This series adds Mediated device support to Linux host kernel. Purpose
of this series is to provide a common interface for mediated device
management that can be used by different devices. This series introduces
Mdev core module that creates and manages mediated devices, VFIO based
driver for mediated devices that are created by mdev core module and
update VFIO type1 IOMMU module to support pinning & unpinning for mediated
devices.
What changed v12-> v13?
- For vfio_pin_pages() and vfio_unpin_pages() input buffer size should be
less than PAGE_SIZE. If vendor driver wants to use for more pages, array
should be split it in chunks of PAGE_SIZE.
- Updating page accounting logic to check if pfns are reserved and account
page only when page is not reserved.
- Updated vfio_mdev module to register notifier and then call
parent->ops->open(mdev), similarly updated for release().
Tested by assigning below combinations of devices to a single VM:
- GPU pass through only
- vGPU device only
- One GPU pass through and one vGPU device
- Linux VM hot plug and unplug vGPU device while GPU pass through device
exist
- Linux VM hot plug and unplug GPU pass through device while vGPU device
exist
Tested with Linux-next upto commit e76d21c40bd6.
Kirti Wankhede (22):
vfio: Mediated device Core driver
vfio: VFIO based driver for Mediated devices
vfio: Rearrange functions to get vfio_group from dev
vfio: Common function to increment container_users
vfio iommu: Added pin and unpin callback functions to
vfio_iommu_driver_ops
vfio iommu type1: Update arguments of vfio_lock_acct
vfio iommu type1: Update argument of vaddr_get_pfn()
vfio iommu type1: Add find_iommu_group() function
vfio iommu type1: Add task structure to vfio_dma
vfio iommu type1: Add support for mediated devices
vfio iommu: Add blocking notifier to notify DMA_UNMAP
vfio: Add notifier callback to parent's ops structure of mdev
vfio: Introduce common function to add capabilities
vfio_pci: Update vfio_pci to use vfio_info_add_capability()
vfio: Introduce vfio_set_irqs_validate_and_prepare()
vfio_pci: Updated to use vfio_set_irqs_validate_and_prepare()
vfio_platform: Updated to use vfio_set_irqs_validate_and_prepare()
vfio: Define device_api strings
docs: Add Documentation for Mediated devices
docs: Sysfs ABI for mediated device framework
docs: Sample driver to demonstrate how to use Mediated device
framework.
MAINTAINERS: Add entry VFIO based Mediated device drivers
Documentation/ABI/testing/sysfs-bus-vfio-mdev | 111 ++
Documentation/vfio-mediated-device.txt | 399 +++++++
MAINTAINERS | 9 +
drivers/vfio/Kconfig | 1 +
drivers/vfio/Makefile | 1 +
drivers/vfio/mdev/Kconfig | 17 +
drivers/vfio/mdev/Makefile | 5 +
drivers/vfio/mdev/mdev_core.c | 388 +++++++
drivers/vfio/mdev/mdev_driver.c | 119 ++
drivers/vfio/mdev/mdev_private.h | 41 +
drivers/vfio/mdev/mdev_sysfs.c | 286 +++++
drivers/vfio/mdev/vfio_mdev.c | 171 +++
drivers/vfio/pci/vfio_pci.c | 83 +-
drivers/vfio/platform/vfio_platform_common.c | 31 +-
drivers/vfio/vfio.c | 341 +++++-
drivers/vfio/vfio_iommu_type1.c | 845 +++++++++++---
include/linux/mdev.h | 177 +++
include/linux/vfio.h | 32 +-
include/uapi/linux/vfio.h | 10 +
samples/vfio-mdev/Makefile | 13 +
samples/vfio-mdev/mtty.c | 1503 +++++++++++++++++++++++++
21 files changed, 4348 insertions(+), 235 deletions(-)
create mode 100644 Documentation/ABI/testing/sysfs-bus-vfio-mdev
create mode 100644 Documentation/vfio-mediated-device.txt
create mode 100644 drivers/vfio/mdev/Kconfig
create mode 100644 drivers/vfio/mdev/Makefile
create mode 100644 drivers/vfio/mdev/mdev_core.c
create mode 100644 drivers/vfio/mdev/mdev_driver.c
create mode 100644 drivers/vfio/mdev/mdev_private.h
create mode 100644 drivers/vfio/mdev/mdev_sysfs.c
create mode 100644 drivers/vfio/mdev/vfio_mdev.c
create mode 100644 include/linux/mdev.h
create mode 100644 samples/vfio-mdev/Makefile
create mode 100644 samples/vfio-mdev/mtty.c
--
2.7.0
vfio_mdev driver registers with mdev core driver.
mdev core driver creates mediated device and calls probe routine of
vfio_mdev driver for each device.
Probe routine of vfio_mdev driver adds mediated device to VFIO core module
This driver forms a shim layer that pass through VFIO devices operations
to vendor driver for mediated devices.
Signed-off-by: Kirti Wankhede <[email protected]>
Signed-off-by: Neo Jia <[email protected]>
Reviewed-by: Jike Song <[email protected]>
Change-Id: I583f4734752971d3d112324d69e2508c88f359ec
---
drivers/vfio/mdev/Kconfig | 7 ++
drivers/vfio/mdev/Makefile | 1 +
drivers/vfio/mdev/mdev_core.c | 16 ++++-
drivers/vfio/mdev/vfio_mdev.c | 148 ++++++++++++++++++++++++++++++++++++++++++
4 files changed, 171 insertions(+), 1 deletion(-)
create mode 100644 drivers/vfio/mdev/vfio_mdev.c
diff --git a/drivers/vfio/mdev/Kconfig b/drivers/vfio/mdev/Kconfig
index 258481d65ebd..1aa0391d74f2 100644
--- a/drivers/vfio/mdev/Kconfig
+++ b/drivers/vfio/mdev/Kconfig
@@ -7,3 +7,10 @@ config VFIO_MDEV
Provides a framework to virtualize devices.
If you don't know what do here, say N.
+
+config VFIO_MDEV_DEVICE
+ tristate "VFIO support for Mediated devices"
+ depends on VFIO && VFIO_MDEV
+ default n
+ help
+ VFIO based driver for mediated devices.
diff --git a/drivers/vfio/mdev/Makefile b/drivers/vfio/mdev/Makefile
index 31bc04801d94..fa2d5ea466ee 100644
--- a/drivers/vfio/mdev/Makefile
+++ b/drivers/vfio/mdev/Makefile
@@ -2,3 +2,4 @@
mdev-y := mdev_core.o mdev_sysfs.o mdev_driver.o
obj-$(CONFIG_VFIO_MDEV) += mdev.o
+obj-$(CONFIG_VFIO_MDEV_DEVICE) += vfio_mdev.o
diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
index 613e8a8a3b2a..1e0714ebc56a 100644
--- a/drivers/vfio/mdev/mdev_core.c
+++ b/drivers/vfio/mdev/mdev_core.c
@@ -354,7 +354,21 @@ int mdev_device_remove(struct device *dev, bool force_remove)
static int __init mdev_init(void)
{
- return mdev_bus_register();
+ int ret;
+
+ ret = mdev_bus_register();
+ if (ret) {
+ pr_err("Failed to register mdev bus\n");
+ return ret;
+ }
+
+ /*
+ * Attempt to load known vfio_mdev. This gives us a working environment
+ * without the user needing to explicitly load vfio_mdev driver.
+ */
+ request_module_nowait("vfio_mdev");
+
+ return ret;
}
static void __exit mdev_exit(void)
diff --git a/drivers/vfio/mdev/vfio_mdev.c b/drivers/vfio/mdev/vfio_mdev.c
new file mode 100644
index 000000000000..ffc36758cb84
--- /dev/null
+++ b/drivers/vfio/mdev/vfio_mdev.c
@@ -0,0 +1,148 @@
+/*
+ * VFIO based driver for Mediated device
+ *
+ * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
+ * Author: Neo Jia <[email protected]>
+ * Kirti Wankhede <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/vfio.h>
+#include <linux/mdev.h>
+
+#include "mdev_private.h"
+
+#define DRIVER_VERSION "0.1"
+#define DRIVER_AUTHOR "NVIDIA Corporation"
+#define DRIVER_DESC "VFIO based driver for Mediated device"
+
+static int vfio_mdev_open(void *device_data)
+{
+ struct mdev_device *mdev = device_data;
+ struct parent_device *parent = mdev->parent;
+ int ret;
+
+ if (unlikely(!parent->ops->open))
+ return -EINVAL;
+
+ if (!try_module_get(THIS_MODULE))
+ return -ENODEV;
+
+ ret = parent->ops->open(mdev);
+ if (ret)
+ module_put(THIS_MODULE);
+
+ return ret;
+}
+
+static void vfio_mdev_release(void *device_data)
+{
+ struct mdev_device *mdev = device_data;
+ struct parent_device *parent = mdev->parent;
+
+ if (likely(parent->ops->release))
+ parent->ops->release(mdev);
+
+ module_put(THIS_MODULE);
+}
+
+static long vfio_mdev_unlocked_ioctl(void *device_data,
+ unsigned int cmd, unsigned long arg)
+{
+ struct mdev_device *mdev = device_data;
+ struct parent_device *parent = mdev->parent;
+
+ if (unlikely(!parent->ops->ioctl))
+ return -EINVAL;
+
+ return parent->ops->ioctl(mdev, cmd, arg);
+}
+
+static ssize_t vfio_mdev_read(void *device_data, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct mdev_device *mdev = device_data;
+ struct parent_device *parent = mdev->parent;
+
+ if (unlikely(!parent->ops->read))
+ return -EINVAL;
+
+ return parent->ops->read(mdev, buf, count, ppos);
+}
+
+static ssize_t vfio_mdev_write(void *device_data, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct mdev_device *mdev = device_data;
+ struct parent_device *parent = mdev->parent;
+
+ if (unlikely(!parent->ops->write))
+ return -EINVAL;
+
+ return parent->ops->write(mdev, buf, count, ppos);
+}
+
+static int vfio_mdev_mmap(void *device_data, struct vm_area_struct *vma)
+{
+ struct mdev_device *mdev = device_data;
+ struct parent_device *parent = mdev->parent;
+
+ if (unlikely(!parent->ops->mmap))
+ return -EINVAL;
+
+ return parent->ops->mmap(mdev, vma);
+}
+
+static const struct vfio_device_ops vfio_mdev_dev_ops = {
+ .name = "vfio-mdev",
+ .open = vfio_mdev_open,
+ .release = vfio_mdev_release,
+ .ioctl = vfio_mdev_unlocked_ioctl,
+ .read = vfio_mdev_read,
+ .write = vfio_mdev_write,
+ .mmap = vfio_mdev_mmap,
+};
+
+int vfio_mdev_probe(struct device *dev)
+{
+ struct mdev_device *mdev = to_mdev_device(dev);
+
+ return vfio_add_group_dev(dev, &vfio_mdev_dev_ops, mdev);
+}
+
+void vfio_mdev_remove(struct device *dev)
+{
+ vfio_del_group_dev(dev);
+}
+
+struct mdev_driver vfio_mdev_driver = {
+ .name = "vfio_mdev",
+ .probe = vfio_mdev_probe,
+ .remove = vfio_mdev_remove,
+};
+
+static int __init vfio_mdev_init(void)
+{
+ return mdev_register_driver(&vfio_mdev_driver, THIS_MODULE);
+}
+
+static void __exit vfio_mdev_exit(void)
+{
+ mdev_unregister_driver(&vfio_mdev_driver);
+}
+
+module_init(vfio_mdev_init)
+module_exit(vfio_mdev_exit)
+
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
--
2.7.0
Added APIs for pining and unpining set of pages. These call back into
backend iommu module to actually pin and unpin pages.
Added two new callback functions to struct vfio_iommu_driver_ops. Backend
IOMMU module that supports pining and unpinning pages for mdev devices
should provide these functions.
Renamed static functions in vfio_type1_iommu.c to resolve conflicts
Signed-off-by: Kirti Wankhede <[email protected]>
Signed-off-by: Neo Jia <[email protected]>
Change-Id: Ia7417723aaae86bec2959ad9ae6c2915ddd340e0
---
drivers/vfio/vfio.c | 103 ++++++++++++++++++++++++++++++++++++++++
drivers/vfio/vfio_iommu_type1.c | 20 ++++----
include/linux/vfio.h | 14 +++++-
3 files changed, 126 insertions(+), 11 deletions(-)
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 2e83bdf007fe..3bf8a01bf67b 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -1799,6 +1799,109 @@ void vfio_info_cap_shift(struct vfio_info_cap *caps, size_t offset)
}
EXPORT_SYMBOL_GPL(vfio_info_cap_shift);
+
+/*
+ * Pin a set of guest PFNs and return their associated host PFNs for local
+ * domain only.
+ * @dev [in] : device
+ * @user_pfn [in]: array of user/guest PFNs to be unpinned. Number of user/guest
+ * PFNs should not be greater than VFIO_PIN_PAGES_MAX_ENTRIES.
+ * @npage [in] :count of elements in array. This count should not be greater
+ * than PAGE_SIZE.
+ * @prot [in] : protection flags
+ * @phys_pfn[out] : array of host PFNs
+ * Return error or number of pages pinned.
+ */
+int vfio_pin_pages(struct device *dev, unsigned long *user_pfn, int npage,
+ int prot, unsigned long *phys_pfn)
+{
+ struct vfio_container *container;
+ struct vfio_group *group;
+ struct vfio_iommu_driver *driver;
+ int ret;
+
+ if (!dev || !user_pfn || !phys_pfn || !npage)
+ return -EINVAL;
+
+ if (npage > VFIO_PIN_PAGES_MAX_ENTRIES)
+ return -E2BIG;
+
+ group = vfio_group_get_from_dev(dev);
+ if (IS_ERR(group))
+ return PTR_ERR(group);
+
+ ret = vfio_group_add_container_user(group);
+ if (ret)
+ goto err_pin_pages;
+
+ container = group->container;
+ down_read(&container->group_lock);
+
+ driver = container->iommu_driver;
+ if (likely(driver && driver->ops->pin_pages))
+ ret = driver->ops->pin_pages(container->iommu_data, user_pfn,
+ npage, prot, phys_pfn);
+ else
+ ret = -ENOTTY;
+
+ up_read(&container->group_lock);
+ vfio_group_try_dissolve_container(group);
+
+err_pin_pages:
+ vfio_group_put(group);
+ return ret;
+}
+EXPORT_SYMBOL(vfio_pin_pages);
+
+/*
+ * Unpin set of host PFNs for local domain only.
+ * @dev [in] : device
+ * @user_pfn [in]: array of user/guest PFNs to be unpinned. Number of user/guest
+ * PFNs should not be greater than VFIO_PIN_PAGES_MAX_ENTRIES.
+ * @npage [in] :count of elements in array. This count should not be greater
+ * than PAGE_SIZE.
+ * Return error or number of pages unpinned.
+ */
+int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn, int npage)
+{
+ struct vfio_container *container;
+ struct vfio_group *group;
+ struct vfio_iommu_driver *driver;
+ int ret;
+
+ if (!dev || !user_pfn || !npage)
+ return -EINVAL;
+
+ if (npage > VFIO_PIN_PAGES_MAX_ENTRIES)
+ return -E2BIG;
+
+ group = vfio_group_get_from_dev(dev);
+ if (IS_ERR(group))
+ return PTR_ERR(group);
+
+ ret = vfio_group_add_container_user(group);
+ if (ret)
+ goto err_unpin_pages;
+
+ container = group->container;
+ down_read(&container->group_lock);
+
+ driver = container->iommu_driver;
+ if (likely(driver && driver->ops->unpin_pages))
+ ret = driver->ops->unpin_pages(container->iommu_data, user_pfn,
+ npage);
+ else
+ ret = -ENOTTY;
+
+ up_read(&container->group_lock);
+ vfio_group_try_dissolve_container(group);
+
+err_unpin_pages:
+ vfio_group_put(group);
+ return ret;
+}
+EXPORT_SYMBOL(vfio_unpin_pages);
+
/**
* Module/class support
*/
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 2ba19424e4a1..9f3d58d3dfaf 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -259,8 +259,8 @@ static int vaddr_get_pfn(unsigned long vaddr, int prot, unsigned long *pfn)
* the iommu can only map chunks of consecutive pfns anyway, so get the
* first page and all consecutive pages with the same locking.
*/
-static long vfio_pin_pages(unsigned long vaddr, long npage,
- int prot, unsigned long *pfn_base)
+static long vfio_pin_pages_remote(unsigned long vaddr, long npage,
+ int prot, unsigned long *pfn_base)
{
unsigned long limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
bool lock_cap = capable(CAP_IPC_LOCK);
@@ -318,8 +318,8 @@ static long vfio_pin_pages(unsigned long vaddr, long npage,
return i;
}
-static long vfio_unpin_pages(unsigned long pfn, long npage,
- int prot, bool do_accounting)
+static long vfio_unpin_pages_remote(unsigned long pfn, long npage,
+ int prot, bool do_accounting)
{
unsigned long unlocked = 0;
long i;
@@ -382,9 +382,9 @@ static void vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma)
if (WARN_ON(!unmapped))
break;
- unlocked += vfio_unpin_pages(phys >> PAGE_SHIFT,
- unmapped >> PAGE_SHIFT,
- dma->prot, false);
+ unlocked += vfio_unpin_pages_remote(phys >> PAGE_SHIFT,
+ unmapped >> PAGE_SHIFT,
+ dma->prot, false);
iova += unmapped;
cond_resched();
@@ -613,8 +613,8 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu,
while (size) {
/* Pin a contiguous chunk of memory */
- npage = vfio_pin_pages(vaddr + dma->size,
- size >> PAGE_SHIFT, prot, &pfn);
+ npage = vfio_pin_pages_remote(vaddr + dma->size,
+ size >> PAGE_SHIFT, prot, &pfn);
if (npage <= 0) {
WARN_ON(!npage);
ret = (int)npage;
@@ -624,7 +624,7 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu,
/* Map it! */
ret = vfio_iommu_map(iommu, iova + dma->size, pfn, npage, prot);
if (ret) {
- vfio_unpin_pages(pfn, npage, prot, true);
+ vfio_unpin_pages_remote(pfn, npage, prot, true);
break;
}
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index 0ecae0b1cd34..420cdc928786 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -75,7 +75,11 @@ struct vfio_iommu_driver_ops {
struct iommu_group *group);
void (*detach_group)(void *iommu_data,
struct iommu_group *group);
-
+ int (*pin_pages)(void *iommu_data, unsigned long *user_pfn,
+ int npage, int prot,
+ unsigned long *phys_pfn);
+ int (*unpin_pages)(void *iommu_data,
+ unsigned long *user_pfn, int npage);
};
extern int vfio_register_iommu_driver(const struct vfio_iommu_driver_ops *ops);
@@ -127,6 +131,14 @@ static inline long vfio_spapr_iommu_eeh_ioctl(struct iommu_group *group,
}
#endif /* CONFIG_EEH */
+#define VFIO_PIN_PAGES_MAX_ENTRIES (PAGE_SIZE/sizeof(unsigned long))
+
+extern int vfio_pin_pages(struct device *dev, unsigned long *user_pfn,
+ int npage, int prot, unsigned long *phys_pfn);
+
+extern int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn,
+ int npage);
+
/*
* IRQfd - generic
*/
--
2.7.0
This change rearrange functions to have common function to increment
container_users
Signed-off-by: Kirti Wankhede <[email protected]>
Signed-off-by: Neo Jia <[email protected]>
Reviewed-by: Jike Song <[email protected]>
Change-Id: I8bdeb352bc8439b107ffd519480fd4dc238677f2
---
drivers/vfio/vfio.c | 34 +++++++++++++++++++++-------------
1 file changed, 21 insertions(+), 13 deletions(-)
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 23bc86c1d05d..2e83bdf007fe 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -1385,6 +1385,23 @@ static bool vfio_group_viable(struct vfio_group *group)
group, vfio_dev_viable) == 0);
}
+static int vfio_group_add_container_user(struct vfio_group *group)
+{
+ if (!atomic_inc_not_zero(&group->container_users))
+ return -EINVAL;
+
+ if (group->noiommu) {
+ atomic_dec(&group->container_users);
+ return -EPERM;
+ }
+ if (!group->container->iommu_driver || !vfio_group_viable(group)) {
+ atomic_dec(&group->container_users);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
static const struct file_operations vfio_device_fops;
static int vfio_group_get_device_fd(struct vfio_group *group, char *buf)
@@ -1694,23 +1711,14 @@ static const struct file_operations vfio_device_fops = {
struct vfio_group *vfio_group_get_external_user(struct file *filep)
{
struct vfio_group *group = filep->private_data;
+ int ret;
if (filep->f_op != &vfio_group_fops)
return ERR_PTR(-EINVAL);
- if (!atomic_inc_not_zero(&group->container_users))
- return ERR_PTR(-EINVAL);
-
- if (group->noiommu) {
- atomic_dec(&group->container_users);
- return ERR_PTR(-EPERM);
- }
-
- if (!group->container->iommu_driver ||
- !vfio_group_viable(group)) {
- atomic_dec(&group->container_users);
- return ERR_PTR(-EINVAL);
- }
+ ret = vfio_group_add_container_user(group);
+ if (ret)
+ return ERR_PTR(ret);
vfio_group_get(group);
--
2.7.0
Update arguments of vaddr_get_pfn() to take struct mm_struct *mm as input
argument.
Signed-off-by: Kirti Wankhede <[email protected]>
Signed-off-by: Neo Jia <[email protected]>
Change-Id: I885fd4cd4a9f66f4ee2c1caf58267464ec239f52
---
drivers/vfio/vfio_iommu_type1.c | 32 ++++++++++++++++++++++++--------
1 file changed, 24 insertions(+), 8 deletions(-)
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 34d17e51dc97..52af5fc01d91 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -230,20 +230,36 @@ static int put_pfn(unsigned long pfn, int prot)
return 0;
}
-static int vaddr_get_pfn(unsigned long vaddr, int prot, unsigned long *pfn)
+static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr,
+ int prot, unsigned long *pfn)
{
struct page *page[1];
struct vm_area_struct *vma;
- int ret = -EFAULT;
+ int ret;
+
+ if (mm == current->mm) {
+ ret = get_user_pages_fast(vaddr, 1, !!(prot & IOMMU_WRITE),
+ page);
+ } else {
+ unsigned int flags = 0;
+
+ if (prot & IOMMU_WRITE)
+ flags |= FOLL_WRITE;
+
+ down_read(&mm->mmap_sem);
+ ret = get_user_pages_remote(NULL, mm, vaddr, 1, flags, page,
+ NULL);
+ up_read(&mm->mmap_sem);
+ }
- if (get_user_pages_fast(vaddr, 1, !!(prot & IOMMU_WRITE), page) == 1) {
+ if (ret == 1) {
*pfn = page_to_pfn(page[0]);
return 0;
}
- down_read(¤t->mm->mmap_sem);
+ down_read(&mm->mmap_sem);
- vma = find_vma_intersection(current->mm, vaddr, vaddr + 1);
+ vma = find_vma_intersection(mm, vaddr, vaddr + 1);
if (vma && vma->vm_flags & VM_PFNMAP) {
*pfn = ((vaddr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
@@ -251,7 +267,7 @@ static int vaddr_get_pfn(unsigned long vaddr, int prot, unsigned long *pfn)
ret = 0;
}
- up_read(¤t->mm->mmap_sem);
+ up_read(&mm->mmap_sem);
return ret;
}
@@ -272,7 +288,7 @@ static long vfio_pin_pages_remote(unsigned long vaddr, long npage,
if (!current->mm)
return -ENODEV;
- ret = vaddr_get_pfn(vaddr, prot, pfn_base);
+ ret = vaddr_get_pfn(current->mm, vaddr, prot, pfn_base);
if (ret)
return ret;
@@ -295,7 +311,7 @@ static long vfio_pin_pages_remote(unsigned long vaddr, long npage,
for (i = 1, vaddr += PAGE_SIZE; i < npage; i++, vaddr += PAGE_SIZE) {
unsigned long pfn = 0;
- ret = vaddr_get_pfn(vaddr, prot, &pfn);
+ ret = vaddr_get_pfn(current->mm, vaddr, prot, &pfn);
if (ret)
break;
--
2.7.0
Add task structure to vfio_dma structure. Task structure is used for:
- During DMA_UNMAP, same task who mapped it or other task who shares same
address space is allowed to unmap, otherwise unmap fails.
QEMU maps few iova ranges initially, then fork threads and from the child
thread calls DMA_UNMAP on previously mapped iova. Since child shares same
address space, DMA_UNMAP is successful.
- Avoid accessing struct mm while process is exiting by acquiring
reference of task's mm during page accounting.
- It is also used to get task mlock capability and rlimit for mlock.
Signed-off-by: Kirti Wankhede <[email protected]>
Signed-off-by: Neo Jia <[email protected]>
Change-Id: I7600f1bea6b384fd589fa72421ccf031bcfd9ac5
---
drivers/vfio/vfio_iommu_type1.c | 137 +++++++++++++++++++++++++---------------
1 file changed, 86 insertions(+), 51 deletions(-)
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index ffe2026f1341..50aca95cf61e 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -36,6 +36,7 @@
#include <linux/uaccess.h>
#include <linux/vfio.h>
#include <linux/workqueue.h>
+#include <linux/pid_namespace.h>
#define DRIVER_VERSION "0.2"
#define DRIVER_AUTHOR "Alex Williamson <[email protected]>"
@@ -75,6 +76,7 @@ struct vfio_dma {
unsigned long vaddr; /* Process virtual addr */
size_t size; /* Map size (bytes) */
int prot; /* IOMMU_READ/WRITE */
+ struct task_struct *task;
};
struct vfio_group {
@@ -277,41 +279,47 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr,
* the iommu can only map chunks of consecutive pfns anyway, so get the
* first page and all consecutive pages with the same locking.
*/
-static long vfio_pin_pages_remote(unsigned long vaddr, long npage,
- int prot, unsigned long *pfn_base)
+static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
+ long npage, int prot, unsigned long *pfn_base)
{
- unsigned long limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
- bool lock_cap = capable(CAP_IPC_LOCK);
+ unsigned long limit;
+ bool lock_cap = ns_capable(task_active_pid_ns(dma->task)->user_ns,
+ CAP_IPC_LOCK);
+ struct mm_struct *mm;
long ret, i;
bool rsvd;
- if (!current->mm)
+ mm = get_task_mm(dma->task);
+ if (!mm)
return -ENODEV;
- ret = vaddr_get_pfn(current->mm, vaddr, prot, pfn_base);
+ ret = vaddr_get_pfn(mm, vaddr, prot, pfn_base);
if (ret)
- return ret;
+ goto pin_pg_remote_exit;
rsvd = is_invalid_reserved_pfn(*pfn_base);
+ limit = task_rlimit(dma->task, RLIMIT_MEMLOCK) >> PAGE_SHIFT;
- if (!rsvd && !lock_cap && current->mm->locked_vm + 1 > limit) {
+ if (!rsvd && !lock_cap && mm->locked_vm + 1 > limit) {
put_pfn(*pfn_base, prot);
pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n", __func__,
limit << PAGE_SHIFT);
- return -ENOMEM;
+ ret = -ENOMEM;
+ goto pin_pg_remote_exit;
}
if (unlikely(disable_hugepages)) {
if (!rsvd)
- vfio_lock_acct(current, 1);
- return 1;
+ vfio_lock_acct(dma->task, 1);
+ ret = 1;
+ goto pin_pg_remote_exit;
}
/* Lock all the consecutive pages from pfn_base */
for (i = 1, vaddr += PAGE_SIZE; i < npage; i++, vaddr += PAGE_SIZE) {
unsigned long pfn = 0;
- ret = vaddr_get_pfn(current->mm, vaddr, prot, &pfn);
+ ret = vaddr_get_pfn(mm, vaddr, prot, &pfn);
if (ret)
break;
@@ -321,8 +329,7 @@ static long vfio_pin_pages_remote(unsigned long vaddr, long npage,
break;
}
- if (!rsvd && !lock_cap &&
- current->mm->locked_vm + i + 1 > limit) {
+ if (!rsvd && !lock_cap && mm->locked_vm + i + 1 > limit) {
put_pfn(pfn, prot);
pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n",
__func__, limit << PAGE_SHIFT);
@@ -331,13 +338,16 @@ static long vfio_pin_pages_remote(unsigned long vaddr, long npage,
}
if (!rsvd)
- vfio_lock_acct(current, i);
+ vfio_lock_acct(dma->task, i);
+ ret = i;
- return i;
+pin_pg_remote_exit:
+ mmput(mm);
+ return ret;
}
-static long vfio_unpin_pages_remote(unsigned long pfn, long npage,
- int prot, bool do_accounting)
+static long vfio_unpin_pages_remote(struct vfio_dma *dma, unsigned long pfn,
+ long npage, int prot, bool do_accounting)
{
unsigned long unlocked = 0;
long i;
@@ -346,7 +356,7 @@ static long vfio_unpin_pages_remote(unsigned long pfn, long npage,
unlocked += put_pfn(pfn++, prot);
if (do_accounting)
- vfio_lock_acct(current, -unlocked);
+ vfio_lock_acct(dma->task, -unlocked);
return unlocked;
}
@@ -400,7 +410,7 @@ static void vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma)
if (WARN_ON(!unmapped))
break;
- unlocked += vfio_unpin_pages_remote(phys >> PAGE_SHIFT,
+ unlocked += vfio_unpin_pages_remote(dma, phys >> PAGE_SHIFT,
unmapped >> PAGE_SHIFT,
dma->prot, false);
iova += unmapped;
@@ -408,13 +418,14 @@ static void vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma)
cond_resched();
}
- vfio_lock_acct(current, -unlocked);
+ vfio_lock_acct(dma->task, -unlocked);
}
static void vfio_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *dma)
{
vfio_unmap_unpin(iommu, dma);
vfio_unlink_dma(iommu, dma);
+ put_task_struct(dma->task);
kfree(dma);
}
@@ -510,6 +521,12 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
while ((dma = vfio_find_dma(iommu, unmap->iova, unmap->size))) {
if (!iommu->v2 && unmap->iova > dma->iova)
break;
+ /*
+ * Task with same address space who mapped this iova range is
+ * allowed to unmap the iova range.
+ */
+ if (dma->task->mm != current->mm)
+ break;
unmapped += dma->size;
vfio_remove_dma(iommu, dma);
}
@@ -576,17 +593,55 @@ unwind:
return ret;
}
+static int vfio_pin_map_dma(struct vfio_iommu *iommu, struct vfio_dma *dma,
+ size_t map_size)
+{
+ dma_addr_t iova = dma->iova;
+ unsigned long vaddr = dma->vaddr;
+ size_t size = map_size;
+ long npage;
+ unsigned long pfn;
+ int ret = 0;
+
+ while (size) {
+ /* Pin a contiguous chunk of memory */
+ npage = vfio_pin_pages_remote(dma, vaddr + dma->size,
+ size >> PAGE_SHIFT, dma->prot,
+ &pfn);
+ if (npage <= 0) {
+ WARN_ON(!npage);
+ ret = (int)npage;
+ break;
+ }
+
+ /* Map it! */
+ ret = vfio_iommu_map(iommu, iova + dma->size, pfn, npage,
+ dma->prot);
+ if (ret) {
+ vfio_unpin_pages_remote(dma, pfn, npage,
+ dma->prot, true);
+ break;
+ }
+
+ size -= npage << PAGE_SHIFT;
+ dma->size += npage << PAGE_SHIFT;
+ }
+
+ if (ret)
+ vfio_remove_dma(iommu, dma);
+
+ return ret;
+}
+
static int vfio_dma_do_map(struct vfio_iommu *iommu,
struct vfio_iommu_type1_dma_map *map)
{
dma_addr_t iova = map->iova;
unsigned long vaddr = map->vaddr;
size_t size = map->size;
- long npage;
int ret = 0, prot = 0;
uint64_t mask;
struct vfio_dma *dma;
- unsigned long pfn;
/* Verify that none of our __u64 fields overflow */
if (map->size != size || map->vaddr != vaddr || map->iova != iova)
@@ -612,47 +667,27 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu,
mutex_lock(&iommu->lock);
if (vfio_find_dma(iommu, iova, size)) {
- mutex_unlock(&iommu->lock);
- return -EEXIST;
+ ret = -EEXIST;
+ goto do_map_err;
}
dma = kzalloc(sizeof(*dma), GFP_KERNEL);
if (!dma) {
- mutex_unlock(&iommu->lock);
- return -ENOMEM;
+ ret = -ENOMEM;
+ goto do_map_err;
}
dma->iova = iova;
dma->vaddr = vaddr;
dma->prot = prot;
+ get_task_struct(current);
+ dma->task = current;
/* Insert zero-sized and grow as we map chunks of it */
vfio_link_dma(iommu, dma);
- while (size) {
- /* Pin a contiguous chunk of memory */
- npage = vfio_pin_pages_remote(vaddr + dma->size,
- size >> PAGE_SHIFT, prot, &pfn);
- if (npage <= 0) {
- WARN_ON(!npage);
- ret = (int)npage;
- break;
- }
-
- /* Map it! */
- ret = vfio_iommu_map(iommu, iova + dma->size, pfn, npage, prot);
- if (ret) {
- vfio_unpin_pages_remote(pfn, npage, prot, true);
- break;
- }
-
- size -= npage << PAGE_SHIFT;
- dma->size += npage << PAGE_SHIFT;
- }
-
- if (ret)
- vfio_remove_dma(iommu, dma);
-
+ ret = vfio_pin_map_dma(iommu, dma, size);
+do_map_err:
mutex_unlock(&iommu->lock);
return ret;
}
--
2.7.0
VFIO IOMMU drivers are designed for the devices which are IOMMU capable.
Mediated device only uses IOMMU APIs, the underlying hardware can be
managed by an IOMMU domain.
Aim of this change is:
- To use most of the code of TYPE1 IOMMU driver for mediated devices
- To support direct assigned device and mediated device in single module
This change adds pin and unpin support for mediated device to TYPE1 IOMMU
backend module. More details:
- Domain for external user is tracked separately in vfio_iommu structure.
It is allocated when group for first mdev device is attached.
- Pages pinned for external domain are tracked in each vfio_dma structure
for that iova range.
- Page tracking rb-tree in vfio_dma keeps <iova, pfn, ref_count>. Key of
rb-tree is iova, but it actually aims to track pfns.
- On external pin request for an iova, page is pinned once, if iova is
already pinned and tracked, ref_count is incremented.
- External unpin request unpins pages only when ref_count is 0.
- Pinned pages list is used to verify unpinning request and to unpin
remaining pages while detaching the group for that device.
- Page accounting is updated to account in its address space where the
pages are pinned/unpinned, i.e dma->task
- Accouting for mdev device is only done if there is no iommu capable
domain in the container. When there is a direct device assigned to the
container and that domain is iommu capable, all pages are already pinned
during DMA_MAP.
- Page accouting is updated on hot plug and unplug mdev device and pass
through device.
Tested by assigning below combinations of devices to a single VM:
- GPU pass through only
- vGPU device only
- One GPU pass through and one vGPU device
- Linux VM hot plug and unplug vGPU device while GPU pass through device
exist
- Linux VM hot plug and unplug GPU pass through device while vGPU device
exist
Signed-off-by: Kirti Wankhede <[email protected]>
Signed-off-by: Neo Jia <[email protected]>
Change-Id: I295d6f0f2e0579b8d9882bfd8fd5a4194b97bd9a
---
drivers/vfio/vfio_iommu_type1.c | 598 +++++++++++++++++++++++++++++++++++-----
1 file changed, 536 insertions(+), 62 deletions(-)
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 50aca95cf61e..0de7c20f66b1 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -37,6 +37,7 @@
#include <linux/vfio.h>
#include <linux/workqueue.h>
#include <linux/pid_namespace.h>
+#include <linux/mdev.h>
#define DRIVER_VERSION "0.2"
#define DRIVER_AUTHOR "Alex Williamson <[email protected]>"
@@ -56,6 +57,7 @@ MODULE_PARM_DESC(disable_hugepages,
struct vfio_iommu {
struct list_head domain_list;
+ struct vfio_domain *external_domain; /* domain for external user */
struct mutex lock;
struct rb_root dma_list;
bool v2;
@@ -76,7 +78,9 @@ struct vfio_dma {
unsigned long vaddr; /* Process virtual addr */
size_t size; /* Map size (bytes) */
int prot; /* IOMMU_READ/WRITE */
+ bool iommu_mapped;
struct task_struct *task;
+ struct rb_root pfn_list; /* Ex-user pinned pfn list */
};
struct vfio_group {
@@ -85,6 +89,21 @@ struct vfio_group {
};
/*
+ * Guest RAM pinning working set or DMA target
+ */
+struct vfio_pfn {
+ struct rb_node node;
+ dma_addr_t iova; /* Device address */
+ unsigned long pfn; /* Host pfn */
+ atomic_t ref_count;
+};
+
+#define IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu) \
+ (!list_empty(&iommu->domain_list))
+
+static int put_pfn(unsigned long pfn, int prot);
+
+/*
* This code handles mapping and unmapping of user data buffers
* into DMA'ble space using the IOMMU
*/
@@ -132,6 +151,97 @@ static void vfio_unlink_dma(struct vfio_iommu *iommu, struct vfio_dma *old)
rb_erase(&old->node, &iommu->dma_list);
}
+/*
+ * Helper Functions for host iova-pfn list
+ */
+static struct vfio_pfn *vfio_find_vpfn(struct vfio_dma *dma, dma_addr_t iova)
+{
+ struct vfio_pfn *vpfn;
+ struct rb_node *node = dma->pfn_list.rb_node;
+
+ while (node) {
+ vpfn = rb_entry(node, struct vfio_pfn, node);
+
+ if (iova < vpfn->iova)
+ node = node->rb_left;
+ else if (iova > vpfn->iova)
+ node = node->rb_right;
+ else
+ return vpfn;
+ }
+ return NULL;
+}
+
+static void vfio_link_pfn(struct vfio_dma *dma,
+ struct vfio_pfn *new)
+{
+ struct rb_node **link, *parent = NULL;
+ struct vfio_pfn *vpfn;
+
+ link = &dma->pfn_list.rb_node;
+ while (*link) {
+ parent = *link;
+ vpfn = rb_entry(parent, struct vfio_pfn, node);
+
+ if (new->iova < vpfn->iova)
+ link = &(*link)->rb_left;
+ else
+ link = &(*link)->rb_right;
+ }
+
+ rb_link_node(&new->node, parent, link);
+ rb_insert_color(&new->node, &dma->pfn_list);
+}
+
+static void vfio_unlink_pfn(struct vfio_dma *dma, struct vfio_pfn *old)
+{
+ rb_erase(&old->node, &dma->pfn_list);
+}
+
+static int vfio_add_to_pfn_list(struct vfio_dma *dma, dma_addr_t iova,
+ unsigned long pfn)
+{
+ struct vfio_pfn *vpfn;
+
+ vpfn = kzalloc(sizeof(*vpfn), GFP_KERNEL);
+ if (!vpfn)
+ return -ENOMEM;
+
+ vpfn->iova = iova;
+ vpfn->pfn = pfn;
+ atomic_set(&vpfn->ref_count, 1);
+ vfio_link_pfn(dma, vpfn);
+ return 0;
+}
+
+static void vfio_remove_from_pfn_list(struct vfio_dma *dma,
+ struct vfio_pfn *vpfn)
+{
+ vfio_unlink_pfn(dma, vpfn);
+ kfree(vpfn);
+}
+
+static struct vfio_pfn *vfio_iova_get_vfio_pfn(struct vfio_dma *dma,
+ unsigned long iova)
+{
+ struct vfio_pfn *vpfn = vfio_find_vpfn(dma, iova);
+
+ if (vpfn)
+ atomic_inc(&vpfn->ref_count);
+ return vpfn;
+}
+
+static int vfio_iova_put_vfio_pfn(struct vfio_dma *dma, struct vfio_pfn *vpfn)
+{
+ int ret = 0;
+
+ if (atomic_dec_and_test(&vpfn->ref_count)) {
+ ret = put_pfn(vpfn->pfn, dma->prot);
+ vfio_remove_from_pfn_list(dma, vpfn);
+ }
+ return ret;
+}
+
struct vwork {
struct mm_struct *mm;
long npage;
@@ -270,7 +380,6 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr,
}
up_read(&mm->mmap_sem);
-
return ret;
}
@@ -280,28 +389,36 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr,
* first page and all consecutive pages with the same locking.
