2023-09-16 00:44:43

by Sean Christopherson

Subject: [PATCH 00/26] KVM: vfio: Hide KVM internals from others

This is a borderline RFC series to hide KVM's internals from the rest of
the kernel, where "internals" means data structures, enums, #defines,
APIs, etc. that are intended to be KVM-only, but are exposed everywhere
due to kvm_host.h (and other headers) living in the global include paths.

The motiviation for hiding KVM's internals is to allow *safely* loading a
"new" KVM module without having to reboot the host. Where "new" doesn't
have to be strictly newer, just a different incarnation of KVM. Hiding
KVM's internals means those assets can change across KVM instances without
breaking things, e.g. would allow modifying the layout of struct kvm_vcpu
to introduce new fields related to a new feature or mitigation for hardware
bugs.

The end goal for all of this is to allow loading and running multiple
instances of KVM (the module) simultaneously on a single host, e.g. to
deploy fixes, mitigations, and/or new features without having to drain
all VMs from the host.

For now, the immediate goal is to get KVM to a state where KVM x86 doesn't
expose anything to the broader world that isn't intended for external
consumption, e.g. the page write-tracking APIs used by KVM-GT.

I say this is borderline RFC because I don't think I've "formally" proposed
the idea of hiding KVM internals before now. I decided not to tag this RFC
because the changes ended up being not _that_ invasive, and everything
before the last six patches is worthwhile even if hiding internals is
ultimately rejected (IMO).

This would ideally be ~5 separate series, and I certainly have no objection
if that's how we want to get this stuff merged. E.g. (1) VFIO cleanups,
(2) drop HAVE_KVM, (3) clean up makefiles, (4) x86 perf cleanup, and
(5) final push for hiding state. The HAVE_KVM and virt/kvm include stuff
isn't strictly necessary, but I included them here because they're
relatively minor (in the grand scheme).

We've explore several alternatives to the #ifdef __KVM__ approach, and
they all sucked, hard. What I really wanted (and still want) to do, is to
bury the bulk of kvm_host.h (and other KVM headers) in virt/kvm, but every
attempt to do that ended in flames. Even with the __KVM__ guards in place,
each architecture's kvm_host.h is too intertwined with the common kvm_host.h,
and trying to extract small-ish pieces just doesn't work (each patch
inevitably snowballed into a gigantic beast).

The other idea we considered (which I thought of, and feel dirty for even
proposing it internally), is to move all headers under virt/kvm, add
virt/kvm/include to the global header path, and then have KVM x86 omit
virt/kvm/include when configured to hide KVM internals. I hate this idea
because it sets a bad precedent, and requires a lot of file movement
without providing any benefit to other architectures. E.g. I hope that
guarding KVM internals with #ifdef __KVM__ will allow us to slowly clean
things up so that some day KVM only exposes a handful of APIs to the rest
of the kernel (probably a pipe dream).

Anish Ghulati (1):
KVM: arm64: Move arm_{psci,hypercalls}.h to an internal KVM path

Sean Christopherson (25):
vfio: Wrap KVM helpers with CONFIG_KVM instead of CONFIG_HAVE_KVM
vfio: Move KVM get/put helpers to colocate it with other KVM related
code
virt: Declare and define vfio_file_set_kvm() iff CONFIG_KVM is enabled
vfio: Add struct to hold KVM assets and dedup group vs. iommufd code
vfio: KVM: Pass get/put helpers from KVM to VFIO, don't do circular
lookup
KVM: Drop CONFIG_KVM_VFIO and just look at KVM+VFIO
x86/idt: Wrap KVM logic with CONFIG_KVM instead of CONFIG_HAVE_KVM
KVM: x86: Stop selecting and depending on HAVE_KVM
KVM: arm64: Stop selecting and depending on HAVE_KVM
KVM: s390: Stop selecting and depending on HAVE_KVM
KVM: MIPS: Make HAVE_KVM a MIPS-only Kconfig
KVM: arm64: Include KVM headers to get forward declarations
KVM: arm64: Move ARM specific headers in include/kvm to arch directory
KVM: Move include/kvm/iodev.h to include/linux as kvm_iodev.h
KVM: MIPS: Stop adding virt/kvm to the arch include path
KVM: PPC: Stop adding virt/kvm to the arch include path
KVM: s390: Stop adding virt/kvm to the arch include path
KVM: Standardize include paths across all architectures
perf/x86: KVM: Have perf define a dedicated struct for getting guest
PEBS data
entry/kvm: Drop @vcpu param from arch_xfer_to_guest_mode_handle_work()
entry/kvm: KVM: Move KVM details related to signal/-EINTR into KVM
proper
KVM: arm64: Move and consolidate "public" functions in asm/kvm_host.h
powerpc/xics: Move declaration of xics_wake_cpu() out of kvm_ppc.h
KVM: PPC: Rearrange code in kvm_ppc.h to isolate "public" information
KVM: Hide KVM internal data structures and values from kernel at-large

MAINTAINERS | 1 -
arch/arm64/Kconfig | 1 -
.../arm64/include/asm/kvm_arch_timer.h | 2 +
arch/arm64/include/asm/kvm_emulate.h | 3 +
arch/arm64/include/asm/kvm_host.h | 57 ++--
arch/arm64/include/asm/kvm_mmu.h | 4 +
.../arm64/include/asm/kvm_pmu.h | 2 +
.../arm64/include/asm/kvm_vgic.h | 2 +-
arch/arm64/kernel/asm-offsets.c | 2 +
arch/arm64/kvm/Kconfig | 2 -
arch/arm64/kvm/Makefile | 2 -
arch/arm64/kvm/arch_timer.c | 5 +-
arch/arm64/kvm/arm.c | 9 +-
{include => arch/arm64}/kvm/arm_hypercalls.h | 0
{include => arch/arm64}/kvm/arm_psci.h | 0
arch/arm64/kvm/guest.c | 2 +-
arch/arm64/kvm/handle_exit.c | 2 +-
arch/arm64/kvm/hyp/Makefile | 4 +-
arch/arm64/kvm/hyp/include/hyp/switch.h | 4 +-
arch/arm64/kvm/hyp/nvhe/Makefile | 3 +-
arch/arm64/kvm/hyp/nvhe/switch.c | 4 +-
arch/arm64/kvm/hyp/vhe/Makefile | 2 +-
arch/arm64/kvm/hyp/vhe/switch.c | 4 +-
arch/arm64/kvm/hypercalls.c | 4 +-
arch/arm64/kvm/pmu-emul.c | 6 +-
arch/arm64/kvm/psci.c | 4 +-
arch/arm64/kvm/pvtime.c | 2 +-
arch/arm64/kvm/reset.c | 3 +-
arch/arm64/kvm/trace_arm.h | 2 +-
arch/arm64/kvm/trng.c | 2 +-
arch/arm64/kvm/vgic/vgic-debug.c | 2 +-
arch/arm64/kvm/vgic/vgic-init.c | 2 +-
arch/arm64/kvm/vgic/vgic-irqfd.c | 2 +-
arch/arm64/kvm/vgic/vgic-kvm-device.c | 2 +-
arch/arm64/kvm/vgic/vgic-mmio-v2.c | 4 +-
arch/arm64/kvm/vgic/vgic-mmio-v3.c | 4 +-
arch/arm64/kvm/vgic/vgic-mmio.c | 6 +-
arch/arm64/kvm/vgic/vgic-v2.c | 2 +-
arch/arm64/kvm/vgic/vgic-v3.c | 2 +-
arch/mips/include/asm/kvm_host.h | 5 +-
arch/mips/kernel/asm-offsets.c | 2 +
arch/mips/kvm/Kconfig | 3 +
arch/mips/kvm/Makefile | 2 -
arch/powerpc/include/asm/kvm_book3s.h | 3 +
arch/powerpc/include/asm/kvm_book3s_64.h | 2 +
arch/powerpc/include/asm/kvm_booke.h | 4 +
arch/powerpc/include/asm/kvm_host.h | 7 +-
arch/powerpc/include/asm/kvm_ppc.h | 306 +++++++++---------
arch/powerpc/include/asm/xics.h | 3 +
arch/powerpc/kernel/asm-offsets.c | 1 +
arch/powerpc/kvm/Kconfig | 1 -
arch/powerpc/kvm/Makefile | 2 -
arch/powerpc/kvm/mpic.c | 2 +-
arch/riscv/include/asm/kvm_host.h | 3 +
arch/riscv/kernel/asm-offsets.c | 1 +
arch/riscv/kvm/Makefile | 2 -
arch/riscv/kvm/aia_aplic.c | 2 +-
arch/riscv/kvm/aia_imsic.c | 2 +-
arch/riscv/kvm/vcpu.c | 2 +-
arch/s390/Kconfig | 1 -
arch/s390/include/asm/kvm_host.h | 7 +-
arch/s390/kernel/asm-offsets.c | 1 +
arch/s390/kvm/Kconfig | 2 -
arch/s390/kvm/Makefile | 2 -
arch/x86/Kconfig | 1 -
arch/x86/events/core.c | 5 +-
arch/x86/events/intel/core.c | 18 +-
arch/x86/events/perf_event.h | 3 +-
arch/x86/include/asm/hardirq.h | 2 +-
arch/x86/include/asm/idtentry.h | 2 +-
arch/x86/include/asm/irq.h | 2 +-
arch/x86/include/asm/irq_vectors.h | 2 +-
arch/x86/include/asm/kvm_host.h | 12 +-
arch/x86/include/asm/perf_event.h | 12 +-
arch/x86/kernel/idt.c | 2 +-
arch/x86/kernel/irq.c | 4 +-
arch/x86/kvm/Kconfig | 3 -
arch/x86/kvm/Makefile | 1 -
arch/x86/kvm/i8254.h | 2 +-
arch/x86/kvm/ioapic.h | 2 +-
arch/x86/kvm/irq.h | 2 +-
arch/x86/kvm/lapic.h | 2 +-
arch/x86/kvm/vmx/pmu_intel.c | 16 +-
arch/x86/kvm/vmx/vmx.c | 11 +-
arch/x86/kvm/vmx/vmx.h | 2 +-
arch/x86/kvm/x86.c | 3 +-
drivers/s390/crypto/vfio_ap_drv.c | 1 +
drivers/s390/crypto/vfio_ap_ops.c | 2 +
drivers/vfio/device_cdev.c | 9 +-
drivers/vfio/group.c | 18 +-
drivers/vfio/vfio.h | 26 +-
drivers/vfio/vfio_main.c | 139 ++++----
include/linux/entry-kvm.h | 10 +-
include/linux/kvm_host.h | 17 +-
include/{kvm/iodev.h => linux/kvm_iodev.h} | 0
include/linux/kvm_types.h | 3 +
include/linux/vfio.h | 6 +-
include/trace/events/kvm.h | 5 +
kernel/entry/kvm.c | 13 +-
scripts/gdb/linux/constants.py.in | 2 +-
scripts/gdb/linux/interrupts.py | 2 +-
tools/arch/x86/include/asm/irq_vectors.h | 2 +-
virt/kvm/Kconfig | 6 -
virt/kvm/Makefile.kvm | 6 +-
virt/kvm/coalesced_mmio.c | 3 +-
virt/kvm/eventfd.c | 2 +-
virt/kvm/kvm_main.c | 3 +-
virt/kvm/vfio.c | 9 +-
virt/kvm/vfio.h | 2 +-
109 files changed, 489 insertions(+), 440 deletions(-)
rename include/kvm/arm_arch_timer.h => arch/arm64/include/asm/kvm_arch_timer.h (98%)
rename include/kvm/arm_pmu.h => arch/arm64/include/asm/kvm_pmu.h (99%)
rename include/kvm/arm_vgic.h => arch/arm64/include/asm/kvm_vgic.h (99%)
rename {include => arch/arm64}/kvm/arm_hypercalls.h (100%)
rename {include => arch/arm64}/kvm/arm_psci.h (100%)
rename include/{kvm/iodev.h => linux/kvm_iodev.h} (100%)


base-commit: 0bb80ecc33a8fb5a682236443c1e740d5c917d1d
--
2.42.0.459.ge4e396fd5e-goog

2023-09-16 01:33:11

by Sean Christopherson

Subject: [PATCH 05/26] vfio: KVM: Pass get/put helpers from KVM to VFIO, don't do circular lookup

Explicitly pass KVM's get/put helpers to VFIO when attaching a VM to
VFIO instead of having VFIO do a symbol lookup back into KVM. Having both
KVM and VFIO do symbol lookups increases the overall complexity and places
an unnecessary dependency on KVM (from VFIO) without adding any value.

Signed-off-by: Sean Christopherson <[email protected]>
---
drivers/vfio/vfio.h | 2 ++
drivers/vfio/vfio_main.c | 74 +++++++++++++++++++---------------------
include/linux/vfio.h | 4 ++-
virt/kvm/vfio.c | 9 +++--
4 files changed, 47 insertions(+), 42 deletions(-)

diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h
index a1f741365075..eec51c7ee822 100644
--- a/drivers/vfio/vfio.h
+++ b/drivers/vfio/vfio.h
@@ -19,6 +19,8 @@ struct vfio_container;

struct vfio_kvm_reference {
struct kvm *kvm;
+ bool (*get_kvm)(struct kvm *kvm);
+ void (*put_kvm)(struct kvm *kvm);
spinlock_t lock;
};

diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index e77e8c6aae2f..1f58ab6dbcd2 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -16,7 +16,6 @@
#include <linux/fs.h>
#include <linux/idr.h>
#include <linux/iommu.h>
-#include <linux/kvm_host.h>
#include <linux/list.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
@@ -1306,38 +1305,22 @@ EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent);
void vfio_device_get_kvm_safe(struct vfio_device *device,
struct vfio_kvm_reference *ref)
{
- void (*pfn)(struct kvm *kvm);
- bool (*fn)(struct kvm *kvm);
- bool ret;
-
lockdep_assert_held(&device->dev_set->lock);

+ /*
+ * Note! The "kvm" and "put_kvm" pointers *must* be transferred to the
+ * device so that the device can put its reference to KVM. KVM can
+ * invoke vfio_device_set_kvm() to detach from VFIO, i.e. nullify all
+ * pointers in @ref, even if a device holds a reference to KVM! That
+ * also means that detaching KVM from VFIO only prevents "new" devices
+ * from using KVM, it doesn't invalidate KVM references in existing
+ * devices.
+ */
spin_lock(&ref->lock);
-
- if (!ref->kvm)
- goto out;
-
- pfn = symbol_get(kvm_put_kvm);
- if (WARN_ON(!pfn))
- goto out;
-
- fn = symbol_get(kvm_get_kvm_safe);
- if (WARN_ON(!fn)) {
- symbol_put(kvm_put_kvm);
- goto out;
+ if (ref->kvm && ref->get_kvm(ref->kvm)) {
+ device->kvm = ref->kvm;
+ device->put_kvm = ref->put_kvm;
}
-
- ret = fn(ref->kvm);
- symbol_put(kvm_get_kvm_safe);
- if (!ret) {
- symbol_put(kvm_put_kvm);
- goto out;
- }
-
- device->put_kvm = pfn;
- device->kvm = ref->kvm;
-
-out:
spin_unlock(&ref->lock);
}

@@ -1353,28 +1336,37 @@ void vfio_device_put_kvm(struct vfio_device *device)

device->put_kvm(device->kvm);
device->put_kvm = NULL;
- symbol_put(kvm_put_kvm);
-
clear:
device->kvm = NULL;
}

static void vfio_device_set_kvm(struct vfio_kvm_reference *ref,
- struct kvm *kvm)
+ struct kvm *kvm,
+ bool (*get_kvm)(struct kvm *kvm),
+ void (*put_kvm)(struct kvm *kvm))
{
+ if (WARN_ON_ONCE(kvm && (!get_kvm || !put_kvm)))
+ return;
+
spin_lock(&ref->lock);
ref->kvm = kvm;
+ ref->get_kvm = get_kvm;
+ ref->put_kvm = put_kvm;
spin_unlock(&ref->lock);
}

-static void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm)
+static void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm,
+ bool (*get_kvm)(struct kvm *kvm),
+ void (*put_kvm)(struct kvm *kvm))
{
#if IS_ENABLED(CONFIG_VFIO_GROUP)
- vfio_device_set_kvm(&group->kvm_ref, kvm);
+ vfio_device_set_kvm(&group->kvm_ref, kvm, get_kvm, put_kvm);
#endif
}

-static void vfio_device_file_set_kvm(struct file *file, struct kvm *kvm)
+static void vfio_device_file_set_kvm(struct file *file, struct kvm *kvm,
+ bool (*get_kvm)(struct kvm *kvm),
+ void (*put_kvm)(struct kvm *kvm))
{
struct vfio_device_file *df = file->private_data;

@@ -1383,27 +1375,31 @@ static void vfio_device_file_set_kvm(struct file *file, struct kvm *kvm)
* be propagated to vfio_device::kvm when the file is bound to
* iommufd successfully in the vfio device cdev path.
*/
- vfio_device_set_kvm(&df->kvm_ref, kvm);
+ vfio_device_set_kvm(&df->kvm_ref, kvm, get_kvm, put_kvm);
}

/**
* vfio_file_set_kvm - Link a kvm with VFIO drivers
* @file: VFIO group file or VFIO device file
* @kvm: KVM to link
+ * @get_kvm: Callback to get a reference to @kvm
+ * @put_kvm: Callback to put a reference to @kvm
*
* When a VFIO device is first opened the KVM will be available in
* device->kvm if one was associated with the file.
*/
-void vfio_file_set_kvm(struct file *file, struct kvm *kvm)
+void vfio_file_set_kvm(struct file *file, struct kvm *kvm,
+ bool (*get_kvm)(struct kvm *kvm),
+ void (*put_kvm)(struct kvm *kvm))
{
struct vfio_group *group;

group = vfio_group_from_file(file);
if (group)
- vfio_group_set_kvm(group, kvm);
+ vfio_group_set_kvm(group, kvm, get_kvm, put_kvm);

if (vfio_device_from_file(file))
- vfio_device_file_set_kvm(file, kvm);
+ vfio_device_file_set_kvm(file, kvm, get_kvm, put_kvm);
}
EXPORT_SYMBOL_GPL(vfio_file_set_kvm);
#endif
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index e80955de266c..35e970e3d3fb 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -312,7 +312,9 @@ static inline bool vfio_file_has_dev(struct file *file, struct vfio_device *devi
bool vfio_file_is_valid(struct file *file);
bool vfio_file_enforced_coherent(struct file *file);
#if IS_ENABLED(CONFIG_KVM)
-void vfio_file_set_kvm(struct file *file, struct kvm *kvm);
+void vfio_file_set_kvm(struct file *file, struct kvm *kvm,
+ bool (*get_kvm)(struct kvm *kvm),
+ void (*put_kvm)(struct kvm *kvm));
#endif

#define VFIO_PIN_PAGES_MAX_ENTRIES (PAGE_SIZE/sizeof(unsigned long))
diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c
index ca24ce120906..f14fcbb34bc6 100644
--- a/virt/kvm/vfio.c
+++ b/virt/kvm/vfio.c
@@ -37,13 +37,18 @@ struct kvm_vfio {

static void kvm_vfio_file_set_kvm(struct file *file, struct kvm *kvm)
{
- void (*fn)(struct file *file, struct kvm *kvm);
+ void (*fn)(struct file *file, struct kvm *kvm,
+ bool (*get_kvm)(struct kvm *kvm),
+ void (*put_kvm)(struct kvm *kvm));

fn = symbol_get(vfio_file_set_kvm);
if (!fn)
return;

- fn(file, kvm);
+ if (kvm)
+ fn(file, kvm, kvm_get_kvm_safe, kvm_put_kvm);
+ else
+ fn(file, kvm, NULL, NULL);

symbol_put(vfio_file_set_kvm);
}
--
2.42.0.459.ge4e396fd5e-goog

2023-09-16 01:36:40

by Sean Christopherson

Subject: [PATCH 09/26] KVM: arm64: Stop selecting and depending on HAVE_KVM

Now that nothing in arm64 or architecture agnostic code consumes HAVE_KVM,
stop selecting it in arm64. This is one of several steps towards deleting
HAVE_KVM from the common KVM Kconfig.

Signed-off-by: Sean Christopherson <[email protected]>
---
arch/arm64/Kconfig | 1 -
arch/arm64/kvm/Kconfig | 1 -
2 files changed, 2 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index b10515c0200b..7d99f132e57c 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -214,7 +214,6 @@ config ARM64
select HAVE_HW_BREAKPOINT if PERF_EVENTS
select HAVE_IOREMAP_PROT
select HAVE_IRQ_TIME_ACCOUNTING
- select HAVE_KVM
select HAVE_MOD_ARCH_SPECIFIC
select HAVE_NMI
select HAVE_PERF_EVENTS
diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index 2b5c332f157d..c76af1973315 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -20,7 +20,6 @@ if VIRTUALIZATION

menuconfig KVM
bool "Kernel-based Virtual Machine (KVM) support"
- depends on HAVE_KVM
select KVM_GENERIC_HARDWARE_ENABLING
select MMU_NOTIFIER
select PREEMPT_NOTIFIERS
--
2.42.0.459.ge4e396fd5e-goog

2023-09-16 02:00:53

by Sean Christopherson

Subject: [PATCH 06/26] KVM: Drop CONFIG_KVM_VFIO and just look at KVM+VFIO

Drop KVM's KVM_VFIO Kconfig, and instead compile in VFIO support if
and only if VFIO itself is enabled. Similar to the recent change to have
VFIO stop looking at HAVE_KVM, compiling in support for talking to VFIO
just because the architecture supports VFIO is nonsensical.

This fixes a bug where RISC-V doesn't select KVM_VFIO, i.e. would silently
fail to do connect KVM and VFIO, even though RISC-V supports VFIO. The
bug is benign as the only driver in all of Linux that actually uses the
KVM reference provided by VFIO is KVM-GT, which is x86/Intel specific.

Signed-off-by: Sean Christopherson <[email protected]>
---
arch/arm64/kvm/Kconfig | 1 -
arch/powerpc/kvm/Kconfig | 1 -
arch/s390/kvm/Kconfig | 1 -
arch/x86/kvm/Kconfig | 1 -
virt/kvm/Kconfig | 3 ---
virt/kvm/Makefile.kvm | 4 +++-
virt/kvm/vfio.h | 2 +-
7 files changed, 4 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index 83c1e09be42e..2b5c332f157d 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -28,7 +28,6 @@ menuconfig KVM
select KVM_MMIO
select KVM_GENERIC_DIRTYLOG_READ_PROTECT
select KVM_XFER_TO_GUEST_WORK
- select KVM_VFIO
select HAVE_KVM_EVENTFD
select HAVE_KVM_IRQFD
select HAVE_KVM_DIRTY_RING_ACQ_REL
diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig
index 902611954200..c4beb49c0eb2 100644
--- a/arch/powerpc/kvm/Kconfig
+++ b/arch/powerpc/kvm/Kconfig
@@ -22,7 +22,6 @@ config KVM
select PREEMPT_NOTIFIERS
select HAVE_KVM_EVENTFD
select HAVE_KVM_VCPU_ASYNC_IOCTL
- select KVM_VFIO
select IRQ_BYPASS_MANAGER
select HAVE_KVM_IRQ_BYPASS
select INTERVAL_TREE
diff --git a/arch/s390/kvm/Kconfig b/arch/s390/kvm/Kconfig
index 45fdf2a9b2e3..459d536116a6 100644
--- a/arch/s390/kvm/Kconfig
+++ b/arch/s390/kvm/Kconfig
@@ -31,7 +31,6 @@ config KVM
select HAVE_KVM_IRQ_ROUTING
select HAVE_KVM_INVALID_WAKEUPS
select HAVE_KVM_NO_POLL
- select KVM_VFIO
select INTERVAL_TREE
select MMU_NOTIFIER
help
diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index ed90f148140d..0f01e5600b5f 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -45,7 +45,6 @@ config KVM
select HAVE_KVM_NO_POLL
select KVM_XFER_TO_GUEST_WORK
select KVM_GENERIC_DIRTYLOG_READ_PROTECT
- select KVM_VFIO
select INTERVAL_TREE
select HAVE_KVM_PM_NOTIFIER if PM
select KVM_GENERIC_HARDWARE_ENABLING
diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig
index 484d0873061c..f0be3b55cea6 100644
--- a/virt/kvm/Kconfig
+++ b/virt/kvm/Kconfig
@@ -59,9 +59,6 @@ config HAVE_KVM_MSI
config HAVE_KVM_CPU_RELAX_INTERCEPT
bool

-config KVM_VFIO
- bool
-
config HAVE_KVM_INVALID_WAKEUPS
bool

diff --git a/virt/kvm/Makefile.kvm b/virt/kvm/Makefile.kvm
index 2c27d5d0c367..29373b59d89a 100644
--- a/virt/kvm/Makefile.kvm
+++ b/virt/kvm/Makefile.kvm
@@ -6,7 +6,9 @@
KVM ?= ../../../virt/kvm

kvm-y := $(KVM)/kvm_main.o $(KVM)/eventfd.o $(KVM)/binary_stats.o
-kvm-$(CONFIG_KVM_VFIO) += $(KVM)/vfio.o
+ifdef CONFIG_VFIO
+kvm-y += $(KVM)/vfio.o
+endif
kvm-$(CONFIG_KVM_MMIO) += $(KVM)/coalesced_mmio.o
kvm-$(CONFIG_KVM_ASYNC_PF) += $(KVM)/async_pf.o
kvm-$(CONFIG_HAVE_KVM_IRQ_ROUTING) += $(KVM)/irqchip.o
diff --git a/virt/kvm/vfio.h b/virt/kvm/vfio.h
index e130a4a03530..af475a323965 100644
--- a/virt/kvm/vfio.h
+++ b/virt/kvm/vfio.h
@@ -2,7 +2,7 @@
#ifndef __KVM_VFIO_H
#define __KVM_VFIO_H

-#ifdef CONFIG_KVM_VFIO
+#if IS_ENABLED(CONFIG_KVM) && IS_ENABLED(CONFIG_VFIO)
int kvm_vfio_ops_init(void);
void kvm_vfio_ops_exit(void);
#else
--
2.42.0.459.ge4e396fd5e-goog

2023-09-16 03:39:11

by Sean Christopherson

Subject: [PATCH 14/26] KVM: arm64: Move ARM specific headers in include/kvm to arch directory

Move kvm/arm_{arch_timer,pmu,vgic}.h to arch/arm64/include/asm and drop
the "arm" prefix from all file names. Now that KVM no longer supports
32-bit ARM, there is no reason to expose ARM specific headers to other
architectures beyond arm64.

Signed-off-by: Sean Christopherson <[email protected]>
---
.../arm64/include/asm/kvm_arch_timer.h | 0
arch/arm64/include/asm/kvm_host.h | 7 +++----
include/kvm/arm_pmu.h => arch/arm64/include/asm/kvm_pmu.h | 0
.../kvm/arm_vgic.h => arch/arm64/include/asm/kvm_vgic.h | 0
arch/arm64/kvm/arch_timer.c | 5 ++---
arch/arm64/kvm/arm.c | 3 +--
arch/arm64/kvm/pmu-emul.c | 6 +++---
arch/arm64/kvm/reset.c | 3 +--
arch/arm64/kvm/trace_arm.h | 2 +-
arch/arm64/kvm/vgic/vgic-debug.c | 2 +-
arch/arm64/kvm/vgic/vgic-init.c | 2 +-
arch/arm64/kvm/vgic/vgic-irqfd.c | 2 +-
arch/arm64/kvm/vgic/vgic-kvm-device.c | 2 +-
arch/arm64/kvm/vgic/vgic-mmio-v2.c | 2 +-
arch/arm64/kvm/vgic/vgic-mmio-v3.c | 2 +-
arch/arm64/kvm/vgic/vgic-mmio.c | 4 ++--
arch/arm64/kvm/vgic/vgic-v2.c | 2 +-
arch/arm64/kvm/vgic/vgic-v3.c | 2 +-
18 files changed, 21 insertions(+), 25 deletions(-)
rename include/kvm/arm_arch_timer.h => arch/arm64/include/asm/kvm_arch_timer.h (100%)
rename include/kvm/arm_pmu.h => arch/arm64/include/asm/kvm_pmu.h (100%)
rename include/kvm/arm_vgic.h => arch/arm64/include/asm/kvm_vgic.h (100%)

diff --git a/include/kvm/arm_arch_timer.h b/arch/arm64/include/asm/kvm_arch_timer.h
similarity index 100%
rename from include/kvm/arm_arch_timer.h
rename to arch/arm64/include/asm/kvm_arch_timer.h
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index af06ccb7ee34..90cfbf420545 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -26,16 +26,15 @@
#include <asm/daifflags.h>
#include <asm/fpsimd.h>
#include <asm/kvm.h>
+#include <asm/kvm_arch_timer.h>
#include <asm/kvm_asm.h>
+#include <asm/kvm_pmu.h>
+#include <asm/kvm_vgic.h>

#define __KVM_HAVE_ARCH_INTC_INITIALIZED

#define KVM_HALT_POLL_NS_DEFAULT 500000

-#include <kvm/arm_vgic.h>
-#include <kvm/arm_arch_timer.h>
-#include <kvm/arm_pmu.h>
-
#define KVM_MAX_VCPUS VGIC_V3_MAX_CPUS

#define KVM_VCPU_MAX_FEATURES 7
diff --git a/include/kvm/arm_pmu.h b/arch/arm64/include/asm/kvm_pmu.h
similarity index 100%
rename from include/kvm/arm_pmu.h
rename to arch/arm64/include/asm/kvm_pmu.h
diff --git a/include/kvm/arm_vgic.h b/arch/arm64/include/asm/kvm_vgic.h
similarity index 100%
rename from include/kvm/arm_vgic.h
rename to arch/arm64/include/asm/kvm_vgic.h
diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c
index 6dcdae4d38cb..5e40bea8f3f3 100644
--- a/arch/arm64/kvm/arch_timer.c
+++ b/arch/arm64/kvm/arch_timer.c
@@ -14,12 +14,11 @@

#include <clocksource/arm_arch_timer.h>
#include <asm/arch_timer.h>
+#include <asm/kvm_arch_timer.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_hyp.h>
#include <asm/kvm_nested.h>
-
-#include <kvm/arm_vgic.h>
-#include <kvm/arm_arch_timer.h>
+#include <asm/kvm_vgic.h>

#include "trace.h"

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 6de1d63b981b..6480628197b4 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -39,10 +39,9 @@
#include <asm/kvm_nested.h>
#include <asm/kvm_pkvm.h>
#include <asm/kvm_emulate.h>
+#include <asm/kvm_pmu.h>
#include <asm/sections.h>

-#include <kvm/arm_pmu.h>
-
#include "arm_hypercalls.h"
#include "arm_psci.h"

diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c
index 6b066e04dc5d..b5d999adce56 100644
--- a/arch/arm64/kvm/pmu-emul.c
+++ b/arch/arm64/kvm/pmu-emul.c
@@ -11,10 +11,10 @@
#include <linux/perf_event.h>
#include <linux/perf/arm_pmu.h>
#include <linux/uaccess.h>
-#include <asm/kvm_emulate.h>
-#include <kvm/arm_pmu.h>
-#include <kvm/arm_vgic.h>
#include <asm/arm_pmuv3.h>
+#include <asm/kvm_emulate.h>
+#include <asm/kvm_pmu.h>
+#include <asm/kvm_vgic.h>

#define PERF_ATTR_CFG1_COUNTER_64BIT BIT(0)

diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index 7a65a35ee4ac..ad5e239774f1 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -17,12 +17,11 @@
#include <linux/string.h>
#include <linux/types.h>

-#include <kvm/arm_arch_timer.h>
-
#include <asm/cpufeature.h>
#include <asm/cputype.h>
#include <asm/fpsimd.h>
#include <asm/ptrace.h>
+#include <asm/kvm_arch_timer.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_emulate.h>
diff --git a/arch/arm64/kvm/trace_arm.h b/arch/arm64/kvm/trace_arm.h
index 8ad53104934d..76ef72de6133 100644
--- a/arch/arm64/kvm/trace_arm.h
+++ b/arch/arm64/kvm/trace_arm.h
@@ -3,7 +3,7 @@
#define _TRACE_ARM_ARM64_KVM_H

