM
> + tristate "Support for Gunyah on Qualcomm platforms"
> + depends on GUNYAH
> + select GUNYAH_PLATFORM_HOOKS
> + select QCOM_SCM
> + help
> + Enable support for interacting with Gunyah on Qualcomm
> + platforms. Interaction with Qualcomm firmware requires
> + extra platform-specific support.
> +
> + Say Y/M here to use Gunyah on Qualcomm platforms.
> diff --git a/drivers/virt/gunyah/Makefile b/drivers/virt/gunyah/Makefile
> index 4fbeee521d60a..2aa9ff038ed02 100644
> --- a/drivers/virt/gunyah/Makefile
> +++ b/drivers/virt/gunyah/Makefile
> @@ -1,6 +1,7 @@
> # SPDX-License-Identifier: GPL-2.0
>
> obj-$(CONFIG_GUNYAH_PLATFORM_HOOKS) += gunyah_platform_hooks.o
> +obj-$(CONFIG_GUNYAH_QCOM_PLATFORM) += gunyah_qcom.o
>
> gunyah-y += rsc_mgr.o rsc_mgr_rpc.o vm_mgr.o vm_mgr_mm.o
> obj-$(CONFIG_GUNYAH) += gunyah.o
> diff --git a/drivers/virt/gunyah/gunyah_qcom.c b/drivers/virt/gunyah/gunyah_qcom.c
> new file mode 100644
> index 0000000000000..f06a598f2e1b3
> --- /dev/null
> +++ b/drivers/virt/gunyah/gunyah_qcom.c
> @@ -0,0 +1,153 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#include <linux/arm-smccc.h>
> +#include <linux/gunyah_rsc_mgr.h>
> +#include <linux/module.h>
> +#include <linux/firmware/qcom/qcom_scm.h>
> +#include <linux/types.h>
> +#include <linux/uuid.h>
> +
> +#define QCOM_SCM_RM_MANAGED_VMID 0x3A
> +#define QCOM_SCM_MAX_MANAGED_VMID 0x3F
> +
> +static int qcom_scm_gh_rm_pre_mem_share(struct gh_rm *rm, struct gh_rm_mem_parcel *mem_parcel)
> +{
> + struct qcom_scm_vmperm *new_perms;
> + u64 src, src_cpy;
> + int ret = 0, i, n;
> + u16 vmid;
> +
> + new_perms = kcalloc(mem_parcel->n_acl_entries, sizeof(*new_perms), GFP_KERNEL);
> + if (!new_perms)
> + return -ENOMEM;
> +
> + for (n = 0; n < mem_parcel->n_acl_entries; n++) {
> + vmid = le16_to_cpu(mem_parcel->acl_entries[n].vmid);
> + if (vmid <= QCOM_SCM_MAX_MANAGED_VMID)
> + new_perms[n].vmid = vmid;
> + else
> + new_perms[n].vmid = QCOM_SCM_RM_MANAGED_VMID;
> + if (mem_parcel->acl_entries[n].perms & GH_RM_ACL_X)
> + new_perms[n].perm |= QCOM_SCM_PERM_EXEC;
> + if (mem_parcel->acl_entries[n].perms & GH_RM_ACL_W)
> + new_perms[n].perm |= QCOM_SCM_PERM_WRITE;
> + if (mem_parcel->acl_entries[n].perms & GH_RM_ACL_R)
> + new_perms[n].perm |= QCOM_SCM_PERM_READ;
> + }
> +
> + src = BIT_ULL(QCOM_SCM_VMID_HLOS);
> +
> + for (i = 0; i < mem_parcel->n_mem_entries; i++) {
> + src_cpy = src;
> + ret = qcom_scm_assign_mem(le64_to_cpu(mem_parcel->mem_entries[i].phys_addr),
> + le64_to_cpu(mem_parcel->mem_entries[i].size),
> + &src_cpy, new_perms, mem_parcel->n_acl_entries);
> + if (ret)
> + break;
> + }
> +
> + if (!ret)
> + goto out;

I was going to complain that you don't unroll the assignments on
failure, but now realized that this "error handling" is backwards and
actually represents the success case.

Please don't do that, goto error_handling || kfree(new_perms); return 0;
here instead.


That also means that you don't need to zero-initialize ret, because you
would goto err_reclaim inside the loop.

> +
> + src = 0;
> + for (n = 0; n < mem_parcel->n_acl_entries; n++) {
> + vmid = le16_to_cpu(mem_parcel->acl_entries[n].vmid);
> + if (vmid <= QCOM_SCM_MAX_MANAGED_VMID)
> + src |= BIT_ULL(vmid);
> + else
> + src |= BIT_ULL(QCOM_SCM_RM_MANAGED_VMID);
> + }
> +
> + new_perms[0].vmid = QCOM_SCM_VMID_HLOS;
> +
> + for (i--; i >= 0; i--) {
> + src_cpy = src;
> + WARN_ON_ONCE(qcom_scm_assign_mem(
> + le64_to_cpu(mem_parcel->mem_entries[i].phys_addr),
> + le64_to_cpu(mem_parcel->mem_entries[i].size),
> + &src_cpy, new_perms, 1));
> + }
> +
> +out:
> + kfree(new_perms);
> + return ret;
> +}

Regards,
Bjorn

2023-08-05 20:26:37

by Bjorn Andersson

[permalink] [raw]
Subject: Re: [PATCH v14 17/25] virt: gunyah: Translate gh_rm_hyp_resource into gunyah_resource

On Tue, Jun 13, 2023 at 10:20:45AM -0700, Elliot Berman wrote:
> diff --git a/drivers/virt/gunyah/rsc_mgr.c b/drivers/virt/gunyah/rsc_mgr.c
[..]
> +struct gh_resource *gh_rm_alloc_resource(struct gh_rm *rm, struct gh_rm_hyp_resource *hyp_resource)
> +{
> + struct gh_resource *ghrsc;
> + int ret;
> +
> + ghrsc = kzalloc(sizeof(*ghrsc), GFP_KERNEL);
> + if (!ghrsc)
> + return NULL;
> +
> + ghrsc->type = hyp_resource->type;
> + ghrsc->capid = le64_to_cpu(hyp_resource->cap_id);
> + ghrsc->irq = IRQ_NOTCONNECTED;
> + ghrsc->rm_label = le32_to_cpu(hyp_resource->resource_label);
> + if (hyp_resource->virq) {
> + struct gh_irq_chip_data irq_data = {
> + .gh_virq = le32_to_cpu(hyp_resource->virq),
> + };
> +
> + ret = irq_domain_alloc_irqs(rm->irq_domain, 1, NUMA_NO_NODE, &irq_data);
> + if (ret < 0) {
> + dev_err(rm->dev,
> + "Failed to allocate interrupt for resource %d label: %d: %d\n",
> + ghrsc->type, ghrsc->rm_label, ret);
> + kfree(ghrsc);
> + return NULL;
> + } else {

No need for the else here, the failure case has already returned.

> + ghrsc->irq = ret;
> + }
> + }
> +
> + return ghrsc;
> +}
[..]
> diff --git a/include/linux/gunyah.h b/include/linux/gunyah.h
> index 982e27d10d57f..4b398b59c2c5a 100644
> --- a/include/linux/gunyah.h
> +++ b/include/linux/gunyah.h
> @@ -27,6 +27,9 @@ struct gh_resource {
> enum gh_resource_type type;
> u64 capid;
> unsigned int irq;
> +
> + struct list_head list;

This is unused.

Regards,
Bjorn