*/
static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
- long npage, int prot, unsigned long *pfn_base)
+ long npage, unsigned long *pfn_base)
{
unsigned long limit;
bool lock_cap = ns_capable(task_active_pid_ns(dma->task)->user_ns,
CAP_IPC_LOCK);
struct mm_struct *mm;
- long ret, i;
+ long ret, i, lock_acct = 0;
bool rsvd;
+ struct vfio_pfn *vpfn;
+ dma_addr_t iova = vaddr - dma->vaddr + dma->iova;
mm = get_task_mm(dma->task);
if (!mm)
return -ENODEV;
- ret = vaddr_get_pfn(mm, vaddr, prot, pfn_base);
+ ret = vaddr_get_pfn(mm, vaddr, dma->prot, pfn_base);
if (ret)
goto pin_pg_remote_exit;
rsvd = is_invalid_reserved_pfn(*pfn_base);
+ if (!rsvd) {
+ vpfn = vfio_find_vpfn(dma, iova);
+ if (!vpfn)
+ lock_acct = 1;
+ }
+
limit = task_rlimit(dma->task, RLIMIT_MEMLOCK) >> PAGE_SHIFT;
- if (!rsvd && !lock_cap && mm->locked_vm + 1 > limit) {
- put_pfn(*pfn_base, prot);
+ if (!rsvd && !lock_cap && mm->locked_vm + lock_acct > limit) {
+ put_pfn(*pfn_base, dma->prot);
pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n", __func__,
limit << PAGE_SHIFT);
ret = -ENOMEM;
@@ -310,35 +427,43 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
if (unlikely(disable_hugepages)) {
if (!rsvd)
- vfio_lock_acct(dma->task, 1);
+ vfio_lock_acct(dma->task, lock_acct);
ret = 1;
goto pin_pg_remote_exit;
}
/* Lock all the consecutive pages from pfn_base */
- for (i = 1, vaddr += PAGE_SIZE; i < npage; i++, vaddr += PAGE_SIZE) {
+ for (i = 1, vaddr += PAGE_SIZE, iova += PAGE_SIZE; i < npage;
+ i++, vaddr += PAGE_SIZE, iova += PAGE_SIZE) {
unsigned long pfn = 0;
- ret = vaddr_get_pfn(mm, vaddr, prot, &pfn);
+ ret = vaddr_get_pfn(mm, vaddr, dma->prot, &pfn);
if (ret)
break;
if (pfn != *pfn_base + i ||
rsvd != is_invalid_reserved_pfn(pfn)) {
- put_pfn(pfn, prot);
+ put_pfn(pfn, dma->prot);
break;
}
- if (!rsvd && !lock_cap && mm->locked_vm + i + 1 > limit) {
- put_pfn(pfn, prot);
+ if (!rsvd && !lock_cap &&
+ mm->locked_vm + lock_acct + 1 > limit) {
+ put_pfn(pfn, dma->prot);
pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n",
__func__, limit << PAGE_SHIFT);
break;
}
+
+ if (!rsvd) {
+ vpfn = vfio_find_vpfn(dma, iova);
+ if (!vpfn)
+ lock_acct++;
+ }
}
if (!rsvd)
- vfio_lock_acct(dma->task, i);
+ vfio_lock_acct(dma->task, lock_acct);
ret = i;
pin_pg_remote_exit:
@@ -346,14 +471,79 @@ pin_pg_remote_exit:
return ret;
}
-static long vfio_unpin_pages_remote(struct vfio_dma *dma, unsigned long pfn,
- long npage, int prot, bool do_accounting)
+static long vfio_unpin_pages_remote(struct vfio_dma *dma, dma_addr_t iova,
+ unsigned long pfn, long npage,
+ bool do_accounting)
{
- unsigned long unlocked = 0;
+ long unlocked = 0, locked = 0;
long i;
- for (i = 0; i < npage; i++)
- unlocked += put_pfn(pfn++, prot);
+ for (i = 0; i < npage; i++) {
+ struct vfio_pfn *vpfn;
+
+ if (put_pfn(pfn++, dma->prot)) {
+ unlocked++;
+ vpfn = vfio_find_vpfn(dma, iova + (i << PAGE_SHIFT));
+ if (vpfn)
+ locked++;
+ }
+ }
+
+ if (do_accounting)
+ vfio_lock_acct(dma->task, locked - unlocked);
+
+ return unlocked;
+}
+
+static int vfio_pin_page_external(struct vfio_dma *dma, unsigned long vaddr,
+ unsigned long *pfn_base, bool do_accounting)
+{
+ unsigned long limit;
+ bool lock_cap = ns_capable(task_active_pid_ns(dma->task)->user_ns,
+ CAP_IPC_LOCK);
+ struct mm_struct *mm;
+ int ret;
+ bool rsvd;
+
+ mm = get_task_mm(dma->task);
+ if (!mm)
+ return -ENODEV;
+
+ ret = vaddr_get_pfn(mm, vaddr, dma->prot, pfn_base);
+ if (ret)
+ goto pin_page_exit;
+
+ rsvd = is_invalid_reserved_pfn(*pfn_base);
+ limit = task_rlimit(dma->task, RLIMIT_MEMLOCK) >> PAGE_SHIFT;
+
+ if (!rsvd && !lock_cap && mm->locked_vm + 1 > limit) {
+ put_pfn(*pfn_base, dma->prot);
+ pr_warn("%s: Task %s (%d) RLIMIT_MEMLOCK (%ld) exceeded\n",
+ __func__, dma->task->comm, task_pid_nr(dma->task),
+ limit << PAGE_SHIFT);
+ ret = -ENOMEM;
+ goto pin_page_exit;
+ }
+
+ if (!rsvd && do_accounting)
+ vfio_lock_acct(dma->task, 1);
+ ret = 1;
+
+pin_page_exit:
+ mmput(mm);
+ return ret;
+}
+
+static int vfio_unpin_page_external(struct vfio_dma *dma, dma_addr_t iova,
+ bool do_accounting)
+{
+ int unlocked;
+ struct vfio_pfn *vpfn = vfio_find_vpfn(dma, iova);
+
+ if (!vpfn)
+ return 0;
+
+ unlocked = vfio_iova_put_vfio_pfn(dma, vpfn);
if (do_accounting)
vfio_lock_acct(dma->task, -unlocked);
@@ -361,14 +551,145 @@ static long vfio_unpin_pages_remote(struct vfio_dma *dma, unsigned long pfn,
return unlocked;
}
-static void vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma)
+static int vfio_iommu_type1_pin_pages(void *iommu_data,
+ unsigned long *user_pfn,
+ int npage, int prot,
+ unsigned long *phys_pfn)
+{
+ struct vfio_iommu *iommu = iommu_data;
+ int i, j, ret;
+ unsigned long remote_vaddr;
+ struct vfio_dma *dma;
+ bool do_accounting;
+
+ if (!iommu || !user_pfn || !phys_pfn)
+ return -EINVAL;
+
+ /* Supported for v2 version only */
+ if (!iommu->v2)
+ return -EACCES;
+
+ mutex_lock(&iommu->lock);
+
+ if (!iommu->external_domain) {
+ ret = -EINVAL;
+ goto pin_done;
+ }
+
+ /*
+ * If iommu capable domain exist in the container then all pages are
+ * already pinned and accounted. Accouting should be done if there is no
+ * iommu capable domain in the container.
+ */
+ do_accounting = !IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu);
+
+ for (i = 0; i < npage; i++) {
+ dma_addr_t iova;
+ struct vfio_pfn *vpfn;
+
+ iova = user_pfn[i] << PAGE_SHIFT;
+ dma = vfio_find_dma(iommu, iova, 0);
+ if (!dma) {
+ ret = -EINVAL;
+ goto pin_unwind;
+ }
+
+ if ((dma->prot & prot) != prot) {
+ ret = -EPERM;
+ goto pin_unwind;
+ }
+
+ vpfn = vfio_iova_get_vfio_pfn(dma, iova);
+ if (vpfn) {
+ phys_pfn[i] = vpfn->pfn;
+ continue;
+ }
+
+ remote_vaddr = dma->vaddr + iova - dma->iova;
+ ret = vfio_pin_page_external(dma, remote_vaddr, &phys_pfn[i],
+ do_accounting);
+ if (ret <= 0) {
+ WARN_ON(!ret);
+ goto pin_unwind;
+ }
+
+ ret = vfio_add_to_pfn_list(dma, iova, phys_pfn[i]);
+ if (ret) {
+ vfio_unpin_page_external(dma, iova, do_accounting);
+ goto pin_unwind;
+ }
+ }
+
+ ret = i;
+ goto pin_done;
+
+pin_unwind:
+ phys_pfn[i] = 0;
+ for (j = 0; j < i; j++) {
+ dma_addr_t iova;
+
+ iova = user_pfn[j] << PAGE_SHIFT;
+ dma = vfio_find_dma(iommu, iova, 0);
+ vfio_unpin_page_external(dma, iova, do_accounting);
+ phys_pfn[j] = 0;
+ }
+pin_done:
+ mutex_unlock(&iommu->lock);
+ return ret;
+}
+
+static int vfio_iommu_type1_unpin_pages(void *iommu_data,
+ unsigned long *user_pfn,
+ int npage)
+{
+ struct vfio_iommu *iommu = iommu_data;
+ bool do_accounting;
+ int i;
+
+ if (!iommu || !user_pfn)
+ return -EINVAL;
+
+ /* Supported for v2 version only */
+ if (!iommu->v2)
+ return -EACCES;
+
+ mutex_lock(&iommu->lock);
+
+ if (!iommu->external_domain) {
+ mutex_unlock(&iommu->lock);
+ return -EINVAL;
+ }
+
+ do_accounting = !IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu);
+ for (i = 0; i < npage; i++) {
+ struct vfio_dma *dma;
+ dma_addr_t iova;
+
+ iova = user_pfn[i] << PAGE_SHIFT;
+ dma = vfio_find_dma(iommu, iova, 0);
+ if (!dma)
+ goto unpin_exit;
+ vfio_unpin_page_external(dma, iova, do_accounting);
+ }
+
+unpin_exit:
+ mutex_unlock(&iommu->lock);
+ return i > npage ? npage : (i > 0 ? i : -EINVAL);
+}
+
+static long vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma,
+ bool do_accounting)
{
dma_addr_t iova = dma->iova, end = dma->iova + dma->size;
struct vfio_domain *domain, *d;
long unlocked = 0;
if (!dma->size)
- return;
+ return 0;
+
+ if (!IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu))
+ return 0;
+
/*
* We use the IOMMU to track the physical addresses, otherwise we'd
* need a much more complicated tracking system. Unfortunately that
@@ -410,20 +731,26 @@ static void vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma)
if (WARN_ON(!unmapped))
break;
- unlocked += vfio_unpin_pages_remote(dma, phys >> PAGE_SHIFT,
+ unlocked += vfio_unpin_pages_remote(dma, iova,
+ phys >> PAGE_SHIFT,
unmapped >> PAGE_SHIFT,
- dma->prot, false);
+ false);
iova += unmapped;
cond_resched();
}
- vfio_lock_acct(dma->task, -unlocked);
+ dma->iommu_mapped = false;
+ if (do_accounting) {
+ vfio_lock_acct(dma->task, -unlocked);
+ return 0;
+ }
+ return unlocked;
}
static void vfio_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *dma)
{
- vfio_unmap_unpin(iommu, dma);
+ vfio_unmap_unpin(iommu, dma, true);
vfio_unlink_dma(iommu, dma);
put_task_struct(dma->task);
kfree(dma);
@@ -606,8 +933,7 @@ static int vfio_pin_map_dma(struct vfio_iommu *iommu, struct vfio_dma *dma,
while (size) {
/* Pin a contiguous chunk of memory */
npage = vfio_pin_pages_remote(dma, vaddr + dma->size,
- size >> PAGE_SHIFT, dma->prot,
- &pfn);
+ size >> PAGE_SHIFT, &pfn);
if (npage <= 0) {
WARN_ON(!npage);
ret = (int)npage;
@@ -618,8 +944,8 @@ static int vfio_pin_map_dma(struct vfio_iommu *iommu, struct vfio_dma *dma,
ret = vfio_iommu_map(iommu, iova + dma->size, pfn, npage,
dma->prot);
if (ret) {
- vfio_unpin_pages_remote(dma, pfn, npage,
- dma->prot, true);
+ vfio_unpin_pages_remote(dma, iova + dma->size, pfn,
+ npage, true);
break;
}
@@ -627,6 +953,8 @@ static int vfio_pin_map_dma(struct vfio_iommu *iommu, struct vfio_dma *dma,
dma->size += npage << PAGE_SHIFT;
}
+ dma->iommu_mapped = true;
+
if (ret)
vfio_remove_dma(iommu, dma);
@@ -682,11 +1010,16 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu,
dma->prot = prot;
get_task_struct(current);
dma->task = current;
+ dma->pfn_list = RB_ROOT;
/* Insert zero-sized and grow as we map chunks of it */
vfio_link_dma(iommu, dma);
- ret = vfio_pin_map_dma(iommu, dma, size);
+ /* Don't pin and map if container doesn't contain IOMMU capable domain*/
+ if (!IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu))
+ dma->size = size;
+ else
+ ret = vfio_pin_map_dma(iommu, dma, size);
do_map_err:
mutex_unlock(&iommu->lock);
return ret;
@@ -715,10 +1048,6 @@ static int vfio_iommu_replay(struct vfio_iommu *iommu,
d = list_first_entry(&iommu->domain_list, struct vfio_domain, next);
n = rb_first(&iommu->dma_list);
- /* If there's not a domain, there better not be any mappings */
- if (WARN_ON(n && !d))
- return -EINVAL;
-
for (; n; n = rb_next(n)) {
struct vfio_dma *dma;
dma_addr_t iova;
@@ -727,21 +1056,49 @@ static int vfio_iommu_replay(struct vfio_iommu *iommu,
iova = dma->iova;
while (iova < dma->iova + dma->size) {
- phys_addr_t phys = iommu_iova_to_phys(d->domain, iova);
+ phys_addr_t phys;
size_t size;
- if (WARN_ON(!phys)) {
- iova += PAGE_SIZE;
- continue;
+ if (dma->iommu_mapped) {
+ phys_addr_t p;
+ dma_addr_t i;
+
+ phys = iommu_iova_to_phys(d->domain, iova);
+
+ if (WARN_ON(!phys)) {
+ iova += PAGE_SIZE;
+ continue;
+ }
+
+ size = PAGE_SIZE;
+ p = phys + size;
+ i = iova + size;
+ while (i < dma->iova + dma->size &&
+ p == iommu_iova_to_phys(d->domain, i)) {
+ size += PAGE_SIZE;
+ p += PAGE_SIZE;
+ i += PAGE_SIZE;
+ }
+ } else {
+ unsigned long pfn;
+ unsigned long vaddr = dma->vaddr +
+ (iova - dma->iova);
+ size_t n = dma->iova + dma->size - iova;
+ long npage;
+
+ npage = vfio_pin_pages_remote(dma, vaddr,
+ n >> PAGE_SHIFT,
+ &pfn);
+ if (npage <= 0) {
+ WARN_ON(!npage);
+ ret = (int)npage;
+ return ret;
+ }
+
+ phys = pfn << PAGE_SHIFT;
+ size = npage << PAGE_SHIFT;
}
- size = PAGE_SIZE;
-
- while (iova + size < dma->iova + dma->size &&
- phys + size == iommu_iova_to_phys(d->domain,
- iova + size))
- size += PAGE_SIZE;
-
ret = iommu_map(domain->domain, iova, phys,
size, dma->prot | domain->prot);
if (ret)
@@ -749,8 +1106,8 @@ static int vfio_iommu_replay(struct vfio_iommu *iommu,
iova += size;
}
+ dma->iommu_mapped = true;
}
-
return 0;
}
@@ -806,7 +1163,7 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
struct vfio_iommu *iommu = iommu_data;
struct vfio_group *group;
struct vfio_domain *domain, *d;
- struct bus_type *bus = NULL;
+ struct bus_type *bus = NULL, *mdev_bus;
int ret;
mutex_lock(&iommu->lock);
@@ -818,6 +1175,13 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
}
}
+ if (iommu->external_domain) {
+ if (find_iommu_group(iommu->external_domain, iommu_group)) {
+ mutex_unlock(&iommu->lock);
+ return -EINVAL;
+ }
+ }
+
group = kzalloc(sizeof(*group), GFP_KERNEL);
domain = kzalloc(sizeof(*domain), GFP_KERNEL);
if (!group || !domain) {
@@ -832,6 +1196,25 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
if (ret)
goto out_free;
+ mdev_bus = symbol_get(mdev_bus_type);
+
+ if (mdev_bus) {
+ if ((bus == mdev_bus) && !iommu_present(bus)) {
+ symbol_put(mdev_bus_type);
+ if (!iommu->external_domain) {
+ INIT_LIST_HEAD(&domain->group_list);
+ iommu->external_domain = domain;
+ } else
+ kfree(domain);
+
+ list_add(&group->next,
+ &iommu->external_domain->group_list);
+ mutex_unlock(&iommu->lock);
+ return 0;
+ }
+ symbol_put(mdev_bus_type);
+ }
+
domain->domain = iommu_domain_alloc(bus);
if (!domain->domain) {
ret = -EIO;
@@ -922,6 +1305,54 @@ static void vfio_iommu_unmap_unpin_all(struct vfio_iommu *iommu)
vfio_remove_dma(iommu, rb_entry(node, struct vfio_dma, node));
}
+static void vfio_iommu_unmap_unpin_reaccount(struct vfio_iommu *iommu)
+{
+ struct rb_node *n, *p;
+
+ n = rb_first(&iommu->dma_list);
+ for (; n; n = rb_next(n)) {
+ struct vfio_dma *dma;
+ long locked = 0, unlocked = 0;
+
+ dma = rb_entry(n, struct vfio_dma, node);
+ unlocked += vfio_unmap_unpin(iommu, dma, false);
+ p = rb_first(&dma->pfn_list);
+ for (; p; p = rb_next(p)) {
+ bool rsvd;
+ struct vfio_pfn *vpfn = rb_entry(p, struct vfio_pfn,
+ node);
+
+ rsvd = is_invalid_reserved_pfn(vpfn->pfn);
+ if (!rsvd)
+ locked++;
+ }
+ vfio_lock_acct(dma->task, locked - unlocked);
+ }
+}
+
+static void vfio_external_unpin_all(struct vfio_iommu *iommu,
+ bool do_accounting)
+{
+ struct rb_node *n, *p;
+
+ n = rb_first(&iommu->dma_list);
+ for (; n; n = rb_next(n)) {
+ struct vfio_dma *dma;
+ int unlocked = 0;
+
+ dma = rb_entry(n, struct vfio_dma, node);
+ while ((p = rb_first(&dma->pfn_list))) {
+ struct vfio_pfn *vpfn = rb_entry(p, struct vfio_pfn,
+ node);
+
+ unlocked += vfio_iova_put_vfio_pfn(dma, vpfn);
+ }
+
+ if (do_accounting)
+ vfio_lock_acct(dma->task, -unlocked);
+ }
+}
+
static void vfio_iommu_type1_detach_group(void *iommu_data,
struct iommu_group *iommu_group)
{
@@ -931,6 +1362,26 @@ static void vfio_iommu_type1_detach_group(void *iommu_data,
mutex_lock(&iommu->lock);
+ if (iommu->external_domain) {
+ domain = iommu->external_domain;
+ group = find_iommu_group(domain, iommu_group);
+ if (group) {
+ list_del(&group->next);
+ kfree(group);
+
+ if (list_empty(&domain->group_list)) {
+ if (!IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu)) {
+ vfio_external_unpin_all(iommu, true);
+ vfio_iommu_unmap_unpin_all(iommu);
+ } else
+ vfio_external_unpin_all(iommu, false);
+ kfree(domain);
+ iommu->external_domain = NULL;
+ }
+ goto detach_group_done;
+ }
+ }
+
list_for_each_entry(domain, &iommu->domain_list, next) {
group = find_iommu_group(domain, iommu_group);
if (!group)
@@ -940,21 +1391,27 @@ static void vfio_iommu_type1_detach_group(void *iommu_data,
list_del(&group->next);
kfree(group);
/*
- * Group ownership provides privilege, if the group
- * list is empty, the domain goes away. If it's the
- * last domain, then all the mappings go away too.
+ * Group ownership provides privilege, if the group list is
+ * empty, the domain goes away. If it's the last domain with
+ * iommu and external domain doesn't exist, then all the
+ * mappings go away too. If it's the last domain with iommu and
+ * external domain exist, update accounting
*/
if (list_empty(&domain->group_list)) {
- if (list_is_singular(&iommu->domain_list))
- vfio_iommu_unmap_unpin_all(iommu);
+ if (list_is_singular(&iommu->domain_list)) {
+ if (!iommu->external_domain)
+ vfio_iommu_unmap_unpin_all(iommu);
+ else
+ vfio_iommu_unmap_unpin_reaccount(iommu);
+ }
iommu_domain_free(domain->domain);
list_del(&domain->next);
kfree(domain);
}
- goto done;
+ break;
}
-done:
+detach_group_done:
mutex_unlock(&iommu->lock);
}
@@ -986,27 +1443,42 @@ static void *vfio_iommu_type1_open(unsigned long arg)
return iommu;
}
+static void vfio_release_domain(struct vfio_domain *domain, bool external)
+{
+ struct vfio_group *group, *group_tmp;
+
+ list_for_each_entry_safe(group, group_tmp,
+ &domain->group_list, next) {
+ if (!external)
+ iommu_detach_group(domain->domain, group->iommu_group);
+ list_del(&group->next);
+ kfree(group);
+ }
+
+ if (!external)
+ iommu_domain_free(domain->domain);
+}
+
static void vfio_iommu_type1_release(void *iommu_data)
{
struct vfio_iommu *iommu = iommu_data;
struct vfio_domain *domain, *domain_tmp;
- struct vfio_group *group, *group_tmp;
+
+ if (iommu->external_domain) {
+ vfio_release_domain(iommu->external_domain, true);
+ vfio_external_unpin_all(iommu, false);
+ kfree(iommu->external_domain);
+ iommu->external_domain = NULL;
+ }
vfio_iommu_unmap_unpin_all(iommu);
list_for_each_entry_safe(domain, domain_tmp,
&iommu->domain_list, next) {
- list_for_each_entry_safe(group, group_tmp,
- &domain->group_list, next) {
- iommu_detach_group(domain->domain, group->iommu_group);
- list_del(&group->next);
- kfree(group);
- }
- iommu_domain_free(domain->domain);
+ vfio_release_domain(domain, false);
list_del(&domain->next);
kfree(domain);
}
-
kfree(iommu);
}
@@ -1110,6 +1582,8 @@ static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = {
.ioctl = vfio_iommu_type1_ioctl,
.attach_group = vfio_iommu_type1_attach_group,
.detach_group = vfio_iommu_type1_detach_group,
+ .pin_pages = vfio_iommu_type1_pin_pages,
+ .unpin_pages = vfio_iommu_type1_unpin_pages,
};
static int __init vfio_iommu_type1_init(void)
--
2.7.0
Update msix_sparse_mmap_cap() to use vfio_info_add_capability()
Update region type capability to use vfio_info_add_capability()
Signed-off-by: Kirti Wankhede <[email protected]>
Signed-off-by: Neo Jia <[email protected]>
Change-Id: I52bb28c7875a6da5a79ddad1843e6088aff58a45
---
drivers/vfio/pci/vfio_pci.c | 49 ++++++++++++++++++---------------------------
1 file changed, 19 insertions(+), 30 deletions(-)
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 031bc08d000d..03b5434f4d5b 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -558,10 +558,9 @@ static int vfio_pci_for_each_slot_or_bus(struct pci_dev *pdev,
static int msix_sparse_mmap_cap(struct vfio_pci_device *vdev,
struct vfio_info_cap *caps)
{
- struct vfio_info_cap_header *header;
struct vfio_region_info_cap_sparse_mmap *sparse;
size_t end, size;
- int nr_areas = 2, i = 0;
+ int nr_areas = 2, i = 0, ret;
end = pci_resource_len(vdev->pdev, vdev->msix_bar);
@@ -572,13 +571,10 @@ static int msix_sparse_mmap_cap(struct vfio_pci_device *vdev,
size = sizeof(*sparse) + (nr_areas * sizeof(*sparse->areas));
- header = vfio_info_cap_add(caps, size,
- VFIO_REGION_INFO_CAP_SPARSE_MMAP, 1);
- if (IS_ERR(header))
- return PTR_ERR(header);
+ sparse = kzalloc(size, GFP_KERNEL);
+ if (!sparse)
+ return -ENOMEM;
- sparse = container_of(header,
- struct vfio_region_info_cap_sparse_mmap, header);
sparse->nr_areas = nr_areas;
if (vdev->msix_offset & PAGE_MASK) {
@@ -594,26 +590,11 @@ static int msix_sparse_mmap_cap(struct vfio_pci_device *vdev,
i++;
}
- return 0;
-}
-
-static int region_type_cap(struct vfio_pci_device *vdev,
- struct vfio_info_cap *caps,
- unsigned int type, unsigned int subtype)
-{
- struct vfio_info_cap_header *header;
- struct vfio_region_info_cap_type *cap;
-
- header = vfio_info_cap_add(caps, sizeof(*cap),
- VFIO_REGION_INFO_CAP_TYPE, 1);
- if (IS_ERR(header))
- return PTR_ERR(header);
-
- cap = container_of(header, struct vfio_region_info_cap_type, header);
- cap->type = type;
- cap->subtype = subtype;
+ ret = vfio_info_add_capability(caps, VFIO_REGION_INFO_CAP_SPARSE_MMAP,
+ sparse);
+ kfree(sparse);
- return 0;
+ return ret;
}
int vfio_pci_register_dev_region(struct vfio_pci_device *vdev,
@@ -752,6 +733,9 @@ static long vfio_pci_ioctl(void *device_data,
break;
default:
+ {
+ struct vfio_region_info_cap_type cap_type;
+
if (info.index >=
VFIO_PCI_NUM_REGIONS + vdev->num_regions)
return -EINVAL;
@@ -762,11 +746,16 @@ static long vfio_pci_ioctl(void *device_data,
info.size = vdev->region[i].size;
info.flags = vdev->region[i].flags;
- ret = region_type_cap(vdev, &caps,
- vdev->region[i].type,
- vdev->region[i].subtype);
+ cap_type.type = vdev->region[i].type;
+ cap_type.subtype = vdev->region[i].subtype;
+
+ ret = vfio_info_add_capability(&caps,
+ VFIO_REGION_INFO_CAP_TYPE,
+ &cap_type);
if (ret)
return ret;
+
+ }
}
if (caps.size) {
--
2.7.0
Added blocking notifier to IOMMU TYPE1 driver to notify vendor drivers
about DMA_UNMAP.
Exported two APIs vfio_register_notifier() and vfio_unregister_notifier().
Notifier should be registered, if external user wants to use
vfio_pin_pages()/vfio_unpin_pages() APIs to pin/unpin pages.
Vendor driver should use VFIO_IOMMU_NOTIFY_DMA_UNMAP action to invalidate
mappings.
Signed-off-by: Kirti Wankhede <[email protected]>
Signed-off-by: Neo Jia <[email protected]>
Change-Id: I5910d0024d6be87f3e8d3e0ca0eaeaaa0b17f271
---
drivers/vfio/vfio.c | 73 +++++++++++++++++++++++++++++++++++++++++
drivers/vfio/vfio_iommu_type1.c | 63 +++++++++++++++++++++++++++++------
include/linux/vfio.h | 11 +++++++
3 files changed, 137 insertions(+), 10 deletions(-)
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 3bf8a01bf67b..fa121d983991 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -1902,6 +1902,79 @@ err_unpin_pages:
}
EXPORT_SYMBOL(vfio_unpin_pages);
+int vfio_register_notifier(struct device *dev, struct notifier_block *nb)
+{
+ struct vfio_container *container;
+ struct vfio_group *group;
+ struct vfio_iommu_driver *driver;
+ ssize_t ret;
+
+ if (!dev || !nb)
+ return -EINVAL;
+
+ group = vfio_group_get_from_dev(dev);
+ if (IS_ERR(group))
+ return PTR_ERR(group);
+
+ ret = vfio_group_add_container_user(group);
+ if (ret)
+ goto err_register_nb;
+
+ container = group->container;
+ down_read(&container->group_lock);
+
+ driver = container->iommu_driver;
+ if (likely(driver && driver->ops->register_notifier))
+ ret = driver->ops->register_notifier(container->iommu_data, nb);
+ else
+ ret = -ENOTTY;
+
+ up_read(&container->group_lock);
+ vfio_group_try_dissolve_container(group);
+
+err_register_nb:
+ vfio_group_put(group);
+ return ret;
+}
+EXPORT_SYMBOL(vfio_register_notifier);
+
+int vfio_unregister_notifier(struct device *dev, struct notifier_block *nb)
+{
+ struct vfio_container *container;
+ struct vfio_group *group;
+ struct vfio_iommu_driver *driver;
+ ssize_t ret;
+
+ if (!dev || !nb)
+ return -EINVAL;
+
+ group = vfio_group_get_from_dev(dev);
+ if (IS_ERR(group))
+ return PTR_ERR(group);
+
+ ret = vfio_group_add_container_user(group);
+ if (ret)
+ goto err_unregister_nb;
+
+ container = group->container;
+ down_read(&container->group_lock);
+
+ driver = container->iommu_driver;
+ if (likely(driver && driver->ops->unregister_notifier))
+ ret = driver->ops->unregister_notifier(container->iommu_data,
+ nb);
+ else
+ ret = -ENOTTY;
+
+ up_read(&container->group_lock);
+ vfio_group_try_dissolve_container(group);
+
+err_unregister_nb:
+ vfio_group_put(group);
+ return ret;
+}
+EXPORT_SYMBOL(vfio_unregister_notifier);
+
/**
* Module/class support
*/
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 0de7c20f66b1..c45a4822784e 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -38,6 +38,7 @@
#include <linux/workqueue.h>
#include <linux/pid_namespace.h>
#include <linux/mdev.h>
+#include <linux/notifier.h>
#define DRIVER_VERSION "0.2"
#define DRIVER_AUTHOR "Alex Williamson <[email protected]>"
@@ -60,6 +61,7 @@ struct vfio_iommu {
struct vfio_domain *external_domain; /* domain for external user */
struct mutex lock;
struct rb_root dma_list;
+ struct blocking_notifier_head notifier;
bool v2;
bool nesting;
};
@@ -571,7 +573,8 @@ static int vfio_iommu_type1_pin_pages(void *iommu_data,
mutex_lock(&iommu->lock);
- if (!iommu->external_domain) {
+ /* Fail if notifier list is empty */
+ if ((!iommu->external_domain) || (!iommu->notifier.head)) {
ret = -EINVAL;
goto pin_done;
}
@@ -854,7 +857,28 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
*/
if (dma->task->mm != current->mm)
break;
+
unmapped += dma->size;
+
+ if (iommu->external_domain && !RB_EMPTY_ROOT(&dma->pfn_list)) {
+ struct vfio_iommu_type1_dma_unmap nb_unmap;
+
+ nb_unmap.iova = dma->iova;
+ nb_unmap.size = dma->size;
+
+ /*
+ * Notifier callback would call vfio_unpin_pages() which
+ * would acquire iommu->lock. Release lock here and
+ * reacquire it again.
+ */
+ mutex_unlock(&iommu->lock);
+ blocking_notifier_call_chain(&iommu->notifier,
+ VFIO_IOMMU_NOTIFY_DMA_UNMAP,
+ &nb_unmap);
+ mutex_lock(&iommu->lock);
+ if (WARN_ON(!RB_EMPTY_ROOT(&dma->pfn_list)))
+ break;
+ }
vfio_remove_dma(iommu, dma);
}
@@ -1439,6 +1463,7 @@ static void *vfio_iommu_type1_open(unsigned long arg)
INIT_LIST_HEAD(&iommu->domain_list);
iommu->dma_list = RB_ROOT;
mutex_init(&iommu->lock);
+ BLOCKING_INIT_NOTIFIER_HEAD(&iommu->notifier);
return iommu;
}
@@ -1574,16 +1599,34 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
return -ENOTTY;
}
+static int vfio_iommu_type1_register_notifier(void *iommu_data,
+ struct notifier_block *nb)
+{
+ struct vfio_iommu *iommu = iommu_data;
+
+ return blocking_notifier_chain_register(&iommu->notifier, nb);
+}
+
+static int vfio_iommu_type1_unregister_notifier(void *iommu_data,
+ struct notifier_block *nb)
+{
+ struct vfio_iommu *iommu = iommu_data;
+
+ return blocking_notifier_chain_unregister(&iommu->notifier, nb);
+}
+
static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = {
- .name = "vfio-iommu-type1",
- .owner = THIS_MODULE,
- .open = vfio_iommu_type1_open,
- .release = vfio_iommu_type1_release,
- .ioctl = vfio_iommu_type1_ioctl,
- .attach_group = vfio_iommu_type1_attach_group,
- .detach_group = vfio_iommu_type1_detach_group,
- .pin_pages = vfio_iommu_type1_pin_pages,
- .unpin_pages = vfio_iommu_type1_unpin_pages,
+ .name = "vfio-iommu-type1",
+ .owner = THIS_MODULE,
+ .open = vfio_iommu_type1_open,
+ .release = vfio_iommu_type1_release,
+ .ioctl = vfio_iommu_type1_ioctl,
+ .attach_group = vfio_iommu_type1_attach_group,
+ .detach_group = vfio_iommu_type1_detach_group,
+ .pin_pages = vfio_iommu_type1_pin_pages,
+ .unpin_pages = vfio_iommu_type1_unpin_pages,
+ .register_notifier = vfio_iommu_type1_register_notifier,
+ .unregister_notifier = vfio_iommu_type1_unregister_notifier,
};
static int __init vfio_iommu_type1_init(void)
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index 420cdc928786..997442398c09 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -80,6 +80,10 @@ struct vfio_iommu_driver_ops {
unsigned long *phys_pfn);
int (*unpin_pages)(void *iommu_data,
unsigned long *user_pfn, int npage);
+ int (*register_notifier)(void *iommu_data,
+ struct notifier_block *nb);
+ int (*unregister_notifier)(void *iommu_data,
+ struct notifier_block *nb);
};
extern int vfio_register_iommu_driver(const struct vfio_iommu_driver_ops *ops);
@@ -139,6 +143,13 @@ extern int vfio_pin_pages(struct device *dev, unsigned long *user_pfn,
extern int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn,
int npage);
+#define VFIO_IOMMU_NOTIFY_DMA_UNMAP 1
+
+extern int vfio_register_notifier(struct device *dev,
+ struct notifier_block *nb);
+
+extern int vfio_unregister_notifier(struct device *dev,
+ struct notifier_block *nb);
/*
* IRQfd - generic
*/
--
2.7.0
Updated vfio_pci.c file to use vfio_set_irqs_validate_and_prepare()
Signed-off-by: Kirti Wankhede <[email protected]>
Signed-off-by: Neo Jia <[email protected]>
Change-Id: I9f3daba89d8dba5cb5b01a8cff420412f30686c7
---
drivers/vfio/pci/vfio_pci.c | 34 +++++++---------------------------
1 file changed, 7 insertions(+), 27 deletions(-)
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 03b5434f4d5b..dcd7c2a99618 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -818,45 +818,25 @@ static long vfio_pci_ioctl(void *device_data,
} else if (cmd == VFIO_DEVICE_SET_IRQS) {
struct vfio_irq_set hdr;
- size_t size;
u8 *data = NULL;
int max, ret = 0;
+ size_t data_size = 0;
minsz = offsetofend(struct vfio_irq_set, count);
if (copy_from_user(&hdr, (void __user *)arg, minsz))
return -EFAULT;
- if (hdr.argsz < minsz || hdr.index >= VFIO_PCI_NUM_IRQS ||
- hdr.count >= (U32_MAX - hdr.start) ||
- hdr.flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK |
- VFIO_IRQ_SET_ACTION_TYPE_MASK))
- return -EINVAL;
-
max = vfio_pci_get_irq_count(vdev, hdr.index);
- if (hdr.start >= max || hdr.start + hdr.count > max)
- return -EINVAL;
- switch (hdr.flags & VFIO_IRQ_SET_DATA_TYPE_MASK) {
- case VFIO_IRQ_SET_DATA_NONE:
- size = 0;
- break;
- case VFIO_IRQ_SET_DATA_BOOL:
- size = sizeof(uint8_t);
- break;
- case VFIO_IRQ_SET_DATA_EVENTFD:
- size = sizeof(int32_t);
- break;
- default:
- return -EINVAL;
- }
-
- if (size) {
- if (hdr.argsz - minsz < hdr.count * size)
- return -EINVAL;
+ ret = vfio_set_irqs_validate_and_prepare(&hdr, max,
+ VFIO_PCI_NUM_IRQS, &data_size);
+ if (ret)
+ return ret;
+ if (data_size) {
data = memdup_user((void __user *)(arg + minsz),
- hdr.count * size);
+ data_size);
if (IS_ERR(data))
return PTR_ERR(data);
}
--
2.7.0
Updated vfio_platform_common.c file to use
vfio_set_irqs_validate_and_prepare()
Signed-off-by: Kirti Wankhede <[email protected]>
Signed-off-by: Neo Jia <[email protected]>
Change-Id: Id87cd6b78ae901610b39bf957974baa6f40cd7b0
---
drivers/vfio/platform/vfio_platform_common.c | 31 +++++++---------------------
1 file changed, 8 insertions(+), 23 deletions(-)
diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
index d78142830754..4c27f4be3c3d 100644
--- a/drivers/vfio/platform/vfio_platform_common.c
+++ b/drivers/vfio/platform/vfio_platform_common.c
@@ -364,36 +364,21 @@ static long vfio_platform_ioctl(void *device_data,
struct vfio_irq_set hdr;
u8 *data = NULL;
int ret = 0;
+ size_t data_size = 0;
minsz = offsetofend(struct vfio_irq_set, count);
if (copy_from_user(&hdr, (void __user *)arg, minsz))
return -EFAULT;
- if (hdr.argsz < minsz)
- return -EINVAL;
-
- if (hdr.index >= vdev->num_irqs)
- return -EINVAL;
-
- if (hdr.flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK |
- VFIO_IRQ_SET_ACTION_TYPE_MASK))
- return -EINVAL;
-
- if (!(hdr.flags & VFIO_IRQ_SET_DATA_NONE)) {
- size_t size;
-
- if (hdr.flags & VFIO_IRQ_SET_DATA_BOOL)
- size = sizeof(uint8_t);
- else if (hdr.flags & VFIO_IRQ_SET_DATA_EVENTFD)
- size = sizeof(int32_t);
- else
- return -EINVAL;
-
- if (hdr.argsz - minsz < size)
- return -EINVAL;
+ ret = vfio_set_irqs_validate_and_prepare(&hdr, vdev->num_irqs,
+ vdev->num_irqs, &data_size);
+ if (ret)
+ return ret;
- data = memdup_user((void __user *)(arg + minsz), size);
+ if (data_size) {
+ data = memdup_user((void __user *)(arg + minsz),
+ data_size);
if (IS_ERR(data))
return PTR_ERR(data);
}
--
2.7.0
Add file Documentation/vfio-mediated-device.txt that include details of
mediated device framework.