#include <asm/kvm_emulate.h>
-#include <kvm/arm_arch_timer.h>
+#include <asm/kvm_arch_timer.h>
#include <linux/tracepoint.h>

#undef TRACE_SYSTEM
diff --git a/arch/arm64/kvm/vgic/vgic-debug.c b/arch/arm64/kvm/vgic/vgic-debug.c
index 07aa0437125a..2d542040008c 100644
--- a/arch/arm64/kvm/vgic/vgic-debug.c
+++ b/arch/arm64/kvm/vgic/vgic-debug.c
@@ -9,7 +9,7 @@
#include <linux/interrupt.h>
#include <linux/kvm_host.h>
#include <linux/seq_file.h>
-#include <kvm/arm_vgic.h>
+#include <asm/kvm_vgic.h>
#include <asm/kvm_mmu.h>
#include "vgic.h"

diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c
index c8c3cb812783..9f548ffac90b 100644
--- a/arch/arm64/kvm/vgic/vgic-init.c
+++ b/arch/arm64/kvm/vgic/vgic-init.c
@@ -7,7 +7,7 @@
#include <linux/interrupt.h>
#include <linux/cpu.h>
#include <linux/kvm_host.h>
-#include <kvm/arm_vgic.h>
+#include <asm/kvm_vgic.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_mmu.h>
#include "vgic.h"
diff --git a/arch/arm64/kvm/vgic/vgic-irqfd.c b/arch/arm64/kvm/vgic/vgic-irqfd.c
index 475059bacedf..c35e1a138617 100644
--- a/arch/arm64/kvm/vgic/vgic-irqfd.c
+++ b/arch/arm64/kvm/vgic/vgic-irqfd.c
@@ -6,7 +6,7 @@
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <trace/events/kvm.h>
-#include <kvm/arm_vgic.h>
+#include <asm/kvm_vgic.h>
#include "vgic.h"

/**
diff --git a/arch/arm64/kvm/vgic/vgic-kvm-device.c b/arch/arm64/kvm/vgic/vgic-kvm-device.c
index 212b73a715c1..2c7027d675c9 100644
--- a/arch/arm64/kvm/vgic/vgic-kvm-device.c
+++ b/arch/arm64/kvm/vgic/vgic-kvm-device.c
@@ -6,7 +6,7 @@
* Author: Marc Zyngier <[email protected]>
*/
#include <linux/kvm_host.h>
-#include <kvm/arm_vgic.h>
+#include <asm/kvm_vgic.h>
#include <linux/uaccess.h>
#include <asm/kvm_mmu.h>
#include <asm/cputype.h>
diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v2.c b/arch/arm64/kvm/vgic/vgic-mmio-v2.c
index e070cda86e12..bba0cfeefffe 100644
--- a/arch/arm64/kvm/vgic/vgic-mmio-v2.c
+++ b/arch/arm64/kvm/vgic/vgic-mmio-v2.c
@@ -9,7 +9,7 @@
#include <linux/nospec.h>

#include <kvm/iodev.h>
-#include <kvm/arm_vgic.h>
+#include <asm/kvm_vgic.h>

#include "vgic.h"
#include "vgic-mmio.h"
diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v3.c b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
index 188d2187eede..d54a90beef61 100644
--- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
@@ -9,11 +9,11 @@
#include <linux/kvm_host.h>
#include <linux/interrupt.h>
#include <kvm/iodev.h>
-#include <kvm/arm_vgic.h>

#include <asm/kvm_emulate.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_mmu.h>
+#include <asm/kvm_vgic.h>

#include "vgic.h"
#include "vgic-mmio.h"
diff --git a/arch/arm64/kvm/vgic/vgic-mmio.c b/arch/arm64/kvm/vgic/vgic-mmio.c
index ff558c05e990..68a3d8062473 100644
--- a/arch/arm64/kvm/vgic/vgic-mmio.c
+++ b/arch/arm64/kvm/vgic/vgic-mmio.c
@@ -10,8 +10,8 @@
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <kvm/iodev.h>
-#include <kvm/arm_arch_timer.h>
-#include <kvm/arm_vgic.h>
+#include <asm/kvm_arch_timer.h>
+#include <asm/kvm_vgic.h>

#include "vgic.h"
#include "vgic-mmio.h"
diff --git a/arch/arm64/kvm/vgic/vgic-v2.c b/arch/arm64/kvm/vgic/vgic-v2.c
index 7e9cdb78f7ce..7eacf1c850a5 100644
--- a/arch/arm64/kvm/vgic/vgic-v2.c
+++ b/arch/arm64/kvm/vgic/vgic-v2.c
@@ -6,7 +6,7 @@
#include <linux/irqchip/arm-gic.h>
#include <linux/kvm.h>
#include <linux/kvm_host.h>
-#include <kvm/arm_vgic.h>
+#include <asm/kvm_vgic.h>
#include <asm/kvm_mmu.h>

#include "vgic.h"
diff --git a/arch/arm64/kvm/vgic/vgic-v3.c b/arch/arm64/kvm/vgic/vgic-v3.c
index 3dfc8b84e03e..e8501828072b 100644
--- a/arch/arm64/kvm/vgic/vgic-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-v3.c
@@ -6,7 +6,7 @@
#include <linux/kstrtox.h>
#include <linux/kvm.h>
#include <linux/kvm_host.h>
-#include <kvm/arm_vgic.h>
+#include <asm/kvm_vgic.h>
#include <asm/kvm_hyp.h>
#include <asm/kvm_mmu.h>
#include <asm/kvm_asm.h>
--
2.42.0.459.ge4e396fd5e-goog

2023-09-16 03:49:00

by Sean Christopherson

Subject: [PATCH 21/26] entry/kvm: Drop @vcpu param from arch_xfer_to_guest_mode_handle_work()

Drop the "struct kvm_vcpu" parameter from
arch_xfer_to_guest_mode_handle_work() as a preparatory step towards
removing the vCPU parameter from xfer_to_guest_mode_work() as well.

Signed-off-by: Sean Christopherson <[email protected]>
---
include/linux/entry-kvm.h | 7 ++-----
kernel/entry/kvm.c | 2 +-
2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/include/linux/entry-kvm.h b/include/linux/entry-kvm.h
index 6813171afccb..e7d90d06e566 100644
--- a/include/linux/entry-kvm.h
+++ b/include/linux/entry-kvm.h
@@ -25,18 +25,15 @@ struct kvm_vcpu;
/**
* arch_xfer_to_guest_mode_handle_work - Architecture specific xfer to guest
* mode work handling function.
- * @vcpu: Pointer to current's VCPU data
* @ti_work: Cached TIF flags gathered in xfer_to_guest_mode_handle_work()
*
* Invoked from xfer_to_guest_mode_handle_work(). Defaults to NOOP. Can be
* replaced by architecture specific code.
*/
-static inline int arch_xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu,
- unsigned long ti_work);
+static inline int arch_xfer_to_guest_mode_handle_work(unsigned long ti_work);

#ifndef arch_xfer_to_guest_mode_work
-static inline int arch_xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu,
- unsigned long ti_work)
+static inline int arch_xfer_to_guest_mode_handle_work(unsigned long ti_work)
{
return 0;
}
diff --git a/kernel/entry/kvm.c b/kernel/entry/kvm.c
index 2e0f75bcb7fd..c2fc39824157 100644
--- a/kernel/entry/kvm.c
+++ b/kernel/entry/kvm.c
@@ -19,7 +19,7 @@ static int xfer_to_guest_mode_work(struct kvm_vcpu *vcpu, unsigned long ti_work)
if (ti_work & _TIF_NOTIFY_RESUME)
resume_user_mode_work(NULL);

- ret = arch_xfer_to_guest_mode_handle_work(vcpu, ti_work);
+ ret = arch_xfer_to_guest_mode_handle_work(ti_work);
if (ret)
return ret;

--
2.42.0.459.ge4e396fd5e-goog

2023-09-16 04:05:09

by Sean Christopherson

Subject: [PATCH 24/26] powerpc/xics: Move declaration of xics_wake_cpu() out of kvm_ppc.h

xics_wake_cpu() is provided by core PPC code, not by KVM. Move its
declaration out of kvm_ppc.h and into xics.h.

Signed-off-by: Sean Christopherson <[email protected]>
---
arch/powerpc/include/asm/kvm_ppc.h | 2 --
arch/powerpc/include/asm/xics.h | 3 +++
2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index b4da8514af43..72fee202d3ec 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -1072,6 +1072,4 @@ static inline ulong kvmppc_get_ea_indexed(struct kvm_vcpu *vcpu, int ra, int rb)
return ea;
}

-extern void xics_wake_cpu(int cpu);
-
#endif /* __POWERPC_KVM_PPC_H__ */
diff --git a/arch/powerpc/include/asm/xics.h b/arch/powerpc/include/asm/xics.h
index 89090485bec1..17a45c022bd9 100644
--- a/arch/powerpc/include/asm/xics.h
+++ b/arch/powerpc/include/asm/xics.h
@@ -32,6 +32,9 @@
extern int icp_native_init(void);
extern void icp_native_flush_interrupt(void);
extern void icp_native_cause_ipi_rm(int cpu);
+#ifdef CONFIG_SMP
+extern void xics_wake_cpu(int cpu);
+#endif
#else
static inline int icp_native_init(void) { return -ENODEV; }
#endif
--
2.42.0.459.ge4e396fd5e-goog

2023-09-16 05:34:37

by Sean Christopherson

Subject: [PATCH 26/26] KVM: Hide KVM internal data structures and values from kernel at-large

Wrap all KVM internal APIs, data structures, values, etc. in public
headers with "#ifdef __KVM__" to effectively hide KVM's internal details
from other subsystems and the kernel at-large. Hiding KVM details for
all architectures will, in the very distant future, allow loading a new
(or old) KVM module without needing to rebuild and reboot the entire
kernel, or to even allow loading and running multiple versions of KVM
simultaneously on a single host.

To allow different instances of KVM modules to freely modify KVM data
structures, enums, #defines, etc., e.g. the struct kvm_vcpu layout, there
must be exactly zero dereferences of KVM-defined structures/values in
non-KVM code (excepting code for architectures that don't support such
shenanigans). Any such references could lead to latent bugs, e.g. as the
kernel would think a KVM structure has layout X, but in reality the
current incarnation of KVM uses layout Y.

In KVM x86, all remaining non-KVM references to KVM details have been now
eliminated. To harden KVM against new references being introduced, hide
KVM's details to ensure that KVM doesn’t create a de facto ABI with the
rest of the kernel.

Use #ifdeffery to hide KVM details as doing so requires, by far, the least
amount of churn and impact on architectures that freely share select KVM
details with the rest of the kernel, e.g. s390, ARM64 and PPC, have
significant usage of KVM-defined APIs, structures, values, etc. E.g.
attempting to extract the "private" chunks into dedicated KVM-internal
headers would require massive churn, even on x86, and it's not obvious the
end result would be a net positive (all attempts at moving code around
failed long before getting anywhere near compiling cleanly).

Another (bad) alternative that would be relative churn-free would be to
move the KVM headers to a dedicated KVM-specific path while maintaining
the generic layout, e.g. something like virt/kvm/include/linux. That
would allow x86 to simply omit the KVM-specific include path. But that
would require modifying the global include path, i.e. would make KVM a
really special snowflake and set the awful precedent that it's "ok" to
add subsystem specific directories to the global include path.

Grant exceptions to asm-offsets.c as needed, and to s390's VFIO AP driver.
Creating a KVM-specific asm-offsets, as was done for x86, adds no value
(x86 did so to avoid exposing vendor specific headers) and doesn't create
much of a "slippery slope" risk. s390's VFIO AP driver on the other hand
is simply too intertwined with KVM to realistically treat it as anything
other than KVM code, despite it living in crypto drivers, e.g. the driver
has some rather crazy lock ordering rules between the device and KVM.

Add a static assert that __KVM__ is defined in trace/events/kvm.h, as that
is effectively a private KVM header that just happens to live in a public
path.

Shuffle a few PPC includes and an s390 declaration as needed, and
opportunistically include kvm_host.h in trace/events.kvm.h instead of
relying on the parent to provide the right includes.

Cc: Anish Ghulati <[email protected]>
Cc: Venkatesh Srinivas <[email protected]>
Cc: Andrew Thornton <[email protected]>
Signed-off-by: Sean Christopherson <[email protected]>
---
arch/arm64/include/asm/kvm_emulate.h | 3 +++
arch/arm64/include/asm/kvm_host.h | 2 ++
arch/arm64/include/asm/kvm_mmu.h | 4 ++++
arch/arm64/kernel/asm-offsets.c | 2 ++
arch/arm64/kvm/hyp/Makefile | 2 +-
arch/arm64/kvm/hyp/nvhe/Makefile | 3 ++-
arch/arm64/kvm/hyp/vhe/Makefile | 2 +-
arch/mips/include/asm/kvm_host.h | 2 ++
arch/mips/kernel/asm-offsets.c | 2 ++
arch/powerpc/include/asm/kvm_book3s.h | 3 +++
arch/powerpc/include/asm/kvm_book3s_64.h | 2 ++
arch/powerpc/include/asm/kvm_booke.h | 4 ++++
arch/powerpc/include/asm/kvm_host.h | 7 ++++---
arch/powerpc/include/asm/kvm_ppc.h | 2 ++
arch/powerpc/kernel/asm-offsets.c | 1 +
arch/riscv/include/asm/kvm_host.h | 3 +++
arch/riscv/kernel/asm-offsets.c | 1 +
arch/s390/include/asm/kvm_host.h | 7 +++++--
arch/s390/kernel/asm-offsets.c | 1 +
arch/x86/include/asm/kvm_host.h | 3 +++
drivers/s390/crypto/vfio_ap_drv.c | 1 +
drivers/s390/crypto/vfio_ap_ops.c | 2 ++
include/linux/kvm_host.h | 4 ++++
include/linux/kvm_types.h | 3 +++
include/trace/events/kvm.h | 5 +++++
virt/kvm/Makefile.kvm | 2 +-
26 files changed, 64 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index 3d6725ff0bf6..5861fa00763b 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -21,6 +21,8 @@
#include <asm/cputype.h>
#include <asm/virt.h>

+#ifdef __KVM__
+
#define CURRENT_EL_SP_EL0_VECTOR 0x0
#define CURRENT_EL_SP_ELx_VECTOR 0x200
#define LOWER_EL_AArch64_VECTOR 0x400
@@ -615,4 +617,5 @@ static __always_inline void kvm_reset_cptr_el2(struct kvm_vcpu *vcpu)

kvm_write_cptr_el2(val);
}
+#endif /* __KVM__ */
#endif /* __ARM64_KVM_EMULATE_H__ */
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 89b40c34f0af..ba4065db5d5c 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -93,6 +93,7 @@ static inline bool kvm_pmu_counter_deferred(struct perf_event_attr *attr)
return (!has_vhe() && attr->exclude_host);
}

+#ifdef __KVM__
DECLARE_STATIC_KEY_FALSE(userspace_irqchip_in_use);

extern unsigned int __ro_after_init kvm_sve_max_vl;
@@ -1149,4 +1150,5 @@ int kvm_trng_call(struct kvm_vcpu *vcpu);
void kvm_arm_vcpu_power_off(struct kvm_vcpu *vcpu);
bool kvm_arm_vcpu_stopped(struct kvm_vcpu *vcpu);

+#endif /* __KVM__ */
#endif /* __ARM64_KVM_HOST_H__ */
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index 96a80e8f6226..9d8c92cda3b6 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -125,6 +125,8 @@ void kvm_update_va_mask(struct alt_instr *alt,
void kvm_compute_layout(void);
void kvm_apply_hyp_relocations(void);

+#ifdef __KVM__
+
#define __hyp_pa(x) (((phys_addr_t)(x)) + hyp_physvirt_offset)

static __always_inline unsigned long __kern_hyp_va(unsigned long v)
@@ -314,5 +316,7 @@ static inline struct kvm *kvm_s2_mmu_to_kvm(struct kvm_s2_mmu *mmu)
{
return container_of(mmu->arch, struct kvm, arch);
}
+
+#endif /* __KVM__ */
#endif /* __ASSEMBLY__ */
#endif /* __ARM64_KVM_MMU_H__ */
diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c
index 5ff1942b04fc..dc02ea9a002c 100644
--- a/arch/arm64/kernel/asm-offsets.c
+++ b/arch/arm64/kernel/asm-offsets.c
@@ -7,6 +7,8 @@
* Copyright (C) 2012 ARM Ltd.
*/

+#define __KVM__
+
#include <linux/arm_sdei.h>
#include <linux/sched.h>
#include <linux/ftrace.h>
diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile
index 4ce8c86967b5..99982b75671a 100644
--- a/arch/arm64/kvm/hyp/Makefile
+++ b/arch/arm64/kvm/hyp/Makefile
@@ -5,6 +5,6 @@

incdir := $(srctree)/$(src)/include
subdir-asflags-y := -I$(incdir) -I$(srctree)/arch/arm64/kvm
-subdir-ccflags-y := -I$(incdir) -I$(srctree)/arch/arm64/kvm
+subdir-ccflags-y := -I$(incdir) -I$(srctree)/arch/arm64/kvm -D__KVM__

obj-$(CONFIG_KVM) += vhe/ nvhe/ pgtable.o
diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile
index 2250253a6429..b5f4750fa16e 100644
--- a/arch/arm64/kvm/hyp/nvhe/Makefile
+++ b/arch/arm64/kvm/hyp/nvhe/Makefile
@@ -9,7 +9,8 @@ asflags-y := -D__KVM_NVHE_HYPERVISOR__ -D__DISABLE_EXPORTS
# there is no way to execute them and any such MMIO access from nVHE KVM
# will explode instantly (Words of Marc Zyngier). So introduce a generic flag
# __DISABLE_TRACE_MMIO__ to disable MMIO tracing for nVHE KVM.
-ccflags-y := -D__KVM_NVHE_HYPERVISOR__ -D__DISABLE_EXPORTS -D__DISABLE_TRACE_MMIO__
+ccflags-y := -D__KVM_NVHE_HYPERVISOR__ -D__DISABLE_EXPORTS \
+ -D__DISABLE_TRACE_MMIO__ -D__KVM__
ccflags-y += -fno-stack-protector \
-DDISABLE_BRANCH_PROFILING \
$(DISABLE_STACKLEAK_PLUGIN)
diff --git a/arch/arm64/kvm/hyp/vhe/Makefile b/arch/arm64/kvm/hyp/vhe/Makefile
index 3b9e5464b5b3..54cd3c444102 100644
--- a/arch/arm64/kvm/hyp/vhe/Makefile
+++ b/arch/arm64/kvm/hyp/vhe/Makefile
@@ -4,7 +4,7 @@
#

asflags-y := -D__KVM_VHE_HYPERVISOR__
-ccflags-y := -D__KVM_VHE_HYPERVISOR__
+ccflags-y := -D__KVM_VHE_HYPERVISOR__ -D__KVM__

obj-y := timer-sr.o sysreg-sr.o debug-sr.o switch.o tlb.o
obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \
diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h
index f8f63d0aa399..6fd7c998d7b9 100644
--- a/arch/mips/include/asm/kvm_host.h
+++ b/arch/mips/include/asm/kvm_host.h
@@ -25,6 +25,7 @@
#include <asm/inst.h>
#include <asm/mipsregs.h>

+#ifdef __KVM__
/* MIPS KVM register ids */
#define MIPS_CP0_32(_R, _S) \
(KVM_REG_MIPS_CP0 | KVM_REG_SIZE_U32 | (8 * (_R) + (_S)))
@@ -897,4 +898,5 @@ static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {}

#define __KVM_HAVE_ARCH_FLUSH_REMOTE_TLBS

+#endif /* __KVM__ */
#endif /* __MIPS_KVM_HOST_H__ */
diff --git a/arch/mips/kernel/asm-offsets.c b/arch/mips/kernel/asm-offsets.c
index d1b11f66f748..8a233bddfea0 100644
--- a/arch/mips/kernel/asm-offsets.c
+++ b/arch/mips/kernel/asm-offsets.c
@@ -9,6 +9,8 @@
* Kevin Kissell, [email protected] and Carsten Langgaard, [email protected]
* Copyright (C) 2000 MIPS Technologies, Inc.
*/
+#define __KVM__
+
#include <linux/compat.h>
#include <linux/types.h>
#include <linux/sched.h>
diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h
index bbf5e2c5fe09..8880bc7c8a32 100644
--- a/arch/powerpc/include/asm/kvm_book3s.h
+++ b/arch/powerpc/include/asm/kvm_book3s.h
@@ -13,6 +13,8 @@
#include <linux/kvm_host.h>
#include <asm/kvm_book3s_asm.h>

+#ifdef __KVM__
+
struct kvmppc_bat {
u64 raw;
u32 bepi;
@@ -483,4 +485,5 @@ static inline u32 kvmppc_pack_vcpu_id(struct kvm *kvm, u32 id)
return packed_id;
}

+#endif /* __KVM__ */
#endif /* __ASM_KVM_BOOK3S_H__ */
diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
index d49065af08e9..a807716ccae6 100644
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -16,6 +16,7 @@
#include <asm/ppc-opcode.h>
#include <asm/pte-walk.h>

+#ifdef __KVM__
/*
* Structure for a nested guest, that is, for a guest that is managed by
* one of our guests.
@@ -679,4 +680,5 @@ extern pte_t *find_kvm_nested_guest_pte(struct kvm *kvm, unsigned long lpid,

#endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */

+#endif /* __KVM__ */
#endif /* __ASM_KVM_BOOK3S_64_H__ */
diff --git a/arch/powerpc/include/asm/kvm_booke.h b/arch/powerpc/include/asm/kvm_booke.h
index 0c3401b2e19e..85ebc0314539 100644
--- a/arch/powerpc/include/asm/kvm_booke.h
+++ b/arch/powerpc/include/asm/kvm_booke.h
@@ -12,6 +12,8 @@
#include <linux/types.h>
#include <linux/kvm_host.h>

+#ifdef __KVM__
+
/*
* Number of available lpids. Only the low-order 6 bits of LPID rgister are
* implemented on e500mc+ cores.
@@ -105,4 +107,6 @@ static inline bool kvmppc_supports_magic_page(struct kvm_vcpu *vcpu)
return false;
#endif
}
+
+#endif /* __KVM__ */
#endif /* __ASM_KVM_BOOKE_H__ */
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 14ee0dece853..1e7a008ce085 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -14,6 +14,7 @@
#include <linux/interrupt.h>
#include <linux/types.h>
#include <linux/kvm_types.h>
+#include <linux/mmu_notifier.h>
#include <linux/threads.h>
#include <linux/spinlock.h>
#include <linux/kvm_para.h>
@@ -25,13 +26,14 @@
#include <asm/cacheflush.h>
#include <asm/hvcall.h>
#include <asm/mce.h>
+#include <asm/cputhreads.h>

+#ifdef __KVM__
#define __KVM_HAVE_ARCH_VCPU_DEBUGFS

#define KVM_MAX_VCPUS NR_CPUS
#define KVM_MAX_VCORES NR_CPUS

-#include <asm/cputhreads.h>

#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
#include <asm/kvm_book3s_asm.h> /* for MAX_SMT_THREADS */
@@ -60,8 +62,6 @@
#define KVM_REQ_EPR_EXIT KVM_ARCH_REQ(1)
#define KVM_REQ_PENDING_TIMER KVM_ARCH_REQ(2)

-#include <linux/mmu_notifier.h>
-
#define KVM_ARCH_WANT_MMU_NOTIFIER

#define HPTEG_CACHE_NUM (1 << 15)
@@ -883,4 +883,5 @@ static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {}
static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {}

+#endif /* __KVM__ */
#endif /* __POWERPC_KVM_HOST_H__ */
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index ead2ad892ebc..03d9998d0111 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -183,6 +183,7 @@ static inline void kvmppc_clear_host_ipi(int cpu)
static inline bool kvm_hv_mode_active(void) { return false; }
#endif

+#ifdef __KVM__
/*
* KVMPPC_INST_SW_BREAKPOINT is debug Instruction
* for supporting software breakpoint.
@@ -1076,4 +1077,5 @@ static inline ulong kvmppc_get_ea_indexed(struct kvm_vcpu *vcpu, int ra, int rb)
return ea;
}

+#endif /* __KVM__ */
#endif /* __POWERPC_KVM_PPC_H__ */
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 9f14d95b8b32..872d44971536 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -8,6 +8,7 @@
* compile this file to assembler, and then extract the
* #defines from the assembly-language output.
*/
+#define __KVM__

#include <linux/compat.h>
#include <linux/signal.h>
diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h
index 1ebf20dfbaa6..a81ae8c4b739 100644
--- a/arch/riscv/include/asm/kvm_host.h
+++ b/arch/riscv/include/asm/kvm_host.h
@@ -22,6 +22,8 @@
#include <asm/kvm_vcpu_timer.h>
#include <asm/kvm_vcpu_pmu.h>

+#ifdef __KVM__
+
#define KVM_MAX_VCPUS 1024

#define KVM_HALT_POLL_NS_DEFAULT 500000
@@ -354,4 +356,5 @@ bool kvm_riscv_vcpu_has_interrupts(struct kvm_vcpu *vcpu, u64 mask);
void kvm_riscv_vcpu_power_off(struct kvm_vcpu *vcpu);
void kvm_riscv_vcpu_power_on(struct kvm_vcpu *vcpu);

+#endif /* __KVM__ */
#endif /* __RISCV_KVM_HOST_H__ */
diff --git a/arch/riscv/kernel/asm-offsets.c b/arch/riscv/kernel/asm-offsets.c
index d6a75aac1d27..476263e78f39 100644
--- a/arch/riscv/kernel/asm-offsets.c
+++ b/arch/riscv/kernel/asm-offsets.c
@@ -5,6 +5,7 @@
*/

#define GENERATING_ASM_OFFSETS
+#define __KVM__

#include <linux/kbuild.h>
#include <linux/mm.h>
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 427f9528a7b6..9153420bb5ac 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -380,6 +380,10 @@ struct sie_page {
__u8 reserved700[2304]; /* 0x0700 */
};

+extern char sie_exit;
+
+#ifdef __KVM__
+
struct kvm_vcpu_stat {
struct kvm_vcpu_stat_generic generic;
u64 exit_userspace;
@@ -1028,8 +1032,6 @@ static inline int sie64a(struct kvm_s390_sie_block *sie_block, u64 *rsa)
return __sie64a(virt_to_phys(sie_block), sie_block, rsa);
}

-extern char sie_exit;
-
bool kvm_s390_pv_is_protected(struct kvm *kvm);
bool kvm_s390_pv_cpu_is_protected(struct kvm_vcpu *vcpu);

@@ -1049,6 +1051,7 @@ static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {}

#define __KVM_HAVE_ARCH_VM_FREE
void kvm_arch_free_vm(struct kvm *kvm);
+#endif /* __KVM__ */

struct zpci_kvm_hook {
int (*kvm_register)(void *opaque, struct kvm *kvm);
diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c
index fa5f6885c74a..22ed673871ee 100644
--- a/arch/s390/kernel/asm-offsets.c
+++ b/arch/s390/kernel/asm-offsets.c
@@ -6,6 +6,7 @@
*/

#define ASM_OFFSETS_C
+#define __KVM__

#include <linux/kbuild.h>
#include <linux/kvm_host.h>
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 29db870dbaae..eda45a937666 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -37,6 +37,8 @@
#include <asm/kvm_vcpu_regs.h>
#include <asm/hyperv-tlfs.h>

+#ifdef __KVM__
+
#define __KVM_HAVE_ARCH_VCPU_DEBUGFS

#define KVM_MAX_VCPUS 1024
@@ -2229,4 +2231,5 @@ int memslot_rmap_alloc(struct kvm_memory_slot *slot, unsigned long npages);
*/
#define KVM_EXIT_HYPERCALL_MBZ GENMASK_ULL(31, 1)

+#endif /* __KVM__ */
#endif /* _ASM_X86_KVM_HOST_H */
diff --git a/drivers/s390/crypto/vfio_ap_drv.c b/drivers/s390/crypto/vfio_ap_drv.c
index a5ab03e42ff1..55744f0f4758 100644
--- a/drivers/s390/crypto/vfio_ap_drv.c
+++ b/drivers/s390/crypto/vfio_ap_drv.c
@@ -7,6 +7,7 @@
* Author(s): Tony Krowiak <[email protected]>
* Pierre Morel <[email protected]>
*/
+#define __KVM__

#include <linux/module.h>
#include <linux/mod_devicetable.h>
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 4db538a55192..0dd98f42e9d5 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -8,6 +8,8 @@
* Halil Pasic <[email protected]>
* Pierre Morel <[email protected]>
*/
+#define __KVM__
+
#include <linux/string.h>
#include <linux/vfio.h>
#include <linux/device.h>
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index d520d6801070..f0afe549c0d6 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -45,6 +45,8 @@
#include <asm/kvm_host.h>
#include <linux/kvm_dirty_ring.h>

+#ifdef __KVM__
+
#ifndef KVM_MAX_VCPU_IDS
#define KVM_MAX_VCPU_IDS KVM_MAX_VCPUS
#endif
@@ -2329,4 +2331,6 @@ static inline void kvm_account_pgtable_pages(void *virt, int nr)
/* Max number of entries allowed for each kvm dirty ring */
#define KVM_DIRTY_RING_MAX_ENTRIES 65536

+#endif /* __KVM__ */
+
#endif
diff --git a/include/linux/kvm_types.h b/include/linux/kvm_types.h
index 6f4737d5046a..4804bce2a655 100644
--- a/include/linux/kvm_types.h
+++ b/include/linux/kvm_types.h
@@ -48,6 +48,8 @@ typedef u64 hfn_t;

typedef hfn_t kvm_pfn_t;

+#ifdef __KVM__
+
enum pfn_cache_usage {
KVM_GUEST_USES_PFN = BIT(0),
KVM_HOST_USES_PFN = BIT(1),
@@ -123,4 +125,5 @@ struct kvm_vcpu_stat_generic {

#define KVM_STATS_NAME_SIZE 48

+#endif /* __KVM__ */
#endif /* __KVM_TYPES_H__ */
diff --git a/include/trace/events/kvm.h b/include/trace/events/kvm.h
index 3bd31ea23fee..aee85527bb74 100644
--- a/include/trace/events/kvm.h
+++ b/include/trace/events/kvm.h
@@ -2,8 +2,13 @@
#if !defined(_TRACE_KVM_MAIN_H) || defined(TRACE_HEADER_MULTI_READ)
#define _TRACE_KVM_MAIN_H

+#include <linux/kvm_host.h>
#include <linux/tracepoint.h>

+#ifndef __KVM__
+static_assert(0, "Do not include trace/events/kvm.h from non-KVM code");
+#endif
+
#undef TRACE_SYSTEM
#define TRACE_SYSTEM kvm

diff --git a/virt/kvm/Makefile.kvm b/virt/kvm/Makefile.kvm
index e85079ad245d..4de10d447ef3 100644
--- a/virt/kvm/Makefile.kvm
+++ b/virt/kvm/Makefile.kvm
@@ -3,7 +3,7 @@
# Makefile for Kernel-based Virtual Machine module
#

-ccflags-y += -I$(srctree)/$(src)
+ccflags-y += -I$(srctree)/$(src) -D__KVM__

KVM ?= ../../../virt/kvm

--
2.42.0.459.ge4e396fd5e-goog

2023-09-16 05:47:35

by Sean Christopherson

Subject: [PATCH 20/26] perf/x86: KVM: Have perf define a dedicated struct for getting guest PEBS data

Have perf define a struct for getting guest PEBS data from KVM instead of
poking into the kvm_pmu structure. Passing in an entire "struct kvm_pmu"
_as an opaque pointer_ to get at three fields is silly, especially since
one of the fields exists purely to convey information to perf, i.e. isn't
used by KVM.

Perf should also own its APIs, i.e. define what fields/data it needs, not
rely on KVM to throw fields into data structures that effectively hold
KVM-internal state.