Signed-off-by: Kirti Wankhede <[email protected]>
Signed-off-by: Neo Jia <[email protected]>
Change-Id: I137dd646442936090d92008b115908b7b2c7bc5d
---
Documentation/vfio-mediated-device.txt | 298 +++++++++++++++++++++++++++++++++
drivers/vfio/mdev/Kconfig | 1 +
2 files changed, 299 insertions(+)
create mode 100644 Documentation/vfio-mediated-device.txt
diff --git a/Documentation/vfio-mediated-device.txt b/Documentation/vfio-mediated-device.txt
new file mode 100644
index 000000000000..fe8bd2e7b26a
--- /dev/null
+++ b/Documentation/vfio-mediated-device.txt
@@ -0,0 +1,298 @@
+/*
+ * VFIO Mediated devices
+ *
+ * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
+ * Author: Neo Jia <[email protected]>
+ * Kirti Wankhede <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+Virtual Function I/O (VFIO) Mediated devices[1]
+===============================================
+
+The number of use cases for virtualizing DMA devices that do not have built-in
+SR_IOV capability is increasing. Previously, to virtualize such devices,
+developers had to create their own management interfaces and APIs, and then
+integrate them with user space software. To simplify integration with user space
+software, we have identified common requirements and a unified management
+interface for such devices.
+
+The VFIO driver framework provides unified APIs for direct device access. It is
+an IOMMU/device-agnostic framework for exposing direct device access to user
+space in a secure, IOMMU-protected environment. This framework is used for
+multiple devices, such as GPUs, network adapters, and compute accelerators. With
+direct device access, virtual machines or user space applications have direct
+access to the physical device. This framework is reused for mediated devices.
+
+The mediated core driver provides a common interface for mediated device
+management that can be used by drivers of different devices. This module
+provides a generic interface to perform these operations:
+
+* Create and destroy a mediated device
+* Add a mediated device to and remove it from a mediated bus driver
+* Add a mediated device to and remove it from an IOMMU group
+
+The mediated core driver also provides an interface to register a bus driver.
+For example, the mediated VFIO mdev driver is designed for mediated devices and
+supports VFIO APIs. The mediated bus driver adds a mediated device to and
+removes it from a VFIO group.
+
+The following high-level block diagram shows the main components and interfaces
+in the VFIO mediated driver framework. The diagram shows NVIDIA, Intel, and IBM
+devices as examples, as these devices are the first devices to use this module.
+
+ +---------------+
+ | |
+ | +-----------+ | mdev_register_driver() +--------------+
+ | | | +<------------------------+ |
+ | | mdev | | | |
+ | | bus | +------------------------>+ vfio_mdev.ko |<-> VFIO user
+ | | driver | | probe()/remove() | | APIs
+ | | | | +--------------+
+ | +-----------+ |
+ | |
+ | MDEV CORE |
+ | MODULE |
+ | mdev.ko |
+ | +-----------+ | mdev_register_device() +--------------+
+ | | | +<------------------------+ |
+ | | | | | nvidia.ko |<-> physical
+ | | | +------------------------>+ | device
+ | | | | callbacks +--------------+
+ | | Physical | |
+ | | device | | mdev_register_device() +--------------+
+ | | interface | |<------------------------+ |
+ | | | | | i915.ko |<-> physical
+ | | | +------------------------>+ | device
+ | | | | callbacks +--------------+
+ | | | |
+ | | | | mdev_register_device() +--------------+
+ | | | +<------------------------+ |
+ | | | | | ccw_device.ko|<-> physical
+ | | | +------------------------>+ | device
+ | | | | callbacks +--------------+
+ | +-----------+ |
+ +---------------+
+
+
+Registration Interfaces
+=======================
+
+The mediated core driver provides the following types of registration
+interfaces:
+
+* Registration interface for a mediated bus driver
+* Physical device driver interface
+
+Registration Interface for a Mediated Bus Driver
+------------------------------------------------
+
+The registration interface for a mediated bus driver provides the following
+structure to represent a mediated device's driver:
+
+ /*
+ * struct mdev_driver [2] - Mediated device's driver
+ * @name: driver name
+ * @probe: called when new device created
+ * @remove: called when device removed
+ * @driver: device driver structure
+ */
+ struct mdev_driver {
+ const char *name;
+ int (*probe) (struct device *dev);
+ void (*remove) (struct device *dev);
+ struct device_driver driver;
+ };
+
+A mediated bus driver for mdev should use this structure in the function calls
+to register and unregister itself with the core driver:
+
+* Register:
+
+ extern int mdev_register_driver(struct mdev_driver *drv,
+ struct module *owner);
+
+* Unregister:
+
+ extern void mdev_unregister_driver(struct mdev_driver *drv);
+
+The mediated bus driver is responsible for adding mediated devices to the VFIO
+group when devices are bound to the driver and removing mediated devices from
+the VFIO when devices are unbound from the driver.
+
+
+Physical Device Driver Interface
+--------------------------------
+
+The physical device driver interface provides the parent_ops[3] structure to
+define the APIs to manage work in the mediated core driver that is related to
+the physical device.
+
+The structures in the parent_ops structure are as follows:
+
+* dev_attr_groups: attributes of the parent device
+* mdev_attr_groups: attributes of the mediated device
+* supported_config: attributes to define supported configurations
+
+The functions in the parent_ops structure are as follows:
+
+* create: allocate basic resources in a driver for a mediated device
+* remove: free resources in a driver when a mediated device is destroyed
+
+The callbacks in the parent_ops structure are as follows:
+
+* open: open callback of mediated device
+* close: close callback of mediated device
+* ioctl: ioctl callback of mediated device
+* read : read emulation callback
+* write: write emulation callback
+* mmap: mmap emulation callback
+* notifier: notifier callback
+
+A driver should use the parent_ops structure in the function call to register
+itself with the mdev core driver:
+
+extern int mdev_register_device(struct device *dev,
+ const struct parent_ops *ops);
+
+However, the parent_ops structure is not required in the function call that a
+driver should use to unregister itself with the mdev core driver:
+
+extern void mdev_unregister_device(struct device *dev);
+
+
+Mediated Device Management Interface Through sysfs
+==================================================
+
+The management interface through sysfs enables user space software, such as
+libvirt, to query and configure mediated devices in a hardware-agnostic fashion.
+This management interface provides flexibility to the underlying physical
+device's driver to support features such as:
+
+* Mediated device hot plug
+* Multiple mediated devices in a single virtual machine
+* Multiple mediated devices from different physical devices
+
+Links in the mdev_bus Class Directory
+-------------------------------------
+The /sys/class/mdev_bus/ directory contains links to devices that are registered
+with the mdev core driver.
+
+Directories and files under the sysfs for Each Physical Device
+--------------------------------------------------------------
+
+|- [parent physical device]
+|--- Vendor-specific-attributes [optional]
+|--- [mdev_supported_types]
+| |--- [<type-id>]
+| | |--- create
+| | |--- name
+| | |--- available_instances
+| | |--- device_api
+| | |--- description
+| | |--- [devices]
+| |--- [<type-id>]
+| | |--- create
+| | |--- name
+| | |--- available_instances
+| | |--- device_api
+| | |--- description
+| | |--- [devices]
+| |--- [<type-id>]
+| |--- create
+| |--- name
+| |--- available_instances
+| |--- device_api
+| |--- description
+| |--- [devices]
+
+* [mdev_supported_types]
+
+ The list of currently supported mediated device types and their details.
+
+ [<type-id>], device_api, and available_instances are mandatory attributes
+ that should be provided by vendor driver.
+
+* [<type-id>]
+
+ The [<type-id>] name is created by adding the the device driver string as a
+ prefix to the string provided by the vendor driver. This format of this name
+ is as follows:
+
+ sprintf(buf, "%s-%s", dev_driver_string(parent->dev), group->name);
+
+* device_api
+
+ This attribute should show which device API is being created, for example,
+ "vfio-pci" for a PCI device.
+
+* available_instances
+
+ This attribute should show the number of devices of type <type-id> that can be
+ created.
+
+* [device]
+
+ This directory contains links to the devices of type <type-id> that have been
+created.
+
+* name
+
+ This attribute should show human readable name. This is optional attribute.
+
+* description
+
+ This attribute should show brief features/description of the type. This is
+ optional attribute.
+
+Directories and Files Under the sysfs for Each mdev Device
+----------------------------------------------------------
+
+|- [parent phy device]
+|--- [$MDEV_UUID]
+ |--- remove
+ |--- mdev_type {link to its type}
+ |--- vendor-specific-attributes [optional]
+
+* remove (write only)
+Writing '1' to the 'remove' file destroys the mdev device. The vendor driver can
+fail the remove() callback if that device is active and the vendor driver
+doesn't support hot unplug.
+
+Example:
+ # echo 1 > /sys/bus/mdev/devices/$mdev_UUID/remove
+
+Mediated device Hot plug:
+------------------------
+
+Mediated devices can be created and assigned at runtime. The procedure to hot
+plug a mediated device is the same as the procedure to hot plug a PCI device.
+
+Translation APIs for Mediated Devices
+=====================================
+
+The following APIs are provided for translating user pfn to host pfn in a VFIO
+driver:
+
+extern int vfio_pin_pages(struct device *dev, unsigned long *user_pfn,
+ int npage, int prot, unsigned long *phys_pfn);
+
+extern int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn,
+ int npage);
+
+These functions call back into the back-end IOMMU module by using the pin_pages
+and unpin_pages callbacks of the struct vfio_iommu_driver_ops[4]. Currently
+these callbacks are supported in the TYPE1 IOMMU module. To enable them for
+other IOMMU backend modules, such as PPC64 sPAPR module, they need to provide
+these two callback functions.
+
+References
+----------
+
+[1] See Documentation/vfio.txt for more information on VFIO.
+[2] struct mdev_driver in include/linux/mdev.h
+[3] struct parent_ops in include/linux/mdev.h
+[4] struct vfio_iommu_driver_ops in include/linux/vfio.h
diff --git a/drivers/vfio/mdev/Kconfig b/drivers/vfio/mdev/Kconfig
index 1aa0391d74f2..70fcc915c0a8 100644
--- a/drivers/vfio/mdev/Kconfig
+++ b/drivers/vfio/mdev/Kconfig
@@ -5,6 +5,7 @@ config VFIO_MDEV
default n
help
Provides a framework to virtualize devices.
+ See Documentation/vfio-mediated-device.txt for more details.
If you don't know what do here, say N.
--
2.7.0
Defined device API strings. Vendor driver using mediated device
framework should use corresponding string for device_api attribute.
Signed-off-by: Kirti Wankhede <[email protected]>
Signed-off-by: Neo Jia <[email protected]>
Change-Id: I42d29f475f02a7132ce13297fbf2b48f1da10995
---
include/uapi/linux/vfio.h | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 255a2113f53c..519eff362c1c 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -203,6 +203,16 @@ struct vfio_device_info {
};
#define VFIO_DEVICE_GET_INFO _IO(VFIO_TYPE, VFIO_BASE + 7)
+/*
+ * Vendor driver using Mediated device framework should provide device_api
+ * attribute in supported type attribute groups. Device API string should be one
+ * of the following corresponding to device flags in vfio_device_info structure.
+ */
+
+#define VFIO_DEVICE_API_PCI_STRING "vfio-pci"
+#define VFIO_DEVICE_API_PLATFORM_STRING "vfio-platform"
+#define VFIO_DEVICE_API_AMBA_STRING "vfio-amba"
+
/**
* VFIO_DEVICE_GET_REGION_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 8,
* struct vfio_region_info)
--
2.7.0
The Sample driver creates mdev device that simulates serial port over PCI
card.
Signed-off-by: Kirti Wankhede <[email protected]>
Signed-off-by: Neo Jia <[email protected]>
Change-Id: I857f8f12f8b275f2498dfe8c628a5cdc7193b1b2
---
Documentation/vfio-mediated-device.txt | 103 ++-
samples/vfio-mdev/Makefile | 13 +
samples/vfio-mdev/mtty.c | 1503 ++++++++++++++++++++++++++++++++
3 files changed, 1618 insertions(+), 1 deletion(-)
create mode 100644 samples/vfio-mdev/Makefile
create mode 100644 samples/vfio-mdev/mtty.c
diff --git a/Documentation/vfio-mediated-device.txt b/Documentation/vfio-mediated-device.txt
index fe8bd2e7b26a..0d2e402af7bb 100644
--- a/Documentation/vfio-mediated-device.txt
+++ b/Documentation/vfio-mediated-device.txt
@@ -289,8 +289,109 @@ these callbacks are supported in the TYPE1 IOMMU module. To enable them for
other IOMMU backend modules, such as PPC64 sPAPR module, they need to provide
these two callback functions.
+Using the Sample Code
+=====================
+
+mtty.c in samples/vfio-mdev/ directory is a sample driver program to
+demonstrate how to use the mediated device framework.
+
+The sample driver creates an mdev device that simulates a serial port over a PCI
+card.
+
+1. Build and load the mtty.ko module.
+
+ This step creates a dummy device, /sys/devices/virtual/mtty/mtty/
+
+ Files in this device directory in sysfs are similar to the following:
+
+ # tree /sys/devices/virtual/mtty/mtty/
+ /sys/devices/virtual/mtty/mtty/
+ |-- mdev_supported_types
+ | |-- mtty-1
+ | | |-- available_instances
+ | | |-- create
+ | | |-- device_api
+ | | |-- devices
+ | | `-- name
+ | `-- mtty-2
+ | |-- available_instances
+ | |-- create
+ | |-- device_api
+ | |-- devices
+ | `-- name
+ |-- mtty_dev
+ | `-- sample_mtty_dev
+ |-- power
+ | |-- autosuspend_delay_ms
+ | |-- control
+ | |-- runtime_active_time
+ | |-- runtime_status
+ | `-- runtime_suspended_time
+ |-- subsystem -> ../../../../class/mtty
+ `-- uevent
+
+2. Create a mediated device by using the dummy device that you created in the
+ previous step.
+
+ # echo "83b8f4f2-509f-382f-3c1e-e6bfe0fa1001" > \
+ /sys/devices/virtual/mtty/mtty/mdev_supported_types/mtty-2/create
+
+3. Add parameters to qemu-kvm.
+
+ -device vfio-pci,\
+ sysfsdev=/sys/bus/mdev/devices/83b8f4f2-509f-382f-3c1e-e6bfe0fa1001
+
+4. Boot the VM.
+
+ In the Linux guest VM, with no hardware on the host, the device appears
+ as follows:
+
+ # lspci -s 00:05.0 -xxvv
+ 00:05.0 Serial controller: Device 4348:3253 (rev 10) (prog-if 02 [16550])
+ Subsystem: Device 4348:3253
+ Physical Slot: 5
+ Control: I/O+ Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr-
+ Stepping- SERR- FastB2B- DisINTx-
+ Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=medium >TAbort-
+ <TAbort- <MAbort- >SERR- <PERR- INTx-
+ Interrupt: pin A routed to IRQ 10
+ Region 0: I/O ports at c150 [size=8]
+ Region 1: I/O ports at c158 [size=8]
+ Kernel driver in use: serial
+ 00: 48 43 53 32 01 00 00 02 10 02 00 07 00 00 00 00
+ 10: 51 c1 00 00 59 c1 00 00 00 00 00 00 00 00 00 00
+ 20: 00 00 00 00 00 00 00 00 00 00 00 00 48 43 53 32
+ 30: 00 00 00 00 00 00 00 00 00 00 00 00 0a 01 00 00
+
+ In the Linux guest VM, dmesg output for the device is as follows:
+
+ serial 0000:00:05.0: PCI INT A -> Link[LNKA] -> GSI 10 (level, high) -> IRQ
+10
+ 0000:00:05.0: ttyS1 at I/O 0xc150 (irq = 10) is a 16550A
+ 0000:00:05.0: ttyS2 at I/O 0xc158 (irq = 10) is a 16550A
+
+
+5. In the Linux guest VM, check the serial ports.
+
+ # setserial -g /dev/ttyS*
+ /dev/ttyS0, UART: 16550A, Port: 0x03f8, IRQ: 4
+ /dev/ttyS1, UART: 16550A, Port: 0xc150, IRQ: 10
+ /dev/ttyS2, UART: 16550A, Port: 0xc158, IRQ: 10
+
+6. Using a minicom or any terminal enulation program, open port /dev/ttyS1 or
+ /dev/ttyS2 with hardware flow control disabled.
+
+7. Type data on the minicom terminal or send data to the terminal emulation
+ program and read the data.
+
+ Data is loop backed from hosts mtty driver.
+
+8. Destroy the mediated device that you created.
+
+ # echo 1 > /sys/bus/mdev/devices/83b8f4f2-509f-382f-3c1e-e6bfe0fa1001/remove
+
References
-----------
+==========
[1] See Documentation/vfio.txt for more information on VFIO.
[2] struct mdev_driver in include/linux/mdev.h
diff --git a/samples/vfio-mdev/Makefile b/samples/vfio-mdev/Makefile
new file mode 100644
index 000000000000..a932edbe38eb
--- /dev/null
+++ b/samples/vfio-mdev/Makefile
@@ -0,0 +1,13 @@
+#
+# Makefile for mtty.c file
+#
+KERNEL_DIR:=/lib/modules/$(shell uname -r)/build
+
+obj-m:=mtty.o
+
+modules clean modules_install:
+ $(MAKE) -C $(KERNEL_DIR) SUBDIRS=$(PWD) $@
+
+default: modules
+
+module: modules
diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c
new file mode 100644
index 000000000000..6b633a4ea333
--- /dev/null
+++ b/samples/vfio-mdev/mtty.c
@@ -0,0 +1,1503 @@
+/*
+ * Mediated virtual PCI serial host device driver
+ *
+ * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
+ * Author: Neo Jia <[email protected]>
+ * Kirti Wankhede <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Sample driver that creates mdev device that simulates serial port over PCI
+ * card.
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/poll.h>
+#include <linux/slab.h>
+#include <linux/cdev.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+#include <linux/uuid.h>
+#include <linux/vfio.h>
+#include <linux/iommu.h>
+#include <linux/sysfs.h>
+#include <linux/ctype.h>
+#include <linux/file.h>
+#include <linux/mdev.h>
+#include <linux/pci.h>
+#include <linux/serial.h>
+#include <uapi/linux/serial_reg.h>
+#include <linux/eventfd.h>
+/*
+ * #defines
+ */
+
+#define VERSION_STRING "0.1"
+#define DRIVER_AUTHOR "NVIDIA Corporation"
+
+#define MTTY_CLASS_NAME "mtty"
+
+#define MTTY_NAME "mtty"
+
+#define MTTY_STRING_LEN 16
+
+#define MTTY_CONFIG_SPACE_SIZE 0xff
+#define MTTY_IO_BAR_SIZE 0x8
+#define MTTY_MMIO_BAR_SIZE 0x100000
+
+#define STORE_LE16(addr, val) (*(u16 *)addr = val)
+#define STORE_LE32(addr, val) (*(u32 *)addr = val)
+
+#define MAX_FIFO_SIZE 16
+
+#define CIRCULAR_BUF_INC_IDX(idx) (idx = (idx + 1) & (MAX_FIFO_SIZE - 1))
+
+#define MTTY_VFIO_PCI_OFFSET_SHIFT 40
+
+#define MTTY_VFIO_PCI_OFFSET_TO_INDEX(off) (off >> MTTY_VFIO_PCI_OFFSET_SHIFT)
+#define MTTY_VFIO_PCI_INDEX_TO_OFFSET(index) \
+ ((u64)(index) << MTTY_VFIO_PCI_OFFSET_SHIFT)
+#define MTTY_VFIO_PCI_OFFSET_MASK \
+ (((u64)(1) << MTTY_VFIO_PCI_OFFSET_SHIFT) - 1)
+#define MAX_MTTYS 24
+
+/*
+ * Global Structures
+ */
+
+struct mtty_dev {
+ dev_t vd_devt;
+ struct class *vd_class;
+ struct cdev vd_cdev;
+ struct idr vd_idr;
+ struct device dev;
+} mtty_dev;
+
+struct mdev_region_info {
+ u64 start;
+ u64 phys_start;
+ u32 size;
+ u64 vfio_offset;
+};
+
+#if defined(DEBUG_REGS)
+const char *wr_reg[] = {
+ "TX",
+ "IER",
+ "FCR",
+ "LCR",
+ "MCR",
+ "LSR",
+ "MSR",
+ "SCR"
+};
+
+const char *rd_reg[] = {
+ "RX",
+ "IER",
+ "IIR",
+ "LCR",
+ "MCR",
+ "LSR",
+ "MSR",
+ "SCR"
+};
+#endif
+
+/* loop back buffer */
+struct rxtx {
+ u8 fifo[MAX_FIFO_SIZE];
+ u8 head, tail;
+ u8 count;
+};
+
+struct serial_port {
+ u8 uart_reg[8]; /* 8 registers */
+ struct rxtx rxtx; /* loop back buffer */
+ bool dlab;
+ bool overrun;
+ u16 divisor;
+ u8 fcr; /* FIFO control register */
+ u8 max_fifo_size;
+ u8 intr_trigger_level; /* interrupt trigger level */
+};
+
+/* State of each mdev device */
+struct mdev_state {
+ int irq_fd;
+ struct eventfd_ctx *intx_evtfd;
+ struct eventfd_ctx *msi_evtfd;
+ int irq_index;
+ u8 *vconfig;
+ struct mutex ops_lock;
+ struct mdev_device *mdev;
+ struct mdev_region_info region_info[VFIO_PCI_NUM_REGIONS];
+ u32 bar_mask[VFIO_PCI_NUM_REGIONS];
+ struct list_head next;
+ struct serial_port s[2];
+ struct mutex rxtx_lock;
+ struct vfio_device_info dev_info;
+ int nr_ports;
+};
+
+struct mutex mdev_list_lock;
+struct list_head mdev_devices_list;
+
+static const struct file_operations vd_fops = {
+ .owner = THIS_MODULE,
+};
+
+/* function prototypes */
+
+static int mtty_trigger_interrupt(uuid_le uuid);
+
+/* Helper functions */
+static struct mdev_state *find_mdev_state_by_uuid(uuid_le uuid)
+{
+ struct mdev_state *mds;
+
+ list_for_each_entry(mds, &mdev_devices_list, next) {
+ if (uuid_le_cmp(mds->mdev->uuid, uuid) == 0)
+ return mds;
+ }
+
+ return NULL;
+}
+
+void dump_buffer(char *buf, uint32_t count)
+{
+#if defined(DEBUG)
+ int i;
+
+ pr_info("Buffer:\n");
+ for (i = 0; i < count; i++) {
+ pr_info("%2x ", *(buf + i));
+ if ((i + 1) % 16 == 0)
+ pr_info("\n");
+ }
+#endif
+}
+
+static void mtty_create_config_space(struct mdev_state *mdev_state)
+{
+ /* PCI dev ID */
+ STORE_LE32((u32 *) &mdev_state->vconfig[0x0], 0x32534348);
+
+ /* Control: I/O+, Mem-, BusMaster- */
+ STORE_LE16((u16 *) &mdev_state->vconfig[0x4], 0x0001);
+
+ /* Status: capabilities list absent */
+ STORE_LE16((u16 *) &mdev_state->vconfig[0x6], 0x0200);
+
+ /* Rev ID */
+ mdev_state->vconfig[0x8] = 0x10;
+
+ /* programming interface class : 16550-compatible serial controller */
+ mdev_state->vconfig[0x9] = 0x02;
+
+ /* Sub class : 00 */
+ mdev_state->vconfig[0xa] = 0x00;
+
+ /* Base class : Simple Communication controllers */
+ mdev_state->vconfig[0xb] = 0x07;
+
+ /* base address registers */
+ /* BAR0: IO space */
+ STORE_LE32((u32 *) &mdev_state->vconfig[0x10], 0x000001);
+ mdev_state->bar_mask[0] = ~(MTTY_IO_BAR_SIZE) + 1;
+
+ if (mdev_state->nr_ports == 2) {
+ /* BAR1: IO space */
+ STORE_LE32((u32 *) &mdev_state->vconfig[0x14], 0x000001);
+ mdev_state->bar_mask[1] = ~(MTTY_IO_BAR_SIZE) + 1;
+ }
+
+ /* Subsystem ID */
+ STORE_LE32((u32 *) &mdev_state->vconfig[0x2c], 0x32534348);
+
+ mdev_state->vconfig[0x34] = 0x00; /* Cap Ptr */
+ mdev_state->vconfig[0x3d] = 0x01; /* interrupt pin (INTA#) */
+
+ /* Vendor specific data */
+ mdev_state->vconfig[0x40] = 0x23;
+ mdev_state->vconfig[0x43] = 0x80;
+ mdev_state->vconfig[0x44] = 0x23;
+ mdev_state->vconfig[0x48] = 0x23;
+ mdev_state->vconfig[0x4c] = 0x23;
+
+ mdev_state->vconfig[0x60] = 0x50;
+ mdev_state->vconfig[0x61] = 0x43;
+ mdev_state->vconfig[0x62] = 0x49;
+ mdev_state->vconfig[0x63] = 0x20;
+ mdev_state->vconfig[0x64] = 0x53;
+ mdev_state->vconfig[0x65] = 0x65;
+ mdev_state->vconfig[0x66] = 0x72;
+ mdev_state->vconfig[0x67] = 0x69;
+ mdev_state->vconfig[0x68] = 0x61;
+ mdev_state->vconfig[0x69] = 0x6c;
+ mdev_state->vconfig[0x6a] = 0x2f;
+ mdev_state->vconfig[0x6b] = 0x55;
+ mdev_state->vconfig[0x6c] = 0x41;
+ mdev_state->vconfig[0x6d] = 0x52;
+ mdev_state->vconfig[0x6e] = 0x54;
+}
+
+static void handle_pci_cfg_write(struct mdev_state *mdev_state, u16 offset,
+ char *buf, u32 count)
+{
+ u32 cfg_addr, bar_mask, bar_index = 0;
+
+ switch (offset) {
+ case 0x04: /* device control */
+ case 0x06: /* device status */
+ /* do nothing */
+ break;
+ case 0x3c: /* interrupt line */
+ mdev_state->vconfig[0x3c] = buf[0];
+ break;
+ case 0x3d:
+ /*
+ * Interrupt Pin is hardwired to INTA.