Signed-off-by: Sean Christopherson <[email protected]>
---
arch/x86/events/core.c | 5 +++--
arch/x86/events/intel/core.c | 18 +++++++++---------
arch/x86/events/perf_event.h | 3 ++-
arch/x86/include/asm/kvm_host.h | 9 ---------
arch/x86/include/asm/perf_event.h | 12 ++++++++++--
arch/x86/kvm/vmx/pmu_intel.c | 16 +++++++++++++---
arch/x86/kvm/vmx/vmx.c | 10 ++++++----
arch/x86/kvm/vmx/vmx.h | 2 +-
8 files changed, 44 insertions(+), 31 deletions(-)

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 185f902e5f28..3b015cfcf41d 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -695,9 +695,10 @@ void x86_pmu_disable_all(void)
}
}

-struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr, void *data)
+struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr,
+ struct x86_guest_pebs *guest_pebs)
{
- return static_call(x86_pmu_guest_get_msrs)(nr, data);
+ return static_call(x86_pmu_guest_get_msrs)(nr, guest_pebs);
}
EXPORT_SYMBOL_GPL(perf_guest_get_msrs);

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index fa355d3658a6..9b848d7ebaaf 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -14,7 +14,6 @@
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/nmi.h>
-#include <linux/kvm_host.h>

#include <asm/cpufeature.h>
#include <asm/hardirq.h>
@@ -4053,11 +4052,11 @@ static int intel_pmu_hw_config(struct perf_event *event)
* when it uses {RD,WR}MSR, which should be handled by the KVM context,
* specifically in the intel_pmu_{get,set}_msr().
*/
-static struct perf_guest_switch_msr *intel_guest_get_msrs(int *nr, void *data)
+static struct perf_guest_switch_msr *intel_guest_get_msrs(int *nr,
+ struct x86_guest_pebs *guest_pebs)
{
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
struct perf_guest_switch_msr *arr = cpuc->guest_switch_msrs;
- struct kvm_pmu *kvm_pmu = (struct kvm_pmu *)data;
u64 intel_ctrl = hybrid(cpuc->pmu, intel_ctrl);
u64 pebs_mask = cpuc->pebs_enabled & x86_pmu.pebs_capable;
int global_ctrl, pebs_enable;
@@ -4090,20 +4089,20 @@ static struct perf_guest_switch_msr *intel_guest_get_msrs(int *nr, void *data)
return arr;
}

- if (!kvm_pmu || !x86_pmu.pebs_ept)
+ if (!guest_pebs || !x86_pmu.pebs_ept)
return arr;

arr[(*nr)++] = (struct perf_guest_switch_msr){
.msr = MSR_IA32_DS_AREA,
.host = (unsigned long)cpuc->ds,
- .guest = kvm_pmu->ds_area,
+ .guest = guest_pebs->ds_area,
};

if (x86_pmu.intel_cap.pebs_baseline) {
arr[(*nr)++] = (struct perf_guest_switch_msr){
.msr = MSR_PEBS_DATA_CFG,
.host = cpuc->active_pebs_data_cfg,
- .guest = kvm_pmu->pebs_data_cfg,
+ .guest = guest_pebs->data_cfg,
};
}

@@ -4119,8 +4118,8 @@ static struct perf_guest_switch_msr *intel_guest_get_msrs(int *nr, void *data)
arr[pebs_enable].guest = 0;
} else {
/* Disable guest PEBS thoroughly for cross-mapped PEBS counters. */
- arr[pebs_enable].guest &= ~kvm_pmu->host_cross_mapped_mask;
- arr[global_ctrl].guest &= ~kvm_pmu->host_cross_mapped_mask;
+ arr[pebs_enable].guest &= ~guest_pebs->cross_mapped_mask;
+ arr[global_ctrl].guest &= ~guest_pebs->cross_mapped_mask;
/* Set hw GLOBAL_CTRL bits for PEBS counter when it runs for guest */
arr[global_ctrl].guest |= arr[pebs_enable].guest;
}
@@ -4128,7 +4127,8 @@ static struct perf_guest_switch_msr *intel_guest_get_msrs(int *nr, void *data)
return arr;
}

-static struct perf_guest_switch_msr *core_guest_get_msrs(int *nr, void *data)
+static struct perf_guest_switch_msr *core_guest_get_msrs(int *nr,
+ struct x86_guest_pebs *guest_pebs)
{
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
struct perf_guest_switch_msr *arr = cpuc->guest_switch_msrs;
diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h
index c8ba2be7585d..d805c9007e35 100644
--- a/arch/x86/events/perf_event.h
+++ b/arch/x86/events/perf_event.h
@@ -920,7 +920,8 @@ struct x86_pmu {
/*
* Intel host/guest support (KVM)
*/
- struct perf_guest_switch_msr *(*guest_get_msrs)(int *nr, void *data);
+ struct perf_guest_switch_msr *(*guest_get_msrs)(int *nr,
+ struct x86_guest_pebs *guest_pebs);

/*
* Check period value for PERF_EVENT_IOC_PERIOD ioctl.
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 1a4def36d5bb..29db870dbaae 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -548,15 +548,6 @@ struct kvm_pmu {
u64 pebs_data_cfg;
u64 pebs_data_cfg_mask;

- /*
- * If a guest counter is cross-mapped to host counter with different
- * index, its PEBS capability will be temporarily disabled.
- *
- * The user should make sure that this mask is updated
- * after disabling interrupts and before perf_guest_get_msrs();
- */
- u64 host_cross_mapped_mask;
-
/*
* The gate to release perf_events not marked in
* pmc_in_use only once in a vcpu time slice.
diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
index 85a9fd5a3ec3..34c2c9a0b02b 100644
--- a/arch/x86/include/asm/perf_event.h
+++ b/arch/x86/include/asm/perf_event.h
@@ -564,11 +564,19 @@ static inline void perf_events_lapic_init(void) { }
static inline void perf_check_microcode(void) { }
#endif

+struct x86_guest_pebs {
+ u64 ds_area;
+ u64 data_cfg;
+ u64 cross_mapped_mask;
+};
+
#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_INTEL)
-extern struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr, void *data);
+extern struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr,
+ struct x86_guest_pebs *guest_pebs);
extern void x86_perf_get_lbr(struct x86_pmu_lbr *lbr);
#else
-struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr, void *data);
+struct perf_guest_switch_msr *perf_guest_get_msrs(int *nr,
+ struct x86_guest_pebs *guest_pebs);
static inline void x86_perf_get_lbr(struct x86_pmu_lbr *lbr)
{
memset(lbr, 0, sizeof(*lbr));
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index f2efa0bf7ae8..3b3929871f7e 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -765,11 +765,20 @@ static void intel_pmu_cleanup(struct kvm_vcpu *vcpu)
intel_pmu_release_guest_lbr_event(vcpu);
}

-void intel_pmu_cross_mapped_check(struct kvm_pmu *pmu)
+u64 intel_pmu_get_cross_mapped_mask(struct kvm_pmu *pmu)
{
- struct kvm_pmc *pmc = NULL;
+ u64 host_cross_mapped_mask;
+ struct kvm_pmc *pmc;
int bit, hw_idx;

+ if (!(pmu->pebs_enable & pmu->global_ctrl))
+ return 0;
+
+ /*
+ * If a guest counter is cross-mapped to host counter with different
+ * index, its PEBS capability will be temporarily disabled.
+ */
+ host_cross_mapped_mask = 0;
for_each_set_bit(bit, (unsigned long *)&pmu->global_ctrl,
X86_PMC_IDX_MAX) {
pmc = intel_pmc_idx_to_pmc(pmu, bit);
@@ -784,8 +793,9 @@ void intel_pmu_cross_mapped_check(struct kvm_pmu *pmu)
*/
hw_idx = pmc->perf_event->hw.idx;
if (hw_idx != pmc->idx && hw_idx > -1)
- pmu->host_cross_mapped_mask |= BIT_ULL(hw_idx);
+ host_cross_mapped_mask |= BIT_ULL(hw_idx);
}
+ return host_cross_mapped_mask;
}

struct kvm_pmu_ops intel_pmu_ops __initdata = {
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 72e3943f3693..faf0071566ef 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7131,12 +7131,14 @@ static void atomic_switch_perf_msrs(struct vcpu_vmx *vmx)
struct perf_guest_switch_msr *msrs;
struct kvm_pmu *pmu = vcpu_to_pmu(&vmx->vcpu);

- pmu->host_cross_mapped_mask = 0;
- if (pmu->pebs_enable & pmu->global_ctrl)
- intel_pmu_cross_mapped_check(pmu);
+ struct x86_guest_pebs guest_pebs = {
+ .ds_area = pmu->ds_area,
+ .data_cfg = pmu->pebs_data_cfg,
+ .cross_mapped_mask = intel_pmu_get_cross_mapped_mask(pmu),
+ };

/* Note, nr_msrs may be garbage if perf_guest_get_msrs() returns NULL. */
- msrs = perf_guest_get_msrs(&nr_msrs, (void *)pmu);
+ msrs = perf_guest_get_msrs(&nr_msrs, &guest_pebs);
if (!msrs)
return;

diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index c2130d2c8e24..476119670d82 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -670,7 +670,7 @@ static inline bool intel_pmu_lbr_is_enabled(struct kvm_vcpu *vcpu)
return !!vcpu_to_lbr_records(vcpu)->nr;
}

-void intel_pmu_cross_mapped_check(struct kvm_pmu *pmu);
+u64 intel_pmu_get_cross_mapped_mask(struct kvm_pmu *pmu);
int intel_pmu_create_guest_lbr_event(struct kvm_vcpu *vcpu);
void vmx_passthrough_lbr_msrs(struct kvm_vcpu *vcpu);

--
2.42.0.459.ge4e396fd5e-goog

2023-09-16 05:48:44

by Sean Christopherson

Subject: [PATCH 17/26] KVM: PPC: Stop adding virt/kvm to the arch include path

Don't add virt/kvm to KVM PPC's include path, the headers in virt/kvm are
intended to be used only by other code in virt/kvm, i.e. are "private" to
the core KVM code. It's not clear that PPC *ever* included a header from
virt/kvm, i.e. odds are good the "-Ivirt/kvm" was copied from a different
architecture's Makefile when PPC support was first added.

Signed-off-by: Sean Christopherson <[email protected]>
---
arch/powerpc/kvm/Makefile | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile
index 5319d889b184..08a0e53d58c7 100644
--- a/arch/powerpc/kvm/Makefile
+++ b/arch/powerpc/kvm/Makefile
@@ -3,7 +3,7 @@
# Makefile for Kernel-based Virtual Machine module
#

-ccflags-y := -Ivirt/kvm -Iarch/powerpc/kvm
+ccflags-y := -Iarch/powerpc/kvm

include $(srctree)/virt/kvm/Makefile.kvm

--
2.42.0.459.ge4e396fd5e-goog

2023-09-16 06:31:16

by Sean Christopherson

Subject: [PATCH 10/26] KVM: s390: Stop selecting and depending on HAVE_KVM

Now that nothing in s390 or architecture agnostic code consumes HAVE_KVM,
stop selecting it in s390. This is one of several steps towards deleting
HAVE_KVM from the common KVM Kconfig.

Signed-off-by: Sean Christopherson <[email protected]>
---
arch/s390/Kconfig | 1 -
arch/s390/kvm/Kconfig | 1 -
2 files changed, 2 deletions(-)

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index ae29e4392664..8a5dca0036d9 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -193,7 +193,6 @@ config S390
select HAVE_KPROBES
select HAVE_KPROBES_ON_FTRACE
select HAVE_KRETPROBES
- select HAVE_KVM
select HAVE_LIVEPATCH
select HAVE_MEMBLOCK_PHYS_MAP
select HAVE_MOD_ARCH_SPECIFIC
diff --git a/arch/s390/kvm/Kconfig b/arch/s390/kvm/Kconfig
index 459d536116a6..9056cee72945 100644
--- a/arch/s390/kvm/Kconfig
+++ b/arch/s390/kvm/Kconfig
@@ -19,7 +19,6 @@ if VIRTUALIZATION
config KVM
def_tristate y
prompt "Kernel-based Virtual Machine (KVM) support"
- depends on HAVE_KVM
select PREEMPT_NOTIFIERS
select HAVE_KVM_CPU_RELAX_INTERCEPT
select HAVE_KVM_VCPU_ASYNC_IOCTL
--
2.42.0.459.ge4e396fd5e-goog

2023-09-16 06:35:54

by Sean Christopherson

Subject: [PATCH 04/26] vfio: Add struct to hold KVM assets and dedup group vs. iommufd code

Add a struct to hold the KVM assets need to manage and pass along KVM
references to VFIO devices. Providing a common struct deduplicates the
group vs. iommufd code, and will make it easier to rework the attachment
logic so that VFIO doesn't have to do a symbol lookup to retrieve the
get/put helpers from KVM.

Signed-off-by: Sean Christopherson <[email protected]>
---
drivers/vfio/device_cdev.c | 9 +-------
drivers/vfio/group.c | 18 ++--------------
drivers/vfio/vfio.h | 22 +++++++++----------
drivers/vfio/vfio_main.c | 43 +++++++++++++++++++++++++++-----------
4 files changed, 45 insertions(+), 47 deletions(-)

diff --git a/drivers/vfio/device_cdev.c b/drivers/vfio/device_cdev.c
index e75da0a70d1f..e484d6d6400a 100644
--- a/drivers/vfio/device_cdev.c
+++ b/drivers/vfio/device_cdev.c
@@ -46,13 +46,6 @@ int vfio_device_fops_cdev_open(struct inode *inode, struct file *filep)
return ret;
}

-static void vfio_df_get_kvm_safe(struct vfio_device_file *df)
-{
- spin_lock(&df->kvm_ref_lock);
- vfio_device_get_kvm_safe(df->device, df->kvm);
- spin_unlock(&df->kvm_ref_lock);
-}
-
long vfio_df_ioctl_bind_iommufd(struct vfio_device_file *df,
struct vfio_device_bind_iommufd __user *arg)
{
@@ -99,7 +92,7 @@ long vfio_df_ioctl_bind_iommufd(struct vfio_device_file *df,
* a reference. This reference is held until device closed.
* Save the pointer in the device for use by drivers.
*/
- vfio_df_get_kvm_safe(df);
+ vfio_device_get_kvm_safe(df->device, &df->kvm_ref);

ret = vfio_df_open(df);
if (ret)
diff --git a/drivers/vfio/group.c b/drivers/vfio/group.c
index 610a429c6191..756e47ff4cf0 100644
--- a/drivers/vfio/group.c
+++ b/drivers/vfio/group.c
@@ -157,13 +157,6 @@ static int vfio_group_ioctl_set_container(struct vfio_group *group,
return ret;
}

-static void vfio_device_group_get_kvm_safe(struct vfio_device *device)
-{
- spin_lock(&device->group->kvm_ref_lock);
- vfio_device_get_kvm_safe(device, device->group->kvm);
- spin_unlock(&device->group->kvm_ref_lock);
-}
-
static int vfio_df_group_open(struct vfio_device_file *df)
{
struct vfio_device *device = df->device;
@@ -184,7 +177,7 @@ static int vfio_df_group_open(struct vfio_device_file *df)
* the pointer in the device for use by drivers.
*/
if (device->open_count == 0)
- vfio_device_group_get_kvm_safe(device);
+ vfio_device_get_kvm_safe(device, &device->group->kvm_ref);

df->iommufd = device->group->iommufd;
if (df->iommufd && vfio_device_is_noiommu(device) && device->open_count == 0) {
@@ -560,7 +553,7 @@ static struct vfio_group *vfio_group_alloc(struct iommu_group *iommu_group,

refcount_set(&group->drivers, 1);
mutex_init(&group->group_lock);
- spin_lock_init(&group->kvm_ref_lock);
+ spin_lock_init(&group->kvm_ref.lock);
INIT_LIST_HEAD(&group->device_list);
mutex_init(&group->device_lock);
group->iommu_group = iommu_group;
@@ -884,13 +877,6 @@ bool vfio_group_enforced_coherent(struct vfio_group *group)
return ret;
}

-void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm)
-{
- spin_lock(&group->kvm_ref_lock);
- group->kvm = kvm;
- spin_unlock(&group->kvm_ref_lock);
-}
-
/**
* vfio_file_has_dev - True if the VFIO file is a handle for device
* @file: VFIO file to check
diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h
index c26d1ad68105..a1f741365075 100644
--- a/drivers/vfio/vfio.h
+++ b/drivers/vfio/vfio.h
@@ -12,18 +12,23 @@
#include <linux/module.h>
#include <linux/vfio.h>

+struct kvm;
struct iommufd_ctx;
struct iommu_group;
struct vfio_container;

+struct vfio_kvm_reference {
+ struct kvm *kvm;
+ spinlock_t lock;
+};
+
struct vfio_device_file {
struct vfio_device *device;
struct vfio_group *group;

u8 access_granted;
u32 devid; /* only valid when iommufd is valid */
- spinlock_t kvm_ref_lock; /* protect kvm field */
- struct kvm *kvm;
+ struct vfio_kvm_reference kvm_ref;
struct iommufd_ctx *iommufd; /* protected by struct vfio_device_set::lock */
};

@@ -88,11 +93,10 @@ struct vfio_group {
#endif
enum vfio_group_type type;
struct mutex group_lock;
- struct kvm *kvm;
+ struct vfio_kvm_reference kvm_ref;
struct file *opened_file;
struct blocking_notifier_head notifier;
struct iommufd_ctx *iommufd;
- spinlock_t kvm_ref_lock;
unsigned int cdev_device_open_cnt;
};

@@ -108,7 +112,6 @@ void vfio_device_group_unuse_iommu(struct vfio_device *device);
void vfio_df_group_close(struct vfio_device_file *df);
struct vfio_group *vfio_group_from_file(struct file *file);
bool vfio_group_enforced_coherent(struct vfio_group *group);
-void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm);
bool vfio_device_has_container(struct vfio_device *device);
int __init vfio_group_init(void);
void vfio_group_cleanup(void);
@@ -171,10 +174,6 @@ static inline bool vfio_group_enforced_coherent(struct vfio_group *group)
return true;
}

-static inline void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm)
-{
-}
-
static inline bool vfio_device_has_container(struct vfio_device *device)
{
return false;
@@ -435,11 +434,12 @@ static inline void vfio_virqfd_exit(void)
#endif

#if IS_ENABLED(CONFIG_KVM)
-void vfio_device_get_kvm_safe(struct vfio_device *device, struct kvm *kvm);
+void vfio_device_get_kvm_safe(struct vfio_device *device,
+ struct vfio_kvm_reference *ref);
void vfio_device_put_kvm(struct vfio_device *device);
#else
static inline void vfio_device_get_kvm_safe(struct vfio_device *device,
- struct kvm *kvm)
+ struct vfio_kvm_reference *ref)
{
}

diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index 124cc88966a7..e77e8c6aae2f 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -397,7 +397,7 @@ vfio_allocate_device_file(struct vfio_device *device)
return ERR_PTR(-ENOMEM);

df->device = device;
- spin_lock_init(&df->kvm_ref_lock);
+ spin_lock_init(&df->kvm_ref.lock);

return df;
}
@@ -1303,7 +1303,8 @@ bool vfio_file_enforced_coherent(struct file *file)
EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent);

#if IS_ENABLED(CONFIG_KVM)
-void vfio_device_get_kvm_safe(struct vfio_device *device, struct kvm *kvm)
+void vfio_device_get_kvm_safe(struct vfio_device *device,
+ struct vfio_kvm_reference *ref)
{
void (*pfn)(struct kvm *kvm);
bool (*fn)(struct kvm *kvm);
@@ -1311,28 +1312,33 @@ void vfio_device_get_kvm_safe(struct vfio_device *device, struct kvm *kvm)

lockdep_assert_held(&device->dev_set->lock);

- if (!kvm)
- return;
+ spin_lock(&ref->lock);
+
+ if (!ref->kvm)
+ goto out;

pfn = symbol_get(kvm_put_kvm);
if (WARN_ON(!pfn))
- return;
+ goto out;

fn = symbol_get(kvm_get_kvm_safe);
if (WARN_ON(!fn)) {
symbol_put(kvm_put_kvm);
- return;
+ goto out;
}

- ret = fn(kvm);
+ ret = fn(ref->kvm);
symbol_put(kvm_get_kvm_safe);
if (!ret) {
symbol_put(kvm_put_kvm);
- return;
+ goto out;
}

device->put_kvm = pfn;
- device->kvm = kvm;
+ device->kvm = ref->kvm;
+
+out:
+ spin_unlock(&ref->lock);
}

void vfio_device_put_kvm(struct vfio_device *device)
@@ -1353,6 +1359,21 @@ void vfio_device_put_kvm(struct vfio_device *device)
device->kvm = NULL;
}

+static void vfio_device_set_kvm(struct vfio_kvm_reference *ref,
+ struct kvm *kvm)
+{
+ spin_lock(&ref->lock);
+ ref->kvm = kvm;
+ spin_unlock(&ref->lock);
+}
+
+static void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm)
+{
+#if IS_ENABLED(CONFIG_VFIO_GROUP)
+ vfio_device_set_kvm(&group->kvm_ref, kvm);
+#endif
+}
+
static void vfio_device_file_set_kvm(struct file *file, struct kvm *kvm)
{
struct vfio_device_file *df = file->private_data;
@@ -1362,9 +1383,7 @@ static void vfio_device_file_set_kvm(struct file *file, struct kvm *kvm)
* be propagated to vfio_device::kvm when the file is bound to
* iommufd successfully in the vfio device cdev path.
*/
- spin_lock(&df->kvm_ref_lock);
- df->kvm = kvm;
- spin_unlock(&df->kvm_ref_lock);
+ vfio_device_set_kvm(&df->kvm_ref, kvm);
}

/**
--
2.42.0.459.ge4e396fd5e-goog

2023-09-16 07:18:24

by Sean Christopherson

Subject: [PATCH 12/26] KVM: arm64: Move arm_{psci,hypercalls}.h to an internal KVM path

From: Anish Ghulati <[email protected]>

Move arm_hypercalls.h and arm_psci.h into arch/arm64/kvm now that KVM
no longer supports 32-bit ARM, i.e. now that there's no reason to make
the hypercall and PSCI APIs "public".

Signed-off-by: Anish Ghulati <[email protected]>
[sean: squash into one patch, write changelog]
Signed-off-by: Sean Christopherson <[email protected]>
---
arch/arm64/kvm/arm.c | 5 +++--
{include => arch/arm64}/kvm/arm_hypercalls.h | 0
{include => arch/arm64}/kvm/arm_psci.h | 0
arch/arm64/kvm/guest.c | 2 +-
arch/arm64/kvm/handle_exit.c | 2 +-
arch/arm64/kvm/hyp/Makefile | 4 ++--
arch/arm64/kvm/hyp/include/hyp/switch.h | 4 ++--
arch/arm64/kvm/hyp/nvhe/switch.c | 4 ++--
arch/arm64/kvm/hyp/vhe/switch.c | 4 ++--
arch/arm64/kvm/hypercalls.c | 4 ++--
arch/arm64/kvm/psci.c | 4 ++--
arch/arm64/kvm/pvtime.c | 2 +-
arch/arm64/kvm/trng.c | 2 +-
13 files changed, 19 insertions(+), 18 deletions(-)
rename {include => arch/arm64}/kvm/arm_hypercalls.h (100%)
rename {include => arch/arm64}/kvm/arm_psci.h (100%)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 4866b3f7b4ea..6de1d63b981b 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -41,9 +41,10 @@
#include <asm/kvm_emulate.h>
#include <asm/sections.h>

-#include <kvm/arm_hypercalls.h>
#include <kvm/arm_pmu.h>
-#include <kvm/arm_psci.h>
+
+#include "arm_hypercalls.h"
+#include "arm_psci.h"

static enum kvm_mode kvm_mode = KVM_MODE_DEFAULT;

diff --git a/include/kvm/arm_hypercalls.h b/arch/arm64/kvm/arm_hypercalls.h
similarity index 100%
rename from include/kvm/arm_hypercalls.h
rename to arch/arm64/kvm/arm_hypercalls.h
diff --git a/include/kvm/arm_psci.h b/arch/arm64/kvm/arm_psci.h
similarity index 100%
rename from include/kvm/arm_psci.h
rename to arch/arm64/kvm/arm_psci.h
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 95f6945c4432..32045ad51ec4 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -18,7 +18,6 @@
#include <linux/string.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
-#include <kvm/arm_hypercalls.h>
#include <asm/cputype.h>
#include <linux/uaccess.h>
#include <asm/fpsimd.h>
@@ -27,6 +26,7 @@
#include <asm/kvm_nested.h>
#include <asm/sigcontext.h>

+#include "arm_hypercalls.h"
#include "trace.h"

const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index 617ae6dea5d5..f1d02d6f8683 100644
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c
@@ -21,7 +21,7 @@
#include <asm/stacktrace/nvhe.h>
#include <asm/traps.h>

-#include <kvm/arm_hypercalls.h>
+#include "arm_hypercalls.h"

#define CREATE_TRACE_POINTS
#include "trace_handle_exit.h"
diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile
index a38dea6186c9..4ce8c86967b5 100644
--- a/arch/arm64/kvm/hyp/Makefile
+++ b/arch/arm64/kvm/hyp/Makefile
@@ -4,7 +4,7 @@
#

incdir := $(srctree)/$(src)/include
-subdir-asflags-y := -I$(incdir)
-subdir-ccflags-y := -I$(incdir)
+subdir-asflags-y := -I$(incdir) -I$(srctree)/arch/arm64/kvm
+subdir-ccflags-y := -I$(incdir) -I$(srctree)/arch/arm64/kvm

obj-$(CONFIG_KVM) += vhe/ nvhe/ pgtable.o
diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h
index 9cfe6bd1dbe4..cd21cf71d7db 100644
--- a/arch/arm64/kvm/hyp/include/hyp/switch.h
+++ b/arch/arm64/kvm/hyp/include/hyp/switch.h
@@ -16,8 +16,6 @@
#include <linux/jump_label.h>
#include <uapi/linux/psci.h>

-#include <kvm/arm_psci.h>
-
#include <asm/barrier.h>
#include <asm/cpufeature.h>
#include <asm/extable.h>
@@ -31,6 +29,8 @@
#include <asm/debug-monitors.h>
#include <asm/processor.h>

+#include "arm_psci.h"
+
struct kvm_exception_table_entry {
int insn, fixup;
};
diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
index c353a06ee7e6..c0553ac36a46 100644
--- a/arch/arm64/kvm/hyp/nvhe/switch.c
+++ b/arch/arm64/kvm/hyp/nvhe/switch.c
@@ -13,8 +13,6 @@
#include <linux/jump_label.h>
#include <uapi/linux/psci.h>

-#include <kvm/arm_psci.h>
-
#include <asm/barrier.h>
#include <asm/cpufeature.h>
#include <asm/kprobes.h>
@@ -29,6 +27,8 @@
#include <nvhe/fixed_config.h>
#include <nvhe/mem_protect.h>

+#include "arm_psci.h"
+
/* Non-VHE specific context */
DEFINE_PER_CPU(struct kvm_host_data, kvm_host_data);
DEFINE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt);
diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c
index 6537f58b1a8c..f7423c890b5c 100644
--- a/arch/arm64/kvm/hyp/vhe/switch.c
+++ b/arch/arm64/kvm/hyp/vhe/switch.c
@@ -13,8 +13,6 @@
#include <linux/percpu.h>
#include <uapi/linux/psci.h>

-#include <kvm/arm_psci.h>
-
#include <asm/barrier.h>
#include <asm/cpufeature.h>
#include <asm/kprobes.h>
@@ -28,6 +26,8 @@
#include <asm/thread_info.h>
#include <asm/vectors.h>

+#include "arm_psci.h"
+
/* VHE specific context */
DEFINE_PER_CPU(struct kvm_host_data, kvm_host_data);
DEFINE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt);
diff --git a/arch/arm64/kvm/hypercalls.c b/arch/arm64/kvm/hypercalls.c
index 7fb4df0456de..d34a31c9ace2 100644
--- a/arch/arm64/kvm/hypercalls.c
+++ b/arch/arm64/kvm/hypercalls.c
@@ -6,8 +6,8 @@

#include <asm/kvm_emulate.h>

-#include <kvm/arm_hypercalls.h>
-#include <kvm/arm_psci.h>
+#include "arm_hypercalls.h"
+#include "arm_psci.h"

#define KVM_ARM_SMCCC_STD_FEATURES \
GENMASK(KVM_REG_ARM_STD_BMAP_BIT_COUNT - 1, 0)
diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c
index 1f69b667332b..c461e15026c9 100644
--- a/arch/arm64/kvm/psci.c
+++ b/arch/arm64/kvm/psci.c
@@ -13,8 +13,8 @@
#include <asm/cputype.h>
#include <asm/kvm_emulate.h>

-#include <kvm/arm_psci.h>
-#include <kvm/arm_hypercalls.h>
+#include "arm_hypercalls.h"
+#include "arm_psci.h"

/*
* This is an implementation of the Power State Coordination Interface
diff --git a/arch/arm64/kvm/pvtime.c b/arch/arm64/kvm/pvtime.c
index 4ceabaa4c30b..b07d250d223c 100644
--- a/arch/arm64/kvm/pvtime.c
+++ b/arch/arm64/kvm/pvtime.c
@@ -8,7 +8,7 @@
#include <asm/kvm_mmu.h>
#include <asm/pvclock-abi.h>

-#include <kvm/arm_hypercalls.h>
+#include "arm_hypercalls.h"

void kvm_update_stolen_time(struct kvm_vcpu *vcpu)
{
diff --git a/arch/arm64/kvm/trng.c b/arch/arm64/kvm/trng.c
index 99bdd7103c9c..b5dc0f09797a 100644
--- a/arch/arm64/kvm/trng.c
+++ b/arch/arm64/kvm/trng.c
@@ -6,7 +6,7 @@

#include <asm/kvm_emulate.h>

-#include <kvm/arm_hypercalls.h>
+#include "arm_hypercalls.h"

#define ARM_SMCCC_TRNG_VERSION_1_0 0x10000UL

--
2.42.0.459.ge4e396fd5e-goog

2023-09-16 07:27:27

by Sean Christopherson

Subject: [PATCH 16/26] KVM: MIPS: Stop adding virt/kvm to the arch include path

Don't add virt/kvm to KVM MIPS' include path, the headers in virt/kvm are
intended to be used only by other code in virt/kvm, i.e. are "private" to
the core KVM code. It's not clear that MIPS *ever* included a header from
virt/kvm, i.e. odds are good the "-Ivirt/kvm" was copied from a different
architecture's Makefile when MIPS support was first added.

Signed-off-by: Sean Christopherson <[email protected]>
---
arch/mips/kvm/Makefile | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/mips/kvm/Makefile b/arch/mips/kvm/Makefile
index 805aeea2166e..96a7cd21b140 100644
--- a/arch/mips/kvm/Makefile
+++ b/arch/mips/kvm/Makefile
@@ -4,7 +4,7 @@

include $(srctree)/virt/kvm/Makefile.kvm

-ccflags-y += -Ivirt/kvm -Iarch/mips/kvm
+ccflags-y += -Iarch/mips/kvm

kvm-$(CONFIG_CPU_HAS_MSA) += msa.o

--
2.42.0.459.ge4e396fd5e-goog

2023-09-16 07:49:53

by Sean Christopherson

Subject: [PATCH 13/26] KVM: arm64: Include KVM headers to get forward declarations

Include include/uapi/linux/kvm.h and include/linux/kvm_types.h in ARM's
public arm_arch_timer.h and arm_pmu.h headers to get forward declarations
of things like "struct kvm_vcpu" and "struct kvm_device_attr", which are
referenced but never declared (neither file includes *any* KVM headers).

The missing includes don't currently cause problems because of the order
of includes in parent files, but that order is largely arbitrary and is
subject to change, e.g. a future commit will move the ARM specific headers
to arch/arm64/include/asm and reorder parent includes to maintain
alphabetic ordering.

Reported-by: kernel test robot <[email protected]>
Signed-off-by: Sean Christopherson <[email protected]>
---
include/kvm/arm_arch_timer.h | 2 ++
include/kvm/arm_pmu.h | 2 ++
2 files changed, 4 insertions(+)

diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h
index bb3cb005873e..e22a15c66288 100644
--- a/include/kvm/arm_arch_timer.h
+++ b/include/kvm/arm_arch_timer.h
@@ -7,6 +7,8 @@
#ifndef __ASM_ARM_KVM_ARCH_TIMER_H
#define __ASM_ARM_KVM_ARCH_TIMER_H

+#include <linux/kvm.h>
+#include <linux/kvm_types.h>
#include <linux/clocksource.h>
#include <linux/hrtimer.h>

diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h
index 31029f4f7be8..e80f1d090579 100644
--- a/include/kvm/arm_pmu.h
+++ b/include/kvm/arm_pmu.h
@@ -7,6 +7,8 @@
#ifndef __ASM_ARM_KVM_PMU_H
#define __ASM_ARM_KVM_PMU_H

+#include <linux/kvm.h>
+#include <linux/kvm_types.h>
#include <linux/perf_event.h>
#include <linux/perf/arm_pmuv3.h>

--
2.42.0.459.ge4e396fd5e-goog

2023-09-16 07:55:41

by Sean Christopherson

Subject: [PATCH 11/26] KVM: MIPS: Make HAVE_KVM a MIPS-only Kconfig

Now that MIPS is the sole remaining user of HAVE_KVM, make HAVE_KVM a
MIPS-only Kconfig. Because most architectures unconditionally support
virtualization, advertising to the kernel at-large that an arch has KVM
just led to a bunch of useless and misguided #ifdefs.

Signed-off-by: Sean Christopherson <[email protected]>
---
arch/mips/kvm/Kconfig | 3 +++
virt/kvm/Kconfig | 3 ---
2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/mips/kvm/Kconfig b/arch/mips/kvm/Kconfig
index a8cdba75f98d..c4508f49caae 100644
--- a/arch/mips/kvm/Kconfig
+++ b/arch/mips/kvm/Kconfig
@@ -4,6 +4,9 @@
#
source "virt/kvm/Kconfig"

+config HAVE_KVM
+ bool
+
menuconfig VIRTUALIZATION
bool "Virtualization"
help
diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig
index f0be3b55cea6..f7bb6c59658e 100644
--- a/virt/kvm/Kconfig
+++ b/virt/kvm/Kconfig
@@ -1,9 +1,6 @@
# SPDX-License-Identifier: GPL-2.0
# KVM common configuration items and defaults

-config HAVE_KVM
- bool
-
config HAVE_KVM_PFNCACHE
bool

--
2.42.0.459.ge4e396fd5e-goog

2023-09-16 08:01:00

by Sean Christopherson

Subject: [PATCH 19/26] KVM: Standardize include paths across all architectures

Standardize KVM's include paths across all architectures by declaring
the KVM-specific includes in the common Makefile.kvm. Having common KVM
"own" the included paths reduces the temptation to unnecessarily add
virt/kvm to arch include paths, and conversely if allowing arch code to
grab headers from virt/kvm becomes desirable, virt/kvm can be added to
all architecture's include path with a single line update.

Having the common KVM makefile append to ccflags also provides a
convenient location to append other things, e.g. KVM-specific #defines.

Note, this changes the behavior of s390 and PPC, as s390 and PPC
previously overwrote ccflags-y instead of adding on. There is no evidence
that overwriting ccflags-y was necessary or even deliberate, as both s390
and PPC switched to the overwrite behavior without so much as a passing
mention when EXTRA_CFLAGS was replaced with ccflags-y (commit c73028a02887
("s390: change to new flag variable") and commit 4108d9ba9091
("powerpc/Makefiles: Change to new flag variables")).

Signed-off-by: Sean Christopherson <[email protected]>
---
arch/arm64/kvm/Makefile | 2 --
arch/mips/kvm/Makefile | 2 --
arch/powerpc/kvm/Makefile | 2 --
arch/riscv/kvm/Makefile | 2 --
arch/s390/kvm/Makefile | 2 --
arch/x86/kvm/Makefile | 1 -
virt/kvm/Makefile.kvm | 2 ++
7 files changed, 2 insertions(+), 11 deletions(-)

diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
index c0c050e53157..3996489baeef 100644
--- a/arch/arm64/kvm/Makefile
+++ b/arch/arm64/kvm/Makefile
@@ -3,8 +3,6 @@
# Makefile for Kernel-based Virtual Machine module
#

-ccflags-y += -I $(srctree)/$(src)
-
include $(srctree)/virt/kvm/Makefile.kvm

obj-$(CONFIG_KVM) += kvm.o
diff --git a/arch/mips/kvm/Makefile b/arch/mips/kvm/Makefile
index 96a7cd21b140..d198e1addea7 100644
--- a/arch/mips/kvm/Makefile
+++ b/arch/mips/kvm/Makefile
@@ -4,8 +4,6 @@

include $(srctree)/virt/kvm/Makefile.kvm

-ccflags-y += -Iarch/mips/kvm
-
kvm-$(CONFIG_CPU_HAS_MSA) += msa.o

kvm-y += mips.o emulate.o entry.o \
diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile
index 08a0e53d58c7..d6c6678ddf65 100644
--- a/arch/powerpc/kvm/Makefile
+++ b/arch/powerpc/kvm/Makefile
@@ -3,8 +3,6 @@
# Makefile for Kernel-based Virtual Machine module
#

-ccflags-y := -Iarch/powerpc/kvm
-
include $(srctree)/virt/kvm/Makefile.kvm

common-objs-y += powerpc.o emulate_loadstore.o
diff --git a/arch/riscv/kvm/Makefile b/arch/riscv/kvm/Makefile
index 4c2067fc59fc..ff7d5f67e229 100644
--- a/arch/riscv/kvm/Makefile
+++ b/arch/riscv/kvm/Makefile
@@ -3,8 +3,6 @@
# Makefile for RISC-V KVM support
#

-ccflags-y += -I $(srctree)/$(src)
-
include $(srctree)/virt/kvm/Makefile.kvm

obj-$(CONFIG_KVM) += kvm.o
diff --git a/arch/s390/kvm/Makefile b/arch/s390/kvm/Makefile
index f17249ab2a72..f8153189e003 100644
--- a/arch/s390/kvm/Makefile
+++ b/arch/s390/kvm/Makefile
@@ -5,8 +5,6 @@

include $(srctree)/virt/kvm/Makefile.kvm

-ccflags-y := -Iarch/s390/kvm
-
kvm-y += kvm-s390.o intercept.o interrupt.o priv.o sigp.o
kvm-y += diag.o gaccess.o guestdbg.o vsie.o pv.o

diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile
index 80e3fe184d17..d13f1a7b7b3d 100644
--- a/arch/x86/kvm/Makefile
+++ b/arch/x86/kvm/Makefile
@@ -1,6 +1,5 @@
# SPDX-License-Identifier: GPL-2.0

-ccflags-y += -I $(srctree)/arch/x86/kvm
ccflags-$(CONFIG_KVM_WERROR) += -Werror

ifeq ($(CONFIG_FRAME_POINTER),y)
diff --git a/virt/kvm/Makefile.kvm b/virt/kvm/Makefile.kvm
index 29373b59d89a..e85079ad245d 100644
--- a/virt/kvm/Makefile.kvm
+++ b/virt/kvm/Makefile.kvm
@@ -3,6 +3,8 @@
# Makefile for Kernel-based Virtual Machine module
#

+ccflags-y += -I$(srctree)/$(src)
+
KVM ?= ../../../virt/kvm

kvm-y := $(KVM)/kvm_main.o $(KVM)/eventfd.o $(KVM)/binary_stats.o
--
2.42.0.459.ge4e396fd5e-goog

2023-09-16 08:17:49

by Sean Christopherson

Subject: [PATCH 18/26] KVM: s390: Stop adding virt/kvm to the arch include path

Don't add virt/kvm to KVM s390's include path, the headers in virt/kvm are
intended to be used only by other code in virt/kvm, i.e. are "private" to
the core KVM code. It's not clear that s390 *ever* included a header from
virt/kvm, i.e. odds are good the "-Ivirt/kvm" was copied from a x86's
Makefile when s390 support was first added.

The only headers in virt/kvm at the time were the x86 specific ioapic.h,
and iodev.h, neither of which shows up as an #include in the diff for the
commit range 37817f2982d0f..e976a2b997fc4.

Signed-off-by: Sean Christopherson <[email protected]>
---
arch/s390/kvm/Makefile | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/s390/kvm/Makefile b/arch/s390/kvm/Makefile
index 02217fb4ae10..f17249ab2a72 100644
--- a/arch/s390/kvm/Makefile
+++ b/arch/s390/kvm/Makefile
@@ -5,7 +5,7 @@

include $(srctree)/virt/kvm/Makefile.kvm

-ccflags-y := -Ivirt/kvm -Iarch/s390/kvm
+ccflags-y := -Iarch/s390/kvm

kvm-y += kvm-s390.o intercept.o interrupt.o priv.o sigp.o
kvm-y += diag.o gaccess.o guestdbg.o vsie.o pv.o
--
2.42.0.459.ge4e396fd5e-goog

2023-09-16 08:52:02

by Sean Christopherson

Subject: [PATCH 15/26] KVM: Move include/kvm/iodev.h to include/linux as kvm_iodev.h

Move iodev.h, the last remaining holdout in include/kvm, to the standard
include/linux directory as kvm_iodev.h and delete include/kvm.

Signed-off-by: Sean Christopherson <[email protected]>
---
MAINTAINERS | 1 -
arch/arm64/include/asm/kvm_vgic.h | 2 +-
arch/arm64/kvm/vgic/vgic-mmio-v2.c | 2 +-
arch/arm64/kvm/vgic/vgic-mmio-v3.c | 2 +-
arch/arm64/kvm/vgic/vgic-mmio.c | 2 +-
arch/mips/include/asm/kvm_host.h | 3 +--
arch/powerpc/kvm/mpic.c | 2 +-
arch/riscv/kvm/aia_aplic.c | 2 +-
arch/riscv/kvm/aia_imsic.c | 2 +-
arch/x86/kvm/i8254.h | 2 +-
arch/x86/kvm/ioapic.h | 2 +-
arch/x86/kvm/irq.h | 2 +-
arch/x86/kvm/lapic.h | 2 +-
include/{kvm/iodev.h => linux/kvm_iodev.h} | 0
virt/kvm/coalesced_mmio.c | 3 +--
virt/kvm/eventfd.c | 2 +-
virt/kvm/kvm_main.c | 3 +--
17 files changed, 15 insertions(+), 19 deletions(-)
rename include/{kvm/iodev.h => linux/kvm_iodev.h} (100%)

diff --git a/MAINTAINERS b/MAINTAINERS
index 90f13281d297..ddc8375d536c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11498,7 +11498,6 @@ W: http://www.linux-kvm.org
T: git git://git.kernel.org/pub/scm/virt/kvm/kvm.git
F: Documentation/virt/kvm/
F: include/asm-generic/kvm*
-F: include/kvm/iodev.h
F: include/linux/kvm*
F: include/trace/events/kvm.h
F: include/uapi/asm-generic/kvm*
diff --git a/arch/arm64/include/asm/kvm_vgic.h b/arch/arm64/include/asm/kvm_vgic.h
index 5b27f94d4fad..2ca52888bc75 100644
--- a/arch/arm64/include/asm/kvm_vgic.h
+++ b/arch/arm64/include/asm/kvm_vgic.h
@@ -13,7 +13,7 @@
#include <linux/spinlock.h>
#include <linux/static_key.h>
#include <linux/types.h>
-#include <kvm/iodev.h>
+#include <linux/kvm_iodev.h>
#include <linux/list.h>
#include <linux/jump_label.h>

diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v2.c b/arch/arm64/kvm/vgic/vgic-mmio-v2.c
index bba0cfeefffe..646053ee892f 100644
--- a/arch/arm64/kvm/vgic/vgic-mmio-v2.c
+++ b/arch/arm64/kvm/vgic/vgic-mmio-v2.c
@@ -6,9 +6,9 @@
#include <linux/irqchip/arm-gic.h>
#include <linux/kvm.h>
#include <linux/kvm_host.h>
+#include <linux/kvm_iodev.h>
#include <linux/nospec.h>

-#include <kvm/iodev.h>
#include <asm/kvm_vgic.h>

#include "vgic.h"
diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v3.c b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
index d54a90beef61..b79a2e860415 100644
--- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c
+++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
@@ -7,8 +7,8 @@
#include <linux/irqchip/arm-gic-v3.h>
#include <linux/kvm.h>
#include <linux/kvm_host.h>
+#include <linux/kvm_iodev.h>
#include <linux/interrupt.h>
-#include <kvm/iodev.h>

#include <asm/kvm_emulate.h>
#include <asm/kvm_arm.h>
diff --git a/arch/arm64/kvm/vgic/vgic-mmio.c b/arch/arm64/kvm/vgic/vgic-mmio.c
index 68a3d8062473..4feca3b1d915 100644
--- a/arch/arm64/kvm/vgic/vgic-mmio.c
+++ b/arch/arm64/kvm/vgic/vgic-mmio.c
@@ -9,7 +9,7 @@
#include <linux/irq.h>
#include <linux/kvm.h>
#include <linux/kvm_host.h>
-#include <kvm/iodev.h>
+#include <linux/kvm_iodev.h>
#include <asm/kvm_arch_timer.h>
#include <asm/kvm_vgic.h>

diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h
index 54a85f1d4f2c..f8f63d0aa399 100644
--- a/arch/mips/include/asm/kvm_host.h
+++ b/arch/mips/include/asm/kvm_host.h
@@ -16,6 +16,7 @@
#include <linux/interrupt.h>
#include <linux/types.h>
#include <linux/kvm.h>
+#include <linux/kvm_iodev.h>
#include <linux/kvm_types.h>
#include <linux/threads.h>
#include <linux/spinlock.h>
@@ -24,8 +25,6 @@
#include <asm/inst.h>
#include <asm/mipsregs.h>

-#include <kvm/iodev.h>
-
/* MIPS KVM register ids */
#define MIPS_CP0_32(_R, _S) \
(KVM_REG_MIPS_CP0 | KVM_REG_SIZE_U32 | (8 * (_R) + (_S)))
diff --git a/arch/powerpc/kvm/mpic.c b/arch/powerpc/kvm/mpic.c
index 23e9c2bd9f27..b25a03251544 100644
--- a/arch/powerpc/kvm/mpic.c
+++ b/arch/powerpc/kvm/mpic.c
@@ -26,6 +26,7 @@
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/kvm_host.h>
+#include <linux/kvm_iodev.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/anon_inodes.h>
@@ -33,7 +34,6 @@
#include <asm/mpic.h>
#include <asm/kvm_para.h>
#include <asm/kvm_ppc.h>
-#include <kvm/iodev.h>

#define MAX_CPU 32
#define MAX_SRC 256
diff --git a/arch/riscv/kvm/aia_aplic.c b/arch/riscv/kvm/aia_aplic.c
index 39e72aa016a4..b49e747f2bad 100644
--- a/arch/riscv/kvm/aia_aplic.c
+++ b/arch/riscv/kvm/aia_aplic.c
@@ -11,7 +11,7 @@
#include <linux/math.h>
#include <linux/spinlock.h>
#include <linux/swab.h>
-#include <kvm/iodev.h>
+#include <linux/kvm_iodev.h>
#include <asm/kvm_aia_aplic.h>

struct aplic_irq {
diff --git a/arch/riscv/kvm/aia_imsic.c b/arch/riscv/kvm/aia_imsic.c
index 6cf23b8adb71..586e466a1c6d 100644
--- a/arch/riscv/kvm/aia_imsic.c
+++ b/arch/riscv/kvm/aia_imsic.c
@@ -10,10 +10,10 @@
#include <linux/atomic.h>
#include <linux/bitmap.h>
#include <linux/kvm_host.h>
+#include <linux/kvm_iodev.h>
#include <linux/math.h>
#include <linux/spinlock.h>
#include <linux/swab.h>
-#include <kvm/iodev.h>
#include <asm/csr.h>
#include <asm/kvm_aia_imsic.h>

diff --git a/arch/x86/kvm/i8254.h b/arch/x86/kvm/i8254.h
index a768212ba821..4de7a0b88e4f 100644
--- a/arch/x86/kvm/i8254.h
+++ b/arch/x86/kvm/i8254.h
@@ -4,7 +4,7 @@

#include <linux/kthread.h>

-#include <kvm/iodev.h>
+#include <linux/kvm_iodev.h>

struct kvm_kpit_channel_state {
u32 count; /* can be 65536 */
diff --git a/arch/x86/kvm/ioapic.h b/arch/x86/kvm/ioapic.h
index 539333ac4b38..2beec2daf1a3 100644
--- a/arch/x86/kvm/ioapic.h
+++ b/arch/x86/kvm/ioapic.h
@@ -3,7 +3,7 @@
#define __KVM_IO_APIC_H

#include <linux/kvm_host.h>
-#include <kvm/iodev.h>
+#include <linux/kvm_iodev.h>
#include "irq.h"

struct kvm;
diff --git a/arch/x86/kvm/irq.h b/arch/x86/kvm/irq.h
index c2d7cfe82d00..f9530e9a66f8 100644
--- a/arch/x86/kvm/irq.h
+++ b/arch/x86/kvm/irq.h
@@ -13,9 +13,9 @@
#include <linux/mm_types.h>
#include <linux/hrtimer.h>
#include <linux/kvm_host.h>
+#include <linux/kvm_iodev.h>
#include <linux/spinlock.h>

-#include <kvm/iodev.h>
#include "lapic.h"

#define PIC_NUM_PINS 16
diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
index 0a0ea4b5dd8c..bfd99ad1882e 100644
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -2,7 +2,7 @@
#ifndef __KVM_X86_LAPIC_H
#define __KVM_X86_LAPIC_H

-#include <kvm/iodev.h>
+#include <linux/kvm_iodev.h>

#include <linux/kvm_host.h>

diff --git a/include/kvm/iodev.h b/include/linux/kvm_iodev.h
similarity index 100%
rename from include/kvm/iodev.h
rename to include/linux/kvm_iodev.h
diff --git a/virt/kvm/coalesced_mmio.c b/virt/kvm/coalesced_mmio.c
index 1b90acb6e3fe..cfcb4b84d632 100644
--- a/virt/kvm/coalesced_mmio.c
+++ b/virt/kvm/coalesced_mmio.c
@@ -9,8 +9,7 @@
*
*/

-#include <kvm/iodev.h>
-
+#include <linux/kvm_iodev.h>
#include <linux/kvm_host.h>
#include <linux/slab.h>
#include <linux/kvm.h>
diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
index 89912a17f5d5..4d7cfb1095fd 100644
--- a/virt/kvm/eventfd.c
+++ b/virt/kvm/eventfd.c
@@ -26,7 +26,7 @@
#include <linux/irqbypass.h>
#include <trace/events/kvm.h>

-#include <kvm/iodev.h>
+#include <linux/kvm_iodev.h>

#ifdef CONFIG_HAVE_KVM_IRQFD

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 486800a7024b..f585a159b4f5 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -13,9 +13,8 @@
* Yaniv Kamay <[email protected]>
*/

-#include <kvm/iodev.h>
-
#include <linux/kvm_host.h>
+#include <linux/kvm_iodev.h>
#include <linux/kvm.h>
#include <linux/module.h>
#include <linux/errno.h>
--
2.42.0.459.ge4e396fd5e-goog

2023-09-16 09:21:48

by Sean Christopherson

Subject: [PATCH 08/26] KVM: x86: Stop selecting and depending on HAVE_KVM

Now that nothing in x86 or architecture agnostic code consumes HAVE_KVM,
stop selecting it in x86. This is one of several steps towards deleting
HAVE_KVM from the common KVM Kconfig.

Signed-off-by: Sean Christopherson <[email protected]>
---
arch/x86/Kconfig | 1 -
arch/x86/kvm/Kconfig | 2 --
2 files changed, 3 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 982b777eadc7..32eb288a4e3a 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -240,7 +240,6 @@ config X86
select HAVE_FUNCTION_ERROR_INJECTION
select HAVE_KRETPROBES
select HAVE_RETHOOK
- select HAVE_KVM
select HAVE_LIVEPATCH if X86_64
select HAVE_MIXED_BREAKPOINTS_REGS
select HAVE_MOD_ARCH_SPECIFIC
diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index 0f01e5600b5f..8c5fb7f57b4c 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -7,7 +7,6 @@ source "virt/kvm/Kconfig"

menuconfig VIRTUALIZATION
bool "Virtualization"
- depends on HAVE_KVM || X86
default y
help
Say Y here to get to see options for using your Linux host to run other
@@ -20,7 +19,6 @@ if VIRTUALIZATION

config KVM
tristate "Kernel-based Virtual Machine (KVM) support"
- depends on HAVE_KVM
depends on HIGH_RES_TIMERS
depends on X86_LOCAL_APIC
select PREEMPT_NOTIFIERS
--
2.42.0.459.ge4e396fd5e-goog

2023-09-16 10:56:54

by Sean Christopherson

Subject: [PATCH 07/26] x86/idt: Wrap KVM logic with CONFIG_KVM instead of CONFIG_HAVE_KVM

Wrap all of the IDT-related code that deals with KVM in CONFIG_KVM instead
of CONFIG_HAVE_KVM. x86 always "has" KVM, i.e. checking CONFIG_HAVE_KVM
is pointless.

Alternatively, the #ifdefs could simply be deleted, but the only potential
value is in printing the number of posted interrupts that end up being
handled by the host, everything else is completely dead code when KVM is
disabled. And if KVM is disabled, there should not be any posted
interrupts, i.e. NOT wiring up the "dummy" handlers and treating IRQs on
those vectors as spurious is the right thing to do.

Signed-off-by: Sean Christopherson <[email protected]>
---
arch/x86/include/asm/hardirq.h | 2 +-
arch/x86/include/asm/idtentry.h | 2 +-
arch/x86/include/asm/irq.h | 2 +-
arch/x86/include/asm/irq_vectors.h | 2 +-
arch/x86/kernel/idt.c | 2 +-
arch/x86/kernel/irq.c | 4 ++--
scripts/gdb/linux/constants.py.in | 2 +-
scripts/gdb/linux/interrupts.py | 2 +-
tools/arch/x86/include/asm/irq_vectors.h | 2 +-
9 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/arch/x86/include/asm/hardirq.h b/arch/x86/include/asm/hardirq.h
index 66837b8c67f1..fbc7722b87d1 100644
--- a/arch/x86/include/asm/hardirq.h
+++ b/arch/x86/include/asm/hardirq.h
@@ -15,7 +15,7 @@ typedef struct {
unsigned int irq_spurious_count;
unsigned int icr_read_retry_count;
#endif
-#ifdef CONFIG_HAVE_KVM
+#if IS_ENABLED(CONFIG_KVM)
unsigned int kvm_posted_intr_ipis;
unsigned int kvm_posted_intr_wakeup_ipis;
unsigned int kvm_posted_intr_nested_ipis;
diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index 05fd175cec7d..8eef16d0d72b 100644
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -671,7 +671,7 @@ DECLARE_IDTENTRY_SYSVEC(IRQ_WORK_VECTOR, sysvec_irq_work);
# endif
#endif

-#ifdef CONFIG_HAVE_KVM
+#if IS_ENABLED(CONFIG_KVM)
DECLARE_IDTENTRY_SYSVEC(POSTED_INTR_VECTOR, sysvec_kvm_posted_intr_ipi);
DECLARE_IDTENTRY_SYSVEC(POSTED_INTR_WAKEUP_VECTOR, sysvec_kvm_posted_intr_wakeup_ipi);
DECLARE_IDTENTRY_SYSVEC(POSTED_INTR_NESTED_VECTOR, sysvec_kvm_posted_intr_nested_ipi);
diff --git a/arch/x86/include/asm/irq.h b/arch/x86/include/asm/irq.h
index 836c170d3087..194dfff84cb1 100644
--- a/arch/x86/include/asm/irq.h
+++ b/arch/x86/include/asm/irq.h
@@ -29,7 +29,7 @@ struct irq_desc;

extern void fixup_irqs(void);

-#ifdef CONFIG_HAVE_KVM
+#if IS_ENABLED(CONFIG_KVM)
extern void kvm_set_posted_intr_wakeup_handler(void (*handler)(void));
#endif

diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_vectors.h
index 3a19904c2db6..3f73ac3ed3a0 100644
--- a/arch/x86/include/asm/irq_vectors.h
+++ b/arch/x86/include/asm/irq_vectors.h
@@ -84,7 +84,7 @@
#define HYPERVISOR_CALLBACK_VECTOR 0xf3

/* Vector for KVM to deliver posted interrupt IPI */
-#ifdef CONFIG_HAVE_KVM
+#if IS_ENABLED(CONFIG_KVM)
#define POSTED_INTR_VECTOR 0xf2
#define POSTED_INTR_WAKEUP_VECTOR 0xf1
#define POSTED_INTR_NESTED_VECTOR 0xf0
diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c
index b786d48f5a0f..a9e6363d88c2 100644
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -149,7 +149,7 @@ static const __initconst struct idt_data apic_idts[] = {
#ifdef CONFIG_X86_LOCAL_APIC
INTG(LOCAL_TIMER_VECTOR, asm_sysvec_apic_timer_interrupt),
INTG(X86_PLATFORM_IPI_VECTOR, asm_sysvec_x86_platform_ipi),
-# ifdef CONFIG_HAVE_KVM
+#if IS_ENABLED(CONFIG_KVM)
INTG(POSTED_INTR_VECTOR, asm_sysvec_kvm_posted_intr_ipi),
INTG(POSTED_INTR_WAKEUP_VECTOR, asm_sysvec_kvm_posted_intr_wakeup_ipi),
INTG(POSTED_INTR_NESTED_VECTOR, asm_sysvec_kvm_posted_intr_nested_ipi),
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 11761c124545..35fde0107901 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -164,7 +164,7 @@ int arch_show_interrupts(struct seq_file *p, int prec)
#if defined(CONFIG_X86_IO_APIC)
seq_printf(p, "%*s: %10u\n", prec, "MIS", atomic_read(&irq_mis_count));
#endif
-#ifdef CONFIG_HAVE_KVM
+#if IS_ENABLED(CONFIG_KVM)
seq_printf(p, "%*s: ", prec, "PIN");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->kvm_posted_intr_ipis);
@@ -290,7 +290,7 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_x86_platform_ipi)
}
#endif

-#ifdef CONFIG_HAVE_KVM
+#if IS_ENABLED(CONFIG_KVM)
static void dummy_handler(void) {}
static void (*kvm_posted_intr_wakeup_handler)(void) = dummy_handler;

diff --git a/scripts/gdb/linux/constants.py.in b/scripts/gdb/linux/constants.py.in
index e3517d4ab8ec..054630f511e0 100644
--- a/scripts/gdb/linux/constants.py.in
+++ b/scripts/gdb/linux/constants.py.in
@@ -129,7 +129,7 @@ LX_CONFIG(CONFIG_X86_MCE_THRESHOLD)
LX_CONFIG(CONFIG_X86_MCE_AMD)
LX_CONFIG(CONFIG_X86_MCE)
LX_CONFIG(CONFIG_X86_IO_APIC)
-LX_CONFIG(CONFIG_HAVE_KVM)
+LX_CONFIG(CONFIG_KVM)
LX_CONFIG(CONFIG_NUMA)
LX_CONFIG(CONFIG_ARM64)
LX_CONFIG(CONFIG_ARM64_4K_PAGES)
diff --git a/scripts/gdb/linux/interrupts.py b/scripts/gdb/linux/interrupts.py
index ef478e273791..66ae5c7690cf 100644
--- a/scripts/gdb/linux/interrupts.py
+++ b/scripts/gdb/linux/interrupts.py
@@ -151,7 +151,7 @@ def x86_show_interupts(prec):
if cnt is not None:
text += "%*s: %10u\n" % (prec, "MIS", cnt['counter'])

- if constants.LX_CONFIG_HAVE_KVM:
+ if constants.LX_CONFIG_KVM:
text += x86_show_irqstat(prec, "PIN", 'kvm_posted_intr_ipis', 'Posted-interrupt notification event')
text += x86_show_irqstat(prec, "NPI", 'kvm_posted_intr_nested_ipis', 'Nested posted-interrupt event')
text += x86_show_irqstat(prec, "PIW", 'kvm_posted_intr_wakeup_ipis', 'Posted-interrupt wakeup event')
diff --git a/tools/arch/x86/include/asm/irq_vectors.h b/tools/arch/x86/include/asm/irq_vectors.h
index 3a19904c2db6..3f73ac3ed3a0 100644
--- a/tools/arch/x86/include/asm/irq_vectors.h
+++ b/tools/arch/x86/include/asm/irq_vectors.h
@@ -84,7 +84,7 @@
#define HYPERVISOR_CALLBACK_VECTOR 0xf3

/* Vector for KVM to deliver posted interrupt IPI */
-#ifdef CONFIG_HAVE_KVM
+#if IS_ENABLED(CONFIG_KVM)
#define POSTED_INTR_VECTOR 0xf2
#define POSTED_INTR_WAKEUP_VECTOR 0xf1
#define POSTED_INTR_NESTED_VECTOR 0xf0
--
2.42.0.459.ge4e396fd5e-goog

2023-09-16 11:42:08

by Sean Christopherson

Subject: [PATCH 03/26] virt: Declare and define vfio_file_set_kvm() iff CONFIG_KVM is enabled

Hide vfio_file_set_kvm() and its unique helpers if KVM is not enabled,
nothing else in the kernel (or out of the kernel) should be using a
KVM specific helper.

Signed-off-by: Sean Christopherson <[email protected]>
---
drivers/vfio/vfio_main.c | 2 +-
include/linux/vfio.h | 2 ++
2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index 6368eed7b7b2..124cc88966a7 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -1352,7 +1352,6 @@ void vfio_device_put_kvm(struct vfio_device *device)
clear:
device->kvm = NULL;
}
-#endif

static void vfio_device_file_set_kvm(struct file *file, struct kvm *kvm)
{
@@ -1388,6 +1387,7 @@ void vfio_file_set_kvm(struct file *file, struct kvm *kvm)
vfio_device_file_set_kvm(file, kvm);
}
EXPORT_SYMBOL_GPL(vfio_file_set_kvm);
+#endif

/*
* Sub-module support
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index 454e9295970c..e80955de266c 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -311,7 +311,9 @@ static inline bool vfio_file_has_dev(struct file *file, struct vfio_device *devi
#endif
bool vfio_file_is_valid(struct file *file);
bool vfio_file_enforced_coherent(struct file *file);
+#if IS_ENABLED(CONFIG_KVM)
void vfio_file_set_kvm(struct file *file, struct kvm *kvm);
+#endif

#define VFIO_PIN_PAGES_MAX_ENTRIES (PAGE_SIZE/sizeof(unsigned long))

--
2.42.0.459.ge4e396fd5e-goog

2023-09-16 12:46:48

by Sean Christopherson

Subject: [PATCH 25/26] KVM: PPC: Rearrange code in kvm_ppc.h to isolate "public" information

Move all declarations and definitions in kvm_ppc.h that are consumed by
things other than KVM to the top of the file. This will allow wrapping
the parts of kvm_ppc.h that are intended only for KVM, i.e. are intended
to be "private" to KVM, with an #ifdef to hide KVM's internal details from
the kernel at-large.