+ * This field is write protected by hardware
+ */
+ break;
+ case 0x10: /* BAR0 */
+ case 0x14: /* BAR1 */
+ if (offset == 0x10)
+ bar_index = 0;
+ else if (offset == 0x14)
+ bar_index = 1;
+
+ if ((mdev_state->nr_ports == 1) && (bar_index == 1)) {
+ STORE_LE32(&mdev_state->vconfig[offset], 0);
+ break;
+ }
+
+ cfg_addr = *(u32 *)buf;
+ pr_info("BAR%d addr 0x%x\n", bar_index, cfg_addr);
+
+ if (cfg_addr == 0xffffffff) {
+ bar_mask = mdev_state->bar_mask[bar_index];
+ cfg_addr = (cfg_addr & bar_mask);
+ }
+
+ cfg_addr |= (mdev_state->vconfig[offset] & 0x3ul);
+ STORE_LE32(&mdev_state->vconfig[offset], cfg_addr);
+ break;
+ case 0x18: /* BAR2 */
+ case 0x1c: /* BAR3 */
+ case 0x20: /* BAR4 */
+ STORE_LE32(&mdev_state->vconfig[offset], 0);
+ break;
+ default:
+ pr_info("PCI config write @0x%x of %d bytes not handled\n",
+ offset, count);
+ break;
+ }
+}
+
+static void handle_bar_write(unsigned int index, struct mdev_state *mdev_state,
+ u16 offset, char *buf, u32 count)
+{
+ u8 data = *buf;
+
+ /* Handle data written by guest */
+ switch (offset) {
+ case UART_TX:
+ /* if DLAB set, data is LSB of divisor */
+ if (mdev_state->s[index].dlab) {
+ mdev_state->s[index].divisor |= data;
+ break;
+ }
+
+ mutex_lock(&mdev_state->rxtx_lock);
+
+ /* save in TX buffer */
+ if (mdev_state->s[index].rxtx.count <
+ mdev_state->s[index].max_fifo_size) {
+ mdev_state->s[index].rxtx.fifo[
+ mdev_state->s[index].rxtx.head] = data;
+ mdev_state->s[index].rxtx.count++;
+ CIRCULAR_BUF_INC_IDX(mdev_state->s[index].rxtx.head);
+ mdev_state->s[index].overrun = false;
+
+ /*
+ * Trigger interrupt if receive data interrupt is
+ * enabled and fifo reached trigger level
+ */
+ if ((mdev_state->s[index].uart_reg[UART_IER] &
+ UART_IER_RDI) &&
+ (mdev_state->s[index].rxtx.count ==
+ mdev_state->s[index].intr_trigger_level)) {
+ /* trigger interrupt */
+#if defined(DEBUG_INTR)
+ pr_err("Serial port %d: Fifo level trigger\n",
+ index);
+#endif
+ mtty_trigger_interrupt(mdev_state->mdev->uuid);
+ }
+ } else {
+#if defined(DEBUG_INTR)
+ pr_err("Serial port %d: Buffer Overflow\n", index);
+#endif
+ mdev_state->s[index].overrun = true;
+
+ /*
+ * Trigger interrupt if receiver line status interrupt
+ * is enabled
+ */
+ if (mdev_state->s[index].uart_reg[UART_IER] &
+ UART_IER_RLSI)
+ mtty_trigger_interrupt(mdev_state->mdev->uuid);
+ }
+ mutex_unlock(&mdev_state->rxtx_lock);
+ break;
+
+ case UART_IER:
+ /* if DLAB set, data is MSB of divisor */
+ if (mdev_state->s[index].dlab)
+ mdev_state->s[index].divisor |= (u16)data << 8;
+ else {
+ mdev_state->s[index].uart_reg[offset] = data;
+ mutex_lock(&mdev_state->rxtx_lock);
+ if ((data & UART_IER_THRI) &&
+ (mdev_state->s[index].rxtx.head ==
+ mdev_state->s[index].rxtx.tail)) {
+#if defined(DEBUG_INTR)
+ pr_err("Serial port %d: IER_THRI write\n",
+ index);
+#endif
+ mtty_trigger_interrupt(mdev_state->mdev->uuid);
+ }
+
+ mutex_unlock(&mdev_state->rxtx_lock);
+ }
+
+ break;
+
+ case UART_FCR:
+ mdev_state->s[index].fcr = data;
+
+ mutex_lock(&mdev_state->rxtx_lock);
+ if (data & (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT)) {
+ /* clear loop back FIFO */
+ mdev_state->s[index].rxtx.count = 0;
+ mdev_state->s[index].rxtx.head = 0;
+ mdev_state->s[index].rxtx.tail = 0;
+ }
+ mutex_unlock(&mdev_state->rxtx_lock);
+
+ switch (data & UART_FCR_TRIGGER_MASK) {
+ case UART_FCR_TRIGGER_1:
+ mdev_state->s[index].intr_trigger_level = 1;
+ break;
+
+ case UART_FCR_TRIGGER_4:
+ mdev_state->s[index].intr_trigger_level = 4;
+ break;
+
+ case UART_FCR_TRIGGER_8:
+ mdev_state->s[index].intr_trigger_level = 8;
+ break;
+
+ case UART_FCR_TRIGGER_14:
+ mdev_state->s[index].intr_trigger_level = 14;
+ break;
+ }
+
+ /*
+ * Set trigger level to 1 otherwise or implement timer with
+ * timeout of 4 characters and on expiring that timer set
+ * Recevice data timeout in IIR register
+ */
+ mdev_state->s[index].intr_trigger_level = 1;
+ if (data & UART_FCR_ENABLE_FIFO)
+ mdev_state->s[index].max_fifo_size = MAX_FIFO_SIZE;
+ else {
+ mdev_state->s[index].max_fifo_size = 1;
+ mdev_state->s[index].intr_trigger_level = 1;
+ }
+
+ break;
+
+ case UART_LCR:
+ if (data & UART_LCR_DLAB) {
+ mdev_state->s[index].dlab = true;
+ mdev_state->s[index].divisor = 0;
+ } else
+ mdev_state->s[index].dlab = false;
+
+ mdev_state->s[index].uart_reg[offset] = data;
+ break;
+
+ case UART_MCR:
+ mdev_state->s[index].uart_reg[offset] = data;
+
+ if ((mdev_state->s[index].uart_reg[UART_IER] & UART_IER_MSI) &&
+ (data & UART_MCR_OUT2)) {
+#if defined(DEBUG_INTR)
+ pr_err("Serial port %d: MCR_OUT2 write\n", index);
+#endif
+ mtty_trigger_interrupt(mdev_state->mdev->uuid);
+ }
+
+ if ((mdev_state->s[index].uart_reg[UART_IER] & UART_IER_MSI) &&
+ (data & (UART_MCR_RTS | UART_MCR_DTR))) {
+#if defined(DEBUG_INTR)
+ pr_err("Serial port %d: MCR RTS/DTR write\n", index);
+#endif
+ mtty_trigger_interrupt(mdev_state->mdev->uuid);
+ }
+ break;
+
+ case UART_LSR:
+ case UART_MSR:
+ /* do nothing */
+ break;
+
+ case UART_SCR:
+ mdev_state->s[index].uart_reg[offset] = data;
+ break;
+
+ default:
+ break;
+ }
+}
+
+static void handle_bar_read(unsigned int index, struct mdev_state *mdev_state,
+ u16 offset, char *buf, u32 count)
+{
+ /* Handle read requests by guest */
+ switch (offset) {
+ case UART_RX:
+ /* if DLAB set, data is LSB of divisor */
+ if (mdev_state->s[index].dlab) {
+ *buf = (u8)mdev_state->s[index].divisor;
+ break;
+ }
+
+ mutex_lock(&mdev_state->rxtx_lock);
+ /* return data in tx buffer */
+ if (mdev_state->s[index].rxtx.head !=
+ mdev_state->s[index].rxtx.tail) {
+ *buf = mdev_state->s[index].rxtx.fifo[
+ mdev_state->s[index].rxtx.tail];
+ mdev_state->s[index].rxtx.count--;
+ CIRCULAR_BUF_INC_IDX(mdev_state->s[index].rxtx.tail);
+ }
+
+ if (mdev_state->s[index].rxtx.head ==
+ mdev_state->s[index].rxtx.tail) {
+ /*
+ * Trigger interrupt if tx buffer empty interrupt is
+ * enabled and fifo is empty
+ */
+#if defined(DEBUG_INTR)
+ pr_err("Serial port %d: Buffer Empty\n", index);
+#endif
+ if (mdev_state->s[index].uart_reg[UART_IER] &
+ UART_IER_THRI)
+ mtty_trigger_interrupt(mdev_state->mdev->uuid);
+ }
+ mutex_unlock(&mdev_state->rxtx_lock);
+
+ break;
+
+ case UART_IER:
+ if (mdev_state->s[index].dlab) {
+ *buf = (u8)(mdev_state->s[index].divisor >> 8);
+ break;
+ }
+ *buf = mdev_state->s[index].uart_reg[offset] & 0x0f;
+ break;
+
+ case UART_IIR:
+ {
+ u8 ier = mdev_state->s[index].uart_reg[UART_IER];
+ *buf = 0;
+
+ mutex_lock(&mdev_state->rxtx_lock);
+ /* Interrupt priority 1: Parity, overrun, framing or break */
+ if ((ier & UART_IER_RLSI) && mdev_state->s[index].overrun)
+ *buf |= UART_IIR_RLSI;
+
+ /* Interrupt priority 2: Fifo trigger level reached */
+ if ((ier & UART_IER_RDI) &&
+ (mdev_state->s[index].rxtx.count ==
+ mdev_state->s[index].intr_trigger_level))
+ *buf |= UART_IIR_RDI;
+
+ /* Interrupt priotiry 3: transmitter holding register empty */
+ if ((ier & UART_IER_THRI) &&
+ (mdev_state->s[index].rxtx.head ==
+ mdev_state->s[index].rxtx.tail))
+ *buf |= UART_IIR_THRI;
+
+ /* Interrupt priotiry 4: Modem status: CTS, DSR, RI or DCD */
+ if ((ier & UART_IER_MSI) &&
+ (mdev_state->s[index].uart_reg[UART_MCR] &
+ (UART_MCR_RTS | UART_MCR_DTR)))
+ *buf |= UART_IIR_MSI;
+
+ /* bit0: 0=> interrupt pending, 1=> no interrupt is pending */
+ if (*buf == 0)
+ *buf = UART_IIR_NO_INT;
+
+ /* set bit 6 & 7 to be 16550 compatible */
+ *buf |= 0xC0;
+ mutex_unlock(&mdev_state->rxtx_lock);
+ }
+ break;
+
+ case UART_LCR:
+ case UART_MCR:
+ *buf = mdev_state->s[index].uart_reg[offset];
+ break;
+
+ case UART_LSR:
+ {
+ u8 lsr = 0;
+
+ mutex_lock(&mdev_state->rxtx_lock);
+ /* atleast one char in FIFO */
+ if (mdev_state->s[index].rxtx.head !=
+ mdev_state->s[index].rxtx.tail)
+ lsr |= UART_LSR_DR;
+
+ /* if FIFO overrun */
+ if (mdev_state->s[index].overrun)
+ lsr |= UART_LSR_OE;
+
+ /* transmit FIFO empty and tramsitter empty */
+ if (mdev_state->s[index].rxtx.head ==
+ mdev_state->s[index].rxtx.tail)
+ lsr |= UART_LSR_TEMT | UART_LSR_THRE;
+
+ mutex_unlock(&mdev_state->rxtx_lock);
+ *buf = lsr;
+ break;
+ }
+ case UART_MSR:
+ *buf = UART_MSR_DSR | UART_MSR_DDSR | UART_MSR_DCD;
+
+ mutex_lock(&mdev_state->rxtx_lock);
+ /* if AFE is 1 and FIFO have space, set CTS bit */
+ if (mdev_state->s[index].uart_reg[UART_MCR] &
+ UART_MCR_AFE) {
+ if (mdev_state->s[index].rxtx.count <
+ mdev_state->s[index].max_fifo_size)
+ *buf |= UART_MSR_CTS | UART_MSR_DCTS;
+ } else
+ *buf |= UART_MSR_CTS | UART_MSR_DCTS;
+ mutex_unlock(&mdev_state->rxtx_lock);
+
+ break;
+
+ case UART_SCR:
+ *buf = mdev_state->s[index].uart_reg[offset];
+ break;
+
+ default:
+ break;
+ }
+}
+
+static void mdev_read_base(struct mdev_state *mdev_state)
+{
+ int index, pos;
+ u32 start_lo, start_hi;
+ u32 mem_type;
+
+ pos = PCI_BASE_ADDRESS_0;
+
+ for (index = 0; index <= VFIO_PCI_BAR5_REGION_INDEX; index++) {
+
+ if (!mdev_state->region_info[index].size)
+ continue;
+
+ start_lo = (*(u32 *)(mdev_state->vconfig + pos)) &
+ PCI_BASE_ADDRESS_MEM_MASK;
+ mem_type = (*(u32 *)(mdev_state->vconfig + pos)) &
+ PCI_BASE_ADDRESS_MEM_TYPE_MASK;
+
+ switch (mem_type) {
+ case PCI_BASE_ADDRESS_MEM_TYPE_64:
+ start_hi = (*(u32 *)(mdev_state->vconfig + pos + 4));
+ pos += 4;
+ break;
+ case PCI_BASE_ADDRESS_MEM_TYPE_32:
+ case PCI_BASE_ADDRESS_MEM_TYPE_1M:
+ /* 1M mem BAR treated as 32-bit BAR */
+ default:
+ /* mem unknown type treated as 32-bit BAR */
+ start_hi = 0;
+ break;
+ }
+ pos += 4;
+ mdev_state->region_info[index].start = ((u64)start_hi << 32) |
+ start_lo;
+ }
+}
+
+static ssize_t mdev_access(struct mdev_device *mdev, char *buf, size_t count,
+ loff_t pos, bool is_write)
+{
+ struct mdev_state *mdev_state;
+ unsigned int index;
+ loff_t offset;
+ int ret = 0;
+
+ if (!mdev || !buf)
+ return -EINVAL;
+
+ mdev_state = mdev_get_drvdata(mdev);
+ if (!mdev_state) {
+ pr_err("%s mdev_state not found\n", __func__);
+ return -EINVAL;
+ }
+
+ mutex_lock(&mdev_state->ops_lock);
+
+ index = MTTY_VFIO_PCI_OFFSET_TO_INDEX(pos);
+ offset = pos & MTTY_VFIO_PCI_OFFSET_MASK;
+ switch (index) {
+ case VFIO_PCI_CONFIG_REGION_INDEX:
+
+#if defined(DEBUG)
+ pr_info("%s: PCI config space %s at offset 0x%llx\n",
+ __func__, is_write ? "write" : "read", offset);
+#endif
+ if (is_write) {
+ dump_buffer(buf, count);
+ handle_pci_cfg_write(mdev_state, offset, buf, count);
+ } else {
+ memcpy(buf, (mdev_state->vconfig + offset), count);
+ dump_buffer(buf, count);
+ }
+
+ break;
+
+ case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
+ if (!mdev_state->region_info[index].start)
+ mdev_read_base(mdev_state);
+
+ if (is_write) {
+ dump_buffer(buf, count);
+
+#if defined(DEBUG_REGS)
+ pr_info("%s: BAR%d WR @0x%llx %s val:0x%02x dlab:%d\n",
+ __func__, index, offset, wr_reg[offset],
+ (u8)*buf, mdev_state->s[index].dlab);
+#endif
+ handle_bar_write(index, mdev_state, offset, buf, count);
+ } else {
+ handle_bar_read(index, mdev_state, offset, buf, count);
+ dump_buffer(buf, count);
+
+#if defined(DEBUG_REGS)
+ pr_info("%s: BAR%d RD @0x%llx %s val:0x%02x dlab:%d\n",
+ __func__, index, offset, rd_reg[offset],
+ (u8)*buf, mdev_state->s[index].dlab);
+#endif
+ }
+ break;
+
+ default:
+ ret = -1;
+ goto accessfailed;
+ }
+
+ ret = count;
+
+
+accessfailed:
+ mutex_unlock(&mdev_state->ops_lock);
+
+ return ret;
+}
+
+int mtty_create(struct kobject *kobj, struct mdev_device *mdev)
+{
+ struct mdev_state *mdev_state;
+ char name[MTTY_STRING_LEN];
+ int nr_ports = 0, i;
+
+ if (!mdev)
+ return -EINVAL;
+
+ for (i = 0; i < 2; i++) {
+ snprintf(name, MTTY_STRING_LEN, "%s-%d",
+ dev_driver_string(mdev->parent->dev), i + 1);
+ if (!strcmp(kobj->name, name)) {
+ nr_ports = i + 1;
+ break;
+ }
+ }
+
+ if (!nr_ports)
+ return -EINVAL;
+
+ mdev_state = kzalloc(sizeof(struct mdev_state), GFP_KERNEL);
+ if (mdev_state == NULL)
+ return -ENOMEM;
+
+ mdev_state->nr_ports = nr_ports;
+ mdev_state->irq_index = -1;
+ mdev_state->s[0].max_fifo_size = MAX_FIFO_SIZE;
+ mdev_state->s[1].max_fifo_size = MAX_FIFO_SIZE;
+ mutex_init(&mdev_state->rxtx_lock);
+ mdev_state->vconfig = kzalloc(MTTY_CONFIG_SPACE_SIZE, GFP_KERNEL);
+
+ if (mdev_state->vconfig == NULL) {
+ kfree(mdev_state);
+ return -ENOMEM;
+ }
+
+ mutex_init(&mdev_state->ops_lock);
+ mdev_state->mdev = mdev;
+ mdev_set_drvdata(mdev, mdev_state);
+
+ mtty_create_config_space(mdev_state);
+
+ mutex_lock(&mdev_list_lock);
+ list_add(&mdev_state->next, &mdev_devices_list);
+ mutex_unlock(&mdev_list_lock);
+
+ return 0;
+}
+
+int mtty_remove(struct mdev_device *mdev)
+{
+ struct mdev_state *mds, *tmp_mds;
+ struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
+ int ret = -EINVAL;
+
+ mutex_lock(&mdev_list_lock);
+ list_for_each_entry_safe(mds, tmp_mds, &mdev_devices_list, next) {
+ if (mdev_state == mds) {
+ list_del(&mdev_state->next);
+ mdev_set_drvdata(mdev, NULL);
+ kfree(mdev_state->vconfig);
+ kfree(mdev_state);
+ ret = 0;
+ break;
+ }
+ }
+ mutex_unlock(&mdev_list_lock);
+
+ return ret;
+}
+
+int mtty_reset(struct mdev_device *mdev)
+{
+ struct mdev_state *mdev_state;
+
+ if (!mdev)
+ return -EINVAL;
+
+ mdev_state = mdev_get_drvdata(mdev);
+ if (!mdev_state)
+ return -EINVAL;
+
+ pr_info("%s: called\n", __func__);
+
+ return 0;
+}
+
+ssize_t mtty_read(struct mdev_device *mdev, char __user *buf, size_t count,
+ loff_t *ppos)
+{
+ unsigned int done = 0;
+ int ret;
+
+ while (count) {
+ size_t filled;
+
+ if (count >= 4 && !(*ppos % 4)) {
+ u32 val;
+
+ ret = mdev_access(mdev, (char *)&val, sizeof(val),
+ *ppos, false);
+ if (ret <= 0)
+ goto read_err;
+
+ if (copy_to_user(buf, &val, sizeof(val)))
+ goto read_err;
+
+ filled = 4;
+ } else if (count >= 2 && !(*ppos % 2)) {
+ u16 val;
+
+ ret = mdev_access(mdev, (char *)&val, sizeof(val),
+ *ppos, false);
+ if (ret <= 0)
+ goto read_err;
+
+ if (copy_to_user(buf, &val, sizeof(val)))
+ goto read_err;
+
+ filled = 2;
+ } else {
+ u8 val;
+
+ ret = mdev_access(mdev, (char *)&val, sizeof(val),
+ *ppos, false);
+ if (ret <= 0)
+ goto read_err;
+
+ if (copy_to_user(buf, &val, sizeof(val)))
+ goto read_err;
+
+ filled = 1;
+ }
+
+ count -= filled;
+ done += filled;
+ *ppos += filled;
+ buf += filled;
+ }
+
+ return done;
+
+read_err:
+ return -EFAULT;
+}
+
+ssize_t mtty_write(struct mdev_device *mdev, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ unsigned int done = 0;
+ int ret;
+
+ while (count) {
+ size_t filled;
+
+ if (count >= 4 && !(*ppos % 4)) {
+ u32 val;
+
+ if (copy_from_user(&val, buf, sizeof(val)))
+ goto write_err;
+
+ ret = mdev_access(mdev, (char *)&val, sizeof(val),
+ *ppos, true);
+ if (ret <= 0)
+ goto write_err;
+
+ filled = 4;
+ } else if (count >= 2 && !(*ppos % 2)) {
+ u16 val;
+
+ if (copy_from_user(&val, buf, sizeof(val)))
+ goto write_err;
+
+ ret = mdev_access(mdev, (char *)&val, sizeof(val),
+ *ppos, true);
+ if (ret <= 0)
+ goto write_err;
+
+ filled = 2;
+ } else {
+ u8 val;
+
+ if (copy_from_user(&val, buf, sizeof(val)))
+ goto write_err;
+
+ ret = mdev_access(mdev, (char *)&val, sizeof(val),
+ *ppos, true);
+ if (ret <= 0)
+ goto write_err;
+
+ filled = 1;
+ }
+ count -= filled;
+ done += filled;
+ *ppos += filled;
+ buf += filled;
+ }
+
+ return done;
+write_err:
+ return -EFAULT;
+}
+
+static int mtty_set_irqs(struct mdev_device *mdev, uint32_t flags,
+ unsigned int index, unsigned int start,
+ unsigned int count, void *data)
+{
+ int ret = 0;
+ struct mdev_state *mdev_state;
+
+ if (!mdev)
+ return -EINVAL;
+
+ mdev_state = mdev_get_drvdata(mdev);
+ if (!mdev_state)
+ return -EINVAL;
+
+ mutex_lock(&mdev_state->ops_lock);
+ switch (index) {
+ case VFIO_PCI_INTX_IRQ_INDEX:
+ switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
+ case VFIO_IRQ_SET_ACTION_MASK:
+ case VFIO_IRQ_SET_ACTION_UNMASK:
+ break;
+ case VFIO_IRQ_SET_ACTION_TRIGGER:
+ {
+ if (flags & VFIO_IRQ_SET_DATA_NONE) {
+ pr_info("%s: disable INTx\n", __func__);
+ if (mdev_state->intx_evtfd)
+ eventfd_ctx_put(mdev_state->intx_evtfd);
+ break;
+ }
+
+ if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
+ int fd = *(int *)data;
+
+ if (fd > 0) {
+ struct eventfd_ctx *evt;
+
+ evt = eventfd_ctx_fdget(fd);
+ if (IS_ERR(evt)) {
+ ret = PTR_ERR(evt);
+ break;
+ }
+ mdev_state->intx_evtfd = evt;
+ mdev_state->irq_fd = fd;
+ mdev_state->irq_index = index;
+ break;
+ }
+ }
+ break;
+ }
+ }
+ break;
+ case VFIO_PCI_MSI_IRQ_INDEX:
+ switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
+ case VFIO_IRQ_SET_ACTION_MASK:
+ case VFIO_IRQ_SET_ACTION_UNMASK:
+ break;
+ case VFIO_IRQ_SET_ACTION_TRIGGER:
+ if (flags & VFIO_IRQ_SET_DATA_NONE) {
+ if (mdev_state->msi_evtfd)
+ eventfd_ctx_put(mdev_state->msi_evtfd);
+ pr_info("%s: disable MSI\n", __func__);
+ mdev_state->irq_index = VFIO_PCI_INTX_IRQ_INDEX;
+ break;
+ }
+ if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
+ int fd = *(int *)data;
+ struct eventfd_ctx *evt;
+
+ if (fd <= 0)
+ break;
+
+ if (mdev_state->msi_evtfd)
+ break;
+
+ evt = eventfd_ctx_fdget(fd);
+ if (IS_ERR(evt)) {
+ ret = PTR_ERR(evt);
+ break;
+ }
+ mdev_state->msi_evtfd = evt;
+ mdev_state->irq_fd = fd;
+ mdev_state->irq_index = index;
+ }
+ break;
+ }
+ break;
+ case VFIO_PCI_MSIX_IRQ_INDEX:
+ pr_info("%s: MSIX_IRQ\n", __func__);
+ break;
+ case VFIO_PCI_ERR_IRQ_INDEX:
+ pr_info("%s: ERR_IRQ\n", __func__);
+ break;
+ case VFIO_PCI_REQ_IRQ_INDEX:
+ pr_info("%s: REQ_IRQ\n", __func__);
+ break;
+ }
+
+ mutex_unlock(&mdev_state->ops_lock);
+ return ret;
+}
+
+static int mtty_trigger_interrupt(uuid_le uuid)
+{
+ int ret = -1;
+ struct mdev_state *mdev_state;
+
+ mdev_state = find_mdev_state_by_uuid(uuid);
+
+ if (!mdev_state) {
+ pr_info("%s: mdev not found\n", __func__);
+ return -EINVAL;
+ }
+
+ if ((mdev_state->irq_index == VFIO_PCI_MSI_IRQ_INDEX) &&
+ (!mdev_state->msi_evtfd))
+ return -EINVAL;
+ else if ((mdev_state->irq_index == VFIO_PCI_INTX_IRQ_INDEX) &&
+ (!mdev_state->intx_evtfd)) {
+ pr_info("%s: Intr eventfd not found\n", __func__);
+ return -EINVAL;
+ }
+
+ if (mdev_state->irq_index == VFIO_PCI_MSI_IRQ_INDEX)
+ ret = eventfd_signal(mdev_state->msi_evtfd, 1);
+ else
+ ret = eventfd_signal(mdev_state->intx_evtfd, 1);
+
+#if defined(DEBUG_INTR)
+ pr_info("Intx triggered\n");
+#endif
+ if (ret != 1)
+ pr_err("%s: eventfd signal failed (%d)\n", __func__, ret);
+
+ return ret;
+}
+
+int mtty_get_region_info(struct mdev_device *mdev,
+ struct vfio_region_info *region_info,
+ u16 *cap_type_id, void **cap_type)
+{
+ unsigned int size = 0;
+ struct mdev_state *mdev_state;
+ int bar_index;
+
+ if (!mdev)
+ return -EINVAL;
+
+ mdev_state = mdev_get_drvdata(mdev);
+ if (!mdev_state)
+ return -EINVAL;
+
+ mutex_lock(&mdev_state->ops_lock);
+ bar_index = region_info->index;
+
+ switch (bar_index) {
+ case VFIO_PCI_CONFIG_REGION_INDEX:
+ size = MTTY_CONFIG_SPACE_SIZE;
+ break;
+ case VFIO_PCI_BAR0_REGION_INDEX:
+ size = MTTY_IO_BAR_SIZE;
+ break;
+ case VFIO_PCI_BAR1_REGION_INDEX:
+ if (mdev_state->nr_ports == 2)
+ size = MTTY_IO_BAR_SIZE;
+ break;
+ default:
+ size = 0;
+ break;
+ }
+
+ mdev_state->region_info[bar_index].size = size;
+ mdev_state->region_info[bar_index].vfio_offset =
+ MTTY_VFIO_PCI_INDEX_TO_OFFSET(bar_index);
+
+ region_info->size = size;
+ region_info->offset = MTTY_VFIO_PCI_INDEX_TO_OFFSET(bar_index);
+ region_info->flags = VFIO_REGION_INFO_FLAG_READ |
+ VFIO_REGION_INFO_FLAG_WRITE;
+ mutex_unlock(&mdev_state->ops_lock);
+ return 0;
+}
+
+int mtty_get_irq_info(struct mdev_device *mdev, struct vfio_irq_info *irq_info)
+{
+ switch (irq_info->index) {
+ case VFIO_PCI_INTX_IRQ_INDEX:
+ case VFIO_PCI_MSI_IRQ_INDEX:
+ case VFIO_PCI_REQ_IRQ_INDEX:
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ irq_info->flags = VFIO_IRQ_INFO_EVENTFD;
+ irq_info->count = 1;
+
+ if (irq_info->index == VFIO_PCI_INTX_IRQ_INDEX)
+ irq_info->flags |= (VFIO_IRQ_INFO_MASKABLE |
+ VFIO_IRQ_INFO_AUTOMASKED);
+ else
+ irq_info->flags |= VFIO_IRQ_INFO_NORESIZE;
+
+ return 0;
+}
+
+int mtty_get_device_info(struct mdev_device *mdev,
+ struct vfio_device_info *dev_info)
+{
+ dev_info->flags = VFIO_DEVICE_FLAGS_PCI;
+ dev_info->num_regions = VFIO_PCI_NUM_REGIONS;
+ dev_info->num_irqs = VFIO_PCI_NUM_IRQS;
+
+ return 0;
+}
+
+static long mtty_ioctl(struct mdev_device *mdev, unsigned int cmd,
+ unsigned long arg)
+{
+ int ret = 0;
+ unsigned long minsz;
+ struct mdev_state *mdev_state;
+
+ if (!mdev)
+ return -EINVAL;
+
+ mdev_state = mdev_get_drvdata(mdev);
+ if (!mdev_state)
+ return -ENODEV;
+
+ switch (cmd) {
+ case VFIO_DEVICE_GET_INFO:
+ {
+ struct vfio_device_info info;
+
+ minsz = offsetofend(struct vfio_device_info, num_irqs);
+
+ if (copy_from_user(&info, (void __user *)arg, minsz))
+ return -EFAULT;
+
+ if (info.argsz < minsz)
+ return -EINVAL;
+
+ ret = mtty_get_device_info(mdev, &info);
+ if (ret)
+ return ret;
+
+ memcpy(&mdev_state->dev_info, &info, sizeof(info));
+
+ return copy_to_user((void __user *)arg, &info, minsz);
+ }
+ case VFIO_DEVICE_GET_REGION_INFO:
+ {
+ struct vfio_region_info info;
+ u16 cap_type_id = 0;
+ void *cap_type = NULL;
+
+ minsz = offsetofend(struct vfio_region_info, offset);
+
+ if (copy_from_user(&info, (void __user *)arg, minsz))
+ return -EFAULT;
+
+ if (info.argsz < minsz)
+ return -EINVAL;
+
+ ret = mtty_get_region_info(mdev, &info, &cap_type_id,
+ &cap_type);
+ if (ret)
+ return ret;
+
+ return copy_to_user((void __user *)arg, &info, minsz);
+ }
+
+ case VFIO_DEVICE_GET_IRQ_INFO:
+ {
+ struct vfio_irq_info info;
+
+ minsz = offsetofend(struct vfio_irq_info, count);
+
+ if (copy_from_user(&info, (void __user *)arg, minsz))
+ return -EFAULT;
+
+ if ((info.argsz < minsz) ||
+ (info.index >= mdev_state->dev_info.num_irqs))
+ return -EINVAL;
+
+ ret = mtty_get_irq_info(mdev, &info);
+ if (ret)
+ return ret;
+
+ if (info.count == -1)
+ return -EINVAL;
+
+ return copy_to_user((void __user *)arg, &info, minsz);
+ }
+ case VFIO_DEVICE_SET_IRQS:
+ {
+ struct vfio_irq_set hdr;
+ u8 *data = NULL, *ptr = NULL;
+ size_t data_size = 0;
+
+ minsz = offsetofend(struct vfio_irq_set, count);
+
+ if (copy_from_user(&hdr, (void __user *)arg, minsz))
+ return -EFAULT;
+
+ ret = vfio_set_irqs_validate_and_prepare(&hdr,
+ mdev_state->dev_info.num_irqs,
+ VFIO_PCI_NUM_IRQS,
+ &data_size);
+ if (ret)
+ return ret;
+
+ if (data_size) {
+ ptr = data = memdup_user((void __user *)(arg + minsz),
+ data_size);
+ if (IS_ERR(data))
+ return PTR_ERR(data);
+ }
+
+ ret = mtty_set_irqs(mdev, hdr.flags, hdr.index, hdr.start,
+ hdr.count, data);
+
+ kfree(ptr);
+ return ret;
+ }
+ case VFIO_DEVICE_RESET:
+ return mtty_reset(mdev);
+ }
+ return -ENOTTY;
+}
+
+int mtty_open(struct mdev_device *mdev)
+{
+ pr_info("%s\n", __func__);
+ return 0;
+}
+
+void mtty_close(struct mdev_device *mdev)
+{
+ pr_info("%s\n", __func__);
+}
+
+static ssize_t
+sample_mtty_dev_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "This is phy device\n");
+}
+
+static DEVICE_ATTR_RO(sample_mtty_dev);
+
+static struct attribute *mtty_dev_attrs[] = {
+ &dev_attr_sample_mtty_dev.attr,
+ NULL,
+};
+
+static const struct attribute_group mtty_dev_group = {
+ .name = "mtty_dev",
+ .attrs = mtty_dev_attrs,
+};
+
+const struct attribute_group *mtty_dev_groups[] = {
+ &mtty_dev_group,
+ NULL,
+};
+
+static ssize_t
+sample_mdev_dev_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct mdev_device *mdev = to_mdev_device(dev);
+
+ if (mdev)
+ return sprintf(buf, "This is MDEV %s\n", dev_name(&mdev->dev));
+
+ return sprintf(buf, "\n");
+}
+
+static DEVICE_ATTR_RO(sample_mdev_dev);
+
+static struct attribute *mdev_dev_attrs[] = {
+ &dev_attr_sample_mdev_dev.attr,
+ NULL,
+};
+
+static const struct attribute_group mdev_dev_group = {
+ .name = "vendor",
+ .attrs = mdev_dev_attrs,
+};
+
+const struct attribute_group *mdev_dev_groups[] = {
+ &mdev_dev_group,
+ NULL,
+};
+
+static ssize_t
+name_show(struct kobject *kobj, struct device *dev, char *buf)
+{
+ char name[MTTY_STRING_LEN];
+ int i;
+ const char *name_str[2] = {"Single port serial", "Dual port serial"};
+
+ for (i = 0; i < 2; i++) {
+ snprintf(name, MTTY_STRING_LEN, "%s-%d",
+ dev_driver_string(dev), i + 1);
+ if (!strcmp(kobj->name, name))
+ return sprintf(buf, "%s\n", name_str[i]);
+ }
+
+ return -EINVAL;
+}
+
+MDEV_TYPE_ATTR_RO(name);
+
+static ssize_t
+available_instances_show(struct kobject *kobj, struct device *dev, char *buf)
+{
+ char name[MTTY_STRING_LEN];
+ int i;
+ struct mdev_state *mds;
+ int ports = 0, used = 0;
+
+ for (i = 0; i < 2; i++) {
+ snprintf(name, MTTY_STRING_LEN, "%s-%d",
+ dev_driver_string(dev), i + 1);
+ if (!strcmp(kobj->name, name)) {
+ ports = i + 1;
+ break;
+ }
+ }
+
+ if (!ports)
+ return -EINVAL;
+
+ list_for_each_entry(mds, &mdev_devices_list, next)
+ used += mds->nr_ports;
+
+ return sprintf(buf, "%d\n", (MAX_MTTYS - used)/ports);
+}
+
+MDEV_TYPE_ATTR_RO(available_instances);
+
+
+static ssize_t device_api_show(struct kobject *kobj, struct device *dev,
+ char *buf)
+{
+ return sprintf(buf, "%s\n", VFIO_DEVICE_API_PCI_STRING);
+}
+
+MDEV_TYPE_ATTR_RO(device_api);
+
+static struct attribute *mdev_types_attrs[] = {
+ &mdev_type_attr_name.attr,
+ &mdev_type_attr_device_api.attr,
+ &mdev_type_attr_available_instances.attr,
+ NULL,
+};
+
+static struct attribute_group mdev_type_group1 = {
+ .name = "1",
+ .attrs = mdev_types_attrs,
+};
+
+static struct attribute_group mdev_type_group2 = {
+ .name = "2",
+ .attrs = mdev_types_attrs,
+};
+
+struct attribute_group *mdev_type_groups[] = {
+ &mdev_type_group1,
+ &mdev_type_group2,
+ NULL,
+};
+
+struct parent_ops mdev_fops = {
+ .owner = THIS_MODULE,
+ .dev_attr_groups = mtty_dev_groups,
+ .mdev_attr_groups = mdev_dev_groups,
+ .supported_type_groups = mdev_type_groups,
+ .create = mtty_create,
+ .remove = mtty_remove,
+ .open = mtty_open,
+ .release = mtty_close,
+ .read = mtty_read,
+ .write = mtty_write,
+ .ioctl = mtty_ioctl,
+};
+
+static void mtty_device_release(struct device *dev)
+{
+ dev_dbg(dev, "mtty: released\n");
+}
+
+static int __init mtty_dev_init(void)
+{
+ int ret = 0;
+
+ pr_info("mtty_dev: %s\n", __func__);
+
+ memset(&mtty_dev, 0, sizeof(mtty_dev));
+
+ idr_init(&mtty_dev.vd_idr);
+
+ ret = alloc_chrdev_region(&mtty_dev.vd_devt, 0, MINORMASK, MTTY_NAME);
+
+ if (ret < 0) {
+ pr_err("Error: failed to register mtty_dev, err:%d\n", ret);
+ return ret;
+ }
+
+ cdev_init(&mtty_dev.vd_cdev, &vd_fops);
+ cdev_add(&mtty_dev.vd_cdev, mtty_dev.vd_devt, MINORMASK);
+
+ pr_info("major_number:%d\n", MAJOR(mtty_dev.vd_devt));
+
+ mtty_dev.vd_class = class_create(THIS_MODULE, MTTY_CLASS_NAME);
+
+ if (IS_ERR(mtty_dev.vd_class)) {
+ pr_err("Error: failed to register mtty_dev class\n");
+ goto failed1;
+ }
+
+ mtty_dev.dev.class = mtty_dev.vd_class;
+ mtty_dev.dev.release = mtty_device_release;
+ dev_set_name(&mtty_dev.dev, "%s", MTTY_NAME);
+
+ ret = device_register(&mtty_dev.dev);
+ if (ret)
+ goto failed2;
+
+ if (mdev_register_device(&mtty_dev.dev, &mdev_fops) != 0)
+ goto failed3;
+
+ mutex_init(&mdev_list_lock);
+ INIT_LIST_HEAD(&mdev_devices_list);
+
+ goto all_done;
+
+failed3:
+
+ device_unregister(&mtty_dev.dev);
+failed2:
+ class_destroy(mtty_dev.vd_class);
+
+failed1:
+ cdev_del(&mtty_dev.vd_cdev);
+ unregister_chrdev_region(mtty_dev.vd_devt, MINORMASK);
+
+all_done:
+ return ret;
+}
+
+static void __exit mtty_dev_exit(void)
+{
+ mtty_dev.dev.bus = NULL;
+ mdev_unregister_device(&mtty_dev.dev);
+
+ device_unregister(&mtty_dev.dev);
+ idr_destroy(&mtty_dev.vd_idr);
+ cdev_del(&mtty_dev.vd_cdev);
+ unregister_chrdev_region(mtty_dev.vd_devt, MINORMASK);
+ class_destroy(mtty_dev.vd_class);
+ mtty_dev.vd_class = NULL;
+ pr_info("mtty_dev: Unloaded!\n");
+}
+
+module_init(mtty_dev_init)
+module_exit(mtty_dev_exit)
+
+MODULE_LICENSE("GPL v2");
+MODULE_INFO(supported, "Test driver that simulate serial port over PCI");
+MODULE_VERSION(VERSION_STRING);
+MODULE_AUTHOR(DRIVER_AUTHOR);
--
2.7.0
Added details of sysfs ABI for mediated device framework
Signed-off-by: Kirti Wankhede <[email protected]>
Signed-off-by: Neo Jia <[email protected]>
Change-Id: Icb0fd4ed58a2fa793fbcb1c3d5009a4403c1f3ac
---
Documentation/ABI/testing/sysfs-bus-vfio-mdev | 111 ++++++++++++++++++++++++++
1 file changed, 111 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-bus-vfio-mdev
diff --git a/Documentation/ABI/testing/sysfs-bus-vfio-mdev b/Documentation/ABI/testing/sysfs-bus-vfio-mdev
new file mode 100644
index 000000000000..452dbe39270e
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-vfio-mdev
@@ -0,0 +1,111 @@
+What: /sys/.../<device>/mdev_supported_types/
+Date: October 2016
+Contact: Kirti Wankhede <[email protected]>
+Description:
+ This directory contains list of directories of currently
+ supported mediated device types and their details for
+ <device>. Supported type attributes are defined by the
+ vendor driver who registers with Mediated device framework.
+ Each supported type is a directory whose name is created
+ by adding the device driver string as a prefix to the
+ string provided by the vendor driver.
+
+What: /sys/.../<device>/mdev_supported_types/<type-id>/
+Date: October 2016
+Contact: Kirti Wankhede <[email protected]>
+Description:
+ This directory gives details of supported type, like name,
+ description, available_instances, device_api etc.
+ 'device_api' and 'available_instances' are mandatory
+ attributes to be provided by vendor driver. 'name',
+ 'description' and other vendor driver specific attributes
+ are optional.
+
+What: /sys/.../mdev_supported_types/<type-id>/create
+Date: October 2016
+Contact: Kirti Wankhede <[email protected]>
+Description:
+ Writing UUID to this file will create mediated device of
+ type <type-id> for parent device <device>. This is a
+ write-only file.
+ For example:
+ # echo "83b8f4f2-509f-382f-3c1e-e6bfe0fa1001" > \
+ /sys/devices/foo/mdev_supported_types/foo-1/create
+
+What: /sys/.../mdev_supported_types/<type-id>/devices/
+Date: October 2016
+Contact: Kirti Wankhede <[email protected]>
+Description:
+ This directory contains symbolic links pointing to mdev
+ devices sysfs entries which are created of this <type-id>.
+
+What: /sys/.../mdev_supported_types/<type-id>/available_instances
+Date: October 2016
+Contact: Kirti Wankhede <[email protected]>
+Description:
+ Reading this attribute will show the number of mediated
+ devices of type <type-id> that can be created. This is a
+ readonly file.
+Users:
+ Userspace applications interested in creating mediated
+ device of that type. Userspace application should check
+ the number of available instances could be created before
+ creating mediated device of this type.
+
+What: /sys/.../mdev_supported_types/<type-id>/device_api
+Date: October 2016
+Contact: Kirti Wankhede <[email protected]>
+Description:
+ Reading this attribute will show VFIO device API supported
+ by this type. For example, "vfio-pci" for a PCI device,
+ "vfio-platform" for platform device.
+
+What: /sys/.../mdev_supported_types/<type-id>/name
+Date: October 2016
+Contact: Kirti Wankhede <[email protected]>
+Description:
+ Reading this attribute will show human readable name of the
+ mediated device that will get created of type <type-id>.
+ This is optional attribute. For example: "Grid M60-0Q"
+Users:
+ Userspace applications interested in knowing the name of
+ a particular <type-id> that can help in understanding the
+ type of mediated device.
+
+What: /sys/.../mdev_supported_types/<type-id>/description
+Date: October 2016
+Contact: Kirti Wankhede <[email protected]>
+Description:
+ Reading this attribute will show description of the type of
+ mediated device that will get created of type <type-id>.
+ This is optional attribute. For example:
+ "2 heads, 512M FB, 2560x1600 maximum resolution"
+Users:
+ Userspace applications interested in knowing the details of
+ a particular <type-id> that can help in understanding the
+ features provided by that type of mediated device.
+
+What: /sys/.../<device>/<UUID>/
+Date: October 2016
+Contact: Kirti Wankhede <[email protected]>
+Description:
+ This directory represents device directory of mediated
+ device. It contains all the attributes related to mediated
+ device.
+
+What: /sys/.../<device>/<UUID>/mdev_type
+Date: October 2016
+Contact: Kirti Wankhede <[email protected]>
+Description:
+ This is symbolic link pointing to supported type, <type-id>
+ directory of which this mediated device is created.
+
+What: /sys/.../<device>/<UUID>/remove
+Date: October 2016
+Contact: Kirti Wankhede <[email protected]>
+Description:
+ Writing '1' to this file destroys the mediated device. The
+ vendor driver can fail the remove() callback if that device
+ is active and the vendor driver doesn't support hot unplug.
+ Example:
+ # echo 1 > /sys/bus/mdev/devices/<UUID>/remove
--
2.7.0
Vendor driver using mediated device framework would use same mechnism to
validate and prepare IRQs. Introducing this function to reduce code
replication in multiple drivers.
Signed-off-by: Kirti Wankhede <[email protected]>
Signed-off-by: Neo Jia <[email protected]>
Change-Id: Ie201f269dda0713ca18a07dc4852500bd8b48309
---
drivers/vfio/vfio.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/vfio.h | 4 ++++
2 files changed, 52 insertions(+)
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index ea88360f4aea..089f3cdd0aa9 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -1858,6 +1858,54 @@ int vfio_info_add_capability(struct vfio_info_cap *caps, int cap_type_id,
}
EXPORT_SYMBOL(vfio_info_add_capability);
+int vfio_set_irqs_validate_and_prepare(struct vfio_irq_set *hdr, int num_irqs,
+ int max_irq_type, size_t *data_size)
+{
+ unsigned long minsz;
+ size_t size;
+
+ minsz = offsetofend(struct vfio_irq_set, count);
+
+ if ((hdr->argsz < minsz) || (hdr->index >= max_irq_type) ||
+ (hdr->count >= (U32_MAX - hdr->start)) ||
+ (hdr->flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK |
+ VFIO_IRQ_SET_ACTION_TYPE_MASK)))
+ return -EINVAL;
+
+ if (data_size)
+ *data_size = 0;
+
+ if (hdr->start >= num_irqs || hdr->start + hdr->count > num_irqs)
+ return -EINVAL;
+
+ switch (hdr->flags & VFIO_IRQ_SET_DATA_TYPE_MASK) {
+ case VFIO_IRQ_SET_DATA_NONE:
+ size = 0;
+ break;
+ case VFIO_IRQ_SET_DATA_BOOL:
+ size = sizeof(uint8_t);
+ break;
+ case VFIO_IRQ_SET_DATA_EVENTFD:
+ size = sizeof(int32_t);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (size) {
+ if (hdr->argsz - minsz < hdr->count * size)
+ return -EINVAL;
+
+ if (!data_size)
+ return -EINVAL;
+
+ *data_size = hdr->count * size;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(vfio_set_irqs_validate_and_prepare);
+
/*
* Pin a set of guest PFNs and return their associated host PFNs for local
* domain only.