Signed-off-by: Sean Christopherson <[email protected]>
---
arch/powerpc/include/asm/kvm_ppc.h | 302 +++++++++++++++--------------
1 file changed, 153 insertions(+), 149 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 72fee202d3ec..ead2ad892ebc 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -30,6 +30,159 @@
#endif
#include <asm/inst.h>

+struct openpic;
+
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+extern void kvm_cma_reserve(void) __init;
+static inline void kvmppc_set_xics_phys(int cpu, unsigned long addr)
+{
+ paca_ptrs[cpu]->kvm_hstate.xics_phys = (void __iomem *)addr;
+}
+
+static inline void kvmppc_set_xive_tima(int cpu,
+ unsigned long phys_addr,
+ void __iomem *virt_addr)
+{
+ paca_ptrs[cpu]->kvm_hstate.xive_tima_phys = (void __iomem *)phys_addr;
+ paca_ptrs[cpu]->kvm_hstate.xive_tima_virt = virt_addr;
+}
+
+static inline u32 kvmppc_get_xics_latch(void)
+{
+ u32 xirr;
+
+ xirr = get_paca()->kvm_hstate.saved_xirr;
+ get_paca()->kvm_hstate.saved_xirr = 0;
+ return xirr;
+}
+
+/*
+ * To avoid the need to unnecessarily exit fully to the host kernel, an IPI to
+ * a CPU thread that's running/napping inside of a guest is by default regarded
+ * as a request to wake the CPU (if needed) and continue execution within the
+ * guest, potentially to process new state like externally-generated
+ * interrupts or IPIs sent from within the guest itself (e.g. H_PROD/H_IPI).
+ *
+ * To force an exit to the host kernel, kvmppc_set_host_ipi() must be called
+ * prior to issuing the IPI to set the corresponding 'host_ipi' flag in the
+ * target CPU's PACA. To avoid unnecessary exits to the host, this flag should
+ * be immediately cleared via kvmppc_clear_host_ipi() by the IPI handler on
+ * the receiving side prior to processing the IPI work.
+ *
+ * NOTE:
+ *
+ * We currently issue an smp_mb() at the beginning of kvmppc_set_host_ipi().
+ * This is to guard against sequences such as the following:
+ *
+ * CPU
+ * X: smp_muxed_ipi_set_message():
+ * X: smp_mb()
+ * X: message[RESCHEDULE] = 1
+ * X: doorbell_global_ipi(42):
+ * X: kvmppc_set_host_ipi(42)
+ * X: ppc_msgsnd_sync()/smp_mb()
+ * X: ppc_msgsnd() -> 42
+ * 42: doorbell_exception(): // from CPU X
+ * 42: ppc_msgsync()
+ * 105: smp_muxed_ipi_set_message():
+ * 105: smb_mb()
+ * // STORE DEFERRED DUE TO RE-ORDERING
+ * --105: message[CALL_FUNCTION] = 1
+ * | 105: doorbell_global_ipi(42):
+ * | 105: kvmppc_set_host_ipi(42)
+ * | 42: kvmppc_clear_host_ipi(42)
+ * | 42: smp_ipi_demux_relaxed()
+ * | 42: // returns to executing guest
+ * | // RE-ORDERED STORE COMPLETES
+ * ->105: message[CALL_FUNCTION] = 1
+ * 105: ppc_msgsnd_sync()/smp_mb()
+ * 105: ppc_msgsnd() -> 42
+ * 42: local_paca->kvm_hstate.host_ipi == 0 // IPI ignored
+ * 105: // hangs waiting on 42 to process messages/call_single_queue
+ *
+ * We also issue an smp_mb() at the end of kvmppc_clear_host_ipi(). This is
+ * to guard against sequences such as the following (as well as to create
+ * a read-side pairing with the barrier in kvmppc_set_host_ipi()):
+ *
+ * CPU
+ * X: smp_muxed_ipi_set_message():
+ * X: smp_mb()
+ * X: message[RESCHEDULE] = 1
+ * X: doorbell_global_ipi(42):
+ * X: kvmppc_set_host_ipi(42)
+ * X: ppc_msgsnd_sync()/smp_mb()
+ * X: ppc_msgsnd() -> 42
+ * 42: doorbell_exception(): // from CPU X
+ * 42: ppc_msgsync()
+ * // STORE DEFERRED DUE TO RE-ORDERING
+ * -- 42: kvmppc_clear_host_ipi(42)
+ * | 42: smp_ipi_demux_relaxed()
+ * | 105: smp_muxed_ipi_set_message():
+ * | 105: smb_mb()
+ * | 105: message[CALL_FUNCTION] = 1
+ * | 105: doorbell_global_ipi(42):
+ * | 105: kvmppc_set_host_ipi(42)
+ * | // RE-ORDERED STORE COMPLETES
+ * -> 42: kvmppc_clear_host_ipi(42)
+ * 42: // returns to executing guest
+ * 105: ppc_msgsnd_sync()/smp_mb()
+ * 105: ppc_msgsnd() -> 42
+ * 42: local_paca->kvm_hstate.host_ipi == 0 // IPI ignored
+ * 105: // hangs waiting on 42 to process messages/call_single_queue
+ */
+static inline void kvmppc_set_host_ipi(int cpu)
+{
+ /*
+ * order stores of IPI messages vs. setting of host_ipi flag
+ *
+ * pairs with the barrier in kvmppc_clear_host_ipi()
+ */
+ smp_mb();
+ WRITE_ONCE(paca_ptrs[cpu]->kvm_hstate.host_ipi, 1);
+}
+
+static inline void kvmppc_clear_host_ipi(int cpu)
+{
+ WRITE_ONCE(paca_ptrs[cpu]->kvm_hstate.host_ipi, 0);
+ /*
+ * order clearing of host_ipi flag vs. processing of IPI messages
+ *
+ * pairs with the barrier in kvmppc_set_host_ipi()
+ */
+ smp_mb();
+}
+
+extern void kvmppc_xics_ipi_action(void);
+
+extern void kvm_hv_vm_activated(void);
+extern void kvm_hv_vm_deactivated(void);
+extern bool kvm_hv_mode_active(void);
+#else
+static inline void __init kvm_cma_reserve(void)
+{}
+
+static inline void kvmppc_set_xics_phys(int cpu, unsigned long addr)
+{}
+
+static inline void kvmppc_set_xive_tima(int cpu,
+ unsigned long phys_addr,
+ void __iomem *virt_addr)
+{}
+
+static inline u32 kvmppc_get_xics_latch(void)
+{
+ return 0;
+}
+
+static inline void kvmppc_set_host_ipi(int cpu)
+{}
+
+static inline void kvmppc_clear_host_ipi(int cpu)
+{}
+
+static inline bool kvm_hv_mode_active(void) { return false; }
+#endif
+
/*
* KVMPPC_INST_SW_BREAKPOINT is debug Instruction
* for supporting software breakpoint.
@@ -443,166 +596,18 @@ void kvmppc_set_pid(struct kvm_vcpu *vcpu, u32 pid);
struct openpic;

#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
-extern void kvm_cma_reserve(void) __init;
-static inline void kvmppc_set_xics_phys(int cpu, unsigned long addr)
-{
- paca_ptrs[cpu]->kvm_hstate.xics_phys = (void __iomem *)addr;
-}
-
-static inline void kvmppc_set_xive_tima(int cpu,
- unsigned long phys_addr,
- void __iomem *virt_addr)
-{
- paca_ptrs[cpu]->kvm_hstate.xive_tima_phys = (void __iomem *)phys_addr;
- paca_ptrs[cpu]->kvm_hstate.xive_tima_virt = virt_addr;
-}
-
-static inline u32 kvmppc_get_xics_latch(void)
-{
- u32 xirr;
-
- xirr = get_paca()->kvm_hstate.saved_xirr;
- get_paca()->kvm_hstate.saved_xirr = 0;
- return xirr;
-}
-
-/*
- * To avoid the need to unnecessarily exit fully to the host kernel, an IPI to
- * a CPU thread that's running/napping inside of a guest is by default regarded
- * as a request to wake the CPU (if needed) and continue execution within the
- * guest, potentially to process new state like externally-generated
- * interrupts or IPIs sent from within the guest itself (e.g. H_PROD/H_IPI).
- *
- * To force an exit to the host kernel, kvmppc_set_host_ipi() must be called
- * prior to issuing the IPI to set the corresponding 'host_ipi' flag in the
- * target CPU's PACA. To avoid unnecessary exits to the host, this flag should
- * be immediately cleared via kvmppc_clear_host_ipi() by the IPI handler on
- * the receiving side prior to processing the IPI work.
- *
- * NOTE:
- *
- * We currently issue an smp_mb() at the beginning of kvmppc_set_host_ipi().
- * This is to guard against sequences such as the following:
- *
- * CPU
- * X: smp_muxed_ipi_set_message():
- * X: smp_mb()
- * X: message[RESCHEDULE] = 1
- * X: doorbell_global_ipi(42):
- * X: kvmppc_set_host_ipi(42)
- * X: ppc_msgsnd_sync()/smp_mb()
- * X: ppc_msgsnd() -> 42
- * 42: doorbell_exception(): // from CPU X
- * 42: ppc_msgsync()
- * 105: smp_muxed_ipi_set_message():
- * 105: smb_mb()
- * // STORE DEFERRED DUE TO RE-ORDERING
- * --105: message[CALL_FUNCTION] = 1
- * | 105: doorbell_global_ipi(42):
- * | 105: kvmppc_set_host_ipi(42)
- * | 42: kvmppc_clear_host_ipi(42)
- * | 42: smp_ipi_demux_relaxed()
- * | 42: // returns to executing guest
- * | // RE-ORDERED STORE COMPLETES
- * ->105: message[CALL_FUNCTION] = 1
- * 105: ppc_msgsnd_sync()/smp_mb()
- * 105: ppc_msgsnd() -> 42
- * 42: local_paca->kvm_hstate.host_ipi == 0 // IPI ignored
- * 105: // hangs waiting on 42 to process messages/call_single_queue
- *
- * We also issue an smp_mb() at the end of kvmppc_clear_host_ipi(). This is
- * to guard against sequences such as the following (as well as to create
- * a read-side pairing with the barrier in kvmppc_set_host_ipi()):
- *
- * CPU
- * X: smp_muxed_ipi_set_message():
- * X: smp_mb()
- * X: message[RESCHEDULE] = 1
- * X: doorbell_global_ipi(42):
- * X: kvmppc_set_host_ipi(42)
- * X: ppc_msgsnd_sync()/smp_mb()
- * X: ppc_msgsnd() -> 42
- * 42: doorbell_exception(): // from CPU X
- * 42: ppc_msgsync()
- * // STORE DEFERRED DUE TO RE-ORDERING
- * -- 42: kvmppc_clear_host_ipi(42)
- * | 42: smp_ipi_demux_relaxed()
- * | 105: smp_muxed_ipi_set_message():
- * | 105: smb_mb()
- * | 105: message[CALL_FUNCTION] = 1
- * | 105: doorbell_global_ipi(42):
- * | 105: kvmppc_set_host_ipi(42)
- * | // RE-ORDERED STORE COMPLETES
- * -> 42: kvmppc_clear_host_ipi(42)
- * 42: // returns to executing guest
- * 105: ppc_msgsnd_sync()/smp_mb()
- * 105: ppc_msgsnd() -> 42
- * 42: local_paca->kvm_hstate.host_ipi == 0 // IPI ignored
- * 105: // hangs waiting on 42 to process messages/call_single_queue
- */
-static inline void kvmppc_set_host_ipi(int cpu)
-{
- /*
- * order stores of IPI messages vs. setting of host_ipi flag
- *
- * pairs with the barrier in kvmppc_clear_host_ipi()
- */
- smp_mb();
- WRITE_ONCE(paca_ptrs[cpu]->kvm_hstate.host_ipi, 1);
-}
-
-static inline void kvmppc_clear_host_ipi(int cpu)
-{
- WRITE_ONCE(paca_ptrs[cpu]->kvm_hstate.host_ipi, 0);
- /*
- * order clearing of host_ipi flag vs. processing of IPI messages
- *
- * pairs with the barrier in kvmppc_set_host_ipi()
- */
- smp_mb();
-}
-
static inline void kvmppc_fast_vcpu_kick(struct kvm_vcpu *vcpu)
{
vcpu->kvm->arch.kvm_ops->fast_vcpu_kick(vcpu);
}

-extern void kvm_hv_vm_activated(void);
-extern void kvm_hv_vm_deactivated(void);
-extern bool kvm_hv_mode_active(void);
-
extern void kvmppc_check_need_tlb_flush(struct kvm *kvm, int pcpu);

#else
-static inline void __init kvm_cma_reserve(void)
-{}
-
-static inline void kvmppc_set_xics_phys(int cpu, unsigned long addr)
-{}
-
-static inline void kvmppc_set_xive_tima(int cpu,
- unsigned long phys_addr,
- void __iomem *virt_addr)
-{}
-
-static inline u32 kvmppc_get_xics_latch(void)
-{
- return 0;
-}
-
-static inline void kvmppc_set_host_ipi(int cpu)
-{}
-
-static inline void kvmppc_clear_host_ipi(int cpu)
-{}
-
static inline void kvmppc_fast_vcpu_kick(struct kvm_vcpu *vcpu)
{
kvm_vcpu_kick(vcpu);
}
-
-static inline bool kvm_hv_mode_active(void) { return false; }
-
#endif

#ifdef CONFIG_PPC_PSERIES
@@ -642,7 +647,6 @@ extern u64 kvmppc_xics_get_icp(struct kvm_vcpu *vcpu);
extern int kvmppc_xics_set_icp(struct kvm_vcpu *vcpu, u64 icpval);
extern int kvmppc_xics_connect_vcpu(struct kvm_device *dev,
struct kvm_vcpu *vcpu, u32 cpu);
-extern void kvmppc_xics_ipi_action(void);
extern void kvmppc_xics_set_mapped(struct kvm *kvm, unsigned long guest_irq,
unsigned long host_irq);
extern void kvmppc_xics_clr_mapped(struct kvm *kvm, unsigned long guest_irq,
--
2.42.0.459.ge4e396fd5e-goog

2023-09-16 13:31:03

by Sean Christopherson

Subject: [PATCH 02/26] vfio: Move KVM get/put helpers to colocate it with other KVM related code

Move the definitions of vfio_device_get_kvm_safe() and vfio_device_put_kvm()
down in vfio_main.c to colocate them with other KVM-specific functions,
e.g. to allow wrapping them all with a single CONFIG_KVM check.

Signed-off-by: Sean Christopherson <[email protected]>
---
drivers/vfio/vfio_main.c | 104 +++++++++++++++++++--------------------
1 file changed, 52 insertions(+), 52 deletions(-)

diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index 80e39f7a6d8f..6368eed7b7b2 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -381,58 +381,6 @@ void vfio_unregister_group_dev(struct vfio_device *device)
}
EXPORT_SYMBOL_GPL(vfio_unregister_group_dev);

-#if IS_ENABLED(CONFIG_KVM)
-void vfio_device_get_kvm_safe(struct vfio_device *device, struct kvm *kvm)
-{
- void (*pfn)(struct kvm *kvm);
- bool (*fn)(struct kvm *kvm);
- bool ret;
-
- lockdep_assert_held(&device->dev_set->lock);
-
- if (!kvm)
- return;
-
- pfn = symbol_get(kvm_put_kvm);
- if (WARN_ON(!pfn))
- return;
-
- fn = symbol_get(kvm_get_kvm_safe);
- if (WARN_ON(!fn)) {
- symbol_put(kvm_put_kvm);
- return;
- }
-
- ret = fn(kvm);
- symbol_put(kvm_get_kvm_safe);
- if (!ret) {
- symbol_put(kvm_put_kvm);
- return;
- }
-
- device->put_kvm = pfn;
- device->kvm = kvm;
-}
-
-void vfio_device_put_kvm(struct vfio_device *device)
-{
- lockdep_assert_held(&device->dev_set->lock);
-
- if (!device->kvm)
- return;
-
- if (WARN_ON(!device->put_kvm))
- goto clear;
-
- device->put_kvm(device->kvm);
- device->put_kvm = NULL;
- symbol_put(kvm_put_kvm);
-
-clear:
- device->kvm = NULL;
-}
-#endif
-
/* true if the vfio_device has open_device() called but not close_device() */
static bool vfio_assert_device_open(struct vfio_device *device)
{
@@ -1354,6 +1302,58 @@ bool vfio_file_enforced_coherent(struct file *file)
}
EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent);

+#if IS_ENABLED(CONFIG_KVM)
+void vfio_device_get_kvm_safe(struct vfio_device *device, struct kvm *kvm)
+{
+ void (*pfn)(struct kvm *kvm);
+ bool (*fn)(struct kvm *kvm);
+ bool ret;
+
+ lockdep_assert_held(&device->dev_set->lock);
+
+ if (!kvm)
+ return;
+
+ pfn = symbol_get(kvm_put_kvm);
+ if (WARN_ON(!pfn))
+ return;
+
+ fn = symbol_get(kvm_get_kvm_safe);
+ if (WARN_ON(!fn)) {
+ symbol_put(kvm_put_kvm);
+ return;
+ }
+
+ ret = fn(kvm);
+ symbol_put(kvm_get_kvm_safe);
+ if (!ret) {
+ symbol_put(kvm_put_kvm);
+ return;
+ }
+
+ device->put_kvm = pfn;
+ device->kvm = kvm;
+}
+
+void vfio_device_put_kvm(struct vfio_device *device)
+{
+ lockdep_assert_held(&device->dev_set->lock);
+
+ if (!device->kvm)
+ return;
+
+ if (WARN_ON(!device->put_kvm))
+ goto clear;
+
+ device->put_kvm(device->kvm);
+ device->put_kvm = NULL;
+ symbol_put(kvm_put_kvm);
+
+clear:
+ device->kvm = NULL;
+}
+#endif
+
static void vfio_device_file_set_kvm(struct file *file, struct kvm *kvm)
{
struct vfio_device_file *df = file->private_data;
--
2.42.0.459.ge4e396fd5e-goog

2023-09-16 14:25:30

by Sean Christopherson

Subject: [PATCH 22/26] entry/kvm: KVM: Move KVM details related to signal/-EINTR into KVM proper

Move KVM's morphing of pending signals into exits to userspace into KVM
proper, and drop the @vcpu param from xfer_to_guest_mode_handle_work().
How KVM responds to -EINTR is a detail that really belongs in KVM itself,
and removing the non-KVM call to kvm_handle_signal_exit() will allow
hiding said API and the definition of "struct kvm_vcpu" from the kernel.

Alternatively, entry/kvm.c could be treated as part of KVM, i.e. be given
access to KVM internals, but that's not obviously better than having KVM
react to -EINTR (though it's not obviously worse either).

Signed-off-by: Sean Christopherson <[email protected]>
---
arch/arm64/kvm/arm.c | 3 +--
arch/riscv/kvm/vcpu.c | 2 +-
arch/x86/kvm/vmx/vmx.c | 1 -
arch/x86/kvm/x86.c | 3 +--
include/linux/entry-kvm.h | 3 +--
include/linux/kvm_host.h | 13 ++++++++++++-
kernel/entry/kvm.c | 11 ++++-------
7 files changed, 20 insertions(+), 16 deletions(-)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 6480628197b4..641df091e46b 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -6,7 +6,6 @@

#include <linux/bug.h>
#include <linux/cpu_pm.h>
-#include <linux/entry-kvm.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/kvm_host.h>
@@ -929,7 +928,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
/*
* Check conditions before entering the guest
*/
- ret = xfer_to_guest_mode_handle_work(vcpu);
+ ret = kvm_xfer_to_guest_mode_handle_work(vcpu);
if (!ret)
ret = 1;

diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
index 82229db1ce73..c313f4e90e70 100644
--- a/arch/riscv/kvm/vcpu.c
+++ b/arch/riscv/kvm/vcpu.c
@@ -667,7 +667,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
run->exit_reason = KVM_EXIT_UNKNOWN;
while (ret > 0) {
/* Check conditions before entering the guest */
- ret = xfer_to_guest_mode_handle_work(vcpu);
+ ret = kvm_xfer_to_guest_mode_handle_work(vcpu);
if (ret)
continue;
ret = 1;
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index faf0071566ef..43b87ad5fde8 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -28,7 +28,6 @@
#include <linux/slab.h>
#include <linux/tboot.h>
#include <linux/trace_events.h>
-#include <linux/entry-kvm.h>

#include <asm/apic.h>
#include <asm/asm.h>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 6c9c81e82e65..aab095f89d9e 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -59,7 +59,6 @@
#include <linux/sched/stat.h>
#include <linux/sched/isolation.h>
#include <linux/mem_encrypt.h>
-#include <linux/entry-kvm.h>
#include <linux/suspend.h>
#include <linux/smp.h>

@@ -10987,7 +10986,7 @@ static int vcpu_run(struct kvm_vcpu *vcpu)

if (__xfer_to_guest_mode_work_pending()) {
kvm_vcpu_srcu_read_unlock(vcpu);
- r = xfer_to_guest_mode_handle_work(vcpu);
+ r = kvm_xfer_to_guest_mode_handle_work(vcpu);
kvm_vcpu_srcu_read_lock(vcpu);
if (r)
return r;
diff --git a/include/linux/entry-kvm.h b/include/linux/entry-kvm.h
index e7d90d06e566..e235a91d28fc 100644
--- a/include/linux/entry-kvm.h
+++ b/include/linux/entry-kvm.h
@@ -42,11 +42,10 @@ static inline int arch_xfer_to_guest_mode_handle_work(unsigned long ti_work)
/**
* xfer_to_guest_mode_handle_work - Check and handle pending work which needs
* to be handled before going to guest mode
- * @vcpu: Pointer to current's VCPU data
*
* Returns: 0 or an error code
*/
-int xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu);
+int xfer_to_guest_mode_handle_work(void);

/**
* xfer_to_guest_mode_prepare - Perform last minute preparation work that
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index fb6c6109fdca..d520d6801070 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -2,7 +2,7 @@
#ifndef __KVM_HOST_H
#define __KVM_HOST_H

-
+#include <linux/entry-kvm.h>
#include <linux/types.h>
#include <linux/hardirq.h>
#include <linux/list.h>
@@ -2293,6 +2293,17 @@ static inline void kvm_handle_signal_exit(struct kvm_vcpu *vcpu)
vcpu->run->exit_reason = KVM_EXIT_INTR;
vcpu->stat.signal_exits++;
}
+
+static inline int kvm_xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu)
+{
+ int r = xfer_to_guest_mode_handle_work();
+
+ if (r) {
+ WARN_ON_ONCE(r != -EINTR);
+ kvm_handle_signal_exit(vcpu);
+ }
+ return r;
+}
#endif /* CONFIG_KVM_XFER_TO_GUEST_WORK */

/*
diff --git a/kernel/entry/kvm.c b/kernel/entry/kvm.c
index c2fc39824157..872617468b4a 100644
--- a/kernel/entry/kvm.c
+++ b/kernel/entry/kvm.c
@@ -1,17 +1,14 @@
// SPDX-License-Identifier: GPL-2.0

#include <linux/entry-kvm.h>
-#include <linux/kvm_host.h>

-static int xfer_to_guest_mode_work(struct kvm_vcpu *vcpu, unsigned long ti_work)
+static int xfer_to_guest_mode_work(unsigned long ti_work)
{
do {
int ret;

- if (ti_work & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL)) {
- kvm_handle_signal_exit(vcpu);
+ if (ti_work & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL))
return -EINTR;
- }

if (ti_work & _TIF_NEED_RESCHED)
schedule();
@@ -28,7 +25,7 @@ static int xfer_to_guest_mode_work(struct kvm_vcpu *vcpu, unsigned long ti_work)
return 0;
}

-int xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu)
+int xfer_to_guest_mode_handle_work(void)
{
unsigned long ti_work;

@@ -44,6 +41,6 @@ int xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu)
if (!(ti_work & XFER_TO_GUEST_MODE_WORK))
return 0;

- return xfer_to_guest_mode_work(vcpu, ti_work);
+ return xfer_to_guest_mode_work(ti_work);
}
EXPORT_SYMBOL_GPL(xfer_to_guest_mode_handle_work);
--
2.42.0.459.ge4e396fd5e-goog

2023-09-18 11:08:21

by Thomas Huth

Subject: Re: [PATCH 18/26] KVM: s390: Stop adding virt/kvm to the arch include path

On 16/09/2023 02.31, Sean Christopherson wrote:
> Don't add virt/kvm to KVM s390's include path, the headers in virt/kvm are
> intended to be used only by other code in virt/kvm, i.e. are "private" to
> the core KVM code. It's not clear that s390 *ever* included a header from
> virt/kvm, i.e. odds are good the "-Ivirt/kvm" was copied from a x86's
> Makefile when s390 support was first added.
>
> The only headers in virt/kvm at the time were the x86 specific ioapic.h,
> and iodev.h, neither of which shows up as an #include in the diff for the
> commit range 37817f2982d0f..e976a2b997fc4.
>
> Signed-off-by: Sean Christopherson <[email protected]>
> ---
> arch/s390/kvm/Makefile | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/s390/kvm/Makefile b/arch/s390/kvm/Makefile
> index 02217fb4ae10..f17249ab2a72 100644
> --- a/arch/s390/kvm/Makefile
> +++ b/arch/s390/kvm/Makefile
> @@ -5,7 +5,7 @@
>
> include $(srctree)/virt/kvm/Makefile.kvm
>
> -ccflags-y := -Ivirt/kvm -Iarch/s390/kvm
> +ccflags-y := -Iarch/s390/kvm
>
> kvm-y += kvm-s390.o intercept.o interrupt.o priv.o sigp.o
> kvm-y += diag.o gaccess.o guestdbg.o vsie.o pv.o

Reviewed-by: Thomas Huth <[email protected]>

2023-09-18 16:30:45

by Claudio Imbrenda

Subject: Re: [PATCH 10/26] KVM: s390: Stop selecting and depending on HAVE_KVM

On Fri, 15 Sep 2023 17:31:02 -0700
Sean Christopherson <[email protected]> wrote:

> Now that nothing in s390 or architecture agnostic code consumes HAVE_KVM,
> stop selecting it in s390. This is one of several steps towards deleting
> HAVE_KVM from the common KVM Kconfig.
>
> Signed-off-by: Sean Christopherson <[email protected]>
> ---
> arch/s390/Kconfig | 1 -
> arch/s390/kvm/Kconfig | 1 -
> 2 files changed, 2 deletions(-)
>
> diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
> index ae29e4392664..8a5dca0036d9 100644
> --- a/arch/s390/Kconfig
> +++ b/arch/s390/Kconfig
> @@ -193,7 +193,6 @@ config S390
> select HAVE_KPROBES
> select HAVE_KPROBES_ON_FTRACE
> select HAVE_KRETPROBES
> - select HAVE_KVM
> select HAVE_LIVEPATCH
> select HAVE_MEMBLOCK_PHYS_MAP
> select HAVE_MOD_ARCH_SPECIFIC
> diff --git a/arch/s390/kvm/Kconfig b/arch/s390/kvm/Kconfig
> index 459d536116a6..9056cee72945 100644
> --- a/arch/s390/kvm/Kconfig
> +++ b/arch/s390/kvm/Kconfig
> @@ -19,7 +19,6 @@ if VIRTUALIZATION
> config KVM
> def_tristate y
> prompt "Kernel-based Virtual Machine (KVM) support"
> - depends on HAVE_KVM
> select PREEMPT_NOTIFIERS
> select HAVE_KVM_CPU_RELAX_INTERCEPT
> select HAVE_KVM_VCPU_ASYNC_IOCTL

it looks like we don't use HAVE_KVM on s390x

Reviewed-by: Claudio Imbrenda <[email protected]>

2023-09-18 16:50:20

by Sean Christopherson

Subject: Re: [PATCH 05/26] vfio: KVM: Pass get/put helpers from KVM to VFIO, don't do circular lookup

On Mon, Sep 18, 2023, Jason Gunthorpe wrote:
> On Fri, Sep 15, 2023 at 05:30:57PM -0700, Sean Christopherson wrote:
> > Explicitly pass KVM's get/put helpers to VFIO when attaching a VM to
> > VFIO instead of having VFIO do a symbol lookup back into KVM. Having both
> > KVM and VFIO do symbol lookups increases the overall complexity and places
> > an unnecessary dependency on KVM (from VFIO) without adding any value.
> >
> > Signed-off-by: Sean Christopherson <[email protected]>
> > ---
> > drivers/vfio/vfio.h | 2 ++
> > drivers/vfio/vfio_main.c | 74 +++++++++++++++++++---------------------
> > include/linux/vfio.h | 4 ++-
> > virt/kvm/vfio.c | 9 +++--
> > 4 files changed, 47 insertions(+), 42 deletions(-)
>
> I don't mind this, but Christoph had disliked my prior attempt to do
> this with function pointers..
>
> The get can be inlined, IIRC, what about putting a pointer to the put
> inside the kvm struct?

That wouldn't allow us to achieve our goal, which is to hide the details of
"struct kvm" from VFIO (and the rest of the kernel).

What's the objection to handing VFIO a function pointer?

> The the normal kvm get/put don't have to exported symbols at all?

The export of kvm_get_kvm_safe() can go away (I forgot to do that in this series),
but kvm_get_kvm() will hang around as it's needed by KVM sub-modules (PPC and x86),
KVMGT (x86), and drivers/s390/crypto/vfio_ap_ops.c (no idea what to call that beast).

Gah, KVMGT doesn't actually need to call get/put, that can be handled by
kvm_page_track_register_notifier().

I am planning on making exports for sub-modules conditional on there actually
being submodules, so that's 2 of the 3 gone, but tackling the s390 crypto driver
is an entirely different story.

2023-09-18 20:11:59

by Jason Gunthorpe

Subject: Re: [PATCH 05/26] vfio: KVM: Pass get/put helpers from KVM to VFIO, don't do circular lookup

On Mon, Sep 18, 2023 at 08:49:57AM -0700, Sean Christopherson wrote:
> On Mon, Sep 18, 2023, Jason Gunthorpe wrote:
> > On Fri, Sep 15, 2023 at 05:30:57PM -0700, Sean Christopherson wrote:
> > > Explicitly pass KVM's get/put helpers to VFIO when attaching a VM to
> > > VFIO instead of having VFIO do a symbol lookup back into KVM. Having both
> > > KVM and VFIO do symbol lookups increases the overall complexity and places
> > > an unnecessary dependency on KVM (from VFIO) without adding any value.
> > >
> > > Signed-off-by: Sean Christopherson <[email protected]>
> > > ---
> > > drivers/vfio/vfio.h | 2 ++
> > > drivers/vfio/vfio_main.c | 74 +++++++++++++++++++---------------------
> > > include/linux/vfio.h | 4 ++-
> > > virt/kvm/vfio.c | 9 +++--
> > > 4 files changed, 47 insertions(+), 42 deletions(-)
> >
> > I don't mind this, but Christoph had disliked my prior attempt to do
> > this with function pointers..
> >
> > The get can be inlined, IIRC, what about putting a pointer to the put
> > inside the kvm struct?
>
> That wouldn't allow us to achieve our goal, which is to hide the details of
> "struct kvm" from VFIO (and the rest of the kernel).

> What's the objection to handing VFIO a function pointer?

Hmm, looks like it was this thread:

https://lore.kernel.org/r/[email protected]

Your rational looks a little better to me.

> > The the normal kvm get/put don't have to exported symbols at all?
>
> The export of kvm_get_kvm_safe() can go away (I forgot to do that in this series),
> but kvm_get_kvm() will hang around as it's needed by KVM sub-modules (PPC and x86),
> KVMGT (x86), and drivers/s390/crypto/vfio_ap_ops.c (no idea what to call that beast).

My thought would be to keep it as an inline, there should be some way
to do that without breaking your desire to hide the bulk of the kvm
struct content. Like put the refcount as the first element in the
struct and just don't ifdef it away?.

Jason

2023-09-18 20:34:08

by Jason Gunthorpe

Subject: Re: [PATCH 06/26] KVM: Drop CONFIG_KVM_VFIO and just look at KVM+VFIO

On Mon, Sep 18, 2023 at 08:52:40AM -0700, Sean Christopherson wrote:

> > I wonder if we should be making the VFIO drivers that need the kvm to
> > ask for it? 'select CONFIG_NEED_VFIO_KVM' or something?
>
> I wondered the same thing, if only to make it easier to track which
> drivers actually end up interacting directly with KVM.

There are two usages I've seen..