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index 236f0e55af11..0bf07d60fbb3 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -114,6 +114,10 @@ extern void vfio_info_cap_shift(struct vfio_info_cap *caps, size_t offset);
extern int vfio_info_add_capability(struct vfio_info_cap *caps,
int cap_type_id, void *cap_type);
+extern int vfio_set_irqs_validate_and_prepare(struct vfio_irq_set *hdr,
+ int num_irqs, int max_irq_type,
+ size_t *data_size);
+
struct pci_dev;
#ifdef CONFIG_EEH
extern void vfio_spapr_pci_eeh_open(struct pci_dev *pdev);
--
2.7.0
Add a notifier calback to parent's ops structure of mdev device so that per
device notifer for vfio module is registered through vfio_mdev module.
Signed-off-by: Kirti Wankhede <[email protected]>
Signed-off-by: Neo Jia <[email protected]>
Change-Id: Iafa6f1721aecdd6e50eb93b153b5621e6d29b637
---
drivers/vfio/mdev/vfio_mdev.c | 25 ++++++++++++++++++++++++-
include/linux/mdev.h | 9 +++++++++
2 files changed, 33 insertions(+), 1 deletion(-)
diff --git a/drivers/vfio/mdev/vfio_mdev.c b/drivers/vfio/mdev/vfio_mdev.c
index ffc36758cb84..4fc63db38829 100644
--- a/drivers/vfio/mdev/vfio_mdev.c
+++ b/drivers/vfio/mdev/vfio_mdev.c
@@ -24,6 +24,15 @@
#define DRIVER_AUTHOR "NVIDIA Corporation"
#define DRIVER_DESC "VFIO based driver for Mediated device"
+static int vfio_mdev_notifier(struct notifier_block *nb, unsigned long action,
+ void *data)
+{
+ struct mdev_device *mdev = container_of(nb, struct mdev_device, nb);
+ struct parent_device *parent = mdev->parent;
+
+ return parent->ops->notifier(mdev, action, data);
+}
+
static int vfio_mdev_open(void *device_data)
{
struct mdev_device *mdev = device_data;
@@ -36,9 +45,18 @@ static int vfio_mdev_open(void *device_data)
if (!try_module_get(THIS_MODULE))
return -ENODEV;
+ if (likely(parent->ops->notifier)) {
+ mdev->nb.notifier_call = vfio_mdev_notifier;
+ if (vfio_register_notifier(&mdev->dev, &mdev->nb))
+ pr_err("Failed to register notifier for mdev\n");
+ }
+
ret = parent->ops->open(mdev);
- if (ret)
+ if (ret) {
+ if (likely(parent->ops->notifier))
+ vfio_unregister_notifier(&mdev->dev, &mdev->nb);
module_put(THIS_MODULE);
+ }
return ret;
}
@@ -51,6 +69,11 @@ static void vfio_mdev_release(void *device_data)
if (likely(parent->ops->release))
parent->ops->release(mdev);
+ if (likely(parent->ops->notifier)) {
+ if (vfio_unregister_notifier(&mdev->dev, &mdev->nb))
+ pr_err("Failed to unregister notifier for mdev\n");
+ }
+
module_put(THIS_MODULE);
}
diff --git a/include/linux/mdev.h b/include/linux/mdev.h
index ec819e9a115a..94c43034c297 100644
--- a/include/linux/mdev.h
+++ b/include/linux/mdev.h
@@ -37,6 +37,7 @@ struct mdev_device {
struct kref ref;
struct list_head next;
struct kobject *type_kobj;
+ struct notifier_block nb;
};
/**
@@ -85,6 +86,12 @@ struct mdev_device {
* @mmap: mmap callback
* @mdev: mediated device structure
* @vma: vma structure
+ * @notifer: Notifier callback, currently only for
+ * VFIO_IOMMU_NOTIFY_DMA_UNMAP action notified duing
+ * DMA_UNMAP call on mapped iova range.
+ * @mdev: mediated device structure
+ * @action: Action for which notifier is called
+ * @data: Data associated with the notifier
* Parent device that support mediated device should be registered with mdev
* module with parent_ops structure.
**/
@@ -106,6 +113,8 @@ struct parent_ops {
ssize_t (*ioctl)(struct mdev_device *mdev, unsigned int cmd,
unsigned long arg);
int (*mmap)(struct mdev_device *mdev, struct vm_area_struct *vma);
+ int (*notifier)(struct mdev_device *mdev, unsigned long action,
+ void *data);
};
/* interface for exporting mdev supported type attributes */
--
2.7.0
Adding myself as a maintainer of mediated device framework,
a sub module of VFIO.
Signed-off-by: Kirti Wankhede <[email protected]>
Signed-off-by: Neo Jia <[email protected]>
Change-Id: I58f6717783e0d4008ca31f4a5c4494696bae8571
---
MAINTAINERS | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 411e3b87b8c2..0cff155c1315 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12754,6 +12754,15 @@ F: drivers/vfio/
F: include/linux/vfio.h
F: include/uapi/linux/vfio.h
+VFIO MEDIATED DEVICE DRIVERS
+M: Kirti Wankhede <[email protected]>
+L: [email protected]
+S: Maintained
+F: Documentation/vfio-mediated-device.txt
+F: drivers/vfio/mdev/
+F: include/linux/mdev.h
+F: samples/vfio-mdev/
+
VFIO PLATFORM DRIVER
M: Baptiste Reynal <[email protected]>
L: [email protected]
--
2.7.0
Vendor driver using mediated device framework should use
vfio_info_add_capability() to add capabilities.
Introduced this function to reduce code duplication in vendor drivers.
vfio_info_cap_shift() manipulated a data buffer to add an offset to each
element in a chain. This data buffer is documented in a uapi header.
Changing vfio_info_cap_shift symbol to be available to all drivers.
Signed-off-by: Kirti Wankhede <[email protected]>
Signed-off-by: Neo Jia <[email protected]>
Change-Id: I6fca329fa2291f37a2c859d0bc97574d9e2ce1a6
---
drivers/vfio/vfio.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++++++-
include/linux/vfio.h | 3 +++
2 files changed, 62 insertions(+), 1 deletion(-)
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index fa121d983991..ea88360f4aea 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -1797,8 +1797,66 @@ void vfio_info_cap_shift(struct vfio_info_cap *caps, size_t offset)
for (tmp = caps->buf; tmp->next; tmp = (void *)tmp + tmp->next - offset)
tmp->next += offset;
}
-EXPORT_SYMBOL_GPL(vfio_info_cap_shift);
+EXPORT_SYMBOL(vfio_info_cap_shift);
+static int sparse_mmap_cap(struct vfio_info_cap *caps, void *cap_type)
+{
+ struct vfio_info_cap_header *header;
+ struct vfio_region_info_cap_sparse_mmap *sparse_cap, *sparse = cap_type;
+ size_t size;
+
+ size = sizeof(*sparse) + sparse->nr_areas * sizeof(*sparse->areas);
+ header = vfio_info_cap_add(caps, size,
+ VFIO_REGION_INFO_CAP_SPARSE_MMAP, 1);
+ if (IS_ERR(header))
+ return PTR_ERR(header);
+
+ sparse_cap = container_of(header,
+ struct vfio_region_info_cap_sparse_mmap, header);
+ sparse_cap->nr_areas = sparse->nr_areas;
+ memcpy(sparse_cap->areas, sparse->areas,
+ sparse->nr_areas * sizeof(*sparse->areas));
+ return 0;
+}
+
+static int region_type_cap(struct vfio_info_cap *caps, void *cap_type)
+{
+ struct vfio_info_cap_header *header;
+ struct vfio_region_info_cap_type *type_cap, *cap = cap_type;
+
+ header = vfio_info_cap_add(caps, sizeof(*cap),
+ VFIO_REGION_INFO_CAP_TYPE, 1);
+ if (IS_ERR(header))
+ return PTR_ERR(header);
+
+ type_cap = container_of(header, struct vfio_region_info_cap_type,
+ header);
+ type_cap->type = cap->type;
+ type_cap->subtype = cap->subtype;
+ return 0;
+}
+
+int vfio_info_add_capability(struct vfio_info_cap *caps, int cap_type_id,
+ void *cap_type)
+{
+ int ret = -EINVAL;
+
+ if (!cap_type)
+ return 0;
+
+ switch (cap_type_id) {
+ case VFIO_REGION_INFO_CAP_SPARSE_MMAP:
+ ret = sparse_mmap_cap(caps, cap_type);
+ break;
+
+ case VFIO_REGION_INFO_CAP_TYPE:
+ ret = region_type_cap(caps, cap_type);
+ break;
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL(vfio_info_add_capability);
/*
* Pin a set of guest PFNs and return their associated host PFNs for local
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index 997442398c09..236f0e55af11 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -111,6 +111,9 @@ extern struct vfio_info_cap_header *vfio_info_cap_add(
struct vfio_info_cap *caps, size_t size, u16 id, u16 version);
extern void vfio_info_cap_shift(struct vfio_info_cap *caps, size_t offset);
+extern int vfio_info_add_capability(struct vfio_info_cap *caps,
+ int cap_type_id, void *cap_type);
+
struct pci_dev;
#ifdef CONFIG_EEH
extern void vfio_spapr_pci_eeh_open(struct pci_dev *pdev);
--
2.7.0
Add find_iommu_group()
Signed-off-by: Kirti Wankhede <[email protected]>
Signed-off-by: Neo Jia <[email protected]>
Reviewed-by: Jike Song <[email protected]>
Reviewed-by: Dong Jia Shi <[email protected]>
Change-Id: I9d372f1ebe9eb01a5a21374b8a2b03f7df73601f
---
drivers/vfio/vfio_iommu_type1.c | 57 ++++++++++++++++++++++++-----------------
1 file changed, 33 insertions(+), 24 deletions(-)
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 52af5fc01d91..ffe2026f1341 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -752,11 +752,24 @@ static void vfio_test_domain_fgsp(struct vfio_domain *domain)
__free_pages(pages, order);
}
+static struct vfio_group *find_iommu_group(struct vfio_domain *domain,
+ struct iommu_group *iommu_group)
+{
+ struct vfio_group *g;
+
+ list_for_each_entry(g, &domain->group_list, next) {
+ if (g->iommu_group == iommu_group)
+ return g;
+ }
+
+ return NULL;
+}
+
static int vfio_iommu_type1_attach_group(void *iommu_data,
struct iommu_group *iommu_group)
{
struct vfio_iommu *iommu = iommu_data;
- struct vfio_group *group, *g;
+ struct vfio_group *group;
struct vfio_domain *domain, *d;
struct bus_type *bus = NULL;
int ret;
@@ -764,10 +777,7 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
mutex_lock(&iommu->lock);
list_for_each_entry(d, &iommu->domain_list, next) {
- list_for_each_entry(g, &d->group_list, next) {
- if (g->iommu_group != iommu_group)
- continue;
-
+ if (find_iommu_group(d, iommu_group)) {
mutex_unlock(&iommu->lock);
return -EINVAL;
}
@@ -887,27 +897,26 @@ static void vfio_iommu_type1_detach_group(void *iommu_data,
mutex_lock(&iommu->lock);
list_for_each_entry(domain, &iommu->domain_list, next) {
- list_for_each_entry(group, &domain->group_list, next) {
- if (group->iommu_group != iommu_group)
- continue;
+ group = find_iommu_group(domain, iommu_group);
+ if (!group)
+ continue;
- iommu_detach_group(domain->domain, iommu_group);
- list_del(&group->next);
- kfree(group);
- /*
- * Group ownership provides privilege, if the group
- * list is empty, the domain goes away. If it's the
- * last domain, then all the mappings go away too.
- */
- if (list_empty(&domain->group_list)) {
- if (list_is_singular(&iommu->domain_list))
- vfio_iommu_unmap_unpin_all(iommu);
- iommu_domain_free(domain->domain);
- list_del(&domain->next);
- kfree(domain);
- }
- goto done;
+ iommu_detach_group(domain->domain, iommu_group);
+ list_del(&group->next);
+ kfree(group);
+ /*
+ * Group ownership provides privilege, if the group
+ * list is empty, the domain goes away. If it's the
+ * last domain, then all the mappings go away too.
+ */
+ if (list_empty(&domain->group_list)) {
+ if (list_is_singular(&iommu->domain_list))
+ vfio_iommu_unmap_unpin_all(iommu);
+ iommu_domain_free(domain->domain);
+ list_del(&domain->next);
+ kfree(domain);
}
+ goto done;
}
done:
--
2.7.0
Added task structure as input argument to vfio_lock_acct() function.
Signed-off-by: Kirti Wankhede <[email protected]>
Signed-off-by: Neo Jia <[email protected]>
Change-Id: I5d3673cc9d3786bb436b395d5f74537f1a36da80
---
drivers/vfio/vfio_iommu_type1.c | 30 ++++++++++++++++--------------
1 file changed, 16 insertions(+), 14 deletions(-)
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 9f3d58d3dfaf..34d17e51dc97 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -150,17 +150,22 @@ static void vfio_lock_acct_bg(struct work_struct *work)
kfree(vwork);
}
-static void vfio_lock_acct(long npage)
+static void vfio_lock_acct(struct task_struct *task, long npage)
{
struct vwork *vwork;
struct mm_struct *mm;
- if (!current->mm || !npage)
+ if (!npage)
+ return;
+
+ mm = get_task_mm(task);
+ if (!mm)
return; /* process exited or nothing to do */
- if (down_write_trylock(¤t->mm->mmap_sem)) {
- current->mm->locked_vm += npage;
- up_write(¤t->mm->mmap_sem);
+ if (down_write_trylock(&mm->mmap_sem)) {
+ mm->locked_vm += npage;
+ up_write(&mm->mmap_sem);
+ mmput(mm);
return;
}
@@ -170,11 +175,8 @@ static void vfio_lock_acct(long npage)
* wouldn't need this silliness
*/
vwork = kmalloc(sizeof(struct vwork), GFP_KERNEL);
- if (!vwork)
- return;
- mm = get_task_mm(current);
- if (!mm) {
- kfree(vwork);
+ if (!vwork) {
+ mmput(mm);
return;
}
INIT_WORK(&vwork->work, vfio_lock_acct_bg);
@@ -285,7 +287,7 @@ static long vfio_pin_pages_remote(unsigned long vaddr, long npage,
if (unlikely(disable_hugepages)) {
if (!rsvd)
- vfio_lock_acct(1);
+ vfio_lock_acct(current, 1);
return 1;
}
@@ -313,7 +315,7 @@ static long vfio_pin_pages_remote(unsigned long vaddr, long npage,
}
if (!rsvd)
- vfio_lock_acct(i);
+ vfio_lock_acct(current, i);
return i;
}
@@ -328,7 +330,7 @@ static long vfio_unpin_pages_remote(unsigned long pfn, long npage,
unlocked += put_pfn(pfn++, prot);
if (do_accounting)
- vfio_lock_acct(-unlocked);
+ vfio_lock_acct(current, -unlocked);
return unlocked;
}
@@ -390,7 +392,7 @@ static void vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma)
cond_resched();
}
- vfio_lock_acct(-unlocked);
+ vfio_lock_acct(current, -unlocked);
}
static void vfio_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *dma)
--
2.7.0
This patch rearranges functions to get vfio_group from device
Signed-off-by: Kirti Wankhede <[email protected]>
Signed-off-by: Neo Jia <[email protected]>
Reviewed-by: Jike Song <[email protected]>
Change-Id: I1f93262bdbab75094bc24b087b29da35ba70c4c6
---
drivers/vfio/vfio.c | 23 ++++++++++++++++-------
1 file changed, 16 insertions(+), 7 deletions(-)
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index d1d70e0b011b..23bc86c1d05d 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -480,6 +480,21 @@ static struct vfio_group *vfio_group_get_from_minor(int minor)
return group;
}
+static struct vfio_group *vfio_group_get_from_dev(struct device *dev)
+{
+ struct iommu_group *iommu_group;
+ struct vfio_group *group;
+
+ iommu_group = iommu_group_get(dev);
+ if (!iommu_group)
+ return NULL;
+
+ group = vfio_group_get_from_iommu(iommu_group);
+ iommu_group_put(iommu_group);
+
+ return group;
+}
+
/**
* Device objects - create, release, get, put, search
*/
@@ -811,16 +826,10 @@ EXPORT_SYMBOL_GPL(vfio_add_group_dev);
*/
struct vfio_device *vfio_device_get_from_dev(struct device *dev)
{
- struct iommu_group *iommu_group;
struct vfio_group *group;
struct vfio_device *device;
- iommu_group = iommu_group_get(dev);
- if (!iommu_group)
- return NULL;
-
- group = vfio_group_get_from_iommu(iommu_group);
- iommu_group_put(iommu_group);
+ group = vfio_group_get_from_dev(dev);
if (!group)
return NULL;
--
2.7.0
Design for Mediated Device Driver:
Main purpose of this driver is to provide a common interface for mediated
device management that can be used by different drivers of different
devices.
This module provides a generic interface to create the device, add it to
mediated bus, add device to IOMMU group and then add it to vfio group.
Below is the high Level block diagram, with Nvidia, Intel and IBM devices
as example, since these are the devices which are going to actively use
this module as of now.
+---------------+
| |
| +-----------+ | mdev_register_driver() +--------------+
| | | +<------------------------+ __init() |
| | mdev | | | |
| | bus | +------------------------>+ |<-> VFIO user
| | driver | | probe()/remove() | vfio_mdev.ko | APIs
| | | | | |
| +-----------+ | +--------------+
| |
| MDEV CORE |
| MODULE |
| mdev.ko |
| +-----------+ | mdev_register_device() +--------------+
| | | +<------------------------+ |
| | | | | nvidia.ko |<-> physical
| | | +------------------------>+ | device
| | | | callback +--------------+
| | Physical | |
| | device | | mdev_register_device() +--------------+
| | interface | |<------------------------+ |
| | | | | i915.ko |<-> physical
| | | +------------------------>+ | device
| | | | callback +--------------+
| | | |
| | | | mdev_register_device() +--------------+
| | | +<------------------------+ |
| | | | | ccw_device.ko|<-> physical
| | | +------------------------>+ | device
| | | | callback +--------------+
| +-----------+ |
+---------------+
Core driver provides two types of registration interfaces:
1. Registration interface for mediated bus driver:
/**
* struct mdev_driver - Mediated device's driver
* @name: driver name
* @probe: called when new device created
* @remove:called when device removed
* @driver:device driver structure
*
**/
struct mdev_driver {
const char *name;
int (*probe) (struct device *dev);
void (*remove) (struct device *dev);
struct device_driver driver;
};
Mediated bus driver for mdev device should use this interface to register
and unregister with core driver respectively:
int mdev_register_driver(struct mdev_driver *drv, struct module *owner);
void mdev_unregister_driver(struct mdev_driver *drv);
Mediated bus driver is responsible to add/delete mediated devices to/from
VFIO group when devices are bound and unbound to the driver.
2. Physical device driver interface
This interface provides vendor driver the set APIs to manage physical
device related work in its driver. APIs are :
* dev_attr_groups: attributes of the parent device.
* mdev_attr_groups: attributes of the mediated device.
* supported_type_groups: attributes to define supported type. This is
mandatory field.
* create: to allocate basic resources in vendor driver for a mediated
device. This is mandatory to be provided by vendor driver.
* remove: to free resources in vendor driver when mediated device is
destroyed. This is mandatory to be provided by vendor driver.
* open: open callback of mediated device
* release: release callback of mediated device
* read : read emulation callback.
* write: write emulation callback.
* ioctl: ioctl callback.
* mmap: mmap emulation callback.
Drivers should use these interfaces to register and unregister device to
mdev core driver respectively:
extern int mdev_register_device(struct device *dev,
const struct parent_ops *ops);
extern void mdev_unregister_device(struct device *dev);
There are no locks to serialize above callbacks in mdev driver and
vfio_mdev driver. If required, vendor driver can have locks to serialize
above APIs in their driver.
Signed-off-by: Kirti Wankhede <[email protected]>
Signed-off-by: Neo Jia <[email protected]>
Reviewed-by: Jike Song <[email protected]>
Reviewed-by: Dong Jia Shi <[email protected]>
Change-Id: I73a5084574270b14541c529461ea2f03c292d510
---
drivers/vfio/Kconfig | 1 +
drivers/vfio/Makefile | 1 +
drivers/vfio/mdev/Kconfig | 9 +
drivers/vfio/mdev/Makefile | 4 +
drivers/vfio/mdev/mdev_core.c | 374 +++++++++++++++++++++++++++++++++++++++
drivers/vfio/mdev/mdev_driver.c | 119 +++++++++++++
drivers/vfio/mdev/mdev_private.h | 41 +++++
drivers/vfio/mdev/mdev_sysfs.c | 286 ++++++++++++++++++++++++++++++
include/linux/mdev.h | 168 ++++++++++++++++++
9 files changed, 1003 insertions(+)
create mode 100644 drivers/vfio/mdev/Kconfig
create mode 100644 drivers/vfio/mdev/Makefile
create mode 100644 drivers/vfio/mdev/mdev_core.c
create mode 100644 drivers/vfio/mdev/mdev_driver.c
create mode 100644 drivers/vfio/mdev/mdev_private.h
create mode 100644 drivers/vfio/mdev/mdev_sysfs.c
create mode 100644 include/linux/mdev.h
diff --git a/drivers/vfio/Kconfig b/drivers/vfio/Kconfig
index da6e2ce77495..23eced02aaf6 100644
--- a/drivers/vfio/Kconfig
+++ b/drivers/vfio/Kconfig
@@ -48,4 +48,5 @@ menuconfig VFIO_NOIOMMU
source "drivers/vfio/pci/Kconfig"
source "drivers/vfio/platform/Kconfig"
+source "drivers/vfio/mdev/Kconfig"
source "virt/lib/Kconfig"
diff --git a/drivers/vfio/Makefile b/drivers/vfio/Makefile
index 7b8a31f63fea..4a23c13b6be4 100644
--- a/drivers/vfio/Makefile
+++ b/drivers/vfio/Makefile
@@ -7,3 +7,4 @@ obj-$(CONFIG_VFIO_IOMMU_SPAPR_TCE) += vfio_iommu_spapr_tce.o
obj-$(CONFIG_VFIO_SPAPR_EEH) += vfio_spapr_eeh.o
obj-$(CONFIG_VFIO_PCI) += pci/
obj-$(CONFIG_VFIO_PLATFORM) += platform/
+obj-$(CONFIG_VFIO_MDEV) += mdev/
diff --git a/drivers/vfio/mdev/Kconfig b/drivers/vfio/mdev/Kconfig
new file mode 100644
index 000000000000..258481d65ebd
--- /dev/null
+++ b/drivers/vfio/mdev/Kconfig
@@ -0,0 +1,9 @@
+
+config VFIO_MDEV
+ tristate "Mediated device driver framework"
+ depends on VFIO
+ default n
+ help
+ Provides a framework to virtualize devices.
+
+ If you don't know what do here, say N.
diff --git a/drivers/vfio/mdev/Makefile b/drivers/vfio/mdev/Makefile
new file mode 100644
index 000000000000..31bc04801d94
--- /dev/null
+++ b/drivers/vfio/mdev/Makefile
@@ -0,0 +1,4 @@
+
+mdev-y := mdev_core.o mdev_sysfs.o mdev_driver.o
+
+obj-$(CONFIG_VFIO_MDEV) += mdev.o
diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
new file mode 100644
index 000000000000..613e8a8a3b2a
--- /dev/null
+++ b/drivers/vfio/mdev/mdev_core.c
@@ -0,0 +1,374 @@
+/*
+ * Mediated device Core Driver
+ *
+ * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
+ * Author: Neo Jia <[email protected]>
+ * Kirti Wankhede <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/uuid.h>
+#include <linux/sysfs.h>
+#include <linux/mdev.h>
+
+#include "mdev_private.h"
+
+#define DRIVER_VERSION "0.1"
+#define DRIVER_AUTHOR "NVIDIA Corporation"
+#define DRIVER_DESC "Mediated device Core Driver"
+
+static LIST_HEAD(parent_list);
+static DEFINE_MUTEX(parent_list_lock);
+static struct class_compat *mdev_bus_compat_class;
+
+static int _find_mdev_device(struct device *dev, void *data)
+{
+ struct mdev_device *mdev;
+
+ if (!dev_is_mdev(dev))
+ return 0;
+
+ mdev = to_mdev_device(dev);
+
+ if (uuid_le_cmp(mdev->uuid, *(uuid_le *)data) == 0)
+ return 1;
+
+ return 0;
+}
+
+static bool mdev_device_exist(struct parent_device *parent, uuid_le uuid)
+{
+ struct device *dev;
+
+ dev = device_find_child(parent->dev, &uuid, _find_mdev_device);
+ if (dev) {
+ put_device(dev);
+ return true;
+ }
+
+ return false;
+}
+
+/* Should be called holding parent_list_lock */
+static struct parent_device *__find_parent_device(struct device *dev)
+{
+ struct parent_device *parent;
+
+ list_for_each_entry(parent, &parent_list, next) {
+ if (parent->dev == dev)
+ return parent;
+ }
+ return NULL;
+}
+
+static void mdev_release_parent(struct kref *kref)
+{
+ struct parent_device *parent = container_of(kref, struct parent_device,
+ ref);
+ struct device *dev = parent->dev;
+
+ kfree(parent);
+ put_device(dev);
+}
+
+static
+inline struct parent_device *mdev_get_parent(struct parent_device *parent)
+{
+ if (parent)
+ kref_get(&parent->ref);
+
+ return parent;
+}
+
+static inline void mdev_put_parent(struct parent_device *parent)
+{
+ if (parent)
+ kref_put(&parent->ref, mdev_release_parent);
+}
+
+static int mdev_device_create_ops(struct kobject *kobj,
+ struct mdev_device *mdev)
+{
+ struct parent_device *parent = mdev->parent;
+ int ret;
+
+ ret = parent->ops->create(kobj, mdev);
+ if (ret)
+ return ret;
+
+ ret = sysfs_create_groups(&mdev->dev.kobj,
+ parent->ops->mdev_attr_groups);
+ if (ret)
+ parent->ops->remove(mdev);
+
+ return ret;
+}
+
+/*
+ * mdev_device_remove_ops gets called from sysfs's 'remove' and when parent
+ * device is being unregistered from mdev device framework.
+ * - 'force_remove' is set to 'false' when called from sysfs's 'remove' which
+ * indicates that if the mdev device is active, used by VMM or userspace
+ * application, vendor driver could return error then don't remove the device.
+ * - 'force_remove' is set to 'true' when called from mdev_unregister_device()
+ * which indicate that parent device is being removed from mdev device
+ * framework so remove mdev device forcefully.
+ */
+static int mdev_device_remove_ops(struct mdev_device *mdev, bool force_remove)
+{
+ struct parent_device *parent = mdev->parent;
+ int ret;
+
+ /*
+ * Vendor driver can return error if VMM or userspace application is
+ * using this mdev device.
+ */
+ ret = parent->ops->remove(mdev);
+ if (ret && !force_remove)
+ return -EBUSY;
+
+ sysfs_remove_groups(&mdev->dev.kobj, parent->ops->mdev_attr_groups);
+ return 0;
+}
+
+static int mdev_device_remove_cb(struct device *dev, void *data)
+{
+ if (!dev_is_mdev(dev))
+ return 0;
+
+ return mdev_device_remove(dev, data ? *(bool *)data : true);
+}
+
+/*
+ * mdev_register_device : Register a device
+ * @dev: device structure representing parent device.
+ * @ops: Parent device operation structure to be registered.
+ *
+ * Add device to list of registered parent devices.
+ * Returns a negative value on error, otherwise 0.
+ */
+int mdev_register_device(struct device *dev, const struct parent_ops *ops)
+{
+ int ret;
+ struct parent_device *parent;
+
+ /* check for mandatory ops */
+ if (!ops || !ops->create || !ops->remove || !ops->supported_type_groups)
+ return -EINVAL;
+
+ dev = get_device(dev);
+ if (!dev)
+ return -EINVAL;
+
+ mutex_lock(&parent_list_lock);
+
+ /* Check for duplicate */
+ parent = __find_parent_device(dev);
+ if (parent) {
+ ret = -EEXIST;
+ goto add_dev_err;
+ }
+
+ parent = kzalloc(sizeof(*parent), GFP_KERNEL);
+ if (!parent) {
+ ret = -ENOMEM;
+ goto add_dev_err;
+ }
+
+ kref_init(&parent->ref);
+ mutex_init(&parent->lock);
+
+ parent->dev = dev;
+ parent->ops = ops;
+
+ if (!mdev_bus_compat_class) {
+ mdev_bus_compat_class = class_compat_register("mdev_bus");
+ if (!mdev_bus_compat_class) {
+ ret = -ENOMEM;
+ goto add_dev_err;
+ }
+ }
+
+ ret = parent_create_sysfs_files(parent);
+ if (ret)
+ goto add_dev_err;
+
+ ret = class_compat_create_link(mdev_bus_compat_class, dev, NULL);
+ if (ret)
+ dev_warn(dev, "Failed to create compatibility class link\n");
+
+ list_add(&parent->next, &parent_list);
+ mutex_unlock(&parent_list_lock);
+
+ dev_info(dev, "MDEV: Registered\n");
+ return 0;
+
+add_dev_err:
+ mutex_unlock(&parent_list_lock);
+ if (parent)
+ mdev_put_parent(parent);
+ else
+ put_device(dev);
+ return ret;
+}
+EXPORT_SYMBOL(mdev_register_device);
+
+/*
+ * mdev_unregister_device : Unregister a parent device
+ * @dev: device structure representing parent device.
+ *
+ * Remove device from list of registered parent devices. Give a chance to free
+ * existing mediated devices for given device.
+ */
+
+void mdev_unregister_device(struct device *dev)
+{
+ struct parent_device *parent;
+ bool force_remove = true;
+
+ mutex_lock(&parent_list_lock);
+ parent = __find_parent_device(dev);
+
+ if (!parent) {
+ mutex_unlock(&parent_list_lock);
+ return;
+ }
+ dev_info(dev, "MDEV: Unregistering\n");
+
+ list_del(&parent->next);
+ class_compat_remove_link(mdev_bus_compat_class, dev, NULL);
+
+ device_for_each_child(dev, (void *)&force_remove,
+ mdev_device_remove_cb);
+
+ parent_remove_sysfs_files(parent);
+
+ mutex_unlock(&parent_list_lock);
+ mdev_put_parent(parent);
+}
+EXPORT_SYMBOL(mdev_unregister_device);
+
+static void mdev_device_release(struct device *dev)
+{
+ struct mdev_device *mdev = to_mdev_device(dev);
+
+ dev_dbg(&mdev->dev, "MDEV: destroying\n");
+ kfree(mdev);
+}
+
+int mdev_device_create(struct kobject *kobj, struct device *dev, uuid_le uuid)
+{
+ int ret;
+ struct mdev_device *mdev;
+ struct parent_device *parent;
+ struct mdev_type *type = to_mdev_type(kobj);
+
+ parent = mdev_get_parent(type->parent);
+ if (!parent)
+ return -EINVAL;
+
+ mutex_lock(&parent->lock);
+
+ /* Check for duplicate */
+ if (mdev_device_exist(parent, uuid)) {
+ ret = -EEXIST;
+ goto create_err;
+ }
+
+ mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
+ if (!mdev) {
+ ret = -ENOMEM;
+ goto create_err;
+ }
+
+ memcpy(&mdev->uuid, &uuid, sizeof(uuid_le));
+ mdev->parent = parent;
+ kref_init(&mdev->ref);
+
+ mdev->dev.parent = dev;
+ mdev->dev.bus = &mdev_bus_type;
+ mdev->dev.release = mdev_device_release;
+ dev_set_name(&mdev->dev, "%pUl", uuid.b);
+
+ ret = device_register(&mdev->dev);
+ if (ret) {
+ put_device(&mdev->dev);
+ goto create_err;
+ }
+
+ ret = mdev_device_create_ops(kobj, mdev);
+ if (ret)
+ goto create_failed;
+
+ ret = mdev_create_sysfs_files(&mdev->dev, type);
+ if (ret) {
+ mdev_device_remove_ops(mdev, true);
+ goto create_failed;
+ }
+
+ mdev->type_kobj = kobj;
+ dev_dbg(&mdev->dev, "MDEV: created\n");
+
+ mutex_unlock(&parent->lock);
+ return ret;
+
+create_failed:
+ device_unregister(&mdev->dev);
+
+create_err:
+ mutex_unlock(&parent->lock);
+ mdev_put_parent(parent);
+ return ret;
+}
+
+int mdev_device_remove(struct device *dev, bool force_remove)
+{
+ struct mdev_device *mdev;
+ struct parent_device *parent;
+ struct mdev_type *type;
+ int ret;
+
+ mdev = to_mdev_device(dev);
+ type = to_mdev_type(mdev->type_kobj);
+ parent = mdev->parent;
+ mutex_lock(&parent->lock);
+
+ ret = mdev_device_remove_ops(mdev, force_remove);
+ if (ret) {
+ mutex_unlock(&parent->lock);
+ return ret;
+ }
+
+ mdev_remove_sysfs_files(dev, type);
+ device_unregister(dev);
+ mutex_unlock(&parent->lock);
+ mdev_put_parent(parent);
+ return ret;
+}
+
+static int __init mdev_init(void)
+{
+ return mdev_bus_register();
+}
+
+static void __exit mdev_exit(void)
+{
+ if (mdev_bus_compat_class)
+ class_compat_unregister(mdev_bus_compat_class);
+
+ mdev_bus_unregister();
+}
+
+module_init(mdev_init)
+module_exit(mdev_exit)
+
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
diff --git a/drivers/vfio/mdev/mdev_driver.c b/drivers/vfio/mdev/mdev_driver.c
new file mode 100644
index 000000000000..6f0391f6f9b6
--- /dev/null
+++ b/drivers/vfio/mdev/mdev_driver.c
@@ -0,0 +1,119 @@
+/*
+ * MDEV driver
+ *
+ * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
+ * Author: Neo Jia <[email protected]>
+ * Kirti Wankhede <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/device.h>
+#include <linux/iommu.h>
+#include <linux/mdev.h>
+
+#include "mdev_private.h"
+
+static int mdev_attach_iommu(struct mdev_device *mdev)
+{
+ int ret;
+ struct iommu_group *group;
+
+ group = iommu_group_alloc();
+ if (IS_ERR(group))
+ return PTR_ERR(group);
+
+ ret = iommu_group_add_device(group, &mdev->dev);
+ if (!ret)
+ dev_info(&mdev->dev, "MDEV: group_id = %d\n",
+ iommu_group_id(group));
+
+ iommu_group_put(group);
+ return ret;
+}
+
+static void mdev_detach_iommu(struct mdev_device *mdev)
+{
+ iommu_group_remove_device(&mdev->dev);
+ dev_info(&mdev->dev, "MDEV: detaching iommu\n");
+}
+
+static int mdev_probe(struct device *dev)
+{
+ struct mdev_driver *drv = to_mdev_driver(dev->driver);
+ struct mdev_device *mdev = to_mdev_device(dev);
+ int ret;
+
+ ret = mdev_attach_iommu(mdev);
+ if (ret)
+ return ret;
+
+ if (drv && drv->probe) {
+ ret = drv->probe(dev);
+ if (ret)
+ mdev_detach_iommu(mdev);
+ }
+
+ return ret;
+}
+
+static int mdev_remove(struct device *dev)
+{
+ struct mdev_driver *drv = to_mdev_driver(dev->driver);
+ struct mdev_device *mdev = to_mdev_device(dev);
+
+ if (drv && drv->remove)
+ drv->remove(dev);
+
+ mdev_detach_iommu(mdev);
+
+ return 0;
+}
+
+struct bus_type mdev_bus_type = {
+ .name = "mdev",
+ .probe = mdev_probe,
+ .remove = mdev_remove,
+};
+EXPORT_SYMBOL_GPL(mdev_bus_type);
+
+/**
+ * mdev_register_driver - register a new MDEV driver
+ * @drv: the driver to register
+ * @owner: module owner of driver to be registered
+ *
+ * Returns a negative value on error, otherwise 0.