GVT's uage is just totally broken:

https://lore.kernel.org/kvm/[email protected]/

It is trying to use KVM to write protect IOVA DMA memory, and it just
doesn't work. If we want to do something like this the core vfio code
should provide this service and it should be wired into KVM
properly.

power and s390 have actual architectural "virtual machines" and they
need actual arch operations to install VFIO devices into those
things. In this regard having the arch opt into the integration would
make some sense. I expect this will get worse in our CC future where
VFIO devices will need to be passed into arch specific CC code
somehow.

This arch stuff isn't cleanly done, the code is sprinkled all over the
place. Some in mdevs, some in PCI arch code, some in #ifdefs..

Maybe the CC people will clean it up instead of making the mess bigger :)

Jason

2023-09-18 21:11:26

by Jason Gunthorpe

Subject: Re: [PATCH 03/26] virt: Declare and define vfio_file_set_kvm() iff CONFIG_KVM is enabled

On Fri, Sep 15, 2023 at 05:30:55PM -0700, Sean Christopherson wrote:
> Hide vfio_file_set_kvm() and its unique helpers if KVM is not enabled,
> nothing else in the kernel (or out of the kernel) should be using a
> KVM specific helper.
>
> Signed-off-by: Sean Christopherson <[email protected]>
> ---
> drivers/vfio/vfio_main.c | 2 +-
> include/linux/vfio.h | 2 ++
> 2 files changed, 3 insertions(+), 1 deletion(-)

Patch subject should be vfio not virt

Reviewed-by: Jason Gunthorpe <[email protected]>

> @@ -1388,6 +1387,7 @@ void vfio_file_set_kvm(struct file *file, struct kvm *kvm)
> vfio_device_file_set_kvm(file, kvm);
> }
> EXPORT_SYMBOL_GPL(vfio_file_set_kvm);
> +#endif

We could even put this in a symbol namespace..

Jason

2023-09-18 22:52:05

by Jason Gunthorpe

Subject: Re: [PATCH 06/26] KVM: Drop CONFIG_KVM_VFIO and just look at KVM+VFIO

On Fri, Sep 15, 2023 at 05:30:58PM -0700, Sean Christopherson wrote:
> Drop KVM's KVM_VFIO Kconfig, and instead compile in VFIO support if
> and only if VFIO itself is enabled. Similar to the recent change to have
> VFIO stop looking at HAVE_KVM, compiling in support for talking to VFIO
> just because the architecture supports VFIO is nonsensical.
>
> This fixes a bug where RISC-V doesn't select KVM_VFIO, i.e. would silently
> fail to do connect KVM and VFIO, even though RISC-V supports VFIO. The
> bug is benign as the only driver in all of Linux that actually uses the
> KVM reference provided by VFIO is KVM-GT, which is x86/Intel specific.

Hmm, I recall that all the S390 drivers need it as well.

static int vfio_ap_mdev_open_device(struct vfio_device *vdev)
{
struct ap_matrix_mdev *matrix_mdev =
container_of(vdev, struct ap_matrix_mdev, vdev);

if (!vdev->kvm)
return -EINVAL;

return vfio_ap_mdev_set_kvm(matrix_mdev, vdev->kvm);


I wonder if we should be making the VFIO drivers that need the kvm to
ask for it? 'select CONFIG_NEED_VFIO_KVM' or something?

Regardless, I fully agree with getting rid of the arch flag.

Reviewed-by: Jason Gunthorpe <[email protected]>

> --- a/virt/kvm/Makefile.kvm
> +++ b/virt/kvm/Makefile.kvm
> @@ -6,7 +6,9 @@
> KVM ?= ../../../virt/kvm
>
> kvm-y := $(KVM)/kvm_main.o $(KVM)/eventfd.o $(KVM)/binary_stats.o
> -kvm-$(CONFIG_KVM_VFIO) += $(KVM)/vfio.o
> +ifdef CONFIG_VFIO
> +kvm-y += $(KVM)/vfio.o
> +endif

I wonder if kvm-m magically works in kbuild so you don't need the ifdef?

Jason

2023-09-18 23:17:03

by Jason Gunthorpe

Subject: Re: [PATCH 02/26] vfio: Move KVM get/put helpers to colocate it with other KVM related code

On Fri, Sep 15, 2023 at 05:30:54PM -0700, Sean Christopherson wrote:
> Move the definitions of vfio_device_get_kvm_safe() and vfio_device_put_kvm()
> down in vfio_main.c to colocate them with other KVM-specific functions,
> e.g. to allow wrapping them all with a single CONFIG_KVM check.
>
> Signed-off-by: Sean Christopherson <[email protected]>
> ---
> drivers/vfio/vfio_main.c | 104 +++++++++++++++++++--------------------
> 1 file changed, 52 insertions(+), 52 deletions(-)

Reviewed-by: Jason Gunthorpe <[email protected]>

Jason

2023-09-18 23:49:26

by Sean Christopherson

Subject: Re: [PATCH 06/26] KVM: Drop CONFIG_KVM_VFIO and just look at KVM+VFIO

On Mon, Sep 18, 2023, Jason Gunthorpe wrote:
> On Fri, Sep 15, 2023 at 05:30:58PM -0700, Sean Christopherson wrote:
> > Drop KVM's KVM_VFIO Kconfig, and instead compile in VFIO support if
> > and only if VFIO itself is enabled. Similar to the recent change to have
> > VFIO stop looking at HAVE_KVM, compiling in support for talking to VFIO
> > just because the architecture supports VFIO is nonsensical.
> >
> > This fixes a bug where RISC-V doesn't select KVM_VFIO, i.e. would silently
> > fail to do connect KVM and VFIO, even though RISC-V supports VFIO. The
> > bug is benign as the only driver in all of Linux that actually uses the
> > KVM reference provided by VFIO is KVM-GT, which is x86/Intel specific.
>
> Hmm, I recall that all the S390 drivers need it as well.
>
> static int vfio_ap_mdev_open_device(struct vfio_device *vdev)
> {
> struct ap_matrix_mdev *matrix_mdev =
> container_of(vdev, struct ap_matrix_mdev, vdev);
>
> if (!vdev->kvm)
> return -EINVAL;
>
> return vfio_ap_mdev_set_kvm(matrix_mdev, vdev->kvm);

Ah, I missed that the KVM reference was routed through VFIO in that case.

> I wonder if we should be making the VFIO drivers that need the kvm to
> ask for it? 'select CONFIG_NEED_VFIO_KVM' or something?

I wondered the same thing, if only to make it easier to track which drivers actually
end up interacting directly with KVM.

> Regardless, I fully agree with getting rid of the arch flag.
>
> Reviewed-by: Jason Gunthorpe <[email protected]>
>
> > --- a/virt/kvm/Makefile.kvm
> > +++ b/virt/kvm/Makefile.kvm
> > @@ -6,7 +6,9 @@
> > KVM ?= ../../../virt/kvm
> >
> > kvm-y := $(KVM)/kvm_main.o $(KVM)/eventfd.o $(KVM)/binary_stats.o
> > -kvm-$(CONFIG_KVM_VFIO) += $(KVM)/vfio.o
> > +ifdef CONFIG_VFIO
> > +kvm-y += $(KVM)/vfio.o
> > +endif
>
> I wonder if kvm-m magically works in kbuild so you don't need the ifdef?

Yeah, that should work, no idea why I added the ifdef.

2023-09-19 00:23:57

by Claudio Imbrenda

Subject: Re: [PATCH 18/26] KVM: s390: Stop adding virt/kvm to the arch include path

On Fri, 15 Sep 2023 17:31:10 -0700
Sean Christopherson <[email protected]> wrote:

> Don't add virt/kvm to KVM s390's include path, the headers in virt/kvm are
> intended to be used only by other code in virt/kvm, i.e. are "private" to
> the core KVM code. It's not clear that s390 *ever* included a header from
> virt/kvm, i.e. odds are good the "-Ivirt/kvm" was copied from a x86's
> Makefile when s390 support was first added.
>
> The only headers in virt/kvm at the time were the x86 specific ioapic.h,
> and iodev.h, neither of which shows up as an #include in the diff for the
> commit range 37817f2982d0f..e976a2b997fc4.
>
> Signed-off-by: Sean Christopherson <[email protected]>
> ---
> arch/s390/kvm/Makefile | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/s390/kvm/Makefile b/arch/s390/kvm/Makefile
> index 02217fb4ae10..f17249ab2a72 100644
> --- a/arch/s390/kvm/Makefile
> +++ b/arch/s390/kvm/Makefile
> @@ -5,7 +5,7 @@
>
> include $(srctree)/virt/kvm/Makefile.kvm
>
> -ccflags-y := -Ivirt/kvm -Iarch/s390/kvm
> +ccflags-y := -Iarch/s390/kvm
>
> kvm-y += kvm-s390.o intercept.o interrupt.o priv.o sigp.o
> kvm-y += diag.o gaccess.o guestdbg.o vsie.o pv.o

Acked-by: Claudio Imbrenda <[email protected]>

2023-09-19 03:30:21

by Jason Gunthorpe

Subject: Re: [PATCH 05/26] vfio: KVM: Pass get/put helpers from KVM to VFIO, don't do circular lookup

On Fri, Sep 15, 2023 at 05:30:57PM -0700, Sean Christopherson wrote:
> Explicitly pass KVM's get/put helpers to VFIO when attaching a VM to
> VFIO instead of having VFIO do a symbol lookup back into KVM. Having both
> KVM and VFIO do symbol lookups increases the overall complexity and places
> an unnecessary dependency on KVM (from VFIO) without adding any value.
>
> Signed-off-by: Sean Christopherson <[email protected]>
> ---
> drivers/vfio/vfio.h | 2 ++
> drivers/vfio/vfio_main.c | 74 +++++++++++++++++++---------------------
> include/linux/vfio.h | 4 ++-
> virt/kvm/vfio.c | 9 +++--
> 4 files changed, 47 insertions(+), 42 deletions(-)

I don't mind this, but Christoph had disliked my prior attempt to do
this with function pointers..

The get can be inlined, IIRC, what about putting a pointer to the put
inside the kvm struct?

The the normal kvm get/put don't have to exported symbols at all?

Jason

2023-09-28 23:48:58

by Alex Williamson

Subject: Re: [PATCH 03/26] virt: Declare and define vfio_file_set_kvm() iff CONFIG_KVM is enabled

On Fri, 15 Sep 2023 17:30:55 -0700
Sean Christopherson <[email protected]> wrote:

> Hide vfio_file_set_kvm() and its unique helpers if KVM is not enabled,
> nothing else in the kernel (or out of the kernel) should be using a
> KVM specific helper.
>
> Signed-off-by: Sean Christopherson <[email protected]>
> ---
> drivers/vfio/vfio_main.c | 2 +-
> include/linux/vfio.h | 2 ++
> 2 files changed, 3 insertions(+), 1 deletion(-)


As Jason noted, s/virt/vfio/ in title.

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


> diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
> index 6368eed7b7b2..124cc88966a7 100644
> --- a/drivers/vfio/vfio_main.c
> +++ b/drivers/vfio/vfio_main.c
> @@ -1352,7 +1352,6 @@ void vfio_device_put_kvm(struct vfio_device *device)
> clear:
> device->kvm = NULL;
> }
> -#endif
>
> static void vfio_device_file_set_kvm(struct file *file, struct kvm *kvm)
> {
> @@ -1388,6 +1387,7 @@ void vfio_file_set_kvm(struct file *file, struct kvm *kvm)
> vfio_device_file_set_kvm(file, kvm);
> }
> EXPORT_SYMBOL_GPL(vfio_file_set_kvm);
> +#endif
>
> /*
> * Sub-module support
> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
> index 454e9295970c..e80955de266c 100644
> --- a/include/linux/vfio.h
> +++ b/include/linux/vfio.h
> @@ -311,7 +311,9 @@ static inline bool vfio_file_has_dev(struct file *file, struct vfio_device *devi
> #endif
> bool vfio_file_is_valid(struct file *file);
> bool vfio_file_enforced_coherent(struct file *file);
> +#if IS_ENABLED(CONFIG_KVM)
> void vfio_file_set_kvm(struct file *file, struct kvm *kvm);
> +#endif
>
> #define VFIO_PIN_PAGES_MAX_ENTRIES (PAGE_SIZE/sizeof(unsigned long))
>

2023-09-29 01:09:00

by Alex Williamson

Subject: Re: [PATCH 06/26] KVM: Drop CONFIG_KVM_VFIO and just look at KVM+VFIO

On Fri, 15 Sep 2023 17:30:58 -0700
Sean Christopherson <[email protected]> wrote:

> Drop KVM's KVM_VFIO Kconfig, and instead compile in VFIO support if
> and only if VFIO itself is enabled. Similar to the recent change to have
> VFIO stop looking at HAVE_KVM, compiling in support for talking to VFIO
> just because the architecture supports VFIO is nonsensical.
>
> This fixes a bug where RISC-V doesn't select KVM_VFIO, i.e. would silently
> fail to do connect KVM and VFIO, even though RISC-V supports VFIO. The
> bug is benign as the only driver in all of Linux that actually uses the
> KVM reference provided by VFIO is KVM-GT, which is x86/Intel specific.
>
> Signed-off-by: Sean Christopherson <[email protected]>
> ---
> arch/arm64/kvm/Kconfig | 1 -
> arch/powerpc/kvm/Kconfig | 1 -
> arch/s390/kvm/Kconfig | 1 -
> arch/x86/kvm/Kconfig | 1 -
> virt/kvm/Kconfig | 3 ---
> virt/kvm/Makefile.kvm | 4 +++-
> virt/kvm/vfio.h | 2 +-
> 7 files changed, 4 insertions(+), 9 deletions(-)


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


> diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
> index 83c1e09be42e..2b5c332f157d 100644
> --- a/arch/arm64/kvm/Kconfig
> +++ b/arch/arm64/kvm/Kconfig
> @@ -28,7 +28,6 @@ menuconfig KVM
> select KVM_MMIO
> select KVM_GENERIC_DIRTYLOG_READ_PROTECT
> select KVM_XFER_TO_GUEST_WORK
> - select KVM_VFIO
> select HAVE_KVM_EVENTFD
> select HAVE_KVM_IRQFD
> select HAVE_KVM_DIRTY_RING_ACQ_REL
> diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig
> index 902611954200..c4beb49c0eb2 100644
> --- a/arch/powerpc/kvm/Kconfig
> +++ b/arch/powerpc/kvm/Kconfig
> @@ -22,7 +22,6 @@ config KVM
> select PREEMPT_NOTIFIERS
> select HAVE_KVM_EVENTFD
> select HAVE_KVM_VCPU_ASYNC_IOCTL
> - select KVM_VFIO
> select IRQ_BYPASS_MANAGER
> select HAVE_KVM_IRQ_BYPASS
> select INTERVAL_TREE
> diff --git a/arch/s390/kvm/Kconfig b/arch/s390/kvm/Kconfig
> index 45fdf2a9b2e3..459d536116a6 100644
> --- a/arch/s390/kvm/Kconfig
> +++ b/arch/s390/kvm/Kconfig
> @@ -31,7 +31,6 @@ config KVM
> select HAVE_KVM_IRQ_ROUTING
> select HAVE_KVM_INVALID_WAKEUPS
> select HAVE_KVM_NO_POLL
> - select KVM_VFIO
> select INTERVAL_TREE
> select MMU_NOTIFIER
> help
> diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
> index ed90f148140d..0f01e5600b5f 100644
> --- a/arch/x86/kvm/Kconfig
> +++ b/arch/x86/kvm/Kconfig
> @@ -45,7 +45,6 @@ config KVM
> select HAVE_KVM_NO_POLL
> select KVM_XFER_TO_GUEST_WORK
> select KVM_GENERIC_DIRTYLOG_READ_PROTECT
> - select KVM_VFIO
> select INTERVAL_TREE
> select HAVE_KVM_PM_NOTIFIER if PM
> select KVM_GENERIC_HARDWARE_ENABLING
> diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig
> index 484d0873061c..f0be3b55cea6 100644
> --- a/virt/kvm/Kconfig
> +++ b/virt/kvm/Kconfig
> @@ -59,9 +59,6 @@ config HAVE_KVM_MSI
> config HAVE_KVM_CPU_RELAX_INTERCEPT
> bool
>
> -config KVM_VFIO
> - bool
> -
> config HAVE_KVM_INVALID_WAKEUPS
> bool
>
> diff --git a/virt/kvm/Makefile.kvm b/virt/kvm/Makefile.kvm
> index 2c27d5d0c367..29373b59d89a 100644
> --- a/virt/kvm/Makefile.kvm
> +++ b/virt/kvm/Makefile.kvm
> @@ -6,7 +6,9 @@
> KVM ?= ../../../virt/kvm
>
> kvm-y := $(KVM)/kvm_main.o $(KVM)/eventfd.o $(KVM)/binary_stats.o
> -kvm-$(CONFIG_KVM_VFIO) += $(KVM)/vfio.o
> +ifdef CONFIG_VFIO
> +kvm-y += $(KVM)/vfio.o
> +endif
> kvm-$(CONFIG_KVM_MMIO) += $(KVM)/coalesced_mmio.o
> kvm-$(CONFIG_KVM_ASYNC_PF) += $(KVM)/async_pf.o
> kvm-$(CONFIG_HAVE_KVM_IRQ_ROUTING) += $(KVM)/irqchip.o
> diff --git a/virt/kvm/vfio.h b/virt/kvm/vfio.h
> index e130a4a03530..af475a323965 100644
> --- a/virt/kvm/vfio.h
> +++ b/virt/kvm/vfio.h
> @@ -2,7 +2,7 @@
> #ifndef __KVM_VFIO_H
> #define __KVM_VFIO_H
>
> -#ifdef CONFIG_KVM_VFIO
> +#if IS_ENABLED(CONFIG_KVM) && IS_ENABLED(CONFIG_VFIO)
> int kvm_vfio_ops_init(void);
> void kvm_vfio_ops_exit(void);
> #else

2023-09-29 05:53:15

by Alex Williamson

Subject: Re: [PATCH 04/26] vfio: Add struct to hold KVM assets and dedup group vs. iommufd code

On Fri, 15 Sep 2023 17:30:56 -0700
Sean Christopherson <[email protected]> wrote:

> Add a struct to hold the KVM assets need to manage and pass along KVM
> references to VFIO devices. Providing a common struct deduplicates the
> group vs. iommufd code, and will make it easier to rework the attachment
> logic so that VFIO doesn't have to do a symbol lookup to retrieve the
> get/put helpers from KVM.
>
> Signed-off-by: Sean Christopherson <[email protected]>
> ---
> drivers/vfio/device_cdev.c | 9 +-------
> drivers/vfio/group.c | 18 ++--------------
> drivers/vfio/vfio.h | 22 +++++++++----------
> drivers/vfio/vfio_main.c | 43 +++++++++++++++++++++++++++-----------
> 4 files changed, 45 insertions(+), 47 deletions(-)


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


> diff --git a/drivers/vfio/device_cdev.c b/drivers/vfio/device_cdev.c
> index e75da0a70d1f..e484d6d6400a 100644
> --- a/drivers/vfio/device_cdev.c
> +++ b/drivers/vfio/device_cdev.c
> @@ -46,13 +46,6 @@ int vfio_device_fops_cdev_open(struct inode *inode, struct file *filep)
> return ret;
> }
>
> -static void vfio_df_get_kvm_safe(struct vfio_device_file *df)
> -{
> - spin_lock(&df->kvm_ref_lock);
> - vfio_device_get_kvm_safe(df->device, df->kvm);
> - spin_unlock(&df->kvm_ref_lock);
> -}
> -
> long vfio_df_ioctl_bind_iommufd(struct vfio_device_file *df,
> struct vfio_device_bind_iommufd __user *arg)
> {
> @@ -99,7 +92,7 @@ long vfio_df_ioctl_bind_iommufd(struct vfio_device_file *df,
> * a reference. This reference is held until device closed.
> * Save the pointer in the device for use by drivers.
> */
> - vfio_df_get_kvm_safe(df);
> + vfio_device_get_kvm_safe(df->device, &df->kvm_ref);
>
> ret = vfio_df_open(df);
> if (ret)
> diff --git a/drivers/vfio/group.c b/drivers/vfio/group.c
> index 610a429c6191..756e47ff4cf0 100644
> --- a/drivers/vfio/group.c
> +++ b/drivers/vfio/group.c
> @@ -157,13 +157,6 @@ static int vfio_group_ioctl_set_container(struct vfio_group *group,
> return ret;
> }
>
> -static void vfio_device_group_get_kvm_safe(struct vfio_device *device)
> -{
> - spin_lock(&device->group->kvm_ref_lock);
> - vfio_device_get_kvm_safe(device, device->group->kvm);
> - spin_unlock(&device->group->kvm_ref_lock);
> -}
> -
> static int vfio_df_group_open(struct vfio_device_file *df)
> {
> struct vfio_device *device = df->device;
> @@ -184,7 +177,7 @@ static int vfio_df_group_open(struct vfio_device_file *df)
> * the pointer in the device for use by drivers.
> */
> if (device->open_count == 0)
> - vfio_device_group_get_kvm_safe(device);
> + vfio_device_get_kvm_safe(device, &device->group->kvm_ref);
>
> df->iommufd = device->group->iommufd;
> if (df->iommufd && vfio_device_is_noiommu(device) && device->open_count == 0) {
> @@ -560,7 +553,7 @@ static struct vfio_group *vfio_group_alloc(struct iommu_group *iommu_group,
>
> refcount_set(&group->drivers, 1);
> mutex_init(&group->group_lock);
> - spin_lock_init(&group->kvm_ref_lock);
> + spin_lock_init(&group->kvm_ref.lock);
> INIT_LIST_HEAD(&group->device_list);
> mutex_init(&group->device_lock);
> group->iommu_group = iommu_group;
> @@ -884,13 +877,6 @@ bool vfio_group_enforced_coherent(struct vfio_group *group)
> return ret;
> }
>
> -void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm)
> -{
> - spin_lock(&group->kvm_ref_lock);
> - group->kvm = kvm;
> - spin_unlock(&group->kvm_ref_lock);
> -}
> -
> /**
> * vfio_file_has_dev - True if the VFIO file is a handle for device
> * @file: VFIO file to check
> diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h
> index c26d1ad68105..a1f741365075 100644
> --- a/drivers/vfio/vfio.h
> +++ b/drivers/vfio/vfio.h
> @@ -12,18 +12,23 @@
> #include <linux/module.h>
> #include <linux/vfio.h>
>
> +struct kvm;
> struct iommufd_ctx;
> struct iommu_group;
> struct vfio_container;
>
> +struct vfio_kvm_reference {
> + struct kvm *kvm;
> + spinlock_t lock;
> +};
> +
> struct vfio_device_file {
> struct vfio_device *device;
> struct vfio_group *group;
>
> u8 access_granted;
> u32 devid; /* only valid when iommufd is valid */
> - spinlock_t kvm_ref_lock; /* protect kvm field */
> - struct kvm *kvm;
> + struct vfio_kvm_reference kvm_ref;
> struct iommufd_ctx *iommufd; /* protected by struct vfio_device_set::lock */
> };
>
> @@ -88,11 +93,10 @@ struct vfio_group {
> #endif
> enum vfio_group_type type;
> struct mutex group_lock;
> - struct kvm *kvm;
> + struct vfio_kvm_reference kvm_ref;
> struct file *opened_file;
> struct blocking_notifier_head notifier;
> struct iommufd_ctx *iommufd;
> - spinlock_t kvm_ref_lock;
> unsigned int cdev_device_open_cnt;
> };
>
> @@ -108,7 +112,6 @@ void vfio_device_group_unuse_iommu(struct vfio_device *device);
> void vfio_df_group_close(struct vfio_device_file *df);
> struct vfio_group *vfio_group_from_file(struct file *file);
> bool vfio_group_enforced_coherent(struct vfio_group *group);
> -void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm);
> bool vfio_device_has_container(struct vfio_device *device);
> int __init vfio_group_init(void);
> void vfio_group_cleanup(void);
> @@ -171,10 +174,6 @@ static inline bool vfio_group_enforced_coherent(struct vfio_group *group)
> return true;
> }
>
> -static inline void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm)
> -{
> -}
> -
> static inline bool vfio_device_has_container(struct vfio_device *device)
> {
> return false;
> @@ -435,11 +434,12 @@ static inline void vfio_virqfd_exit(void)
> #endif
>
> #if IS_ENABLED(CONFIG_KVM)
> -void vfio_device_get_kvm_safe(struct vfio_device *device, struct kvm *kvm);
> +void vfio_device_get_kvm_safe(struct vfio_device *device,
> + struct vfio_kvm_reference *ref);
> void vfio_device_put_kvm(struct vfio_device *device);
> #else
> static inline void vfio_device_get_kvm_safe(struct vfio_device *device,
> - struct kvm *kvm)
> + struct vfio_kvm_reference *ref)
> {
> }
>
> diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
> index 124cc88966a7..e77e8c6aae2f 100644
> --- a/drivers/vfio/vfio_main.c
> +++ b/drivers/vfio/vfio_main.c
> @@ -397,7 +397,7 @@ vfio_allocate_device_file(struct vfio_device *device)
> return ERR_PTR(-ENOMEM);
>
> df->device = device;
> - spin_lock_init(&df->kvm_ref_lock);
> + spin_lock_init(&df->kvm_ref.lock);
>
> return df;
> }
> @@ -1303,7 +1303,8 @@ bool vfio_file_enforced_coherent(struct file *file)
> EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent);
>
> #if IS_ENABLED(CONFIG_KVM)
> -void vfio_device_get_kvm_safe(struct vfio_device *device, struct kvm *kvm)
> +void vfio_device_get_kvm_safe(struct vfio_device *device,
> + struct vfio_kvm_reference *ref)
> {
> void (*pfn)(struct kvm *kvm);
> bool (*fn)(struct kvm *kvm);
> @@ -1311,28 +1312,33 @@ void vfio_device_get_kvm_safe(struct vfio_device *device, struct kvm *kvm)
>
> lockdep_assert_held(&device->dev_set->lock);
>
> - if (!kvm)
> - return;
> + spin_lock(&ref->lock);
> +
> + if (!ref->kvm)
> + goto out;
>
> pfn = symbol_get(kvm_put_kvm);
> if (WARN_ON(!pfn))
> - return;
> + goto out;
>
> fn = symbol_get(kvm_get_kvm_safe);
> if (WARN_ON(!fn)) {
> symbol_put(kvm_put_kvm);
> - return;
> + goto out;
> }
>
> - ret = fn(kvm);
> + ret = fn(ref->kvm);
> symbol_put(kvm_get_kvm_safe);
> if (!ret) {
> symbol_put(kvm_put_kvm);
> - return;
> + goto out;
> }
>
> device->put_kvm = pfn;
> - device->kvm = kvm;
> + device->kvm = ref->kvm;
> +
> +out:
> + spin_unlock(&ref->lock);
> }
>
> void vfio_device_put_kvm(struct vfio_device *device)
> @@ -1353,6 +1359,21 @@ void vfio_device_put_kvm(struct vfio_device *device)
> device->kvm = NULL;
> }
>
> +static void vfio_device_set_kvm(struct vfio_kvm_reference *ref,
> + struct kvm *kvm)
> +{
> + spin_lock(&ref->lock);
> + ref->kvm = kvm;
> + spin_unlock(&ref->lock);
> +}
> +
> +static void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm)
> +{
> +#if IS_ENABLED(CONFIG_VFIO_GROUP)
> + vfio_device_set_kvm(&group->kvm_ref, kvm);
> +#endif
> +}
> +
> static void vfio_device_file_set_kvm(struct file *file, struct kvm *kvm)
> {
> struct vfio_device_file *df = file->private_data;
> @@ -1362,9 +1383,7 @@ static void vfio_device_file_set_kvm(struct file *file, struct kvm *kvm)
> * be propagated to vfio_device::kvm when the file is bound to
> * iommufd successfully in the vfio device cdev path.
> */
> - spin_lock(&df->kvm_ref_lock);
> - df->kvm = kvm;
> - spin_unlock(&df->kvm_ref_lock);
> + vfio_device_set_kvm(&df->kvm_ref, kvm);
> }
>
> /**

2023-09-29 07:43:01

by Alex Williamson

Subject: Re: [PATCH 05/26] vfio: KVM: Pass get/put helpers from KVM to VFIO, don't do circular lookup

On Fri, 15 Sep 2023 17:30:57 -0700
Sean Christopherson <[email protected]> wrote:

> Explicitly pass KVM's get/put helpers to VFIO when attaching a VM to
> VFIO instead of having VFIO do a symbol lookup back into KVM. Having both
> KVM and VFIO do symbol lookups increases the overall complexity and places
> an unnecessary dependency on KVM (from VFIO) without adding any value.
>
> Signed-off-by: Sean Christopherson <[email protected]>
> ---
> drivers/vfio/vfio.h | 2 ++
> drivers/vfio/vfio_main.c | 74 +++++++++++++++++++---------------------
> include/linux/vfio.h | 4 ++-
> virt/kvm/vfio.c | 9 +++--
> 4 files changed, 47 insertions(+), 42 deletions(-)