+ **/
+int mdev_register_driver(struct mdev_driver *drv, struct module *owner)
+{
+ /* initialize common driver fields */
+ drv->driver.name = drv->name;
+ drv->driver.bus = &mdev_bus_type;
+ drv->driver.owner = owner;
+
+ /* register with core */
+ return driver_register(&drv->driver);
+}
+EXPORT_SYMBOL(mdev_register_driver);
+
+/*
+ * mdev_unregister_driver - unregister MDEV driver
+ * @drv: the driver to unregister
+ */
+void mdev_unregister_driver(struct mdev_driver *drv)
+{
+ driver_unregister(&drv->driver);
+}
+EXPORT_SYMBOL(mdev_unregister_driver);
+
+int mdev_bus_register(void)
+{
+ return bus_register(&mdev_bus_type);
+}
+
+void mdev_bus_unregister(void)
+{
+ bus_unregister(&mdev_bus_type);
+}
diff --git a/drivers/vfio/mdev/mdev_private.h b/drivers/vfio/mdev/mdev_private.h
new file mode 100644
index 000000000000..d35097cbf3d7
--- /dev/null
+++ b/drivers/vfio/mdev/mdev_private.h
@@ -0,0 +1,41 @@
+/*
+ * Mediated device interal definitions
+ *
+ * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
+ * Author: Neo Jia <[email protected]>
+ * Kirti Wankhede <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef MDEV_PRIVATE_H
+#define MDEV_PRIVATE_H
+
+int mdev_bus_register(void);
+void mdev_bus_unregister(void);
+
+struct mdev_type {
+ struct kobject kobj;
+ struct kobject *devices_kobj;
+ struct parent_device *parent;
+ struct list_head next;
+ struct attribute_group *group;
+};
+
+#define to_mdev_type_attr(_attr) \
+ container_of(_attr, struct mdev_type_attribute, attr)
+#define to_mdev_type(_kobj) \
+ container_of(_kobj, struct mdev_type, kobj)
+
+int parent_create_sysfs_files(struct parent_device *parent);
+void parent_remove_sysfs_files(struct parent_device *parent);
+
+int mdev_create_sysfs_files(struct device *dev, struct mdev_type *type);
+void mdev_remove_sysfs_files(struct device *dev, struct mdev_type *type);
+
+int mdev_device_create(struct kobject *kobj, struct device *dev, uuid_le uuid);
+int mdev_device_remove(struct device *dev, bool force_remove);
+
+#endif /* MDEV_PRIVATE_H */
diff --git a/drivers/vfio/mdev/mdev_sysfs.c b/drivers/vfio/mdev/mdev_sysfs.c
new file mode 100644
index 000000000000..1a53deb2ee10
--- /dev/null
+++ b/drivers/vfio/mdev/mdev_sysfs.c
@@ -0,0 +1,286 @@
+/*
+ * File attributes for Mediated devices
+ *
+ * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
+ * Author: Neo Jia <[email protected]>
+ * Kirti Wankhede <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/sysfs.h>
+#include <linux/ctype.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/uuid.h>
+#include <linux/mdev.h>
+
+#include "mdev_private.h"
+
+/* Static functions */
+
+static ssize_t mdev_type_attr_show(struct kobject *kobj,
+ struct attribute *__attr, char *buf)
+{
+ struct mdev_type_attribute *attr = to_mdev_type_attr(__attr);
+ struct mdev_type *type = to_mdev_type(kobj);
+ ssize_t ret = -EIO;
+
+ if (attr->show)
+ ret = attr->show(kobj, type->parent->dev, buf);
+ return ret;
+}
+
+static ssize_t mdev_type_attr_store(struct kobject *kobj,
+ struct attribute *__attr,
+ const char *buf, size_t count)
+{
+ struct mdev_type_attribute *attr = to_mdev_type_attr(__attr);
+ struct mdev_type *type = to_mdev_type(kobj);
+ ssize_t ret = -EIO;
+
+ if (attr->store)
+ ret = attr->store(&type->kobj, type->parent->dev, buf, count);
+ return ret;
+}
+
+static const struct sysfs_ops mdev_type_sysfs_ops = {
+ .show = mdev_type_attr_show,
+ .store = mdev_type_attr_store,
+};
+
+static ssize_t create_store(struct kobject *kobj, struct device *dev,
+ const char *buf, size_t count)
+{
+ char *str;
+ uuid_le uuid;
+ int ret;
+
+ if ((count < UUID_STRING_LEN) || (count > UUID_STRING_LEN + 1))
+ return -EINVAL;
+
+ str = kstrndup(buf, count, GFP_KERNEL);
+ if (!str)
+ return -ENOMEM;
+
+ ret = uuid_le_to_bin(str, &uuid);
+ kfree(str);
+ if (ret)
+ return ret;
+
+ ret = mdev_device_create(kobj, dev, uuid);
+ if (ret)
+ return ret;
+
+ return count;
+}
+
+MDEV_TYPE_ATTR_WO(create);
+
+static void mdev_type_release(struct kobject *kobj)
+{
+ struct mdev_type *type = to_mdev_type(kobj);
+
+ pr_debug("Releasing group %s\n", kobj->name);
+ kfree(type);
+}
+
+static struct kobj_type mdev_type_ktype = {
+ .sysfs_ops = &mdev_type_sysfs_ops,
+ .release = mdev_type_release,
+};
+
+struct mdev_type *add_mdev_supported_type(struct parent_device *parent,
+ struct attribute_group *group)
+{
+ struct mdev_type *type;
+ int ret;
+
+ if (!group->name) {
+ pr_err("%s: Type name empty!\n", __func__);
+ return ERR_PTR(-EINVAL);
+ }
+
+ type = kzalloc(sizeof(*type), GFP_KERNEL);
+ if (!type)
+ return ERR_PTR(-ENOMEM);
+
+ type->kobj.kset = parent->mdev_types_kset;
+
+ ret = kobject_init_and_add(&type->kobj, &mdev_type_ktype, NULL,
+ "%s-%s", dev_driver_string(parent->dev),
+ group->name);
+ if (ret) {
+ kfree(type);
+ return ERR_PTR(ret);
+ }
+
+ ret = sysfs_create_file(&type->kobj, &mdev_type_attr_create.attr);
+ if (ret)
+ goto attr_create_failed;
+
+ type->devices_kobj = kobject_create_and_add("devices", &type->kobj);
+ if (!type->devices_kobj) {
+ ret = -ENOMEM;
+ goto attr_devices_failed;
+ }
+
+ ret = sysfs_create_files(&type->kobj,
+ (const struct attribute **)group->attrs);
+ if (ret) {
+ ret = -ENOMEM;
+ goto attrs_failed;
+ }
+
+ type->group = group;
+ type->parent = parent;
+ return type;
+
+attrs_failed:
+ kobject_put(type->devices_kobj);
+attr_devices_failed:
+ sysfs_remove_file(&type->kobj, &mdev_type_attr_create.attr);
+attr_create_failed:
+ kobject_del(&type->kobj);
+ kobject_put(&type->kobj);
+ return ERR_PTR(ret);
+}
+
+static void remove_mdev_supported_type(struct mdev_type *type)
+{
+ sysfs_remove_files(&type->kobj,
+ (const struct attribute **)type->group->attrs);
+ kobject_put(type->devices_kobj);
+ sysfs_remove_file(&type->kobj, &mdev_type_attr_create.attr);
+ kobject_del(&type->kobj);
+ kobject_put(&type->kobj);
+}
+
+static int add_mdev_supported_type_groups(struct parent_device *parent)
+{
+ int i;
+
+ for (i = 0; parent->ops->supported_type_groups[i]; i++) {
+ struct mdev_type *type;
+
+ type = add_mdev_supported_type(parent,
+ parent->ops->supported_type_groups[i]);
+ if (IS_ERR(type)) {
+ struct mdev_type *ltype, *tmp;
+
+ list_for_each_entry_safe(ltype, tmp, &parent->type_list,
+ next) {
+ list_del(<ype->next);
+ remove_mdev_supported_type(ltype);
+ }
+ return PTR_ERR(type);
+ }
+ list_add(&type->next, &parent->type_list);
+ }
+ return 0;
+}
+
+/* mdev sysfs functions */
+void parent_remove_sysfs_files(struct parent_device *parent)
+{
+ struct mdev_type *type, *tmp;
+
+ list_for_each_entry_safe(type, tmp, &parent->type_list, next) {
+ list_del(&type->next);
+ remove_mdev_supported_type(type);
+ }
+
+ sysfs_remove_groups(&parent->dev->kobj, parent->ops->dev_attr_groups);
+ kset_unregister(parent->mdev_types_kset);
+}
+
+int parent_create_sysfs_files(struct parent_device *parent)
+{
+ int ret;
+
+ parent->mdev_types_kset = kset_create_and_add("mdev_supported_types",
+ NULL, &parent->dev->kobj);
+
+ if (!parent->mdev_types_kset)
+ return -ENOMEM;
+
+ INIT_LIST_HEAD(&parent->type_list);
+
+ ret = sysfs_create_groups(&parent->dev->kobj,
+ parent->ops->dev_attr_groups);
+ if (ret)
+ goto create_err;
+
+ ret = add_mdev_supported_type_groups(parent);
+ if (ret)
+ sysfs_remove_groups(&parent->dev->kobj,
+ parent->ops->dev_attr_groups);
+ else
+ return ret;
+
+create_err:
+ kset_unregister(parent->mdev_types_kset);
+ return ret;
+}
+
+static ssize_t remove_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ unsigned long val;
+
+ if (kstrtoul(buf, 0, &val) < 0)
+ return -EINVAL;
+
+ if (val && device_remove_file_self(dev, attr)) {
+ int ret;
+
+ ret = mdev_device_remove(dev, false);
+ if (ret) {
+ device_create_file(dev, attr);
+ return ret;
+ }
+ }
+
+ return count;
+}
+
+static DEVICE_ATTR_WO(remove);
+
+static const struct attribute *mdev_device_attrs[] = {
+ &dev_attr_remove.attr,
+ NULL,
+};
+
+int mdev_create_sysfs_files(struct device *dev, struct mdev_type *type)
+{
+ int ret;
+
+ ret = sysfs_create_files(&dev->kobj, mdev_device_attrs);
+ if (ret)
+ return ret;
+
+ ret = sysfs_create_link(type->devices_kobj, &dev->kobj, dev_name(dev));
+ if (ret)
+ goto device_link_failed;
+
+ ret = sysfs_create_link(&dev->kobj, &type->kobj, "mdev_type");
+ if (ret)
+ goto type_link_failed;
+
+ return ret;
+
+type_link_failed:
+ sysfs_remove_link(type->devices_kobj, dev_name(dev));
+device_link_failed:
+ sysfs_remove_files(&dev->kobj, mdev_device_attrs);
+ return ret;
+}
+
+void mdev_remove_sysfs_files(struct device *dev, struct mdev_type *type)
+{
+ sysfs_remove_link(&dev->kobj, "mdev_type");
+ sysfs_remove_link(type->devices_kobj, dev_name(dev));
+ sysfs_remove_files(&dev->kobj, mdev_device_attrs);
+}
diff --git a/include/linux/mdev.h b/include/linux/mdev.h
new file mode 100644
index 000000000000..ec819e9a115a
--- /dev/null
+++ b/include/linux/mdev.h
@@ -0,0 +1,168 @@
+/*
+ * Mediated device definition
+ *
+ * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
+ * Author: Neo Jia <[email protected]>
+ * Kirti Wankhede <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef MDEV_H
+#define MDEV_H
+
+/* Parent device */
+struct parent_device {
+ struct device *dev;
+ const struct parent_ops *ops;
+
+ /* internal */
+ struct kref ref;
+ struct mutex lock;
+ struct list_head next;
+ struct kset *mdev_types_kset;
+ struct list_head type_list;
+};
+
+/* Mediated device */
+struct mdev_device {
+ struct device dev;
+ struct parent_device *parent;
+ uuid_le uuid;
+ void *driver_data;
+
+ /* internal */
+ struct kref ref;
+ struct list_head next;
+ struct kobject *type_kobj;
+};
+
+/**
+ * struct parent_ops - Structure to be registered for each parent device to
+ * register the device to mdev module.
+ *
+ * @owner: The module owner.
+ * @dev_attr_groups: Attributes of the parent device.
+ * @mdev_attr_groups: Attributes of the mediated device.
+ * @supported_type_groups: Attributes to define supported types. It is mandatory
+ * to provide supported types.
+ * @create: Called to allocate basic resources in parent device's
+ * driver for a particular mediated device. It is
+ * mandatory to provide create ops.
+ * @kobj: kobject of type for which 'create' is called.
+ * @mdev: mdev_device structure on of mediated device
+ * that is being created
+ * Returns integer: success (0) or error (< 0)
+ * @remove: Called to free resources in parent device's driver for a
+ * a mediated device. It is mandatory to provide 'remove'
+ * ops.
+ * @mdev: mdev_device device structure which is being
+ * destroyed
+ * Returns integer: success (0) or error (< 0)
+ * @open: Open mediated device.
+ * @mdev: mediated device.
+ * Returns integer: success (0) or error (< 0)
+ * @release: release mediated device
+ * @mdev: mediated device.
+ * @read: Read emulation callback
+ * @mdev: mediated device structure
+ * @buf: read buffer
+ * @count: number of bytes to read
+ * @ppos: address.
+ * Retuns number on bytes read on success or error.
+ * @write: Write emulation callback
+ * @mdev: mediated device structure
+ * @buf: write buffer
+ * @count: number of bytes to be written
+ * @ppos: address.
+ * Retuns number on bytes written on success or error.
+ * @ioctl: IOCTL callback
+ * @mdev: mediated device structure
+ * @cmd: ioctl command
+ * @arg: arguments to ioctl
+ * @mmap: mmap callback
+ * @mdev: mediated device structure
+ * @vma: vma structure
+ * Parent device that support mediated device should be registered with mdev
+ * module with parent_ops structure.
+ **/
+
+struct parent_ops {
+ struct module *owner;
+ const struct attribute_group **dev_attr_groups;
+ const struct attribute_group **mdev_attr_groups;
+ struct attribute_group **supported_type_groups;
+
+ int (*create)(struct kobject *kobj, struct mdev_device *mdev);
+ int (*remove)(struct mdev_device *mdev);
+ int (*open)(struct mdev_device *mdev);
+ void (*release)(struct mdev_device *mdev);
+ ssize_t (*read)(struct mdev_device *mdev, char __user *buf,
+ size_t count, loff_t *ppos);
+ ssize_t (*write)(struct mdev_device *mdev, const char __user *buf,
+ size_t count, loff_t *ppos);
+ ssize_t (*ioctl)(struct mdev_device *mdev, unsigned int cmd,
+ unsigned long arg);
+ int (*mmap)(struct mdev_device *mdev, struct vm_area_struct *vma);
+};
+
+/* interface for exporting mdev supported type attributes */
+struct mdev_type_attribute {
+ struct attribute attr;
+ ssize_t (*show)(struct kobject *kobj, struct device *dev, char *buf);
+ ssize_t (*store)(struct kobject *kobj, struct device *dev,
+ const char *buf, size_t count);
+};
+
+#define MDEV_TYPE_ATTR(_name, _mode, _show, _store) \
+struct mdev_type_attribute mdev_type_attr_##_name = \
+ __ATTR(_name, _mode, _show, _store)
+#define MDEV_TYPE_ATTR_RW(_name) \
+ struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_RW(_name)
+#define MDEV_TYPE_ATTR_RO(_name) \
+ struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_RO(_name)
+#define MDEV_TYPE_ATTR_WO(_name) \
+ struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_WO(_name)
+
+/**
+ * struct mdev_driver - Mediated device driver
+ * @name: driver name
+ * @probe: called when new device created
+ * @remove: called when device removed
+ * @driver: device driver structure
+ *
+ **/
+struct mdev_driver {
+ const char *name;
+ int (*probe)(struct device *dev);
+ void (*remove)(struct device *dev);
+ struct device_driver driver;
+};
+
+#define to_mdev_driver(drv) container_of(drv, struct mdev_driver, driver)
+#define to_mdev_device(dev) container_of(dev, struct mdev_device, dev)
+
+static inline void *mdev_get_drvdata(struct mdev_device *mdev)
+{
+ return mdev->driver_data;
+}
+
+static inline void mdev_set_drvdata(struct mdev_device *mdev, void *data)
+{
+ mdev->driver_data = data;
+}
+
+extern struct bus_type mdev_bus_type;
+
+#define dev_is_mdev(d) ((d)->bus == &mdev_bus_type)
+
+extern int mdev_register_device(struct device *dev,
+ const struct parent_ops *ops);
+extern void mdev_unregister_device(struct device *dev);
+
+extern int mdev_register_driver(struct mdev_driver *drv, struct module *owner);
+extern void mdev_unregister_driver(struct mdev_driver *drv);
+
+#endif /* MDEV_H */
--
2.7.0
On Tue, 15 Nov 2016 20:59:53 +0530
Kirti Wankhede <[email protected]> wrote:
> VFIO IOMMU drivers are designed for the devices which are IOMMU capable.
> Mediated device only uses IOMMU APIs, the underlying hardware can be
> managed by an IOMMU domain.
>
> Aim of this change is:
> - To use most of the code of TYPE1 IOMMU driver for mediated devices
> - To support direct assigned device and mediated device in single module
>
> This change adds pin and unpin support for mediated device to TYPE1 IOMMU
> backend module. More details:
> - Domain for external user is tracked separately in vfio_iommu structure.
> It is allocated when group for first mdev device is attached.
> - Pages pinned for external domain are tracked in each vfio_dma structure
> for that iova range.
> - Page tracking rb-tree in vfio_dma keeps <iova, pfn, ref_count>. Key of
> rb-tree is iova, but it actually aims to track pfns.
> - On external pin request for an iova, page is pinned once, if iova is
> already pinned and tracked, ref_count is incremented.
> - External unpin request unpins pages only when ref_count is 0.
> - Pinned pages list is used to verify unpinning request and to unpin
> remaining pages while detaching the group for that device.
> - Page accounting is updated to account in its address space where the
> pages are pinned/unpinned, i.e dma->task
> - Accouting for mdev device is only done if there is no iommu capable
> domain in the container. When there is a direct device assigned to the
> container and that domain is iommu capable, all pages are already pinned
> during DMA_MAP.
> - Page accouting is updated on hot plug and unplug mdev device and pass
> through device.
>
> Tested by assigning below combinations of devices to a single VM:
> - GPU pass through only
> - vGPU device only
> - One GPU pass through and one vGPU device
> - Linux VM hot plug and unplug vGPU device while GPU pass through device
> exist
> - Linux VM hot plug and unplug GPU pass through device while vGPU device
> exist
>
> Signed-off-by: Kirti Wankhede <[email protected]>
> Signed-off-by: Neo Jia <[email protected]>
> Change-Id: I295d6f0f2e0579b8d9882bfd8fd5a4194b97bd9a
> ---
> drivers/vfio/vfio_iommu_type1.c | 598 +++++++++++++++++++++++++++++++++++-----
> 1 file changed, 536 insertions(+), 62 deletions(-)
>
> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
> index 50aca95cf61e..0de7c20f66b1 100644
> --- a/drivers/vfio/vfio_iommu_type1.c
> +++ b/drivers/vfio/vfio_iommu_type1.c
> @@ -37,6 +37,7 @@
> #include <linux/vfio.h>
> #include <linux/workqueue.h>
> #include <linux/pid_namespace.h>
> +#include <linux/mdev.h>
>
> #define DRIVER_VERSION "0.2"
> #define DRIVER_AUTHOR "Alex Williamson <[email protected]>"
> @@ -56,6 +57,7 @@ MODULE_PARM_DESC(disable_hugepages,
>
> struct vfio_iommu {
> struct list_head domain_list;
> + struct vfio_domain *external_domain; /* domain for external user */
> struct mutex lock;
> struct rb_root dma_list;
> bool v2;
> @@ -76,7 +78,9 @@ struct vfio_dma {
> unsigned long vaddr; /* Process virtual addr */
> size_t size; /* Map size (bytes) */
> int prot; /* IOMMU_READ/WRITE */
> + bool iommu_mapped;
> struct task_struct *task;
> + struct rb_root pfn_list; /* Ex-user pinned pfn list */
> };
>
> struct vfio_group {
> @@ -85,6 +89,21 @@ struct vfio_group {
> };
>
> /*
> + * Guest RAM pinning working set or DMA target
> + */
> +struct vfio_pfn {
> + struct rb_node node;
> + dma_addr_t iova; /* Device address */
> + unsigned long pfn; /* Host pfn */
> + atomic_t ref_count;
> +};
> +
> +#define IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu) \
> + (!list_empty(&iommu->domain_list))
> +
> +static int put_pfn(unsigned long pfn, int prot);
> +
> +/*
> * This code handles mapping and unmapping of user data buffers
> * into DMA'ble space using the IOMMU
> */
> @@ -132,6 +151,97 @@ static void vfio_unlink_dma(struct vfio_iommu *iommu, struct vfio_dma *old)
> rb_erase(&old->node, &iommu->dma_list);
> }
>
> +/*
> + * Helper Functions for host iova-pfn list
> + */
> +static struct vfio_pfn *vfio_find_vpfn(struct vfio_dma *dma, dma_addr_t iova)
> +{
> + struct vfio_pfn *vpfn;
> + struct rb_node *node = dma->pfn_list.rb_node;
> +
> + while (node) {
> + vpfn = rb_entry(node, struct vfio_pfn, node);
> +
> + if (iova < vpfn->iova)
> + node = node->rb_left;
> + else if (iova > vpfn->iova)
> + node = node->rb_right;
> + else
> + return vpfn;
> + }
> + return NULL;
> +}
> +
> +static void vfio_link_pfn(struct vfio_dma *dma,
> + struct vfio_pfn *new)
> +{
> + struct rb_node **link, *parent = NULL;
> + struct vfio_pfn *vpfn;
> +
> + link = &dma->pfn_list.rb_node;
> + while (*link) {
> + parent = *link;
> + vpfn = rb_entry(parent, struct vfio_pfn, node);
> +
> + if (new->iova < vpfn->iova)
> + link = &(*link)->rb_left;
> + else
> + link = &(*link)->rb_right;
> + }
> +
> + rb_link_node(&new->node, parent, link);
> + rb_insert_color(&new->node, &dma->pfn_list);
> +}
> +
> +static void vfio_unlink_pfn(struct vfio_dma *dma, struct vfio_pfn *old)
> +{
> + rb_erase(&old->node, &dma->pfn_list);
> +}
> +
> +static int vfio_add_to_pfn_list(struct vfio_dma *dma, dma_addr_t iova,
> + unsigned long pfn)
> +{
> + struct vfio_pfn *vpfn;
> +
> + vpfn = kzalloc(sizeof(*vpfn), GFP_KERNEL);
> + if (!vpfn)
> + return -ENOMEM;
> +
> + vpfn->iova = iova;
> + vpfn->pfn = pfn;
> + atomic_set(&vpfn->ref_count, 1);
> + vfio_link_pfn(dma, vpfn);
> + return 0;
> +}
> +
> +static void vfio_remove_from_pfn_list(struct vfio_dma *dma,
> + struct vfio_pfn *vpfn)
> +{
> + vfio_unlink_pfn(dma, vpfn);
> + kfree(vpfn);
> +}
> +
> +static struct vfio_pfn *vfio_iova_get_vfio_pfn(struct vfio_dma *dma,
> + unsigned long iova)
> +{
> + struct vfio_pfn *vpfn = vfio_find_vpfn(dma, iova);
> +
> + if (vpfn)
> + atomic_inc(&vpfn->ref_count);
> + return vpfn;
> +}
> +
> +static int vfio_iova_put_vfio_pfn(struct vfio_dma *dma, struct vfio_pfn *vpfn)
> +{
> + int ret = 0;
> +
> + if (atomic_dec_and_test(&vpfn->ref_count)) {
> + ret = put_pfn(vpfn->pfn, dma->prot);
> + vfio_remove_from_pfn_list(dma, vpfn);
> + }
> + return ret;
> +}
> +
> struct vwork {
> struct mm_struct *mm;
> long npage;
> @@ -270,7 +380,6 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr,
> }
>
> up_read(&mm->mmap_sem);
> -
> return ret;
> }
>
> @@ -280,28 +389,36 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr,
> * first page and all consecutive pages with the same locking.
> */
> static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
> - long npage, int prot, unsigned long *pfn_base)
> + long npage, unsigned long *pfn_base)
> {
> unsigned long limit;
> bool lock_cap = ns_capable(task_active_pid_ns(dma->task)->user_ns,
> CAP_IPC_LOCK);
> struct mm_struct *mm;
> - long ret, i;
> + long ret, i, lock_acct = 0;
> bool rsvd;
> + struct vfio_pfn *vpfn;
nit, we only ever check whether it exists, we don't need a variable for
that.
> + dma_addr_t iova = vaddr - dma->vaddr + dma->iova;
>
> mm = get_task_mm(dma->task);
> if (!mm)
> return -ENODEV;
>
> - ret = vaddr_get_pfn(mm, vaddr, prot, pfn_base);
> + ret = vaddr_get_pfn(mm, vaddr, dma->prot, pfn_base);
> if (ret)
> goto pin_pg_remote_exit;
>
> rsvd = is_invalid_reserved_pfn(*pfn_base);
> + if (!rsvd) {
> + vpfn = vfio_find_vpfn(dma, iova);
> + if (!vpfn)
> + lock_acct = 1;
> + }
> +
> limit = task_rlimit(dma->task, RLIMIT_MEMLOCK) >> PAGE_SHIFT;
>
> - if (!rsvd && !lock_cap && mm->locked_vm + 1 > limit) {
> - put_pfn(*pfn_base, prot);
> + if (!rsvd && !lock_cap && mm->locked_vm + lock_acct > limit) {
> + put_pfn(*pfn_base, dma->prot);
> pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n", __func__,
> limit << PAGE_SHIFT);
> ret = -ENOMEM;
> @@ -310,35 +427,43 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
>
> if (unlikely(disable_hugepages)) {
> if (!rsvd)
> - vfio_lock_acct(dma->task, 1);
> + vfio_lock_acct(dma->task, lock_acct);
nit, if we only update lock_acct for !rsvd pages, we don't need to test
(!rsvd).
> ret = 1;
> goto pin_pg_remote_exit;
> }
>
> /* Lock all the consecutive pages from pfn_base */
> - for (i = 1, vaddr += PAGE_SIZE; i < npage; i++, vaddr += PAGE_SIZE) {
> + for (i = 1, vaddr += PAGE_SIZE, iova += PAGE_SIZE; i < npage;
> + i++, vaddr += PAGE_SIZE, iova += PAGE_SIZE) {
> unsigned long pfn = 0;
>
> - ret = vaddr_get_pfn(mm, vaddr, prot, &pfn);
> + ret = vaddr_get_pfn(mm, vaddr, dma->prot, &pfn);
> if (ret)
> break;
>
> if (pfn != *pfn_base + i ||
> rsvd != is_invalid_reserved_pfn(pfn)) {
> - put_pfn(pfn, prot);
> + put_pfn(pfn, dma->prot);
> break;
> }
>
> - if (!rsvd && !lock_cap && mm->locked_vm + i + 1 > limit) {
> - put_pfn(pfn, prot);
> + if (!rsvd && !lock_cap &&
> + mm->locked_vm + lock_acct + 1 > limit) {
This is still wrong, if the page is already in pfn_list and we're at
the locked memory limit, we unnecessarily error here. We need to know
whether or not we're accounting it before we can do this test.
> + put_pfn(pfn, dma->prot);
> pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n",
> __func__, limit << PAGE_SHIFT);
> break;
> }
> +
> + if (!rsvd) {
> + vpfn = vfio_find_vpfn(dma, iova);
> + if (!vpfn)
> + lock_acct++;
> + }
> }
>
> if (!rsvd)
> - vfio_lock_acct(dma->task, i);
> + vfio_lock_acct(dma->task, lock_acct);
> ret = i;
>
> pin_pg_remote_exit:
See attached for my attempt (untested) to fix this, and the nits noted
below
> @@ -346,14 +471,79 @@ pin_pg_remote_exit:
> return ret;
> }
>
> -static long vfio_unpin_pages_remote(struct vfio_dma *dma, unsigned long pfn,
> - long npage, int prot, bool do_accounting)
> +static long vfio_unpin_pages_remote(struct vfio_dma *dma, dma_addr_t iova,
> + unsigned long pfn, long npage,
> + bool do_accounting)
> {
> - unsigned long unlocked = 0;
> + long unlocked = 0, locked = 0;
> long i;
>
> - for (i = 0; i < npage; i++)
> - unlocked += put_pfn(pfn++, prot);
> + for (i = 0; i < npage; i++) {
> + struct vfio_pfn *vpfn;
> +
> + if (put_pfn(pfn++, dma->prot)) {
> + unlocked++;
> + vpfn = vfio_find_vpfn(dma, iova + (i << PAGE_SHIFT));
> + if (vpfn)
We don't need vpfn:
if (vfio_find_vpfn(dma, iova + (i << PAGE_SHIFT)))
locked++;
> + locked++;
> + }
> + }
> +
> + if (do_accounting)
> + vfio_lock_acct(dma->task, locked - unlocked);
> +
> + return unlocked;
> +}
> +
> +static int vfio_pin_page_external(struct vfio_dma *dma, unsigned long vaddr,
> + unsigned long *pfn_base, bool do_accounting)
> +{
> + unsigned long limit;
> + bool lock_cap = ns_capable(task_active_pid_ns(dma->task)->user_ns,
> + CAP_IPC_LOCK);
> + struct mm_struct *mm;
> + int ret;
> + bool rsvd;
> +
> + mm = get_task_mm(dma->task);
> + if (!mm)
> + return -ENODEV;
> +
> + ret = vaddr_get_pfn(mm, vaddr, dma->prot, pfn_base);
> + if (ret)
> + goto pin_page_exit;
> +
> + rsvd = is_invalid_reserved_pfn(*pfn_base);
> + limit = task_rlimit(dma->task, RLIMIT_MEMLOCK) >> PAGE_SHIFT;
> +
> + if (!rsvd && !lock_cap && mm->locked_vm + 1 > limit) {
> + put_pfn(*pfn_base, dma->prot);
> + pr_warn("%s: Task %s (%d) RLIMIT_MEMLOCK (%ld) exceeded\n",
> + __func__, dma->task->comm, task_pid_nr(dma->task),
> + limit << PAGE_SHIFT);
> + ret = -ENOMEM;
> + goto pin_page_exit;
> + }
> +
> + if (!rsvd && do_accounting)
> + vfio_lock_acct(dma->task, 1);
> + ret = 1;
> +
> +pin_page_exit:
> + mmput(mm);
> + return ret;
> +}
> +
> +static int vfio_unpin_page_external(struct vfio_dma *dma, dma_addr_t iova,
> + bool do_accounting)
> +{
> + int unlocked;
> + struct vfio_pfn *vpfn = vfio_find_vpfn(dma, iova);
> +
> + if (!vpfn)
> + return 0;
> +
> + unlocked = vfio_iova_put_vfio_pfn(dma, vpfn);
>
> if (do_accounting)
> vfio_lock_acct(dma->task, -unlocked);
> @@ -361,14 +551,145 @@ static long vfio_unpin_pages_remote(struct vfio_dma *dma, unsigned long pfn,
> return unlocked;
> }
>
> -static void vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma)
> +static int vfio_iommu_type1_pin_pages(void *iommu_data,
> + unsigned long *user_pfn,
> + int npage, int prot,
> + unsigned long *phys_pfn)
> +{
> + struct vfio_iommu *iommu = iommu_data;
> + int i, j, ret;
> + unsigned long remote_vaddr;
> + struct vfio_dma *dma;
> + bool do_accounting;
> +
> + if (!iommu || !user_pfn || !phys_pfn)
> + return -EINVAL;
> +
> + /* Supported for v2 version only */
> + if (!iommu->v2)
> + return -EACCES;
> +
> + mutex_lock(&iommu->lock);
> +
> + if (!iommu->external_domain) {
> + ret = -EINVAL;
> + goto pin_done;
> + }
> +
> + /*
> + * If iommu capable domain exist in the container then all pages are
> + * already pinned and accounted. Accouting should be done if there is no
> + * iommu capable domain in the container.
> + */
> + do_accounting = !IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu);
> +
> + for (i = 0; i < npage; i++) {
> + dma_addr_t iova;
> + struct vfio_pfn *vpfn;
> +
> + iova = user_pfn[i] << PAGE_SHIFT;
> + dma = vfio_find_dma(iommu, iova, 0);
> + if (!dma) {
> + ret = -EINVAL;
> + goto pin_unwind;
> + }
> +
> + if ((dma->prot & prot) != prot) {
> + ret = -EPERM;
> + goto pin_unwind;
> + }
> +
> + vpfn = vfio_iova_get_vfio_pfn(dma, iova);
> + if (vpfn) {
> + phys_pfn[i] = vpfn->pfn;
> + continue;
> + }
> +
> + remote_vaddr = dma->vaddr + iova - dma->iova;
> + ret = vfio_pin_page_external(dma, remote_vaddr, &phys_pfn[i],
> + do_accounting);
> + if (ret <= 0) {
> + WARN_ON(!ret);
> + goto pin_unwind;
> + }
> +
> + ret = vfio_add_to_pfn_list(dma, iova, phys_pfn[i]);
> + if (ret) {
> + vfio_unpin_page_external(dma, iova, do_accounting);
> + goto pin_unwind;
> + }
> + }
> +
> + ret = i;
> + goto pin_done;
> +
> +pin_unwind:
> + phys_pfn[i] = 0;
> + for (j = 0; j < i; j++) {
> + dma_addr_t iova;
> +
> + iova = user_pfn[j] << PAGE_SHIFT;
> + dma = vfio_find_dma(iommu, iova, 0);
> + vfio_unpin_page_external(dma, iova, do_accounting);
> + phys_pfn[j] = 0;
> + }
> +pin_done:
> + mutex_unlock(&iommu->lock);
> + return ret;
> +}
> +
> +static int vfio_iommu_type1_unpin_pages(void *iommu_data,
> + unsigned long *user_pfn,
> + int npage)
> +{
> + struct vfio_iommu *iommu = iommu_data;
> + bool do_accounting;
> + int i;
> +
> + if (!iommu || !user_pfn)
> + return -EINVAL;
> +
> + /* Supported for v2 version only */
> + if (!iommu->v2)
> + return -EACCES;
> +
> + mutex_lock(&iommu->lock);
> +
> + if (!iommu->external_domain) {
> + mutex_unlock(&iommu->lock);
> + return -EINVAL;
> + }
> +
> + do_accounting = !IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu);
> + for (i = 0; i < npage; i++) {
> + struct vfio_dma *dma;
> + dma_addr_t iova;
> +
> + iova = user_pfn[i] << PAGE_SHIFT;
> + dma = vfio_find_dma(iommu, iova, 0);
> + if (!dma)
> + goto unpin_exit;
> + vfio_unpin_page_external(dma, iova, do_accounting);
> + }
> +
> +unpin_exit:
> + mutex_unlock(&iommu->lock);
> + return i > npage ? npage : (i > 0 ? i : -EINVAL);
> +}
> +
> +static long vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma,
> + bool do_accounting)
> {
> dma_addr_t iova = dma->iova, end = dma->iova + dma->size;
> struct vfio_domain *domain, *d;
> long unlocked = 0;
>
> if (!dma->size)
> - return;
> + return 0;
> +
> + if (!IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu))
> + return 0;
> +
> /*
> * We use the IOMMU to track the physical addresses, otherwise we'd
> * need a much more complicated tracking system. Unfortunately that
> @@ -410,20 +731,26 @@ static void vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma)
> if (WARN_ON(!unmapped))
> break;
>
> - unlocked += vfio_unpin_pages_remote(dma, phys >> PAGE_SHIFT,
> + unlocked += vfio_unpin_pages_remote(dma, iova,
> + phys >> PAGE_SHIFT,
> unmapped >> PAGE_SHIFT,
> - dma->prot, false);
> + false);
> iova += unmapped;
>
> cond_resched();
> }
>
> - vfio_lock_acct(dma->task, -unlocked);
> + dma->iommu_mapped = false;
> + if (do_accounting) {
> + vfio_lock_acct(dma->task, -unlocked);
> + return 0;
> + }
> + return unlocked;
> }
>
> static void vfio_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *dma)
> {
> - vfio_unmap_unpin(iommu, dma);
> + vfio_unmap_unpin(iommu, dma, true);
> vfio_unlink_dma(iommu, dma);
> put_task_struct(dma->task);
> kfree(dma);
> @@ -606,8 +933,7 @@ static int vfio_pin_map_dma(struct vfio_iommu *iommu, struct vfio_dma *dma,
> while (size) {
> /* Pin a contiguous chunk of memory */
> npage = vfio_pin_pages_remote(dma, vaddr + dma->size,
> - size >> PAGE_SHIFT, dma->prot,
> - &pfn);
> + size >> PAGE_SHIFT, &pfn);
> if (npage <= 0) {
> WARN_ON(!npage);
> ret = (int)npage;
> @@ -618,8 +944,8 @@ static int vfio_pin_map_dma(struct vfio_iommu *iommu, struct vfio_dma *dma,
> ret = vfio_iommu_map(iommu, iova + dma->size, pfn, npage,
> dma->prot);
> if (ret) {
> - vfio_unpin_pages_remote(dma, pfn, npage,
> - dma->prot, true);
> + vfio_unpin_pages_remote(dma, iova + dma->size, pfn,
> + npage, true);
> break;
> }
>
> @@ -627,6 +953,8 @@ static int vfio_pin_map_dma(struct vfio_iommu *iommu, struct vfio_dma *dma,
> dma->size += npage << PAGE_SHIFT;
> }
>
> + dma->iommu_mapped = true;
> +
> if (ret)
> vfio_remove_dma(iommu, dma);
>
> @@ -682,11 +1010,16 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu,
> dma->prot = prot;
> get_task_struct(current);
> dma->task = current;
> + dma->pfn_list = RB_ROOT;
>
> /* Insert zero-sized and grow as we map chunks of it */
> vfio_link_dma(iommu, dma);
>
> - ret = vfio_pin_map_dma(iommu, dma, size);
> + /* Don't pin and map if container doesn't contain IOMMU capable domain*/
> + if (!IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu))
> + dma->size = size;
> + else
> + ret = vfio_pin_map_dma(iommu, dma, size);
> do_map_err:
> mutex_unlock(&iommu->lock);
> return ret;
> @@ -715,10 +1048,6 @@ static int vfio_iommu_replay(struct vfio_iommu *iommu,
> d = list_first_entry(&iommu->domain_list, struct vfio_domain, next);
> n = rb_first(&iommu->dma_list);
>
> - /* If there's not a domain, there better not be any mappings */
> - if (WARN_ON(n && !d))
> - return -EINVAL;
> -
> for (; n; n = rb_next(n)) {
> struct vfio_dma *dma;
> dma_addr_t iova;
> @@ -727,21 +1056,49 @@ static int vfio_iommu_replay(struct vfio_iommu *iommu,
> iova = dma->iova;
>
> while (iova < dma->iova + dma->size) {
> - phys_addr_t phys = iommu_iova_to_phys(d->domain, iova);
> + phys_addr_t phys;
> size_t size;
>
> - if (WARN_ON(!phys)) {
> - iova += PAGE_SIZE;
> - continue;
> + if (dma->iommu_mapped) {
> + phys_addr_t p;
> + dma_addr_t i;
> +
> + phys = iommu_iova_to_phys(d->domain, iova);
> +
> + if (WARN_ON(!phys)) {
> + iova += PAGE_SIZE;
> + continue;
> + }
> +
> + size = PAGE_SIZE;
> + p = phys + size;
> + i = iova + size;
> + while (i < dma->iova + dma->size &&
> + p == iommu_iova_to_phys(d->domain, i)) {
> + size += PAGE_SIZE;
> + p += PAGE_SIZE;
> + i += PAGE_SIZE;
> + }
> + } else {
> + unsigned long pfn;
> + unsigned long vaddr = dma->vaddr +
> + (iova - dma->iova);
> + size_t n = dma->iova + dma->size - iova;
> + long npage;
> +
> + npage = vfio_pin_pages_remote(dma, vaddr,
> + n >> PAGE_SHIFT,
> + &pfn);
> + if (npage <= 0) {
> + WARN_ON(!npage);
> + ret = (int)npage;
> + return ret;
> + }
> +
> + phys = pfn << PAGE_SHIFT;
> + size = npage << PAGE_SHIFT;
> }
>
> - size = PAGE_SIZE;
> -
> - while (iova + size < dma->iova + dma->size &&
> - phys + size == iommu_iova_to_phys(d->domain,
> - iova + size))
> - size += PAGE_SIZE;
> -
> ret = iommu_map(domain->domain, iova, phys,
> size, dma->prot | domain->prot);
> if (ret)
> @@ -749,8 +1106,8 @@ static int vfio_iommu_replay(struct vfio_iommu *iommu,
>
> iova += size;
> }
> + dma->iommu_mapped = true;
> }
> -
> return 0;
> }
>
> @@ -806,7 +1163,7 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
> struct vfio_iommu *iommu = iommu_data;
> struct vfio_group *group;
> struct vfio_domain *domain, *d;
> - struct bus_type *bus = NULL;
> + struct bus_type *bus = NULL, *mdev_bus;
> int ret;
>
> mutex_lock(&iommu->lock);
> @@ -818,6 +1175,13 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
> }
> }
>
> + if (iommu->external_domain) {
> + if (find_iommu_group(iommu->external_domain, iommu_group)) {
> + mutex_unlock(&iommu->lock);
> + return -EINVAL;
> + }
> + }
> +
> group = kzalloc(sizeof(*group), GFP_KERNEL);
> domain = kzalloc(sizeof(*domain), GFP_KERNEL);
> if (!group || !domain) {
> @@ -832,6 +1196,25 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
> if (ret)
> goto out_free;
>
> + mdev_bus = symbol_get(mdev_bus_type);
> +
> + if (mdev_bus) {
> + if ((bus == mdev_bus) && !iommu_present(bus)) {
> + symbol_put(mdev_bus_type);
> + if (!iommu->external_domain) {
> + INIT_LIST_HEAD(&domain->group_list);
> + iommu->external_domain = domain;
> + } else
> + kfree(domain);
> +
> + list_add(&group->next,
> + &iommu->external_domain->group_list);
> + mutex_unlock(&iommu->lock);
> + return 0;
> + }
> + symbol_put(mdev_bus_type);
> + }
> +
> domain->domain = iommu_domain_alloc(bus);
> if (!domain->domain) {
> ret = -EIO;
> @@ -922,6 +1305,54 @@ static void vfio_iommu_unmap_unpin_all(struct vfio_iommu *iommu)
> vfio_remove_dma(iommu, rb_entry(node, struct vfio_dma, node));
> }
>
> +static void vfio_iommu_unmap_unpin_reaccount(struct vfio_iommu *iommu)
> +{
> + struct rb_node *n, *p;
> +
> + n = rb_first(&iommu->dma_list);
> + for (; n; n = rb_next(n)) {
> + struct vfio_dma *dma;
> + long locked = 0, unlocked = 0;
> +
> + dma = rb_entry(n, struct vfio_dma, node);
> + unlocked += vfio_unmap_unpin(iommu, dma, false);
> + p = rb_first(&dma->pfn_list);
> + for (; p; p = rb_next(p)) {
> + bool rsvd;
> + struct vfio_pfn *vpfn = rb_entry(p, struct vfio_pfn,
> + node);
> +
> + rsvd = is_invalid_reserved_pfn(vpfn->pfn);
> + if (!rsvd)
We don't need to save rsvd:
if (!is_invalid_reserved_pfn(vpfn->pfn))
locked++;
> + locked++;
> + }
> + vfio_lock_acct(dma->task, locked - unlocked);
> + }
> +}
> +
> +static void vfio_external_unpin_all(struct vfio_iommu *iommu,
> + bool do_accounting)
> +{
> + struct rb_node *n, *p;
> +
> + n = rb_first(&iommu->dma_list);
> + for (; n; n = rb_next(n)) {
> + struct vfio_dma *dma;
> + int unlocked = 0;
> +
> + dma = rb_entry(n, struct vfio_dma, node);
> + while ((p = rb_first(&dma->pfn_list))) {
> + struct vfio_pfn *vpfn = rb_entry(p, struct vfio_pfn,
> + node);
> +
> + unlocked += vfio_iova_put_vfio_pfn(dma, vpfn);
> + }
> +
> + if (do_accounting)
> + vfio_lock_acct(dma->task, -unlocked);
> + }
> +}
> +
> static void vfio_iommu_type1_detach_group(void *iommu_data,
> struct iommu_group *iommu_group)
> {
> @@ -931,6 +1362,26 @@ static void vfio_iommu_type1_detach_group(void *iommu_data,
>
> mutex_lock(&iommu->lock);
>
> + if (iommu->external_domain) {
> + domain = iommu->external_domain;
Using the domain variable here actually makes this more difficult to
follow.
> + group = find_iommu_group(domain, iommu_group);
> + if (group) {
> + list_del(&group->next);
> + kfree(group);
> +
> + if (list_empty(&domain->group_list)) {
For example here we need to look back and see that domain is
iommu->external_domain.
> + if (!IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu)) {
> + vfio_external_unpin_all(iommu, true);
> + vfio_iommu_unmap_unpin_all(iommu);
> + } else
> + vfio_external_unpin_all(iommu, false);
> + kfree(domain);
> + iommu->external_domain = NULL;
And here, if we called kfree(iommu->external_domain), then set it to
NULL it's a little more cohesive.
> + }
> + goto detach_group_done;
> + }
> + }
> +
I almost wrote a big comment here about how we should be invalidating
the vendor drivers mappings via the notifier in the next patch rather
than clearing them ourselves here, but in the case where the group list
is empty, I think you're correct that we know through the way vfio
works that the device has been released and by that, the vendor driver
should be well informed that its mappings are invalid.
However, it seems that this invites sloppy behavior from the vendor
driver. Take for instance the !list_empty case. This would imply that
we have multiple mdev devices, potentially each with pinned pages. If
the vendor driver does not unpin their pages on device release, then
we're going to be left with a non-empty pfn_list when the user does an
unmap of that range, which will hit the WARN_ON that I encouraged you to
add. A warning/bug is still correct in that case, but I wonder if
we're going to hit that more than we'd like due to poorly behaved
vendor drivers and how we might make the code more robust to prevent
that.
If we say that a vendor driver MUST unpin all mappings when the device
is released, shouldn't that happen before we get here, so perhaps we
can WARN_ON if there are actually any external mappings to unpin here?
We may not be able to figure out which vendor driver is broken when
there are multiple devices, but it should break in the same way when
there's only one and it should show up in casual testing that way.
I don't think I'd call this a gating issue to taking this series, but
I'd like to address it as a follow-on before we get through the rc
cycle.
> list_for_each_entry(domain, &iommu->domain_list, next) {
> group = find_iommu_group(domain, iommu_group);
> if (!group)
> @@ -940,21 +1391,27 @@ static void vfio_iommu_type1_detach_group(void *iommu_data,
> list_del(&group->next);
> kfree(group);
> /*
> - * Group ownership provides privilege, if the group
> - * list is empty, the domain goes away. If it's the
> - * last domain, then all the mappings go away too.
> + * Group ownership provides privilege, if the group list is
> + * empty, the domain goes away. If it's the last domain with
> + * iommu and external domain doesn't exist, then all the
> + * mappings go away too. If it's the last domain with iommu and
> + * external domain exist, update accounting
> */
> if (list_empty(&domain->group_list)) {
> - if (list_is_singular(&iommu->domain_list))
> - vfio_iommu_unmap_unpin_all(iommu);
> + if (list_is_singular(&iommu->domain_list)) {
> + if (!iommu->external_domain)
> + vfio_iommu_unmap_unpin_all(iommu);
> + else
> + vfio_iommu_unmap_unpin_reaccount(iommu);
> + }
> iommu_domain_free(domain->domain);
> list_del(&domain->next);
> kfree(domain);
> }
> - goto done;
> + break;
> }
>
> -done:
> +detach_group_done:
> mutex_unlock(&iommu->lock);
> }
>
> @@ -986,27 +1443,42 @@ static void *vfio_iommu_type1_open(unsigned long arg)
> return iommu;
> }
>
> +static void vfio_release_domain(struct vfio_domain *domain, bool external)
> +{
> + struct vfio_group *group, *group_tmp;
> +
> + list_for_each_entry_safe(group, group_tmp,
> + &domain->group_list, next) {
> + if (!external)
> + iommu_detach_group(domain->domain, group->iommu_group);
> + list_del(&group->next);
> + kfree(group);
> + }
> +
> + if (!external)
> + iommu_domain_free(domain->domain);
> +}
> +
> static void vfio_iommu_type1_release(void *iommu_data)
> {
> struct vfio_iommu *iommu = iommu_data;
> struct vfio_domain *domain, *domain_tmp;
> - struct vfio_group *group, *group_tmp;
> +
> + if (iommu->external_domain) {
> + vfio_release_domain(iommu->external_domain, true);
> + vfio_external_unpin_all(iommu, false);
> + kfree(iommu->external_domain);
> + iommu->external_domain = NULL;
> + }
Same as above, it seems like something is broken in the vendor driver
if we get here and still have anything pinned. We should be screaming
about that since it's our only mechanism to make sure the vendor driver
unpins pages on device release.
>
> vfio_iommu_unmap_unpin_all(iommu);
>
> list_for_each_entry_safe(domain, domain_tmp,
> &iommu->domain_list, next) {
> - list_for_each_entry_safe(group, group_tmp,
> - &domain->group_list, next) {
> - iommu_detach_group(domain->domain, group->iommu_group);
> - list_del(&group->next);
> - kfree(group);
> - }
> - iommu_domain_free(domain->domain);
> + vfio_release_domain(domain, false);
> list_del(&domain->next);
> kfree(domain);
> }
> -
> kfree(iommu);
> }
>
> @@ -1110,6 +1582,8 @@ static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = {
> .ioctl = vfio_iommu_type1_ioctl,
> .attach_group = vfio_iommu_type1_attach_group,
> .detach_group = vfio_iommu_type1_detach_group,
> + .pin_pages = vfio_iommu_type1_pin_pages,
> + .unpin_pages = vfio_iommu_type1_unpin_pages,
> };
>
> static int __init vfio_iommu_type1_init(void)
On Tue, 15 Nov 2016 20:59:54 +0530
Kirti Wankhede <[email protected]> wrote:
> Added blocking notifier to IOMMU TYPE1 driver to notify vendor drivers
> about DMA_UNMAP.
> Exported two APIs vfio_register_notifier() and vfio_unregister_notifier().
> Notifier should be registered, if external user wants to use
> vfio_pin_pages()/vfio_unpin_pages() APIs to pin/unpin pages.
> Vendor driver should use VFIO_IOMMU_NOTIFY_DMA_UNMAP action to invalidate
> mappings.
>
> Signed-off-by: Kirti Wankhede <[email protected]>
> Signed-off-by: Neo Jia <[email protected]>
> Change-Id: I5910d0024d6be87f3e8d3e0ca0eaeaaa0b17f271
> ---
> drivers/vfio/vfio.c | 73 +++++++++++++++++++++++++++++++++++++++++
> drivers/vfio/vfio_iommu_type1.c | 63 +++++++++++++++++++++++++++++------
> include/linux/vfio.h | 11 +++++++
> 3 files changed, 137 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
> index 3bf8a01bf67b..fa121d983991 100644
> --- a/drivers/vfio/vfio.c
> +++ b/drivers/vfio/vfio.c
> @@ -1902,6 +1902,79 @@ err_unpin_pages:
> }
> EXPORT_SYMBOL(vfio_unpin_pages);
>
> +int vfio_register_notifier(struct device *dev, struct notifier_block *nb)
> +{
> + struct vfio_container *container;
> + struct vfio_group *group;
> + struct vfio_iommu_driver *driver;
> + ssize_t ret;
> +
> + if (!dev || !nb)
> + return -EINVAL;
> +
> + group = vfio_group_get_from_dev(dev);
> + if (IS_ERR(group))
> + return PTR_ERR(group);
> +
> + ret = vfio_group_add_container_user(group);
> + if (ret)
> + goto err_register_nb;
> +
> + container = group->container;
> + down_read(&container->group_lock);
> +
> + driver = container->iommu_driver;
> + if (likely(driver && driver->ops->register_notifier))
> + ret = driver->ops->register_notifier(container->iommu_data, nb);
> + else
> + ret = -ENOTTY;
> +
> + up_read(&container->group_lock);
> + vfio_group_try_dissolve_container(group);
> +
> +err_register_nb:
> + vfio_group_put(group);
> + return ret;
> +}
> +EXPORT_SYMBOL(vfio_register_notifier);
> +
> +int vfio_unregister_notifier(struct device *dev, struct notifier_block *nb)
> +{
> + struct vfio_container *container;
> + struct vfio_group *group;
> + struct vfio_iommu_driver *driver;
> + ssize_t ret;
> +
> + if (!dev || !nb)
> + return -EINVAL;
> +
> + group = vfio_group_get_from_dev(dev);
> + if (IS_ERR(group))
> + return PTR_ERR(group);
> +
> + ret = vfio_group_add_container_user(group);
> + if (ret)
> + goto err_unregister_nb;
> +
> + container = group->container;
> + down_read(&container->group_lock);
> +
> + driver = container->iommu_driver;
> + if (likely(driver && driver->ops->unregister_notifier))
> + ret = driver->ops->unregister_notifier(container->iommu_data,
> + nb);
> + else
> + ret = -ENOTTY;
> +
> + up_read(&container->group_lock);
> + vfio_group_try_dissolve_container(group);
> +
> +err_unregister_nb:
> + vfio_group_put(group);
> + return ret;
> +}
> +EXPORT_SYMBOL(vfio_unregister_notifier);
> +
> /**
> * Module/class support
> */
> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
> index 0de7c20f66b1..c45a4822784e 100644
> --- a/drivers/vfio/vfio_iommu_type1.c
> +++ b/drivers/vfio/vfio_iommu_type1.c
> @@ -38,6 +38,7 @@
> #include <linux/workqueue.h>
> #include <linux/pid_namespace.h>
> #include <linux/mdev.h>
> +#include <linux/notifier.h>
>
> #define DRIVER_VERSION "0.2"
> #define DRIVER_AUTHOR "Alex Williamson <[email protected]>"
> @@ -60,6 +61,7 @@ struct vfio_iommu {
> struct vfio_domain *external_domain; /* domain for external user */
> struct mutex lock;
> struct rb_root dma_list;
> + struct blocking_notifier_head notifier;
> bool v2;
> bool nesting;
> };
> @@ -571,7 +573,8 @@ static int vfio_iommu_type1_pin_pages(void *iommu_data,
>
> mutex_lock(&iommu->lock);
>
> - if (!iommu->external_domain) {
> + /* Fail if notifier list is empty */
> + if ((!iommu->external_domain) || (!iommu->notifier.head)) {
> ret = -EINVAL;
> goto pin_done;
> }
> @@ -854,7 +857,28 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
> */
> if (dma->task->mm != current->mm)
> break;
> +
> unmapped += dma->size;
> +
> + if (iommu->external_domain && !RB_EMPTY_ROOT(&dma->pfn_list)) {
> + struct vfio_iommu_type1_dma_unmap nb_unmap;
> +
> + nb_unmap.iova = dma->iova;
> + nb_unmap.size = dma->size;
> +
> + /*
> + * Notifier callback would call vfio_unpin_pages() which
> + * would acquire iommu->lock. Release lock here and
> + * reacquire it again.
> + */
> + mutex_unlock(&iommu->lock);
> + blocking_notifier_call_chain(&iommu->notifier,
> + VFIO_IOMMU_NOTIFY_DMA_UNMAP,
> + &nb_unmap);
> + mutex_lock(&iommu->lock);
> + if (WARN_ON(!RB_EMPTY_ROOT(&dma->pfn_list)))
> + break;
> + }
Why exactly do we need to notify per vfio_dma rather than per unmap
request? If we do the latter we can send the notify first, limiting us
to races where a page is pinned between the notify and the locking,
whereas here, even our dma pointer is suspect once we re-acquire the
lock, we don't technically know if another unmap could have removed
that already. Perhaps something like this (untested):
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index ee9a680..8504501 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -785,6 +785,8 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
struct vfio_dma *dma;
size_t unmapped = 0;
int ret = 0;
+ struct vfio_iommu_type1_dma_unmap nb_unmap = { .iova = unmap->iova,
+ .size = unmap->size };
mask = ((uint64_t)1 << __ffs(vfio_pgsize_bitmap(iommu))) - 1;
@@ -795,6 +797,14 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
WARN_ON(mask & PAGE_MASK);
+ /*
+ * Notify anyone (mdev vendor drivers) to invalidate and unmap
+ * iovas within the range we're about to unmap. Vendor drivers MUST
+ * unpin pages in response to an invalidation.
+ */
+ blocking_notifier_call_chain(&iommu->notifier,
+ VFIO_IOMMU_NOTIFY_DMA_UNMAP, &nb_unmap);
+
mutex_lock(&iommu->lock);
/*
@@ -853,25 +863,8 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
unmapped += dma->size;
- if (iommu->external_domain && !RB_EMPTY_ROOT(&dma->pfn_list)) {
- struct vfio_iommu_type1_dma_unmap nb_unmap;
+ WARN_ON(!RB_EMPTY_ROOT(&dma->pfn_list));
- nb_unmap.iova = dma->iova;
- nb_unmap.size = dma->size;
-
- /*
- * Notifier callback would call vfio_unpin_pages() which
- * would acquire iommu->lock. Release lock here and
- * reacquire it again.
- */
- mutex_unlock(&iommu->lock);
- blocking_notifier_call_chain(&iommu->notifier,
- VFIO_IOMMU_NOTIFY_DMA_UNMAP,
- &nb_unmap);
- mutex_lock(&iommu->lock);
- if (WARN_ON(!RB_EMPTY_ROOT(&dma->pfn_list)))
- break;
- }
vfio_remove_dma(iommu, dma);
}
> vfio_remove_dma(iommu, dma);
> }
>
> @@ -1439,6 +1463,7 @@ static void *vfio_iommu_type1_open(unsigned long arg)
> INIT_LIST_HEAD(&iommu->domain_list);
> iommu->dma_list = RB_ROOT;
> mutex_init(&iommu->lock);
> + BLOCKING_INIT_NOTIFIER_HEAD(&iommu->notifier);
>
> return iommu;
> }
> @@ -1574,16 +1599,34 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
> return -ENOTTY;
> }
>
> +static int vfio_iommu_type1_register_notifier(void *iommu_data,
> + struct notifier_block *nb)
> +{
> + struct vfio_iommu *iommu = iommu_data;
> +
> + return blocking_notifier_chain_register(&iommu->notifier, nb);
> +}
> +
> +static int vfio_iommu_type1_unregister_notifier(void *iommu_data,
> + struct notifier_block *nb)
> +{
> + struct vfio_iommu *iommu = iommu_data;
> +
> + return blocking_notifier_chain_unregister(&iommu->notifier, nb);
> +}
> +
> static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = {
> - .name = "vfio-iommu-type1",
> - .owner = THIS_MODULE,
> - .open = vfio_iommu_type1_open,
> - .release = vfio_iommu_type1_release,
> - .ioctl = vfio_iommu_type1_ioctl,
> - .attach_group = vfio_iommu_type1_attach_group,
> - .detach_group = vfio_iommu_type1_detach_group,
> - .pin_pages = vfio_iommu_type1_pin_pages,
> - .unpin_pages = vfio_iommu_type1_unpin_pages,
> + .name = "vfio-iommu-type1",
> + .owner = THIS_MODULE,
> + .open = vfio_iommu_type1_open,
> + .release = vfio_iommu_type1_release,
> + .ioctl = vfio_iommu_type1_ioctl,
> + .attach_group = vfio_iommu_type1_attach_group,
> + .detach_group = vfio_iommu_type1_detach_group,
> + .pin_pages = vfio_iommu_type1_pin_pages,
> + .unpin_pages = vfio_iommu_type1_unpin_pages,
> + .register_notifier = vfio_iommu_type1_register_notifier,
> + .unregister_notifier = vfio_iommu_type1_unregister_notifier,
> };
>
> static int __init vfio_iommu_type1_init(void)
> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
> index 420cdc928786..997442398c09 100644
> --- a/include/linux/vfio.h
> +++ b/include/linux/vfio.h
> @@ -80,6 +80,10 @@ struct vfio_iommu_driver_ops {
> unsigned long *phys_pfn);
> int (*unpin_pages)(void *iommu_data,
> unsigned long *user_pfn, int npage);
> + int (*register_notifier)(void *iommu_data,
> + struct notifier_block *nb);
> + int (*unregister_notifier)(void *iommu_data,
> + struct notifier_block *nb);
> };
>
> extern int vfio_register_iommu_driver(const struct vfio_iommu_driver_ops *ops);
> @@ -139,6 +143,13 @@ extern int vfio_pin_pages(struct device *dev, unsigned long *user_pfn,
> extern int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn,
> int npage);
>
> +#define VFIO_IOMMU_NOTIFY_DMA_UNMAP 1
> +
> +extern int vfio_register_notifier(struct device *dev,
> + struct notifier_block *nb);
> +
> +extern int vfio_unregister_notifier(struct device *dev,
> + struct notifier_block *nb);
> /*
> * IRQfd - generic
> */
On 11/16/2016 3:49 AM, Alex Williamson wrote:
> On Tue, 15 Nov 2016 20:59:54 +0530
> Kirti Wankhede <[email protected]> wrote:
>
...
>> @@ -854,7 +857,28 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
>> */
>> if (dma->task->mm != current->mm)
>> break;
>> +
>> unmapped += dma->size;
>> +
>> + if (iommu->external_domain && !RB_EMPTY_ROOT(&dma->pfn_list)) {
>> + struct vfio_iommu_type1_dma_unmap nb_unmap;
>> +
>> + nb_unmap.iova = dma->iova;
>> + nb_unmap.size = dma->size;
>> +
>> + /*
>> + * Notifier callback would call vfio_unpin_pages() which
>> + * would acquire iommu->lock. Release lock here and
>> + * reacquire it again.
>> + */
>> + mutex_unlock(&iommu->lock);
>> + blocking_notifier_call_chain(&iommu->notifier,
>> + VFIO_IOMMU_NOTIFY_DMA_UNMAP,
>> + &nb_unmap);
>> + mutex_lock(&iommu->lock);
>> + if (WARN_ON(!RB_EMPTY_ROOT(&dma->pfn_list)))
>> + break;
>> + }
>
>
> Why exactly do we need to notify per vfio_dma rather than per unmap
> request? If we do the latter we can send the notify first, limiting us
> to races where a page is pinned between the notify and the locking,
> whereas here, even our dma pointer is suspect once we re-acquire the
> lock, we don't technically know if another unmap could have removed
> that already. Perhaps something like this (untested):
>
There are checks to validate unmap request, like v2 check and who is
calling unmap and is it allowed for that task to unmap. Before these
checks its not sure that unmap region range which asked for would be
unmapped all. Notify call should be at the place where its sure that the
range provided to notify call is definitely going to be removed. My
change do that.
Thanks,
Kirti
> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
> index ee9a680..8504501 100644
> --- a/drivers/vfio/vfio_iommu_type1.c
> +++ b/drivers/vfio/vfio_iommu_type1.c
> @@ -785,6 +785,8 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
> struct vfio_dma *dma;
> size_t unmapped = 0;
> int ret = 0;
> + struct vfio_iommu_type1_dma_unmap nb_unmap = { .iova = unmap->iova,
> + .size = unmap->size };
>
> mask = ((uint64_t)1 << __ffs(vfio_pgsize_bitmap(iommu))) - 1;
>
> @@ -795,6 +797,14 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
>
> WARN_ON(mask & PAGE_MASK);
>
> + /*
> + * Notify anyone (mdev vendor drivers) to invalidate and unmap
> + * iovas within the range we're about to unmap. Vendor drivers MUST
> + * unpin pages in response to an invalidation.
> + */
> + blocking_notifier_call_chain(&iommu->notifier,
> + VFIO_IOMMU_NOTIFY_DMA_UNMAP, &nb_unmap);
> +
> mutex_lock(&iommu->lock);
>
> /*
> @@ -853,25 +863,8 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
>
> unmapped += dma->size;
>
> - if (iommu->external_domain && !RB_EMPTY_ROOT(&dma->pfn_list)) {
> - struct vfio_iommu_type1_dma_unmap nb_unmap;
> + WARN_ON(!RB_EMPTY_ROOT(&dma->pfn_list));
>
> - nb_unmap.iova = dma->iova;
> - nb_unmap.size = dma->size;
> -
> - /*
> - * Notifier callback would call vfio_unpin_pages() which
> - * would acquire iommu->lock. Release lock here and
> - * reacquire it again.
> - */
> - mutex_unlock(&iommu->lock);
> - blocking_notifier_call_chain(&iommu->notifier,
> - VFIO_IOMMU_NOTIFY_DMA_UNMAP,
> - &nb_unmap);
> - mutex_lock(&iommu->lock);
> - if (WARN_ON(!RB_EMPTY_ROOT(&dma->pfn_list)))
> - break;
> - }
> vfio_remove_dma(iommu, dma);
> }
>
>
>
>> vfio_remove_dma(iommu, dma);
>> }
>>
On Wed, 16 Nov 2016 08:16:15 +0530
Kirti Wankhede <[email protected]> wrote:
> On 11/16/2016 3:49 AM, Alex Williamson wrote:
> > On Tue, 15 Nov 2016 20:59:54 +0530
> > Kirti Wankhede <[email protected]> wrote:
> >
> ...
>
> >> @@ -854,7 +857,28 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
> >> */
> >> if (dma->task->mm != current->mm)
> >> break;
> >> +
> >> unmapped += dma->size;
> >> +
> >> + if (iommu->external_domain && !RB_EMPTY_ROOT(&dma->pfn_list)) {
> >> + struct vfio_iommu_type1_dma_unmap nb_unmap;
> >> +
> >> + nb_unmap.iova = dma->iova;
> >> + nb_unmap.size = dma->size;
> >> +
> >> + /*
> >> + * Notifier callback would call vfio_unpin_pages() which
> >> + * would acquire iommu->lock. Release lock here and
> >> + * reacquire it again.
> >> + */
> >> + mutex_unlock(&iommu->lock);
> >> + blocking_notifier_call_chain(&iommu->notifier,
> >> + VFIO_IOMMU_NOTIFY_DMA_UNMAP,
> >> + &nb_unmap);
> >> + mutex_lock(&iommu->lock);
> >> + if (WARN_ON(!RB_EMPTY_ROOT(&dma->pfn_list)))
> >> + break;
> >> + }
> >
> >
> > Why exactly do we need to notify per vfio_dma rather than per unmap
> > request? If we do the latter we can send the notify first, limiting us
> > to races where a page is pinned between the notify and the locking,
> > whereas here, even our dma pointer is suspect once we re-acquire the
> > lock, we don't technically know if another unmap could have removed
> > that already. Perhaps something like this (untested):
> >
>
> There are checks to validate unmap request, like v2 check and who is
> calling unmap and is it allowed for that task to unmap. Before these
> checks its not sure that unmap region range which asked for would be
> unmapped all. Notify call should be at the place where its sure that the
> range provided to notify call is definitely going to be removed. My
> change do that.
Ok, but that does solve the problem. What about this (untested):
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index ee9a680..50cafdf 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -782,9 +782,9 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
struct vfio_iommu_type1_dma_unmap *unmap)
{
uint64_t mask;
- struct vfio_dma *dma;
+ struct vfio_dma *dma, *dma_last = NULL;
size_t unmapped = 0;
- int ret = 0;
+ int ret = 0, retries;
mask = ((uint64_t)1 << __ffs(vfio_pgsize_bitmap(iommu))) - 1;
@@ -794,7 +794,7 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
return -EINVAL;
WARN_ON(mask & PAGE_MASK);
-
+again:
mutex_lock(&iommu->lock);
/*
@@ -851,11 +851,16 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
if (dma->task->mm != current->mm)
break;
- unmapped += dma->size;
-
- if (iommu->external_domain && !RB_EMPTY_ROOT(&dma->pfn_list)) {
+ if (!RB_EMPTY_ROOT(&dma->pfn_list)) {
struct vfio_iommu_type1_dma_unmap nb_unmap;
+ if (dma_last == dma) {
+ BUG_ON(++retries > 10);
+ } else {
+ dma_last = dma;
+ retries = 0;
+ }
+
nb_unmap.iova = dma->iova;
nb_unmap.size = dma->size;
@@ -868,11 +873,11 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
blocking_notifier_call_chain(&iommu->notifier,
VFIO_IOMMU_NOTIFY_DMA_UNMAP,
&nb_unmap);
- mutex_lock(&iommu->lock);
- if (WARN_ON(!RB_EMPTY_ROOT(&dma->pfn_list)))
- break;
+ goto again:
}
+ unmapped += dma->size;
vfio_remove_dma(iommu, dma);
+
}
unlock:
On Tue, 15 Nov 2016 20:16:12 -0700
Alex Williamson <[email protected]> wrote:
> On Wed, 16 Nov 2016 08:16:15 +0530
> Kirti Wankhede <[email protected]> wrote:
>
> > On 11/16/2016 3:49 AM, Alex Williamson wrote:
> > > On Tue, 15 Nov 2016 20:59:54 +0530
> > > Kirti Wankhede <[email protected]> wrote:
> > >
> > ...
> >
> > >> @@ -854,7 +857,28 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
> > >> */
> > >> if (dma->task->mm != current->mm)
> > >> break;
> > >> +
> > >> unmapped += dma->size;
> > >> +
> > >> + if (iommu->external_domain && !RB_EMPTY_ROOT(&dma->pfn_list)) {
> > >> + struct vfio_iommu_type1_dma_unmap nb_unmap;
> > >> +
> > >> + nb_unmap.iova = dma->iova;
> > >> + nb_unmap.size = dma->size;
> > >> +
> > >> + /*
> > >> + * Notifier callback would call vfio_unpin_pages() which
> > >> + * would acquire iommu->lock. Release lock here and
> > >> + * reacquire it again.
> > >> + */
> > >> + mutex_unlock(&iommu->lock);
> > >> + blocking_notifier_call_chain(&iommu->notifier,
> > >> + VFIO_IOMMU_NOTIFY_DMA_UNMAP,
> > >> + &nb_unmap);
> > >> + mutex_lock(&iommu->lock);
> > >> + if (WARN_ON(!RB_EMPTY_ROOT(&dma->pfn_list)))
> > >> + break;
> > >> + }
> > >
> > >
> > > Why exactly do we need to notify per vfio_dma rather than per unmap
> > > request? If we do the latter we can send the notify first, limiting us
> > > to races where a page is pinned between the notify and the locking,
> > > whereas here, even our dma pointer is suspect once we re-acquire the
> > > lock, we don't technically know if another unmap could have removed
> > > that already. Perhaps something like this (untested):
> > >
> >
> > There are checks to validate unmap request, like v2 check and who is
> > calling unmap and is it allowed for that task to unmap. Before these
> > checks its not sure that unmap region range which asked for would be
> > unmapped all. Notify call should be at the place where its sure that the
> > range provided to notify call is definitely going to be removed. My
> > change do that.
>
> Ok, but that does solve the problem. What about this (untested):
s/does/does not/
BTW, I like how the retries here fill the gap in my previous proposal
where we could still race re-pinning. We've given it an honest shot or
someone is not participating if we've retried 10 times. I don't
understand why the test for iommu->external_domain was there, clearly
if the list is not empty, we need to notify. Thanks,
Alex
> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
> index ee9a680..50cafdf 100644
> --- a/drivers/vfio/vfio_iommu_type1.c
> +++ b/drivers/vfio/vfio_iommu_type1.c
> @@ -782,9 +782,9 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
> struct vfio_iommu_type1_dma_unmap *unmap)
> {
> uint64_t mask;
> - struct vfio_dma *dma;
> + struct vfio_dma *dma, *dma_last = NULL;
> size_t unmapped = 0;
> - int ret = 0;
> + int ret = 0, retries;
>
> mask = ((uint64_t)1 << __ffs(vfio_pgsize_bitmap(iommu))) - 1;
>
> @@ -794,7 +794,7 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
> return -EINVAL;
>
> WARN_ON(mask & PAGE_MASK);
> -
> +again:
> mutex_lock(&iommu->lock);
>
> /*
> @@ -851,11 +851,16 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
> if (dma->task->mm != current->mm)
> break;
>
> - unmapped += dma->size;
> -
> - if (iommu->external_domain && !RB_EMPTY_ROOT(&dma->pfn_list)) {
> + if (!RB_EMPTY_ROOT(&dma->pfn_list)) {
> struct vfio_iommu_type1_dma_unmap nb_unmap;
>
> + if (dma_last == dma) {
> + BUG_ON(++retries > 10);
> + } else {
> + dma_last = dma;
> + retries = 0;
> + }
> +
> nb_unmap.iova = dma->iova;
> nb_unmap.size = dma->size;
>
> @@ -868,11 +873,11 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
> blocking_notifier_call_chain(&iommu->notifier,
> VFIO_IOMMU_NOTIFY_DMA_UNMAP,
> &nb_unmap);
> - mutex_lock(&iommu->lock);
> - if (WARN_ON(!RB_EMPTY_ROOT(&dma->pfn_list)))
> - break;
> + goto again:
> }
> + unmapped += dma->size;
> vfio_remove_dma(iommu, dma);
> +
> }
>
> unlock:
On 11/16/2016 8:55 AM, Alex Williamson wrote:
> On Tue, 15 Nov 2016 20:16:12 -0700
> Alex Williamson <[email protected]> wrote:
>
>> On Wed, 16 Nov 2016 08:16:15 +0530
>> Kirti Wankhede <[email protected]> wrote:
>>
>>> On 11/16/2016 3:49 AM, Alex Williamson wrote:
>>>> On Tue, 15 Nov 2016 20:59:54 +0530
>>>> Kirti Wankhede <[email protected]> wrote:
>>>>
>>> ...
>>>
>>>>> @@ -854,7 +857,28 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
>>>>> */
>>>>> if (dma->task->mm != current->mm)
>>>>> break;
>>>>> +
>>>>> unmapped += dma->size;
>>>>> +
>>>>> + if (iommu->external_domain && !RB_EMPTY_ROOT(&dma->pfn_list)) {
>>>>> + struct vfio_iommu_type1_dma_unmap nb_unmap;
>>>>> +
>>>>> + nb_unmap.iova = dma->iova;
>>>>> + nb_unmap.size = dma->size;
>>>>> +
>>>>> + /*
>>>>> + * Notifier callback would call vfio_unpin_pages() which
>>>>> + * would acquire iommu->lock. Release lock here and
>>>>> + * reacquire it again.
>>>>> + */
>>>>> + mutex_unlock(&iommu->lock);
>>>>> + blocking_notifier_call_chain(&iommu->notifier,
>>>>> + VFIO_IOMMU_NOTIFY_DMA_UNMAP,
>>>>> + &nb_unmap);
>>>>> + mutex_lock(&iommu->lock);
>>>>> + if (WARN_ON(!RB_EMPTY_ROOT(&dma->pfn_list)))
>>>>> + break;
>>>>> + }
>>>>
>>>>
>>>> Why exactly do we need to notify per vfio_dma rather than per unmap
>>>> request? If we do the latter we can send the notify first, limiting us
>>>> to races where a page is pinned between the notify and the locking,
>>>> whereas here, even our dma pointer is suspect once we re-acquire the
>>>> lock, we don't technically know if another unmap could have removed
>>>> that already. Perhaps something like this (untested):
>>>>
>>>
>>> There are checks to validate unmap request, like v2 check and who is
>>> calling unmap and is it allowed for that task to unmap. Before these
>>> checks its not sure that unmap region range which asked for would be
>>> unmapped all. Notify call should be at the place where its sure that the
>>> range provided to notify call is definitely going to be removed. My
>>> change do that.
>>
>> Ok, but that does solve the problem. What about this (untested):
>
> s/does/does not/
>
> BTW, I like how the retries here fill the gap in my previous proposal
> where we could still race re-pinning. We've given it an honest shot or
> someone is not participating if we've retried 10 times. I don't
> understand why the test for iommu->external_domain was there, clearly
> if the list is not empty, we need to notify. Thanks,
>
Ok. Retry is good to give a chance to unpin all. But is it really
required to use BUG_ON() that would panic the host. I think WARN_ON
should be fine and then when container is closed or when the last group
is removed from the container, vfio_iommu_type1_release() is called and
we have a chance to unpin it all.