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


> diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h
> index a1f741365075..eec51c7ee822 100644
> --- a/drivers/vfio/vfio.h
> +++ b/drivers/vfio/vfio.h
> @@ -19,6 +19,8 @@ struct vfio_container;
>
> struct vfio_kvm_reference {
> struct kvm *kvm;
> + bool (*get_kvm)(struct kvm *kvm);
> + void (*put_kvm)(struct kvm *kvm);
> spinlock_t lock;
> };
>
> diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
> index e77e8c6aae2f..1f58ab6dbcd2 100644
> --- a/drivers/vfio/vfio_main.c
> +++ b/drivers/vfio/vfio_main.c
> @@ -16,7 +16,6 @@
> #include <linux/fs.h>
> #include <linux/idr.h>
> #include <linux/iommu.h>
> -#include <linux/kvm_host.h>
> #include <linux/list.h>
> #include <linux/miscdevice.h>
> #include <linux/module.h>
> @@ -1306,38 +1305,22 @@ EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent);
> void vfio_device_get_kvm_safe(struct vfio_device *device,
> struct vfio_kvm_reference *ref)
> {
> - void (*pfn)(struct kvm *kvm);
> - bool (*fn)(struct kvm *kvm);
> - bool ret;
> -
> lockdep_assert_held(&device->dev_set->lock);
>
> + /*
> + * Note! The "kvm" and "put_kvm" pointers *must* be transferred to the
> + * device so that the device can put its reference to KVM. KVM can
> + * invoke vfio_device_set_kvm() to detach from VFIO, i.e. nullify all
> + * pointers in @ref, even if a device holds a reference to KVM! That
> + * also means that detaching KVM from VFIO only prevents "new" devices
> + * from using KVM, it doesn't invalidate KVM references in existing
> + * devices.
> + */
> spin_lock(&ref->lock);
> -
> - if (!ref->kvm)
> - goto out;
> -
> - pfn = symbol_get(kvm_put_kvm);
> - if (WARN_ON(!pfn))
> - goto out;
> -
> - fn = symbol_get(kvm_get_kvm_safe);
> - if (WARN_ON(!fn)) {
> - symbol_put(kvm_put_kvm);
> - goto out;
> + if (ref->kvm && ref->get_kvm(ref->kvm)) {
> + device->kvm = ref->kvm;
> + device->put_kvm = ref->put_kvm;
> }
> -
> - ret = fn(ref->kvm);
> - symbol_put(kvm_get_kvm_safe);
> - if (!ret) {
> - symbol_put(kvm_put_kvm);
> - goto out;
> - }
> -
> - device->put_kvm = pfn;
> - device->kvm = ref->kvm;
> -
> -out:
> spin_unlock(&ref->lock);
> }
>
> @@ -1353,28 +1336,37 @@ void vfio_device_put_kvm(struct vfio_device *device)
>
> device->put_kvm(device->kvm);
> device->put_kvm = NULL;
> - symbol_put(kvm_put_kvm);
> -
> clear:
> device->kvm = NULL;
> }
>
> static void vfio_device_set_kvm(struct vfio_kvm_reference *ref,
> - struct kvm *kvm)
> + struct kvm *kvm,
> + bool (*get_kvm)(struct kvm *kvm),
> + void (*put_kvm)(struct kvm *kvm))
> {
> + if (WARN_ON_ONCE(kvm && (!get_kvm || !put_kvm)))
> + return;
> +
> spin_lock(&ref->lock);
> ref->kvm = kvm;
> + ref->get_kvm = get_kvm;
> + ref->put_kvm = put_kvm;
> spin_unlock(&ref->lock);
> }
>
> -static void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm)
> +static void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm,
> + bool (*get_kvm)(struct kvm *kvm),
> + void (*put_kvm)(struct kvm *kvm))
> {
> #if IS_ENABLED(CONFIG_VFIO_GROUP)
> - vfio_device_set_kvm(&group->kvm_ref, kvm);
> + vfio_device_set_kvm(&group->kvm_ref, kvm, get_kvm, put_kvm);
> #endif
> }
>
> -static void vfio_device_file_set_kvm(struct file *file, struct kvm *kvm)
> +static void vfio_device_file_set_kvm(struct file *file, struct kvm *kvm,
> + bool (*get_kvm)(struct kvm *kvm),
> + void (*put_kvm)(struct kvm *kvm))
> {
> struct vfio_device_file *df = file->private_data;
>
> @@ -1383,27 +1375,31 @@ static void vfio_device_file_set_kvm(struct file *file, struct kvm *kvm)
> * be propagated to vfio_device::kvm when the file is bound to
> * iommufd successfully in the vfio device cdev path.
> */
> - vfio_device_set_kvm(&df->kvm_ref, kvm);
> + vfio_device_set_kvm(&df->kvm_ref, kvm, get_kvm, put_kvm);
> }
>
> /**
> * vfio_file_set_kvm - Link a kvm with VFIO drivers
> * @file: VFIO group file or VFIO device file
> * @kvm: KVM to link
> + * @get_kvm: Callback to get a reference to @kvm
> + * @put_kvm: Callback to put a reference to @kvm
> *
> * When a VFIO device is first opened the KVM will be available in
> * device->kvm if one was associated with the file.
> */
> -void vfio_file_set_kvm(struct file *file, struct kvm *kvm)
> +void vfio_file_set_kvm(struct file *file, struct kvm *kvm,
> + bool (*get_kvm)(struct kvm *kvm),
> + void (*put_kvm)(struct kvm *kvm))
> {
> struct vfio_group *group;
>
> group = vfio_group_from_file(file);
> if (group)
> - vfio_group_set_kvm(group, kvm);
> + vfio_group_set_kvm(group, kvm, get_kvm, put_kvm);
>
> if (vfio_device_from_file(file))
> - vfio_device_file_set_kvm(file, kvm);
> + vfio_device_file_set_kvm(file, kvm, get_kvm, put_kvm);
> }
> EXPORT_SYMBOL_GPL(vfio_file_set_kvm);
> #endif
> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
> index e80955de266c..35e970e3d3fb 100644
> --- a/include/linux/vfio.h
> +++ b/include/linux/vfio.h
> @@ -312,7 +312,9 @@ static inline bool vfio_file_has_dev(struct file *file, struct vfio_device *devi
> bool vfio_file_is_valid(struct file *file);
> bool vfio_file_enforced_coherent(struct file *file);
> #if IS_ENABLED(CONFIG_KVM)
> -void vfio_file_set_kvm(struct file *file, struct kvm *kvm);
> +void vfio_file_set_kvm(struct file *file, struct kvm *kvm,
> + bool (*get_kvm)(struct kvm *kvm),
> + void (*put_kvm)(struct kvm *kvm));
> #endif
>
> #define VFIO_PIN_PAGES_MAX_ENTRIES (PAGE_SIZE/sizeof(unsigned long))
> diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c
> index ca24ce120906..f14fcbb34bc6 100644
> --- a/virt/kvm/vfio.c
> +++ b/virt/kvm/vfio.c
> @@ -37,13 +37,18 @@ struct kvm_vfio {
>
> static void kvm_vfio_file_set_kvm(struct file *file, struct kvm *kvm)
> {
> - void (*fn)(struct file *file, struct kvm *kvm);
> + void (*fn)(struct file *file, struct kvm *kvm,
> + bool (*get_kvm)(struct kvm *kvm),
> + void (*put_kvm)(struct kvm *kvm));
>
> fn = symbol_get(vfio_file_set_kvm);
> if (!fn)
> return;
>
> - fn(file, kvm);
> + if (kvm)
> + fn(file, kvm, kvm_get_kvm_safe, kvm_put_kvm);
> + else
> + fn(file, kvm, NULL, NULL);
>
> symbol_put(vfio_file_set_kvm);
> }

2023-09-29 09:52:06

by Alex Williamson

Subject: Re: [PATCH 02/26] vfio: Move KVM get/put helpers to colocate it with other KVM related code

On Fri, 15 Sep 2023 17:30:54 -0700
Sean Christopherson <[email protected]> wrote:

> Move the definitions of vfio_device_get_kvm_safe() and vfio_device_put_kvm()
> down in vfio_main.c to colocate them with other KVM-specific functions,
> e.g. to allow wrapping them all with a single CONFIG_KVM check.
>
> Signed-off-by: Sean Christopherson <[email protected]>
> ---
> drivers/vfio/vfio_main.c | 104 +++++++++++++++++++--------------------
> 1 file changed, 52 insertions(+), 52 deletions(-)


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


> diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
> index 80e39f7a6d8f..6368eed7b7b2 100644
> --- a/drivers/vfio/vfio_main.c
> +++ b/drivers/vfio/vfio_main.c
> @@ -381,58 +381,6 @@ void vfio_unregister_group_dev(struct vfio_device *device)
> }
> EXPORT_SYMBOL_GPL(vfio_unregister_group_dev);
>
> -#if IS_ENABLED(CONFIG_KVM)
> -void vfio_device_get_kvm_safe(struct vfio_device *device, struct kvm *kvm)
> -{
> - void (*pfn)(struct kvm *kvm);
> - bool (*fn)(struct kvm *kvm);
> - bool ret;
> -
> - lockdep_assert_held(&device->dev_set->lock);
> -
> - if (!kvm)
> - return;
> -
> - pfn = symbol_get(kvm_put_kvm);
> - if (WARN_ON(!pfn))
> - return;
> -
> - fn = symbol_get(kvm_get_kvm_safe);
> - if (WARN_ON(!fn)) {
> - symbol_put(kvm_put_kvm);
> - return;
> - }
> -
> - ret = fn(kvm);
> - symbol_put(kvm_get_kvm_safe);
> - if (!ret) {
> - symbol_put(kvm_put_kvm);
> - return;
> - }
> -
> - device->put_kvm = pfn;
> - device->kvm = kvm;
> -}
> -
> -void vfio_device_put_kvm(struct vfio_device *device)
> -{
> - lockdep_assert_held(&device->dev_set->lock);
> -
> - if (!device->kvm)
> - return;
> -
> - if (WARN_ON(!device->put_kvm))
> - goto clear;
> -
> - device->put_kvm(device->kvm);
> - device->put_kvm = NULL;
> - symbol_put(kvm_put_kvm);
> -
> -clear:
> - device->kvm = NULL;
> -}
> -#endif
> -
> /* true if the vfio_device has open_device() called but not close_device() */
> static bool vfio_assert_device_open(struct vfio_device *device)
> {
> @@ -1354,6 +1302,58 @@ bool vfio_file_enforced_coherent(struct file *file)
> }
> EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent);
>
> +#if IS_ENABLED(CONFIG_KVM)
> +void vfio_device_get_kvm_safe(struct vfio_device *device, struct kvm *kvm)
> +{
> + void (*pfn)(struct kvm *kvm);
> + bool (*fn)(struct kvm *kvm);
> + bool ret;
> +
> + lockdep_assert_held(&device->dev_set->lock);
> +
> + if (!kvm)
> + return;
> +
> + pfn = symbol_get(kvm_put_kvm);
> + if (WARN_ON(!pfn))
> + return;
> +
> + fn = symbol_get(kvm_get_kvm_safe);
> + if (WARN_ON(!fn)) {
> + symbol_put(kvm_put_kvm);
> + return;
> + }
> +
> + ret = fn(kvm);
> + symbol_put(kvm_get_kvm_safe);
> + if (!ret) {
> + symbol_put(kvm_put_kvm);
> + return;
> + }
> +
> + device->put_kvm = pfn;
> + device->kvm = kvm;
> +}
> +
> +void vfio_device_put_kvm(struct vfio_device *device)
> +{
> + lockdep_assert_held(&device->dev_set->lock);
> +
> + if (!device->kvm)
> + return;
> +
> + if (WARN_ON(!device->put_kvm))
> + goto clear;
> +
> + device->put_kvm(device->kvm);
> + device->put_kvm = NULL;
> + symbol_put(kvm_put_kvm);
> +
> +clear:
> + device->kvm = NULL;
> +}
> +#endif
> +
> static void vfio_device_file_set_kvm(struct file *file, struct kvm *kvm)
> {
> struct vfio_device_file *df = file->private_data;

2023-12-02 00:56:41

by Sean Christopherson

Subject: Re: [PATCH 05/26] vfio: KVM: Pass get/put helpers from KVM to VFIO, don't do circular lookup

On Mon, Sep 18, 2023, Jason Gunthorpe wrote:
> On Mon, Sep 18, 2023 at 08:49:57AM -0700, Sean Christopherson wrote:
> > On Mon, Sep 18, 2023, Jason Gunthorpe wrote:
> > > On Fri, Sep 15, 2023 at 05:30:57PM -0700, Sean Christopherson wrote:
> > > > Explicitly pass KVM's get/put helpers to VFIO when attaching a VM to
> > > > VFIO instead of having VFIO do a symbol lookup back into KVM. Having both
> > > > KVM and VFIO do symbol lookups increases the overall complexity and places
> > > > an unnecessary dependency on KVM (from VFIO) without adding any value.
> > > >
> > > > Signed-off-by: Sean Christopherson <[email protected]>
> > > > ---
> > > > drivers/vfio/vfio.h | 2 ++
> > > > drivers/vfio/vfio_main.c | 74 +++++++++++++++++++---------------------
> > > > include/linux/vfio.h | 4 ++-
> > > > virt/kvm/vfio.c | 9 +++--
> > > > 4 files changed, 47 insertions(+), 42 deletions(-)
> > >
> > > I don't mind this, but Christoph had disliked my prior attempt to do
> > > this with function pointers..
> > >
> > > The get can be inlined, IIRC, what about putting a pointer to the put
> > > inside the kvm struct?
> >
> > That wouldn't allow us to achieve our goal, which is to hide the details of
> > "struct kvm" from VFIO (and the rest of the kernel).
>
> > What's the objection to handing VFIO a function pointer?
>
> Hmm, looks like it was this thread:
>
> https://lore.kernel.org/r/[email protected]
>
> Your rational looks a little better to me.
>
> > > The the normal kvm get/put don't have to exported symbols at all?
> >
> > The export of kvm_get_kvm_safe() can go away (I forgot to do that in this series),
> > but kvm_get_kvm() will hang around as it's needed by KVM sub-modules (PPC and x86),
> > KVMGT (x86), and drivers/s390/crypto/vfio_ap_ops.c (no idea what to call that beast).
>
> My thought would be to keep it as an inline, there should be some way
> to do that without breaking your desire to hide the bulk of the kvm
> struct content. Like put the refcount as the first element in the
> struct and just don't ifdef it away?.

That doesn't work because of the need to invoke kvm_destroy_vm() when the last
reference is put, i.e. all of kvm_destroy_vm() would need to be inlined (LOL) or
VFIO would need to do a symbol lookup on kvm_destroy_vm(), which puts back us at
square one.

There's one more wrinkle: this patch is buggy in that it doesn't ensure the liveliness
of KVM-the-module, i.e. nothing prevents userspace from unloading kvm.ko while VFIO
still holds a reference to a kvm structure, and so invoking ->put_kvm() could jump
into freed code. To fix that, KVM would also need to pass along a module pointer :-(

One thought would be to have vac.ko (tentative name), which is the "base" module
that will hold the KVM/virtualization bits that need to be singletons, i.e. can't
be per-KVM, provide the symbols needed for VFIO to manage references. But that
just ends up moving the module reference trickiness into VAC+KVM, e.g. vac.ko would
still need to be handed a function pointer in order to call back into the correct
kvm.ko code.

Hrm, but I suspect the vac.ko <=> kvm.ko interactions will need to deal with
module shenanigans anyways, and the shenanigans would only affect crazy people
like us that actually want multiple KVM modules.

I'll plan on going that route. The very worst case scenario is that it just punts
this conversation down to a possibile future. Dropping this patch and the previous
prep patch won't meaningful affect the goals of this series, as only kvm_get_kvm_safe()
and kvm_get_kvm() would need to be exposed outside of #ifdef __KVM__. Then we can
figure out what to do with them if/when the whole multi-KVM thing comes along.

2023-12-03 14:10:41

by Jason Gunthorpe

Subject: Re: [PATCH 05/26] vfio: KVM: Pass get/put helpers from KVM to VFIO, don't do circular lookup

On Fri, Dec 01, 2023 at 04:51:55PM -0800, Sean Christopherson wrote:

> There's one more wrinkle: this patch is buggy in that it doesn't ensure the liveliness
> of KVM-the-module, i.e. nothing prevents userspace from unloading kvm.ko while VFIO
> still holds a reference to a kvm structure, and so invoking ->put_kvm() could jump
> into freed code. To fix that, KVM would also need to pass along a module pointer :-(

Maybe we should be refcounting the struct file not the struct kvm?

Then we don't need special helpers and it keeps the module alive correctly.

Jason

2023-12-13 02:23:05

by Sean Christopherson

Subject: Re: [PATCH 05/26] vfio: KVM: Pass get/put helpers from KVM to VFIO, don't do circular lookup

On Sun, Dec 03, 2023, Jason Gunthorpe wrote:
> On Fri, Dec 01, 2023 at 04:51:55PM -0800, Sean Christopherson wrote:
>
> > There's one more wrinkle: this patch is buggy in that it doesn't ensure the liveliness
> > of KVM-the-module, i.e. nothing prevents userspace from unloading kvm.ko while VFIO
> > still holds a reference to a kvm structure, and so invoking ->put_kvm() could jump
> > into freed code. To fix that, KVM would also need to pass along a module pointer :-(
>
> Maybe we should be refcounting the struct file not the struct kvm?
>
> Then we don't need special helpers and it keeps the module alive correctly.

Huh. It took my brain a while to catch up, but this seems comically obvious in
hindsight. I *love* this approach, both conceptually and from a code perspective.

Handing VFIO (and any other external entities) a file makes it so that KVM effectively
interacts with users via files, regardless of whether the user lives in userspace
or the kernel. That makes it easier to reason about the safety of operations,
e.g. in addition to ensuring KVM-the-module is pinned, having a file pointer allows
KVM to verify that the incoming pointer does indeed represent a VM. Which isn't
necessary by any means, but it's a nice sanity check.

From a code perspective, it's far cleaner than manually grabbing module references,
and having only a file pointers makes it a wee bit harder for non-KVM code to
poke into KVM, e.g. keeps us honest.

Assuming nothing blows up in testing, I'll go this route for v2.

Thanks!

2023-12-14 06:04:56

by Anup Patel

Subject: Re: [PATCH 15/26] KVM: Move include/kvm/iodev.h to include/linux as kvm_iodev.h

On Sat, Sep 16, 2023 at 6:01 AM Sean Christopherson <[email protected]> wrote:
>
> Move iodev.h, the last remaining holdout in include/kvm, to the standard
> include/linux directory as kvm_iodev.h and delete include/kvm.
>
> Signed-off-by: Sean Christopherson <[email protected]>

For KVM RISC-V:
Acked-by: Anup Patel <[email protected]>

Regards,
Anup

> ---
> MAINTAINERS | 1 -
> arch/arm64/include/asm/kvm_vgic.h | 2 +-
> arch/arm64/kvm/vgic/vgic-mmio-v2.c | 2 +-
> arch/arm64/kvm/vgic/vgic-mmio-v3.c | 2 +-
> arch/arm64/kvm/vgic/vgic-mmio.c | 2 +-
> arch/mips/include/asm/kvm_host.h | 3 +--
> arch/powerpc/kvm/mpic.c | 2 +-
> arch/riscv/kvm/aia_aplic.c | 2 +-
> arch/riscv/kvm/aia_imsic.c | 2 +-
> arch/x86/kvm/i8254.h | 2 +-
> arch/x86/kvm/ioapic.h | 2 +-
> arch/x86/kvm/irq.h | 2 +-
> arch/x86/kvm/lapic.h | 2 +-
> include/{kvm/iodev.h => linux/kvm_iodev.h} | 0
> virt/kvm/coalesced_mmio.c | 3 +--
> virt/kvm/eventfd.c | 2 +-
> virt/kvm/kvm_main.c | 3 +--
> 17 files changed, 15 insertions(+), 19 deletions(-)
> rename include/{kvm/iodev.h => linux/kvm_iodev.h} (100%)
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 90f13281d297..ddc8375d536c 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -11498,7 +11498,6 @@ W: http://www.linux-kvm.org
> T: git git://git.kernel.org/pub/scm/virt/kvm/kvm.git
> F: Documentation/virt/kvm/
> F: include/asm-generic/kvm*
> -F: include/kvm/iodev.h
> F: include/linux/kvm*
> F: include/trace/events/kvm.h
> F: include/uapi/asm-generic/kvm*
> diff --git a/arch/arm64/include/asm/kvm_vgic.h b/arch/arm64/include/asm/kvm_vgic.h
> index 5b27f94d4fad..2ca52888bc75 100644
> --- a/arch/arm64/include/asm/kvm_vgic.h
> +++ b/arch/arm64/include/asm/kvm_vgic.h
> @@ -13,7 +13,7 @@
> #include <linux/spinlock.h>
> #include <linux/static_key.h>
> #include <linux/types.h>
> -#include <kvm/iodev.h>
> +#include <linux/kvm_iodev.h>
> #include <linux/list.h>
> #include <linux/jump_label.h>
>
> diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v2.c b/arch/arm64/kvm/vgic/vgic-mmio-v2.c
> index bba0cfeefffe..646053ee892f 100644
> --- a/arch/arm64/kvm/vgic/vgic-mmio-v2.c
> +++ b/arch/arm64/kvm/vgic/vgic-mmio-v2.c
> @@ -6,9 +6,9 @@
> #include <linux/irqchip/arm-gic.h>
> #include <linux/kvm.h>
> #include <linux/kvm_host.h>
> +#include <linux/kvm_iodev.h>
> #include <linux/nospec.h>
>
> -#include <kvm/iodev.h>
> #include <asm/kvm_vgic.h>
>
> #include "vgic.h"
> diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v3.c b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
> index d54a90beef61..b79a2e860415 100644
> --- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c
> +++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c
> @@ -7,8 +7,8 @@
> #include <linux/irqchip/arm-gic-v3.h>
> #include <linux/kvm.h>
> #include <linux/kvm_host.h>
> +#include <linux/kvm_iodev.h>
> #include <linux/interrupt.h>
> -#include <kvm/iodev.h>
>
> #include <asm/kvm_emulate.h>
> #include <asm/kvm_arm.h>
> diff --git a/arch/arm64/kvm/vgic/vgic-mmio.c b/arch/arm64/kvm/vgic/vgic-mmio.c
> index 68a3d8062473..4feca3b1d915 100644
> --- a/arch/arm64/kvm/vgic/vgic-mmio.c
> +++ b/arch/arm64/kvm/vgic/vgic-mmio.c
> @@ -9,7 +9,7 @@
> #include <linux/irq.h>
> #include <linux/kvm.h>
> #include <linux/kvm_host.h>
> -#include <kvm/iodev.h>
> +#include <linux/kvm_iodev.h>
> #include <asm/kvm_arch_timer.h>
> #include <asm/kvm_vgic.h>
>
> diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h
> index 54a85f1d4f2c..f8f63d0aa399 100644
> --- a/arch/mips/include/asm/kvm_host.h
> +++ b/arch/mips/include/asm/kvm_host.h
> @@ -16,6 +16,7 @@
> #include <linux/interrupt.h>
> #include <linux/types.h>
> #include <linux/kvm.h>
> +#include <linux/kvm_iodev.h>
> #include <linux/kvm_types.h>
> #include <linux/threads.h>
> #include <linux/spinlock.h>
> @@ -24,8 +25,6 @@
> #include <asm/inst.h>
> #include <asm/mipsregs.h>
>
> -#include <kvm/iodev.h>
> -
> /* MIPS KVM register ids */
> #define MIPS_CP0_32(_R, _S) \
> (KVM_REG_MIPS_CP0 | KVM_REG_SIZE_U32 | (8 * (_R) + (_S)))
> diff --git a/arch/powerpc/kvm/mpic.c b/arch/powerpc/kvm/mpic.c
> index 23e9c2bd9f27..b25a03251544 100644
> --- a/arch/powerpc/kvm/mpic.c
> +++ b/arch/powerpc/kvm/mpic.c
> @@ -26,6 +26,7 @@
> #include <linux/slab.h>
> #include <linux/mutex.h>
> #include <linux/kvm_host.h>
> +#include <linux/kvm_iodev.h>
> #include <linux/errno.h>
> #include <linux/fs.h>
> #include <linux/anon_inodes.h>
> @@ -33,7 +34,6 @@
> #include <asm/mpic.h>
> #include <asm/kvm_para.h>
> #include <asm/kvm_ppc.h>
> -#include <kvm/iodev.h>
>
> #define MAX_CPU 32
> #define MAX_SRC 256
> diff --git a/arch/riscv/kvm/aia_aplic.c b/arch/riscv/kvm/aia_aplic.c
> index 39e72aa016a4..b49e747f2bad 100644
> --- a/arch/riscv/kvm/aia_aplic.c
> +++ b/arch/riscv/kvm/aia_aplic.c
> @@ -11,7 +11,7 @@
> #include <linux/math.h>
> #include <linux/spinlock.h>
> #include <linux/swab.h>
> -#include <kvm/iodev.h>
> +#include <linux/kvm_iodev.h>
> #include <asm/kvm_aia_aplic.h>
>
> struct aplic_irq {
> diff --git a/arch/riscv/kvm/aia_imsic.c b/arch/riscv/kvm/aia_imsic.c
> index 6cf23b8adb71..586e466a1c6d 100644
> --- a/arch/riscv/kvm/aia_imsic.c
> +++ b/arch/riscv/kvm/aia_imsic.c
> @@ -10,10 +10,10 @@
> #include <linux/atomic.h>
> #include <linux/bitmap.h>
> #include <linux/kvm_host.h>
> +#include <linux/kvm_iodev.h>
> #include <linux/math.h>
> #include <linux/spinlock.h>
> #include <linux/swab.h>
> -#include <kvm/iodev.h>
> #include <asm/csr.h>
> #include <asm/kvm_aia_imsic.h>
>
> diff --git a/arch/x86/kvm/i8254.h b/arch/x86/kvm/i8254.h
> index a768212ba821..4de7a0b88e4f 100644
> --- a/arch/x86/kvm/i8254.h
> +++ b/arch/x86/kvm/i8254.h
> @@ -4,7 +4,7 @@
>
> #include <linux/kthread.h>
>
> -#include <kvm/iodev.h>
> +#include <linux/kvm_iodev.h>
>
> struct kvm_kpit_channel_state {
> u32 count; /* can be 65536 */
> diff --git a/arch/x86/kvm/ioapic.h b/arch/x86/kvm/ioapic.h
> index 539333ac4b38..2beec2daf1a3 100644
> --- a/arch/x86/kvm/ioapic.h
> +++ b/arch/x86/kvm/ioapic.h
> @@ -3,7 +3,7 @@
> #define __KVM_IO_APIC_H
>
> #include <linux/kvm_host.h>
> -#include <kvm/iodev.h>
> +#include <linux/kvm_iodev.h>
> #include "irq.h"
>
> struct kvm;
> diff --git a/arch/x86/kvm/irq.h b/arch/x86/kvm/irq.h
> index c2d7cfe82d00..f9530e9a66f8 100644
> --- a/arch/x86/kvm/irq.h
> +++ b/arch/x86/kvm/irq.h
> @@ -13,9 +13,9 @@
> #include <linux/mm_types.h>
> #include <linux/hrtimer.h>
> #include <linux/kvm_host.h>
> +#include <linux/kvm_iodev.h>
> #include <linux/spinlock.h>
>
> -#include <kvm/iodev.h>
> #include "lapic.h"
>
> #define PIC_NUM_PINS 16
> diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
> index 0a0ea4b5dd8c..bfd99ad1882e 100644
> --- a/arch/x86/kvm/lapic.h
> +++ b/arch/x86/kvm/lapic.h
> @@ -2,7 +2,7 @@
> #ifndef __KVM_X86_LAPIC_H
> #define __KVM_X86_LAPIC_H
>
> -#include <kvm/iodev.h>
> +#include <linux/kvm_iodev.h>
>
> #include <linux/kvm_host.h>
>
> diff --git a/include/kvm/iodev.h b/include/linux/kvm_iodev.h
> similarity index 100%
> rename from include/kvm/iodev.h
> rename to include/linux/kvm_iodev.h
> diff --git a/virt/kvm/coalesced_mmio.c b/virt/kvm/coalesced_mmio.c
> index 1b90acb6e3fe..cfcb4b84d632 100644
> --- a/virt/kvm/coalesced_mmio.c
> +++ b/virt/kvm/coalesced_mmio.c
> @@ -9,8 +9,7 @@
> *
> */
>
> -#include <kvm/iodev.h>
> -
> +#include <linux/kvm_iodev.h>
> #include <linux/kvm_host.h>
> #include <linux/slab.h>
> #include <linux/kvm.h>
> diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
> index 89912a17f5d5..4d7cfb1095fd 100644
> --- a/virt/kvm/eventfd.c
> +++ b/virt/kvm/eventfd.c
> @@ -26,7 +26,7 @@
> #include <linux/irqbypass.h>
> #include <trace/events/kvm.h>
>
> -#include <kvm/iodev.h>
> +#include <linux/kvm_iodev.h>
>
> #ifdef CONFIG_HAVE_KVM_IRQFD
>
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 486800a7024b..f585a159b4f5 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -13,9 +13,8 @@
> * Yaniv Kamay <[email protected]>
> */
>
> -#include <kvm/iodev.h>
> -
> #include <linux/kvm_host.h>
> +#include <linux/kvm_iodev.h>
> #include <linux/kvm.h>
> #include <linux/module.h>
> #include <linux/errno.h>
> --
> 2.42.0.459.ge4e396fd5e-goog
>

2023-12-14 06:14:16

by Anup Patel

Subject: Re: [PATCH 22/26] entry/kvm: KVM: Move KVM details related to signal/-EINTR into KVM proper

On Sat, Sep 16, 2023 at 6:02 AM Sean Christopherson <[email protected]> wrote:
>
> Move KVM's morphing of pending signals into exits to userspace into KVM
> proper, and drop the @vcpu param from xfer_to_guest_mode_handle_work().
> How KVM responds to -EINTR is a detail that really belongs in KVM itself,
> and removing the non-KVM call to kvm_handle_signal_exit() will allow
> hiding said API and the definition of "struct kvm_vcpu" from the kernel.
>
> Alternatively, entry/kvm.c could be treated as part of KVM, i.e. be given
> access to KVM internals, but that's not obviously better than having KVM
> react to -EINTR (though it's not obviously worse either).
>
> Signed-off-by: Sean Christopherson <[email protected]>

For KVM RISC-V:
Anup Patel <[email protected]>

Regards,
Anup

> ---
> arch/arm64/kvm/arm.c | 3 +--
> arch/riscv/kvm/vcpu.c | 2 +-
> arch/x86/kvm/vmx/vmx.c | 1 -
> arch/x86/kvm/x86.c | 3 +--
> include/linux/entry-kvm.h | 3 +--
> include/linux/kvm_host.h | 13 ++++++++++++-
> kernel/entry/kvm.c | 11 ++++-------
> 7 files changed, 20 insertions(+), 16 deletions(-)
>
> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
> index 6480628197b4..641df091e46b 100644
> --- a/arch/arm64/kvm/arm.c
> +++ b/arch/arm64/kvm/arm.c
> @@ -6,7 +6,6 @@
>
> #include <linux/bug.h>
> #include <linux/cpu_pm.h>
> -#include <linux/entry-kvm.h>
> #include <linux/errno.h>
> #include <linux/err.h>
> #include <linux/kvm_host.h>
> @@ -929,7 +928,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
> /*
> * Check conditions before entering the guest
> */
> - ret = xfer_to_guest_mode_handle_work(vcpu);
> + ret = kvm_xfer_to_guest_mode_handle_work(vcpu);
> if (!ret)
> ret = 1;
>
> diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
> index 82229db1ce73..c313f4e90e70 100644
> --- a/arch/riscv/kvm/vcpu.c
> +++ b/arch/riscv/kvm/vcpu.c
> @@ -667,7 +667,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
> run->exit_reason = KVM_EXIT_UNKNOWN;
> while (ret > 0) {
> /* Check conditions before entering the guest */
> - ret = xfer_to_guest_mode_handle_work(vcpu);
> + ret = kvm_xfer_to_guest_mode_handle_work(vcpu);
> if (ret)
> continue;
> ret = 1;
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index faf0071566ef..43b87ad5fde8 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -28,7 +28,6 @@
> #include <linux/slab.h>
> #include <linux/tboot.h>
> #include <linux/trace_events.h>
> -#include <linux/entry-kvm.h>
>
> #include <asm/apic.h>
> #include <asm/asm.h>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 6c9c81e82e65..aab095f89d9e 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -59,7 +59,6 @@
> #include <linux/sched/stat.h>
> #include <linux/sched/isolation.h>
> #include <linux/mem_encrypt.h>
> -#include <linux/entry-kvm.h>
> #include <linux/suspend.h>
> #include <linux/smp.h>
>
> @@ -10987,7 +10986,7 @@ static int vcpu_run(struct kvm_vcpu *vcpu)
>
> if (__xfer_to_guest_mode_work_pending()) {
> kvm_vcpu_srcu_read_unlock(vcpu);
> - r = xfer_to_guest_mode_handle_work(vcpu);
> + r = kvm_xfer_to_guest_mode_handle_work(vcpu);
> kvm_vcpu_srcu_read_lock(vcpu);
> if (r)
> return r;
> diff --git a/include/linux/entry-kvm.h b/include/linux/entry-kvm.h
> index e7d90d06e566..e235a91d28fc 100644
> --- a/include/linux/entry-kvm.h
> +++ b/include/linux/entry-kvm.h
> @@ -42,11 +42,10 @@ static inline int arch_xfer_to_guest_mode_handle_work(unsigned long ti_work)
> /**
> * xfer_to_guest_mode_handle_work - Check and handle pending work which needs
> * to be handled before going to guest mode
> - * @vcpu: Pointer to current's VCPU data
> *
> * Returns: 0 or an error code
> */
> -int xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu);
> +int xfer_to_guest_mode_handle_work(void);
>
> /**
> * xfer_to_guest_mode_prepare - Perform last minute preparation work that
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index fb6c6109fdca..d520d6801070 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -2,7 +2,7 @@
> #ifndef __KVM_HOST_H
> #define __KVM_HOST_H
>
> -
> +#include <linux/entry-kvm.h>
> #include <linux/types.h>
> #include <linux/hardirq.h>
> #include <linux/list.h>
> @@ -2293,6 +2293,17 @@ static inline void kvm_handle_signal_exit(struct kvm_vcpu *vcpu)
> vcpu->run->exit_reason = KVM_EXIT_INTR;
> vcpu->stat.signal_exits++;
> }
> +
> +static inline int kvm_xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu)
> +{
> + int r = xfer_to_guest_mode_handle_work();
> +
> + if (r) {
> + WARN_ON_ONCE(r != -EINTR);
> + kvm_handle_signal_exit(vcpu);
> + }
> + return r;
> +}
> #endif /* CONFIG_KVM_XFER_TO_GUEST_WORK */
>
> /*
> diff --git a/kernel/entry/kvm.c b/kernel/entry/kvm.c
> index c2fc39824157..872617468b4a 100644
> --- a/kernel/entry/kvm.c
> +++ b/kernel/entry/kvm.c
> @@ -1,17 +1,14 @@
> // SPDX-License-Identifier: GPL-2.0
>
> #include <linux/entry-kvm.h>
> -#include <linux/kvm_host.h>
>
> -static int xfer_to_guest_mode_work(struct kvm_vcpu *vcpu, unsigned long ti_work)
> +static int xfer_to_guest_mode_work(unsigned long ti_work)
> {
> do {
> int ret;
>
> - if (ti_work & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL)) {
> - kvm_handle_signal_exit(vcpu);
> + if (ti_work & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL))
> return -EINTR;
> - }
>
> if (ti_work & _TIF_NEED_RESCHED)
> schedule();
> @@ -28,7 +25,7 @@ static int xfer_to_guest_mode_work(struct kvm_vcpu *vcpu, unsigned long ti_work)
> return 0;
> }
>
> -int xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu)
> +int xfer_to_guest_mode_handle_work(void)
> {
> unsigned long ti_work;
>
> @@ -44,6 +41,6 @@ int xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu)
> if (!(ti_work & XFER_TO_GUEST_MODE_WORK))
> return 0;
>
> - return xfer_to_guest_mode_work(vcpu, ti_work);
> + return xfer_to_guest_mode_work(ti_work);
> }
> EXPORT_SYMBOL_GPL(xfer_to_guest_mode_handle_work);
> --
> 2.42.0.459.ge4e396fd5e-goog
>