Thanks,
Kirti
> Alex
>
>> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
>> index ee9a680..50cafdf 100644
>> --- a/drivers/vfio/vfio_iommu_type1.c
>> +++ b/drivers/vfio/vfio_iommu_type1.c
>> @@ -782,9 +782,9 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
>> struct vfio_iommu_type1_dma_unmap *unmap)
>> {
>> uint64_t mask;
>> - struct vfio_dma *dma;
>> + struct vfio_dma *dma, *dma_last = NULL;
>> size_t unmapped = 0;
>> - int ret = 0;
>> + int ret = 0, retries;
>>
>> mask = ((uint64_t)1 << __ffs(vfio_pgsize_bitmap(iommu))) - 1;
>>
>> @@ -794,7 +794,7 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
>> return -EINVAL;
>>
>> WARN_ON(mask & PAGE_MASK);
>> -
>> +again:
>> mutex_lock(&iommu->lock);
>>
>> /*
>> @@ -851,11 +851,16 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
>> if (dma->task->mm != current->mm)
>> break;
>>
>> - unmapped += dma->size;
>> -
>> - if (iommu->external_domain && !RB_EMPTY_ROOT(&dma->pfn_list)) {
>> + if (!RB_EMPTY_ROOT(&dma->pfn_list)) {
>> struct vfio_iommu_type1_dma_unmap nb_unmap;
>>
>> + if (dma_last == dma) {
>> + BUG_ON(++retries > 10);
>> + } else {
>> + dma_last = dma;
>> + retries = 0;
>> + }
>> +
>> nb_unmap.iova = dma->iova;
>> nb_unmap.size = dma->size;
>>
>> @@ -868,11 +873,11 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
>> blocking_notifier_call_chain(&iommu->notifier,
>> VFIO_IOMMU_NOTIFY_DMA_UNMAP,
>> &nb_unmap);
>> - mutex_lock(&iommu->lock);
>> - if (WARN_ON(!RB_EMPTY_ROOT(&dma->pfn_list)))
>> - break;
>> + goto again:
>> }
>> + unmapped += dma->size;
>> vfio_remove_dma(iommu, dma);
>> +
>> }
>>
>> unlock:
>
On Wed, 16 Nov 2016 09:13:37 +0530
Kirti Wankhede <[email protected]> wrote:
> On 11/16/2016 8:55 AM, Alex Williamson wrote:
> > On Tue, 15 Nov 2016 20:16:12 -0700
> > Alex Williamson <[email protected]> wrote:
> >
> >> On Wed, 16 Nov 2016 08:16:15 +0530
> >> Kirti Wankhede <[email protected]> wrote:
> >>
> >>> On 11/16/2016 3:49 AM, Alex Williamson wrote:
> >>>> On Tue, 15 Nov 2016 20:59:54 +0530
> >>>> Kirti Wankhede <[email protected]> wrote:
> >>>>
> >>> ...
> >>>
> >>>>> @@ -854,7 +857,28 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
> >>>>> */
> >>>>> if (dma->task->mm != current->mm)
> >>>>> break;
> >>>>> +
> >>>>> unmapped += dma->size;
> >>>>> +
> >>>>> + if (iommu->external_domain && !RB_EMPTY_ROOT(&dma->pfn_list)) {
> >>>>> + struct vfio_iommu_type1_dma_unmap nb_unmap;
> >>>>> +
> >>>>> + nb_unmap.iova = dma->iova;
> >>>>> + nb_unmap.size = dma->size;
> >>>>> +
> >>>>> + /*
> >>>>> + * Notifier callback would call vfio_unpin_pages() which
> >>>>> + * would acquire iommu->lock. Release lock here and
> >>>>> + * reacquire it again.
> >>>>> + */
> >>>>> + mutex_unlock(&iommu->lock);
> >>>>> + blocking_notifier_call_chain(&iommu->notifier,
> >>>>> + VFIO_IOMMU_NOTIFY_DMA_UNMAP,
> >>>>> + &nb_unmap);
> >>>>> + mutex_lock(&iommu->lock);
> >>>>> + if (WARN_ON(!RB_EMPTY_ROOT(&dma->pfn_list)))
> >>>>> + break;
> >>>>> + }
> >>>>
> >>>>
> >>>> Why exactly do we need to notify per vfio_dma rather than per unmap
> >>>> request? If we do the latter we can send the notify first, limiting us
> >>>> to races where a page is pinned between the notify and the locking,
> >>>> whereas here, even our dma pointer is suspect once we re-acquire the
> >>>> lock, we don't technically know if another unmap could have removed
> >>>> that already. Perhaps something like this (untested):
> >>>>
> >>>
> >>> There are checks to validate unmap request, like v2 check and who is
> >>> calling unmap and is it allowed for that task to unmap. Before these
> >>> checks its not sure that unmap region range which asked for would be
> >>> unmapped all. Notify call should be at the place where its sure that the
> >>> range provided to notify call is definitely going to be removed. My
> >>> change do that.
> >>
> >> Ok, but that does solve the problem. What about this (untested):
> >
> > s/does/does not/
> >
> > BTW, I like how the retries here fill the gap in my previous proposal
> > where we could still race re-pinning. We've given it an honest shot or
> > someone is not participating if we've retried 10 times. I don't
> > understand why the test for iommu->external_domain was there, clearly
> > if the list is not empty, we need to notify. Thanks,
> >
>
> Ok. Retry is good to give a chance to unpin all. But is it really
> required to use BUG_ON() that would panic the host. I think WARN_ON
> should be fine and then when container is closed or when the last group
> is removed from the container, vfio_iommu_type1_release() is called and
> we have a chance to unpin it all.
See my comments on patch 10/22, we need to be vigilant that the vendor
driver is participating. I don't think we should be cleaning up after
the vendor driver on release, if we need to do that, it implies we
already have problems in multi-mdev containers since we'll be left with
pfn_list entries that no longer have an owner. Thanks,
Alex
On 11/16/2016 9:28 AM, Alex Williamson wrote:
> On Wed, 16 Nov 2016 09:13:37 +0530
> Kirti Wankhede <[email protected]> wrote:
>
>> On 11/16/2016 8:55 AM, Alex Williamson wrote:
>>> On Tue, 15 Nov 2016 20:16:12 -0700
>>> Alex Williamson <[email protected]> wrote:
>>>
>>>> On Wed, 16 Nov 2016 08:16:15 +0530
>>>> Kirti Wankhede <[email protected]> wrote:
>>>>
>>>>> On 11/16/2016 3:49 AM, Alex Williamson wrote:
>>>>>> On Tue, 15 Nov 2016 20:59:54 +0530
>>>>>> Kirti Wankhede <[email protected]> wrote:
>>>>>>
>>>>> ...
>>>>>
>>>>>>> @@ -854,7 +857,28 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
>>>>>>> */
>>>>>>> if (dma->task->mm != current->mm)
>>>>>>> break;
>>>>>>> +
>>>>>>> unmapped += dma->size;
>>>>>>> +
>>>>>>> + if (iommu->external_domain && !RB_EMPTY_ROOT(&dma->pfn_list)) {
>>>>>>> + struct vfio_iommu_type1_dma_unmap nb_unmap;
>>>>>>> +
>>>>>>> + nb_unmap.iova = dma->iova;
>>>>>>> + nb_unmap.size = dma->size;
>>>>>>> +
>>>>>>> + /*
>>>>>>> + * Notifier callback would call vfio_unpin_pages() which
>>>>>>> + * would acquire iommu->lock. Release lock here and
>>>>>>> + * reacquire it again.
>>>>>>> + */
>>>>>>> + mutex_unlock(&iommu->lock);
>>>>>>> + blocking_notifier_call_chain(&iommu->notifier,
>>>>>>> + VFIO_IOMMU_NOTIFY_DMA_UNMAP,
>>>>>>> + &nb_unmap);
>>>>>>> + mutex_lock(&iommu->lock);
>>>>>>> + if (WARN_ON(!RB_EMPTY_ROOT(&dma->pfn_list)))
>>>>>>> + break;
>>>>>>> + }
>>>>>>
>>>>>>
>>>>>> Why exactly do we need to notify per vfio_dma rather than per unmap
>>>>>> request? If we do the latter we can send the notify first, limiting us
>>>>>> to races where a page is pinned between the notify and the locking,
>>>>>> whereas here, even our dma pointer is suspect once we re-acquire the
>>>>>> lock, we don't technically know if another unmap could have removed
>>>>>> that already. Perhaps something like this (untested):
>>>>>>
>>>>>
>>>>> There are checks to validate unmap request, like v2 check and who is
>>>>> calling unmap and is it allowed for that task to unmap. Before these
>>>>> checks its not sure that unmap region range which asked for would be
>>>>> unmapped all. Notify call should be at the place where its sure that the
>>>>> range provided to notify call is definitely going to be removed. My
>>>>> change do that.
>>>>
>>>> Ok, but that does solve the problem. What about this (untested):
>>>
>>> s/does/does not/
>>>
>>> BTW, I like how the retries here fill the gap in my previous proposal
>>> where we could still race re-pinning. We've given it an honest shot or
>>> someone is not participating if we've retried 10 times. I don't
>>> understand why the test for iommu->external_domain was there, clearly
>>> if the list is not empty, we need to notify. Thanks,
>>>
>>
>> Ok. Retry is good to give a chance to unpin all. But is it really
>> required to use BUG_ON() that would panic the host. I think WARN_ON
>> should be fine and then when container is closed or when the last group
>> is removed from the container, vfio_iommu_type1_release() is called and
>> we have a chance to unpin it all.
>
> See my comments on patch 10/22, we need to be vigilant that the vendor
> driver is participating. I don't think we should be cleaning up after
> the vendor driver on release, if we need to do that, it implies we
> already have problems in multi-mdev containers since we'll be left with
> pfn_list entries that no longer have an owner. Thanks,
>
If any vendor driver doesn't clean its pinned pages and there are
entries in pfn_list with no owner, that would be indicated by WARN_ON,
which should be fixed by that vendor driver. I still feel it shouldn't
cause host panic.
When such warning is seen with multiple mdev devices in container, it is
easy to isolate and find which vendor driver is not cleaning their
stuff, same warning would be seen with single mdev device in a
container. To isolate and find which vendor driver is culprit check with
one mdev device at a time.
Finally, we have a chance to clean all residue from
vfio_iommu_type1_release() so that vfio_iommu_type1 module doesn't leave
any leaks.
Thanks,
Kirti
On Wed, 16 Nov 2016 09:46:20 +0530
Kirti Wankhede <[email protected]> wrote:
> On 11/16/2016 9:28 AM, Alex Williamson wrote:
> > On Wed, 16 Nov 2016 09:13:37 +0530
> > Kirti Wankhede <[email protected]> wrote:
> >
> >> On 11/16/2016 8:55 AM, Alex Williamson wrote:
> >>> On Tue, 15 Nov 2016 20:16:12 -0700
> >>> Alex Williamson <[email protected]> wrote:
> >>>
> >>>> On Wed, 16 Nov 2016 08:16:15 +0530
> >>>> Kirti Wankhede <[email protected]> wrote:
> >>>>
> >>>>> On 11/16/2016 3:49 AM, Alex Williamson wrote:
> >>>>>> On Tue, 15 Nov 2016 20:59:54 +0530
> >>>>>> Kirti Wankhede <[email protected]> wrote:
> >>>>>>
> >>>>> ...
> >>>>>
> >>>>>>> @@ -854,7 +857,28 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
> >>>>>>> */
> >>>>>>> if (dma->task->mm != current->mm)
> >>>>>>> break;
> >>>>>>> +
> >>>>>>> unmapped += dma->size;
> >>>>>>> +
> >>>>>>> + if (iommu->external_domain && !RB_EMPTY_ROOT(&dma->pfn_list)) {
> >>>>>>> + struct vfio_iommu_type1_dma_unmap nb_unmap;
> >>>>>>> +
> >>>>>>> + nb_unmap.iova = dma->iova;
> >>>>>>> + nb_unmap.size = dma->size;
> >>>>>>> +
> >>>>>>> + /*
> >>>>>>> + * Notifier callback would call vfio_unpin_pages() which
> >>>>>>> + * would acquire iommu->lock. Release lock here and
> >>>>>>> + * reacquire it again.
> >>>>>>> + */
> >>>>>>> + mutex_unlock(&iommu->lock);
> >>>>>>> + blocking_notifier_call_chain(&iommu->notifier,
> >>>>>>> + VFIO_IOMMU_NOTIFY_DMA_UNMAP,
> >>>>>>> + &nb_unmap);
> >>>>>>> + mutex_lock(&iommu->lock);
> >>>>>>> + if (WARN_ON(!RB_EMPTY_ROOT(&dma->pfn_list)))
> >>>>>>> + break;
> >>>>>>> + }
> >>>>>>
> >>>>>>
> >>>>>> Why exactly do we need to notify per vfio_dma rather than per unmap
> >>>>>> request? If we do the latter we can send the notify first, limiting us
> >>>>>> to races where a page is pinned between the notify and the locking,
> >>>>>> whereas here, even our dma pointer is suspect once we re-acquire the
> >>>>>> lock, we don't technically know if another unmap could have removed
> >>>>>> that already. Perhaps something like this (untested):
> >>>>>>
> >>>>>
> >>>>> There are checks to validate unmap request, like v2 check and who is
> >>>>> calling unmap and is it allowed for that task to unmap. Before these
> >>>>> checks its not sure that unmap region range which asked for would be
> >>>>> unmapped all. Notify call should be at the place where its sure that the
> >>>>> range provided to notify call is definitely going to be removed. My
> >>>>> change do that.
> >>>>
> >>>> Ok, but that does solve the problem. What about this (untested):
> >>>
> >>> s/does/does not/
> >>>
> >>> BTW, I like how the retries here fill the gap in my previous proposal
> >>> where we could still race re-pinning. We've given it an honest shot or
> >>> someone is not participating if we've retried 10 times. I don't
> >>> understand why the test for iommu->external_domain was there, clearly
> >>> if the list is not empty, we need to notify. Thanks,
> >>>
> >>
> >> Ok. Retry is good to give a chance to unpin all. But is it really
> >> required to use BUG_ON() that would panic the host. I think WARN_ON
> >> should be fine and then when container is closed or when the last group
> >> is removed from the container, vfio_iommu_type1_release() is called and
> >> we have a chance to unpin it all.
> >
> > See my comments on patch 10/22, we need to be vigilant that the vendor
> > driver is participating. I don't think we should be cleaning up after
> > the vendor driver on release, if we need to do that, it implies we
> > already have problems in multi-mdev containers since we'll be left with
> > pfn_list entries that no longer have an owner. Thanks,
> >
>
> If any vendor driver doesn't clean its pinned pages and there are
> entries in pfn_list with no owner, that would be indicated by WARN_ON,
> which should be fixed by that vendor driver. I still feel it shouldn't
> cause host panic.
> When such warning is seen with multiple mdev devices in container, it is
> easy to isolate and find which vendor driver is not cleaning their
> stuff, same warning would be seen with single mdev device in a
> container. To isolate and find which vendor driver is culprit check with
> one mdev device at a time.
> Finally, we have a chance to clean all residue from
> vfio_iommu_type1_release() so that vfio_iommu_type1 module doesn't leave
> any leaks.
How can we claim that we've resolved anything by unpinning the
residue? In fact, is it actually safe to unpin any residue left by the
vendor driver or does it imply that we're promoting a simple memory
leak to a security issue because we can't verify whether the vendor
driver has disabled access to that pfn, which may not reference a user
page after we unpin it. That, in addition to the fact that I don't
need to figure out how to break from the loop with a BUG_ON, is why I
chose that rather than a WARN_ON. The release path could probably be a
WARN_ON since the user no longer has access to the device, so we have a
consistency error with the vendor driver, but we're probably not
promoting it further by unpinning the pages. Thanks,
Alex
On 11/16/2016 8:33 AM, Dong Jia Shi wrote:
> * Kirti Wankhede <[email protected]> [2016-11-15 20:59:48 +0530]:
>
> Hi Kirti,
>
>> Added APIs for pining and unpining set of pages. These call back into
>> backend iommu module to actually pin and unpin pages.
>> Added two new callback functions to struct vfio_iommu_driver_ops. Backend
>> IOMMU module that supports pining and unpinning pages for mdev devices
>> should provide these functions.
>>
>> Renamed static functions in vfio_type1_iommu.c to resolve conflicts
>>
>> Signed-off-by: Kirti Wankhede <[email protected]>
>> Signed-off-by: Neo Jia <[email protected]>
>> Change-Id: Ia7417723aaae86bec2959ad9ae6c2915ddd340e0
>> ---
>> drivers/vfio/vfio.c | 103 ++++++++++++++++++++++++++++++++++++++++
>> drivers/vfio/vfio_iommu_type1.c | 20 ++++----
>> include/linux/vfio.h | 14 +++++-
>> 3 files changed, 126 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
>> index 2e83bdf007fe..3bf8a01bf67b 100644
>> --- a/drivers/vfio/vfio.c
>> +++ b/drivers/vfio/vfio.c
>> @@ -1799,6 +1799,109 @@ void vfio_info_cap_shift(struct vfio_info_cap *caps, size_t offset)
>> }
>> EXPORT_SYMBOL_GPL(vfio_info_cap_shift);
>>
>> +
>> +/*
>> + * Pin a set of guest PFNs and return their associated host PFNs for local
>> + * domain only.
>> + * @dev [in] : device
>> + * @user_pfn [in]: array of user/guest PFNs to be unpinned. Number of user/guest
>> + * PFNs should not be greater than VFIO_PIN_PAGES_MAX_ENTRIES.
> Move the second sentence to the @npage section?
>
>> + * @npage [in] :count of elements in array. This count should not be greater
>> + * than PAGE_SIZE.
> And remove the second sentence here.
>
>> + * @prot [in] : protection flags
>> + * @phys_pfn[out] : array of host PFNs
> nit:
> I saw three differnt styles here:
> @xxx [in] :xxxxxxx
> @xxx [in]: xxxxxxx
> @xxx[out]: xxxxxxx
>
> Frankly speeking, I didn't think the [in|out] flags helps much.
>
>> + * Return error or number of pages pinned.
>> + */
>> +int vfio_pin_pages(struct device *dev, unsigned long *user_pfn, int npage,
>> + int prot, unsigned long *phys_pfn)
>> +{
>> + struct vfio_container *container;
>> + struct vfio_group *group;
>> + struct vfio_iommu_driver *driver;
>> + int ret;
>> +
>> + if (!dev || !user_pfn || !phys_pfn || !npage)
>> + return -EINVAL;
>> +
>> + if (npage > VFIO_PIN_PAGES_MAX_ENTRIES)
>> + return -E2BIG;
>> +
>> + group = vfio_group_get_from_dev(dev);
>> + if (IS_ERR(group))
>> + return PTR_ERR(group);
>> +
>> + ret = vfio_group_add_container_user(group);
>> + if (ret)
>> + goto err_pin_pages;
>> +
>> + container = group->container;
>> + down_read(&container->group_lock);
>> +
>> + driver = container->iommu_driver;
>> + if (likely(driver && driver->ops->pin_pages))
>> + ret = driver->ops->pin_pages(container->iommu_data, user_pfn,
>> + npage, prot, phys_pfn);
>> + else
>> + ret = -ENOTTY;
>> +
>> + up_read(&container->group_lock);
>> + vfio_group_try_dissolve_container(group);
>> +
>> +err_pin_pages:
>> + vfio_group_put(group);
>> + return ret;
>> +}
>> +EXPORT_SYMBOL(vfio_pin_pages);
>> +
>> +/*
>> + * Unpin set of host PFNs for local domain only.
>> + * @dev [in] : device
>> + * @user_pfn [in]: array of user/guest PFNs to be unpinned. Number of user/guest
>> + * PFNs should not be greater than VFIO_PIN_PAGES_MAX_ENTRIES.
>> + * @npage [in] :count of elements in array. This count should not be greater
>> + * than PAGE_SIZE.
> Same nits as above here.
>
>> + * Return error or number of pages unpinned.
>> + */
> [...]
>
>> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
>> index 0ecae0b1cd34..420cdc928786 100644
>> --- a/include/linux/vfio.h
>> +++ b/include/linux/vfio.h
>> @@ -75,7 +75,11 @@ struct vfio_iommu_driver_ops {
>> struct iommu_group *group);
>> void (*detach_group)(void *iommu_data,
>> struct iommu_group *group);
>> -
>> + int (*pin_pages)(void *iommu_data, unsigned long *user_pfn,
>> + int npage, int prot,
>> + unsigned long *phys_pfn);
>> + int (*unpin_pages)(void *iommu_data,
>> + unsigned long *user_pfn, int npage);
>> };
>>
>> extern int vfio_register_iommu_driver(const struct vfio_iommu_driver_ops *ops);
>> @@ -127,6 +131,14 @@ static inline long vfio_spapr_iommu_eeh_ioctl(struct iommu_group *group,
>> }
>> #endif /* CONFIG_EEH */
>>
>> +#define VFIO_PIN_PAGES_MAX_ENTRIES (PAGE_SIZE/sizeof(unsigned long))
>> +
>> +extern int vfio_pin_pages(struct device *dev, unsigned long *user_pfn,
>> + int npage, int prot, unsigned long *phys_pfn);
>> +
>> +extern int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn,
>> + int npage);
>> +
> Move this hunk up to the "External user API" section?
>
Ok
>> /*
>> * IRQfd - generic
>> */
>> --
>> 2.7.0
>>
>
> The code looks good to me.
>
Thanks.
On 11/16/2016 7:59 AM, Dong Jia Shi wrote:
> * Kirti Wankhede <[email protected]> [2016-11-15 20:59:45 +0530]:
>
> Hi Kirti,
>
>> vfio_mdev driver registers with mdev core driver.
>> mdev core driver creates mediated device and calls probe routine of
>> vfio_mdev driver for each device.
>> Probe routine of vfio_mdev driver adds mediated device to VFIO core module
>>
>> This driver forms a shim layer that pass through VFIO devices operations
>> to vendor driver for mediated devices.
>>
>> Signed-off-by: Kirti Wankhede <[email protected]>
>> Signed-off-by: Neo Jia <[email protected]>
>> Reviewed-by: Jike Song <[email protected]>
>>
>> Change-Id: I583f4734752971d3d112324d69e2508c88f359ec
>> ---
>> drivers/vfio/mdev/Kconfig | 7 ++
>> drivers/vfio/mdev/Makefile | 1 +
>> drivers/vfio/mdev/mdev_core.c | 16 ++++-
>> drivers/vfio/mdev/vfio_mdev.c | 148 ++++++++++++++++++++++++++++++++++++++++++
>> 4 files changed, 171 insertions(+), 1 deletion(-)
>> create mode 100644 drivers/vfio/mdev/vfio_mdev.c
>>
>> diff --git a/drivers/vfio/mdev/Kconfig b/drivers/vfio/mdev/Kconfig
>> index 258481d65ebd..1aa0391d74f2 100644
>> --- a/drivers/vfio/mdev/Kconfig
>> +++ b/drivers/vfio/mdev/Kconfig
>> @@ -7,3 +7,10 @@ config VFIO_MDEV
>> Provides a framework to virtualize devices.
>>
>> If you don't know what do here, say N.
>> +
>> +config VFIO_MDEV_DEVICE
>> + tristate "VFIO support for Mediated devices"
> ^^^^^^^^^^^^^^^^
>
>> + depends on VFIO && VFIO_MDEV
>> + default n
>> + help
>> + VFIO based driver for mediated devices.
> ^^^^^^^^^^^^^^^^
> nit:
> s/mediated/Mediated/
>
> I saw in many places you use the term "Mediated device", so I guess this
> is what you preferred to name them.
>
>> diff --git a/drivers/vfio/mdev/Makefile b/drivers/vfio/mdev/Makefile
>> index 31bc04801d94..fa2d5ea466ee 100644
>> --- a/drivers/vfio/mdev/Makefile
>> +++ b/drivers/vfio/mdev/Makefile
>> @@ -2,3 +2,4 @@
>> mdev-y := mdev_core.o mdev_sysfs.o mdev_driver.o
>>
>> obj-$(CONFIG_VFIO_MDEV) += mdev.o
>> +obj-$(CONFIG_VFIO_MDEV_DEVICE) += vfio_mdev.o
>> diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
>> index 613e8a8a3b2a..1e0714ebc56a 100644
>> --- a/drivers/vfio/mdev/mdev_core.c
>> +++ b/drivers/vfio/mdev/mdev_core.c
>> @@ -354,7 +354,21 @@ int mdev_device_remove(struct device *dev, bool force_remove)
>>
>> static int __init mdev_init(void)
>> {
>> - return mdev_bus_register();
>> + int ret;
>> +
>> + ret = mdev_bus_register();
>> + if (ret) {
>> + pr_err("Failed to register mdev bus\n");
> If you want to report an error message here, you should do it in a
> previous patch where you introduce the call for mdev_bus_register.
>
Removing this error message.
>> + return ret;
>> + }
>> +
>> + /*
>> + * Attempt to load known vfio_mdev. This gives us a working environment
>> + * without the user needing to explicitly load vfio_mdev driver.
>> + */
>> + request_module_nowait("vfio_mdev");
>> +
>> + return ret;
>> }
>>
>> static void __exit mdev_exit(void)
> [...]
>
> Please:
> Reviewed-by: Dong Jia Shi <[email protected]>
>
Thanks.
On 11/16/2016 11:36 AM, Dong Jia Shi wrote:
> * Kirti Wankhede <[email protected]> [2016-11-15 20:59:52 +0530]:
>
> Hi Kirti,
>
> [...]
> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
>
>> @@ -331,13 +338,16 @@ static long vfio_pin_pages_remote(unsigned long vaddr, long npage,
>> }
>>
>> if (!rsvd)
>> - vfio_lock_acct(current, i);
>> + vfio_lock_acct(dma->task, i);
>> + ret = i;
>>
>> - return i;
>> +pin_pg_remote_exit:
> out_mmput sounds a better name to me.
>
>> + mmput(mm);
>> + return ret;
>> }
>>
> [...]
>
>> @@ -510,6 +521,12 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
>> while ((dma = vfio_find_dma(iommu, unmap->iova, unmap->size))) {
>> if (!iommu->v2 && unmap->iova > dma->iova)
>> break;
>> + /*
>> + * Task with same address space who mapped this iova range is
>> + * allowed to unmap the iova range.
>> + */
>> + if (dma->task->mm != current->mm)
> How about:
> if (dma->task != current)
>
As I mentioned in comment above this and commit description, if a
process calls DMA_MAP, forks a thread and then child thread calls
DMA_UNMAP, this should be allowed since address space is same for parent
process and child. QEMU also works that way.
>> + break;
>> unmapped += dma->size;
>> vfio_remove_dma(iommu, dma);
>> }
>> @@ -576,17 +593,55 @@ unwind:
>> return ret;
>> }
>>
>> +static int vfio_pin_map_dma(struct vfio_iommu *iommu, struct vfio_dma *dma,
>> + size_t map_size)
> Do you factor out this function for future usage?
> I didn't find the other callers.
>
This is pulled out to make caller simple and short. Otherwise
vfio_dma_do_map() would have become a long function.
>> +{
>> + dma_addr_t iova = dma->iova;
>> + unsigned long vaddr = dma->vaddr;
>> + size_t size = map_size;
>> + long npage;
>> + unsigned long pfn;
>> + int ret = 0;
>> +
>> + while (size) {
>> + /* Pin a contiguous chunk of memory */
>> + npage = vfio_pin_pages_remote(dma, vaddr + dma->size,
>> + size >> PAGE_SHIFT, dma->prot,
>> + &pfn);
>> + if (npage <= 0) {
>> + WARN_ON(!npage);
>> + ret = (int)npage;
>> + break;
>> + }
>> +
>> + /* Map it! */
>> + ret = vfio_iommu_map(iommu, iova + dma->size, pfn, npage,
>> + dma->prot);
>> + if (ret) {
>> + vfio_unpin_pages_remote(dma, pfn, npage,
>> + dma->prot, true);
>> + break;
>> + }
>> +
>> + size -= npage << PAGE_SHIFT;
>> + dma->size += npage << PAGE_SHIFT;
>> + }
>> +
>> + if (ret)
>> + vfio_remove_dma(iommu, dma);
>> +
>> + return ret;
>> +}
>> +
>> static int vfio_dma_do_map(struct vfio_iommu *iommu,
>> struct vfio_iommu_type1_dma_map *map)
>> {
>> dma_addr_t iova = map->iova;
>> unsigned long vaddr = map->vaddr;
>> size_t size = map->size;
>> - long npage;
>> int ret = 0, prot = 0;
>> uint64_t mask;
>> struct vfio_dma *dma;
>> - unsigned long pfn;
>>
>> /* Verify that none of our __u64 fields overflow */
>> if (map->size != size || map->vaddr != vaddr || map->iova != iova)
>> @@ -612,47 +667,27 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu,
>> mutex_lock(&iommu->lock);
>>
>> if (vfio_find_dma(iommu, iova, size)) {
>> - mutex_unlock(&iommu->lock);
>> - return -EEXIST;
>> + ret = -EEXIST;
>> + goto do_map_err;
>> }
>>
>> dma = kzalloc(sizeof(*dma), GFP_KERNEL);
>> if (!dma) {
>> - mutex_unlock(&iommu->lock);
>> - return -ENOMEM;
>> + ret = -ENOMEM;
>> + goto do_map_err;
>> }
>>
>> dma->iova = iova;
>> dma->vaddr = vaddr;
>> dma->prot = prot;
>> + get_task_struct(current);
>> + dma->task = current;
>>
>> /* Insert zero-sized and grow as we map chunks of it */
>> vfio_link_dma(iommu, dma);
>>
>> - while (size) {
>> - /* Pin a contiguous chunk of memory */
>> - npage = vfio_pin_pages_remote(vaddr + dma->size,
>> - size >> PAGE_SHIFT, prot, &pfn);
>> - if (npage <= 0) {
>> - WARN_ON(!npage);
>> - ret = (int)npage;
>> - break;
>> - }
>> -
>> - /* Map it! */
>> - ret = vfio_iommu_map(iommu, iova + dma->size, pfn, npage, prot);
>> - if (ret) {
>> - vfio_unpin_pages_remote(pfn, npage, prot, true);
>> - break;
>> - }
>> -
>> - size -= npage << PAGE_SHIFT;
>> - dma->size += npage << PAGE_SHIFT;
>> - }
>> -
>> - if (ret)
>> - vfio_remove_dma(iommu, dma);
>> -
>> + ret = vfio_pin_map_dma(iommu, dma, size);
>> +do_map_err:
> Rename to out_unlock?
>
>> mutex_unlock(&iommu->lock);
>> return ret;
>> }
>> --
>> 2.7.0
>>
>
> Otherwise, LGTM!
>
Thanks.
Kirti.
On 11/16/2016 10:06 AM, Alex Williamson wrote:
> On Wed, 16 Nov 2016 09:46:20 +0530
> Kirti Wankhede <[email protected]> wrote:
>
>> On 11/16/2016 9:28 AM, Alex Williamson wrote:
>>> On Wed, 16 Nov 2016 09:13:37 +0530
>>> Kirti Wankhede <[email protected]> wrote:
>>>
>>>> On 11/16/2016 8:55 AM, Alex Williamson wrote:
>>>>> On Tue, 15 Nov 2016 20:16:12 -0700
>>>>> Alex Williamson <[email protected]> wrote:
>>>>>
>>>>>> On Wed, 16 Nov 2016 08:16:15 +0530
>>>>>> Kirti Wankhede <[email protected]> wrote:
>>>>>>
>>>>>>> On 11/16/2016 3:49 AM, Alex Williamson wrote:
>>>>>>>> On Tue, 15 Nov 2016 20:59:54 +0530
>>>>>>>> Kirti Wankhede <[email protected]> wrote:
>>>>>>>>
>>>>>>> ...
>>>>>>>
>>>>>>>>> @@ -854,7 +857,28 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
>>>>>>>>> */
>>>>>>>>> if (dma->task->mm != current->mm)
>>>>>>>>> break;
>>>>>>>>> +
>>>>>>>>> unmapped += dma->size;
>>>>>>>>> +
>>>>>>>>> + if (iommu->external_domain && !RB_EMPTY_ROOT(&dma->pfn_list)) {
>>>>>>>>> + struct vfio_iommu_type1_dma_unmap nb_unmap;
>>>>>>>>> +
>>>>>>>>> + nb_unmap.iova = dma->iova;
>>>>>>>>> + nb_unmap.size = dma->size;
>>>>>>>>> +
>>>>>>>>> + /*
>>>>>>>>> + * Notifier callback would call vfio_unpin_pages() which
>>>>>>>>> + * would acquire iommu->lock. Release lock here and
>>>>>>>>> + * reacquire it again.
>>>>>>>>> + */
>>>>>>>>> + mutex_unlock(&iommu->lock);
>>>>>>>>> + blocking_notifier_call_chain(&iommu->notifier,
>>>>>>>>> + VFIO_IOMMU_NOTIFY_DMA_UNMAP,
>>>>>>>>> + &nb_unmap);
>>>>>>>>> + mutex_lock(&iommu->lock);
>>>>>>>>> + if (WARN_ON(!RB_EMPTY_ROOT(&dma->pfn_list)))
>>>>>>>>> + break;
>>>>>>>>> + }
>>>>>>>>
>>>>>>>>
>>>>>>>> Why exactly do we need to notify per vfio_dma rather than per unmap
>>>>>>>> request? If we do the latter we can send the notify first, limiting us
>>>>>>>> to races where a page is pinned between the notify and the locking,
>>>>>>>> whereas here, even our dma pointer is suspect once we re-acquire the
>>>>>>>> lock, we don't technically know if another unmap could have removed
>>>>>>>> that already. Perhaps something like this (untested):
>>>>>>>>
>>>>>>>
>>>>>>> There are checks to validate unmap request, like v2 check and who is
>>>>>>> calling unmap and is it allowed for that task to unmap. Before these
>>>>>>> checks its not sure that unmap region range which asked for would be
>>>>>>> unmapped all. Notify call should be at the place where its sure that the
>>>>>>> range provided to notify call is definitely going to be removed. My
>>>>>>> change do that.
>>>>>>
>>>>>> Ok, but that does solve the problem. What about this (untested):
>>>>>
>>>>> s/does/does not/
>>>>>
>>>>> BTW, I like how the retries here fill the gap in my previous proposal
>>>>> where we could still race re-pinning. We've given it an honest shot or
>>>>> someone is not participating if we've retried 10 times. I don't
>>>>> understand why the test for iommu->external_domain was there, clearly
>>>>> if the list is not empty, we need to notify. Thanks,
>>>>>
>>>>
>>>> Ok. Retry is good to give a chance to unpin all. But is it really
>>>> required to use BUG_ON() that would panic the host. I think WARN_ON
>>>> should be fine and then when container is closed or when the last group
>>>> is removed from the container, vfio_iommu_type1_release() is called and
>>>> we have a chance to unpin it all.
>>>
>>> See my comments on patch 10/22, we need to be vigilant that the vendor
>>> driver is participating. I don't think we should be cleaning up after
>>> the vendor driver on release, if we need to do that, it implies we
>>> already have problems in multi-mdev containers since we'll be left with
>>> pfn_list entries that no longer have an owner. Thanks,
>>>
>>
>> If any vendor driver doesn't clean its pinned pages and there are
>> entries in pfn_list with no owner, that would be indicated by WARN_ON,
>> which should be fixed by that vendor driver. I still feel it shouldn't
>> cause host panic.
>> When such warning is seen with multiple mdev devices in container, it is
>> easy to isolate and find which vendor driver is not cleaning their
>> stuff, same warning would be seen with single mdev device in a
>> container. To isolate and find which vendor driver is culprit check with
>> one mdev device at a time.
>> Finally, we have a chance to clean all residue from
>> vfio_iommu_type1_release() so that vfio_iommu_type1 module doesn't leave
>> any leaks.
>
> How can we claim that we've resolved anything by unpinning the
> residue? In fact, is it actually safe to unpin any residue left by the
> vendor driver or does it imply that we're promoting a simple memory
> leak to a security issue because we can't verify whether the vendor
> driver has disabled access to that pfn, which may not reference a user
> page after we unpin it. That, in addition to the fact that I don't
> need to figure out how to break from the loop with a BUG_ON, is why I
> chose that rather than a WARN_ON. The release path could probably be a
> WARN_ON since the user no longer has access to the device, so we have a
> consistency error with the vendor driver, but we're probably not
> promoting it further by unpinning the pages. Thanks,
>
Ok. Agree with the security concern you mentioned.
Changing to BUG_ON as you suggested in vfio_dma_do_unmap() and replacing
'unpinning remaining pages on detach_group and release' with 'WARN_ON'
if there are unpinned pages.
Thanks,
Kirti
On 11/16/2016 12:07 PM, Dong Jia Shi wrote:
> * Kirti Wankhede <[email protected]> [2016-11-15 20:59:55 +0530]:
>
> Hi Kirti,
>
> [...]
>
>> diff --git a/drivers/vfio/mdev/vfio_mdev.c b/drivers/vfio/mdev/vfio_mdev.c
>> index ffc36758cb84..4fc63db38829 100644
>> --- a/drivers/vfio/mdev/vfio_mdev.c
>> +++ b/drivers/vfio/mdev/vfio_mdev.c
>> @@ -24,6 +24,15 @@
>> #define DRIVER_AUTHOR "NVIDIA Corporation"
>> #define DRIVER_DESC "VFIO based driver for Mediated device"
>>
>> +static int vfio_mdev_notifier(struct notifier_block *nb, unsigned long action,
>> + void *data)
>> +{
>> + struct mdev_device *mdev = container_of(nb, struct mdev_device, nb);
>> + struct parent_device *parent = mdev->parent;
>> +
>> + return parent->ops->notifier(mdev, action, data);
>> +}
>> +
>> static int vfio_mdev_open(void *device_data)
>> {
>> struct mdev_device *mdev = device_data;
>> @@ -36,9 +45,18 @@ static int vfio_mdev_open(void *device_data)
>> if (!try_module_get(THIS_MODULE))
>> return -ENODEV;
>>
>> + if (likely(parent->ops->notifier)) {
>> + mdev->nb.notifier_call = vfio_mdev_notifier;
>> + if (vfio_register_notifier(&mdev->dev, &mdev->nb))
>> + pr_err("Failed to register notifier for mdev\n");
> I think we should just return here if the error value is not -ENOTTY.
>
It might be the case where iommu backend module might not support
.register_notifier(). In that case vfio_register_notifier() returns
-ENOTTY and that should not fail this open() call
Changing it to:
ret = vfio_register_notifier(&mdev->dev, &mdev->nb);
if (ret && (ret != -ENOTTY)) {
pr_err("Failed to register notifier for mdev\n");
module_put(THIS_MODULE);
return ret;
}
Thanks,
Kirti