2023-12-14 06:15:04

by Anup Patel

Subject: Re: [PATCH 19/26] KVM: Standardize include paths across all architectures

On Sat, Sep 16, 2023 at 6:01 AM Sean Christopherson <[email protected]> wrote:
>
> Standardize KVM's include paths across all architectures by declaring
> the KVM-specific includes in the common Makefile.kvm. Having common KVM
> "own" the included paths reduces the temptation to unnecessarily add
> virt/kvm to arch include paths, and conversely if allowing arch code to
> grab headers from virt/kvm becomes desirable, virt/kvm can be added to
> all architecture's include path with a single line update.
>
> Having the common KVM makefile append to ccflags also provides a
> convenient location to append other things, e.g. KVM-specific #defines.
>
> Note, this changes the behavior of s390 and PPC, as s390 and PPC
> previously overwrote ccflags-y instead of adding on. There is no evidence
> that overwriting ccflags-y was necessary or even deliberate, as both s390
> and PPC switched to the overwrite behavior without so much as a passing
> mention when EXTRA_CFLAGS was replaced with ccflags-y (commit c73028a02887
> ("s390: change to new flag variable") and commit 4108d9ba9091
> ("powerpc/Makefiles: Change to new flag variables")).
>
> Signed-off-by: Sean Christopherson <[email protected]>

For KVM RISC-V:
Acked-by: Anup Patel <[email protected]>

Regards,
Anup

> ---
> arch/arm64/kvm/Makefile | 2 --
> arch/mips/kvm/Makefile | 2 --
> arch/powerpc/kvm/Makefile | 2 --
> arch/riscv/kvm/Makefile | 2 --
> arch/s390/kvm/Makefile | 2 --
> arch/x86/kvm/Makefile | 1 -
> virt/kvm/Makefile.kvm | 2 ++
> 7 files changed, 2 insertions(+), 11 deletions(-)
>
> diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
> index c0c050e53157..3996489baeef 100644
> --- a/arch/arm64/kvm/Makefile
> +++ b/arch/arm64/kvm/Makefile
> @@ -3,8 +3,6 @@
> # Makefile for Kernel-based Virtual Machine module
> #
>
> -ccflags-y += -I $(srctree)/$(src)
> -
> include $(srctree)/virt/kvm/Makefile.kvm
>
> obj-$(CONFIG_KVM) += kvm.o
> diff --git a/arch/mips/kvm/Makefile b/arch/mips/kvm/Makefile
> index 96a7cd21b140..d198e1addea7 100644
> --- a/arch/mips/kvm/Makefile
> +++ b/arch/mips/kvm/Makefile
> @@ -4,8 +4,6 @@
>
> include $(srctree)/virt/kvm/Makefile.kvm
>
> -ccflags-y += -Iarch/mips/kvm
> -
> kvm-$(CONFIG_CPU_HAS_MSA) += msa.o
>
> kvm-y += mips.o emulate.o entry.o \
> diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile
> index 08a0e53d58c7..d6c6678ddf65 100644
> --- a/arch/powerpc/kvm/Makefile
> +++ b/arch/powerpc/kvm/Makefile
> @@ -3,8 +3,6 @@
> # Makefile for Kernel-based Virtual Machine module
> #
>
> -ccflags-y := -Iarch/powerpc/kvm
> -
> include $(srctree)/virt/kvm/Makefile.kvm
>
> common-objs-y += powerpc.o emulate_loadstore.o
> diff --git a/arch/riscv/kvm/Makefile b/arch/riscv/kvm/Makefile
> index 4c2067fc59fc..ff7d5f67e229 100644
> --- a/arch/riscv/kvm/Makefile
> +++ b/arch/riscv/kvm/Makefile
> @@ -3,8 +3,6 @@
> # Makefile for RISC-V KVM support
> #
>
> -ccflags-y += -I $(srctree)/$(src)
> -
> include $(srctree)/virt/kvm/Makefile.kvm
>
> obj-$(CONFIG_KVM) += kvm.o
> diff --git a/arch/s390/kvm/Makefile b/arch/s390/kvm/Makefile
> index f17249ab2a72..f8153189e003 100644
> --- a/arch/s390/kvm/Makefile
> +++ b/arch/s390/kvm/Makefile
> @@ -5,8 +5,6 @@
>
> include $(srctree)/virt/kvm/Makefile.kvm
>
> -ccflags-y := -Iarch/s390/kvm
> -
> kvm-y += kvm-s390.o intercept.o interrupt.o priv.o sigp.o
> kvm-y += diag.o gaccess.o guestdbg.o vsie.o pv.o
>
> diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile
> index 80e3fe184d17..d13f1a7b7b3d 100644
> --- a/arch/x86/kvm/Makefile
> +++ b/arch/x86/kvm/Makefile
> @@ -1,6 +1,5 @@
> # SPDX-License-Identifier: GPL-2.0
>
> -ccflags-y += -I $(srctree)/arch/x86/kvm
> ccflags-$(CONFIG_KVM_WERROR) += -Werror
>
> ifeq ($(CONFIG_FRAME_POINTER),y)
> diff --git a/virt/kvm/Makefile.kvm b/virt/kvm/Makefile.kvm
> index 29373b59d89a..e85079ad245d 100644
> --- a/virt/kvm/Makefile.kvm
> +++ b/virt/kvm/Makefile.kvm
> @@ -3,6 +3,8 @@
> # Makefile for Kernel-based Virtual Machine module
> #
>
> +ccflags-y += -I$(srctree)/$(src)
> +
> KVM ?= ../../../virt/kvm
>
> kvm-y := $(KVM)/kvm_main.o $(KVM)/eventfd.o $(KVM)/binary_stats.o
> --
> 2.42.0.459.ge4e396fd5e-goog
>

2023-12-14 06:21:16

by Anup Patel

Subject: Re: [PATCH 26/26] KVM: Hide KVM internal data structures and values from kernel at-large

On Sat, Sep 16, 2023 at 6:02 AM Sean Christopherson <[email protected]> wrote:
>
> Wrap all KVM internal APIs, data structures, values, etc. in public
> headers with "#ifdef __KVM__" to effectively hide KVM's internal details
> from other subsystems and the kernel at-large. Hiding KVM details for
> all architectures will, in the very distant future, allow loading a new
> (or old) KVM module without needing to rebuild and reboot the entire
> kernel, or to even allow loading and running multiple versions of KVM
> simultaneously on a single host.
>
> To allow different instances of KVM modules to freely modify KVM data
> structures, enums, #defines, etc., e.g. the struct kvm_vcpu layout, there
> must be exactly zero dereferences of KVM-defined structures/values in
> non-KVM code (excepting code for architectures that don't support such
> shenanigans). Any such references could lead to latent bugs, e.g. as the
> kernel would think a KVM structure has layout X, but in reality the
> current incarnation of KVM uses layout Y.
>
> In KVM x86, all remaining non-KVM references to KVM details have been now
> eliminated. To harden KVM against new references being introduced, hide
> KVM's details to ensure that KVM doesn’t create a de facto ABI with the
> rest of the kernel.
>
> Use #ifdeffery to hide KVM details as doing so requires, by far, the least
> amount of churn and impact on architectures that freely share select KVM
> details with the rest of the kernel, e.g. s390, ARM64 and PPC, have
> significant usage of KVM-defined APIs, structures, values, etc. E.g.
> attempting to extract the "private" chunks into dedicated KVM-internal
> headers would require massive churn, even on x86, and it's not obvious the
> end result would be a net positive (all attempts at moving code around
> failed long before getting anywhere near compiling cleanly).
>
> Another (bad) alternative that would be relative churn-free would be to
> move the KVM headers to a dedicated KVM-specific path while maintaining
> the generic layout, e.g. something like virt/kvm/include/linux. That
> would allow x86 to simply omit the KVM-specific include path. But that
> would require modifying the global include path, i.e. would make KVM a
> really special snowflake and set the awful precedent that it's "ok" to
> add subsystem specific directories to the global include path.
>
> Grant exceptions to asm-offsets.c as needed, and to s390's VFIO AP driver.
> Creating a KVM-specific asm-offsets, as was done for x86, adds no value
> (x86 did so to avoid exposing vendor specific headers) and doesn't create
> much of a "slippery slope" risk. s390's VFIO AP driver on the other hand
> is simply too intertwined with KVM to realistically treat it as anything
> other than KVM code, despite it living in crypto drivers, e.g. the driver
> has some rather crazy lock ordering rules between the device and KVM.
>
> Add a static assert that __KVM__ is defined in trace/events/kvm.h, as that
> is effectively a private KVM header that just happens to live in a public
> path.
>
> Shuffle a few PPC includes and an s390 declaration as needed, and
> opportunistically include kvm_host.h in trace/events.kvm.h instead of
> relying on the parent to provide the right includes.
>
> Cc: Anish Ghulati <[email protected]>
> Cc: Venkatesh Srinivas <[email protected]>
> Cc: Andrew Thornton <[email protected]>
> Signed-off-by: Sean Christopherson <[email protected]>

For KVM RISC-V:
Anup Patel <[email protected]>

Regards,
Anup

> ---
> arch/arm64/include/asm/kvm_emulate.h | 3 +++
> arch/arm64/include/asm/kvm_host.h | 2 ++
> arch/arm64/include/asm/kvm_mmu.h | 4 ++++
> arch/arm64/kernel/asm-offsets.c | 2 ++
> arch/arm64/kvm/hyp/Makefile | 2 +-
> arch/arm64/kvm/hyp/nvhe/Makefile | 3 ++-
> arch/arm64/kvm/hyp/vhe/Makefile | 2 +-
> arch/mips/include/asm/kvm_host.h | 2 ++
> arch/mips/kernel/asm-offsets.c | 2 ++
> arch/powerpc/include/asm/kvm_book3s.h | 3 +++
> arch/powerpc/include/asm/kvm_book3s_64.h | 2 ++
> arch/powerpc/include/asm/kvm_booke.h | 4 ++++
> arch/powerpc/include/asm/kvm_host.h | 7 ++++---
> arch/powerpc/include/asm/kvm_ppc.h | 2 ++
> arch/powerpc/kernel/asm-offsets.c | 1 +
> arch/riscv/include/asm/kvm_host.h | 3 +++
> arch/riscv/kernel/asm-offsets.c | 1 +
> arch/s390/include/asm/kvm_host.h | 7 +++++--
> arch/s390/kernel/asm-offsets.c | 1 +
> arch/x86/include/asm/kvm_host.h | 3 +++
> drivers/s390/crypto/vfio_ap_drv.c | 1 +
> drivers/s390/crypto/vfio_ap_ops.c | 2 ++
> include/linux/kvm_host.h | 4 ++++
> include/linux/kvm_types.h | 3 +++
> include/trace/events/kvm.h | 5 +++++
> virt/kvm/Makefile.kvm | 2 +-
> 26 files changed, 64 insertions(+), 9 deletions(-)
>
> diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
> index 3d6725ff0bf6..5861fa00763b 100644
> --- a/arch/arm64/include/asm/kvm_emulate.h
> +++ b/arch/arm64/include/asm/kvm_emulate.h
> @@ -21,6 +21,8 @@
> #include <asm/cputype.h>
> #include <asm/virt.h>
>
> +#ifdef __KVM__
> +
> #define CURRENT_EL_SP_EL0_VECTOR 0x0
> #define CURRENT_EL_SP_ELx_VECTOR 0x200
> #define LOWER_EL_AArch64_VECTOR 0x400
> @@ -615,4 +617,5 @@ static __always_inline void kvm_reset_cptr_el2(struct kvm_vcpu *vcpu)
>
> kvm_write_cptr_el2(val);
> }
> +#endif /* __KVM__ */
> #endif /* __ARM64_KVM_EMULATE_H__ */
> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> index 89b40c34f0af..ba4065db5d5c 100644
> --- a/arch/arm64/include/asm/kvm_host.h
> +++ b/arch/arm64/include/asm/kvm_host.h
> @@ -93,6 +93,7 @@ static inline bool kvm_pmu_counter_deferred(struct perf_event_attr *attr)
> return (!has_vhe() && attr->exclude_host);
> }
>
> +#ifdef __KVM__
> DECLARE_STATIC_KEY_FALSE(userspace_irqchip_in_use);
>
> extern unsigned int __ro_after_init kvm_sve_max_vl;
> @@ -1149,4 +1150,5 @@ int kvm_trng_call(struct kvm_vcpu *vcpu);
> void kvm_arm_vcpu_power_off(struct kvm_vcpu *vcpu);
> bool kvm_arm_vcpu_stopped(struct kvm_vcpu *vcpu);
>
> +#endif /* __KVM__ */
> #endif /* __ARM64_KVM_HOST_H__ */
> diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
> index 96a80e8f6226..9d8c92cda3b6 100644
> --- a/arch/arm64/include/asm/kvm_mmu.h
> +++ b/arch/arm64/include/asm/kvm_mmu.h
> @@ -125,6 +125,8 @@ void kvm_update_va_mask(struct alt_instr *alt,
> void kvm_compute_layout(void);
> void kvm_apply_hyp_relocations(void);
>
> +#ifdef __KVM__
> +
> #define __hyp_pa(x) (((phys_addr_t)(x)) + hyp_physvirt_offset)
>
> static __always_inline unsigned long __kern_hyp_va(unsigned long v)
> @@ -314,5 +316,7 @@ static inline struct kvm *kvm_s2_mmu_to_kvm(struct kvm_s2_mmu *mmu)
> {
> return container_of(mmu->arch, struct kvm, arch);
> }
> +
> +#endif /* __KVM__ */
> #endif /* __ASSEMBLY__ */
> #endif /* __ARM64_KVM_MMU_H__ */
> diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c
> index 5ff1942b04fc..dc02ea9a002c 100644
> --- a/arch/arm64/kernel/asm-offsets.c
> +++ b/arch/arm64/kernel/asm-offsets.c
> @@ -7,6 +7,8 @@
> * Copyright (C) 2012 ARM Ltd.
> */
>
> +#define __KVM__
> +
> #include <linux/arm_sdei.h>
> #include <linux/sched.h>
> #include <linux/ftrace.h>
> diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile
> index 4ce8c86967b5..99982b75671a 100644
> --- a/arch/arm64/kvm/hyp/Makefile
> +++ b/arch/arm64/kvm/hyp/Makefile
> @@ -5,6 +5,6 @@
>
> incdir := $(srctree)/$(src)/include
> subdir-asflags-y := -I$(incdir) -I$(srctree)/arch/arm64/kvm
> -subdir-ccflags-y := -I$(incdir) -I$(srctree)/arch/arm64/kvm
> +subdir-ccflags-y := -I$(incdir) -I$(srctree)/arch/arm64/kvm -D__KVM__
>
> obj-$(CONFIG_KVM) += vhe/ nvhe/ pgtable.o
> diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile
> index 2250253a6429..b5f4750fa16e 100644
> --- a/arch/arm64/kvm/hyp/nvhe/Makefile
> +++ b/arch/arm64/kvm/hyp/nvhe/Makefile
> @@ -9,7 +9,8 @@ asflags-y := -D__KVM_NVHE_HYPERVISOR__ -D__DISABLE_EXPORTS
> # there is no way to execute them and any such MMIO access from nVHE KVM
> # will explode instantly (Words of Marc Zyngier). So introduce a generic flag
> # __DISABLE_TRACE_MMIO__ to disable MMIO tracing for nVHE KVM.
> -ccflags-y := -D__KVM_NVHE_HYPERVISOR__ -D__DISABLE_EXPORTS -D__DISABLE_TRACE_MMIO__
> +ccflags-y := -D__KVM_NVHE_HYPERVISOR__ -D__DISABLE_EXPORTS \
> + -D__DISABLE_TRACE_MMIO__ -D__KVM__
> ccflags-y += -fno-stack-protector \
> -DDISABLE_BRANCH_PROFILING \
> $(DISABLE_STACKLEAK_PLUGIN)
> diff --git a/arch/arm64/kvm/hyp/vhe/Makefile b/arch/arm64/kvm/hyp/vhe/Makefile
> index 3b9e5464b5b3..54cd3c444102 100644
> --- a/arch/arm64/kvm/hyp/vhe/Makefile
> +++ b/arch/arm64/kvm/hyp/vhe/Makefile
> @@ -4,7 +4,7 @@
> #
>
> asflags-y := -D__KVM_VHE_HYPERVISOR__
> -ccflags-y := -D__KVM_VHE_HYPERVISOR__
> +ccflags-y := -D__KVM_VHE_HYPERVISOR__ -D__KVM__
>
> obj-y := timer-sr.o sysreg-sr.o debug-sr.o switch.o tlb.o
> obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \
> diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h
> index f8f63d0aa399..6fd7c998d7b9 100644
> --- a/arch/mips/include/asm/kvm_host.h
> +++ b/arch/mips/include/asm/kvm_host.h
> @@ -25,6 +25,7 @@
> #include <asm/inst.h>
> #include <asm/mipsregs.h>
>
> +#ifdef __KVM__
> /* MIPS KVM register ids */
> #define MIPS_CP0_32(_R, _S) \
> (KVM_REG_MIPS_CP0 | KVM_REG_SIZE_U32 | (8 * (_R) + (_S)))
> @@ -897,4 +898,5 @@ static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {}
>
> #define __KVM_HAVE_ARCH_FLUSH_REMOTE_TLBS
>
> +#endif /* __KVM__ */
> #endif /* __MIPS_KVM_HOST_H__ */
> diff --git a/arch/mips/kernel/asm-offsets.c b/arch/mips/kernel/asm-offsets.c
> index d1b11f66f748..8a233bddfea0 100644
> --- a/arch/mips/kernel/asm-offsets.c
> +++ b/arch/mips/kernel/asm-offsets.c
> @@ -9,6 +9,8 @@
> * Kevin Kissell, [email protected] and Carsten Langgaard, [email protected]
> * Copyright (C) 2000 MIPS Technologies, Inc.
> */
> +#define __KVM__
> +
> #include <linux/compat.h>
> #include <linux/types.h>
> #include <linux/sched.h>
> diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h
> index bbf5e2c5fe09..8880bc7c8a32 100644
> --- a/arch/powerpc/include/asm/kvm_book3s.h
> +++ b/arch/powerpc/include/asm/kvm_book3s.h
> @@ -13,6 +13,8 @@
> #include <linux/kvm_host.h>
> #include <asm/kvm_book3s_asm.h>
>
> +#ifdef __KVM__
> +
> struct kvmppc_bat {
> u64 raw;
> u32 bepi;
> @@ -483,4 +485,5 @@ static inline u32 kvmppc_pack_vcpu_id(struct kvm *kvm, u32 id)
> return packed_id;
> }
>
> +#endif /* __KVM__ */
> #endif /* __ASM_KVM_BOOK3S_H__ */
> diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
> index d49065af08e9..a807716ccae6 100644
> --- a/arch/powerpc/include/asm/kvm_book3s_64.h
> +++ b/arch/powerpc/include/asm/kvm_book3s_64.h
> @@ -16,6 +16,7 @@
> #include <asm/ppc-opcode.h>
> #include <asm/pte-walk.h>
>
> +#ifdef __KVM__
> /*
> * Structure for a nested guest, that is, for a guest that is managed by
> * one of our guests.
> @@ -679,4 +680,5 @@ extern pte_t *find_kvm_nested_guest_pte(struct kvm *kvm, unsigned long lpid,
>
> #endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */
>
> +#endif /* __KVM__ */
> #endif /* __ASM_KVM_BOOK3S_64_H__ */
> diff --git a/arch/powerpc/include/asm/kvm_booke.h b/arch/powerpc/include/asm/kvm_booke.h
> index 0c3401b2e19e..85ebc0314539 100644
> --- a/arch/powerpc/include/asm/kvm_booke.h
> +++ b/arch/powerpc/include/asm/kvm_booke.h
> @@ -12,6 +12,8 @@
> #include <linux/types.h>
> #include <linux/kvm_host.h>
>
> +#ifdef __KVM__
> +
> /*
> * Number of available lpids. Only the low-order 6 bits of LPID rgister are
> * implemented on e500mc+ cores.
> @@ -105,4 +107,6 @@ static inline bool kvmppc_supports_magic_page(struct kvm_vcpu *vcpu)
> return false;
> #endif
> }
> +
> +#endif /* __KVM__ */
> #endif /* __ASM_KVM_BOOKE_H__ */
> diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
> index 14ee0dece853..1e7a008ce085 100644
> --- a/arch/powerpc/include/asm/kvm_host.h
> +++ b/arch/powerpc/include/asm/kvm_host.h
> @@ -14,6 +14,7 @@
> #include <linux/interrupt.h>
> #include <linux/types.h>
> #include <linux/kvm_types.h>
> +#include <linux/mmu_notifier.h>
> #include <linux/threads.h>
> #include <linux/spinlock.h>
> #include <linux/kvm_para.h>
> @@ -25,13 +26,14 @@
> #include <asm/cacheflush.h>
> #include <asm/hvcall.h>
> #include <asm/mce.h>
> +#include <asm/cputhreads.h>
>
> +#ifdef __KVM__
> #define __KVM_HAVE_ARCH_VCPU_DEBUGFS
>
> #define KVM_MAX_VCPUS NR_CPUS
> #define KVM_MAX_VCORES NR_CPUS
>
> -#include <asm/cputhreads.h>
>
> #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
> #include <asm/kvm_book3s_asm.h> /* for MAX_SMT_THREADS */
> @@ -60,8 +62,6 @@
> #define KVM_REQ_EPR_EXIT KVM_ARCH_REQ(1)
> #define KVM_REQ_PENDING_TIMER KVM_ARCH_REQ(2)
>
> -#include <linux/mmu_notifier.h>
> -
> #define KVM_ARCH_WANT_MMU_NOTIFIER
>
> #define HPTEG_CACHE_NUM (1 << 15)
> @@ -883,4 +883,5 @@ static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
> static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {}
> static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {}
>
> +#endif /* __KVM__ */
> #endif /* __POWERPC_KVM_HOST_H__ */
> diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
> index ead2ad892ebc..03d9998d0111 100644
> --- a/arch/powerpc/include/asm/kvm_ppc.h
> +++ b/arch/powerpc/include/asm/kvm_ppc.h
> @@ -183,6 +183,7 @@ static inline void kvmppc_clear_host_ipi(int cpu)
> static inline bool kvm_hv_mode_active(void) { return false; }
> #endif
>
> +#ifdef __KVM__
> /*
> * KVMPPC_INST_SW_BREAKPOINT is debug Instruction
> * for supporting software breakpoint.
> @@ -1076,4 +1077,5 @@ static inline ulong kvmppc_get_ea_indexed(struct kvm_vcpu *vcpu, int ra, int rb)
> return ea;
> }
>
> +#endif /* __KVM__ */
> #endif /* __POWERPC_KVM_PPC_H__ */
> diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
> index 9f14d95b8b32..872d44971536 100644
> --- a/arch/powerpc/kernel/asm-offsets.c
> +++ b/arch/powerpc/kernel/asm-offsets.c
> @@ -8,6 +8,7 @@
> * compile this file to assembler, and then extract the
> * #defines from the assembly-language output.
> */
> +#define __KVM__
>
> #include <linux/compat.h>
> #include <linux/signal.h>
> diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h
> index 1ebf20dfbaa6..a81ae8c4b739 100644
> --- a/arch/riscv/include/asm/kvm_host.h
> +++ b/arch/riscv/include/asm/kvm_host.h
> @@ -22,6 +22,8 @@
> #include <asm/kvm_vcpu_timer.h>
> #include <asm/kvm_vcpu_pmu.h>
>
> +#ifdef __KVM__
> +
> #define KVM_MAX_VCPUS 1024
>
> #define KVM_HALT_POLL_NS_DEFAULT 500000
> @@ -354,4 +356,5 @@ bool kvm_riscv_vcpu_has_interrupts(struct kvm_vcpu *vcpu, u64 mask);
> void kvm_riscv_vcpu_power_off(struct kvm_vcpu *vcpu);
> void kvm_riscv_vcpu_power_on(struct kvm_vcpu *vcpu);
>
> +#endif /* __KVM__ */
> #endif /* __RISCV_KVM_HOST_H__ */
> diff --git a/arch/riscv/kernel/asm-offsets.c b/arch/riscv/kernel/asm-offsets.c
> index d6a75aac1d27..476263e78f39 100644
> --- a/arch/riscv/kernel/asm-offsets.c
> +++ b/arch/riscv/kernel/asm-offsets.c
> @@ -5,6 +5,7 @@
> */
>
> #define GENERATING_ASM_OFFSETS
> +#define __KVM__
>
> #include <linux/kbuild.h>
> #include <linux/mm.h>
> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
> index 427f9528a7b6..9153420bb5ac 100644
> --- a/arch/s390/include/asm/kvm_host.h
> +++ b/arch/s390/include/asm/kvm_host.h
> @@ -380,6 +380,10 @@ struct sie_page {
> __u8 reserved700[2304]; /* 0x0700 */
> };
>
> +extern char sie_exit;
> +
> +#ifdef __KVM__
> +
> struct kvm_vcpu_stat {
> struct kvm_vcpu_stat_generic generic;
> u64 exit_userspace;
> @@ -1028,8 +1032,6 @@ static inline int sie64a(struct kvm_s390_sie_block *sie_block, u64 *rsa)
> return __sie64a(virt_to_phys(sie_block), sie_block, rsa);
> }
>
> -extern char sie_exit;
> -
> bool kvm_s390_pv_is_protected(struct kvm *kvm);
> bool kvm_s390_pv_cpu_is_protected(struct kvm_vcpu *vcpu);
>
> @@ -1049,6 +1051,7 @@ static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {}
>
> #define __KVM_HAVE_ARCH_VM_FREE
> void kvm_arch_free_vm(struct kvm *kvm);
> +#endif /* __KVM__ */
>
> struct zpci_kvm_hook {
> int (*kvm_register)(void *opaque, struct kvm *kvm);
> diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c
> index fa5f6885c74a..22ed673871ee 100644
> --- a/arch/s390/kernel/asm-offsets.c
> +++ b/arch/s390/kernel/asm-offsets.c
> @@ -6,6 +6,7 @@
> */
>
> #define ASM_OFFSETS_C
> +#define __KVM__
>
> #include <linux/kbuild.h>
> #include <linux/kvm_host.h>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 29db870dbaae..eda45a937666 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -37,6 +37,8 @@
> #include <asm/kvm_vcpu_regs.h>
> #include <asm/hyperv-tlfs.h>
>
> +#ifdef __KVM__
> +
> #define __KVM_HAVE_ARCH_VCPU_DEBUGFS
>
> #define KVM_MAX_VCPUS 1024
> @@ -2229,4 +2231,5 @@ int memslot_rmap_alloc(struct kvm_memory_slot *slot, unsigned long npages);
> */
> #define KVM_EXIT_HYPERCALL_MBZ GENMASK_ULL(31, 1)
>
> +#endif /* __KVM__ */
> #endif /* _ASM_X86_KVM_HOST_H */
> diff --git a/drivers/s390/crypto/vfio_ap_drv.c b/drivers/s390/crypto/vfio_ap_drv.c
> index a5ab03e42ff1..55744f0f4758 100644
> --- a/drivers/s390/crypto/vfio_ap_drv.c
> +++ b/drivers/s390/crypto/vfio_ap_drv.c
> @@ -7,6 +7,7 @@
> * Author(s): Tony Krowiak <[email protected]>
> * Pierre Morel <[email protected]>
> */
> +#define __KVM__
>
> #include <linux/module.h>
> #include <linux/mod_devicetable.h>
> diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
> index 4db538a55192..0dd98f42e9d5 100644
> --- a/drivers/s390/crypto/vfio_ap_ops.c
> +++ b/drivers/s390/crypto/vfio_ap_ops.c
> @@ -8,6 +8,8 @@
> * Halil Pasic <[email protected]>
> * Pierre Morel <[email protected]>
> */
> +#define __KVM__
> +
> #include <linux/string.h>
> #include <linux/vfio.h>
> #include <linux/device.h>
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index d520d6801070..f0afe549c0d6 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -45,6 +45,8 @@
> #include <asm/kvm_host.h>
> #include <linux/kvm_dirty_ring.h>
>
> +#ifdef __KVM__
> +
> #ifndef KVM_MAX_VCPU_IDS
> #define KVM_MAX_VCPU_IDS KVM_MAX_VCPUS
> #endif
> @@ -2329,4 +2331,6 @@ static inline void kvm_account_pgtable_pages(void *virt, int nr)
> /* Max number of entries allowed for each kvm dirty ring */
> #define KVM_DIRTY_RING_MAX_ENTRIES 65536
>
> +#endif /* __KVM__ */
> +
> #endif
> diff --git a/include/linux/kvm_types.h b/include/linux/kvm_types.h
> index 6f4737d5046a..4804bce2a655 100644
> --- a/include/linux/kvm_types.h
> +++ b/include/linux/kvm_types.h
> @@ -48,6 +48,8 @@ typedef u64 hfn_t;
>
> typedef hfn_t kvm_pfn_t;
>
> +#ifdef __KVM__
> +
> enum pfn_cache_usage {
> KVM_GUEST_USES_PFN = BIT(0),
> KVM_HOST_USES_PFN = BIT(1),
> @@ -123,4 +125,5 @@ struct kvm_vcpu_stat_generic {
>
> #define KVM_STATS_NAME_SIZE 48
>
> +#endif /* __KVM__ */
> #endif /* __KVM_TYPES_H__ */
> diff --git a/include/trace/events/kvm.h b/include/trace/events/kvm.h
> index 3bd31ea23fee..aee85527bb74 100644
> --- a/include/trace/events/kvm.h
> +++ b/include/trace/events/kvm.h
> @@ -2,8 +2,13 @@
> #if !defined(_TRACE_KVM_MAIN_H) || defined(TRACE_HEADER_MULTI_READ)
> #define _TRACE_KVM_MAIN_H
>
> +#include <linux/kvm_host.h>
> #include <linux/tracepoint.h>
>
> +#ifndef __KVM__
> +static_assert(0, "Do not include trace/events/kvm.h from non-KVM code");
> +#endif
> +
> #undef TRACE_SYSTEM
> #define TRACE_SYSTEM kvm
>
> diff --git a/virt/kvm/Makefile.kvm b/virt/kvm/Makefile.kvm
> index e85079ad245d..4de10d447ef3 100644
> --- a/virt/kvm/Makefile.kvm
> +++ b/virt/kvm/Makefile.kvm
> @@ -3,7 +3,7 @@
> # Makefile for Kernel-based Virtual Machine module
> #
>
> -ccflags-y += -I$(srctree)/$(src)
> +ccflags-y += -I$(srctree)/$(src) -D__KVM__
>
> KVM ?= ../../../virt/kvm
>
> --
> 2.42.0.459.ge4e396fd5e-goog
>