path: root/Documentation/driver-api
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authorLinus Torvalds <>2021-04-28 17:19:47 -0700
committerLinus Torvalds <>2021-04-28 17:19:47 -0700
commit238da4d004856ac5f832899f6f3fa27c0102381f (patch)
tree5f71d17600ee4e16a3176116059a350949f5aa5e /Documentation/driver-api
parent35655ceb31b56cd1cb52635a725dfcdb9662d7b7 (diff)
parentadaeb718d46f6b42a3fc1dffd4f946f26b33779a (diff)
Merge tag 'vfio-v5.13-rc1' of git://
Pull VFIO updates from Alex Williamson: - Embed struct vfio_device into vfio driver structures (Jason Gunthorpe) - Make vfio_mdev type safe (Jason Gunthorpe) - Remove vfio-pci NVLink2 extensions for POWER9 (Christoph Hellwig) - Update vfio-pci IGD extensions for OpRegion 2.1+ (Fred Gao) - Various spelling/blank line fixes (Zhen Lei, Zhou Wang, Bhaskar Chowdhury) - Simplify unpin_pages error handling (Shenming Lu) - Fix i915 mdev Kconfig dependency (Arnd Bergmann) - Remove unused structure member (Keqian Zhu) * tag 'vfio-v5.13-rc1' of git:// (43 commits) vfio/gvt: fix DRM_I915_GVT dependency on VFIO_MDEV vfio/iommu_type1: Remove unused pinned_page_dirty_scope in vfio_iommu vfio/mdev: Correct the function signatures for the mdev_type_attributes vfio/mdev: Remove kobj from mdev_parent_ops->create() vfio/gvt: Use mdev_get_type_group_id() vfio/gvt: Make DRM_I915_GVT depend on VFIO_MDEV vfio/mbochs: Use mdev_get_type_group_id() vfio/mdpy: Use mdev_get_type_group_id() vfio/mtty: Use mdev_get_type_group_id() vfio/mdev: Add mdev/mtype_get_type_group_id() vfio/mdev: Remove duplicate storage of parent in mdev_device vfio/mdev: Add missing error handling to dev_set_name() vfio/mdev: Reorganize mdev_device_create() vfio/mdev: Add missing reference counting to mdev_type vfio/mdev: Expose mdev_get/put_parent to mdev_private.h vfio/mdev: Use struct mdev_type in struct mdev_device vfio/mdev: Simplify driver registration vfio/mdev: Add missing typesafety around mdev_device vfio/mdev: Do not allow a mdev_type to have a NULL parent pointer vfio/mdev: Fix missing static's on MDEV_TYPE_ATTR's ...
Diffstat (limited to 'Documentation/driver-api')
2 files changed, 30 insertions, 27 deletions
diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentation/driver-api/vfio-mediated-device.rst
index 25eb7d5b834b..1779b85f014e 100644
--- a/Documentation/driver-api/vfio-mediated-device.rst
+++ b/Documentation/driver-api/vfio-mediated-device.rst
@@ -98,15 +98,13 @@ 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);
+ int (*probe) (struct mdev_device *dev);
+ void (*remove) (struct mdev_device *dev);
struct device_driver driver;
@@ -115,8 +113,7 @@ to register and unregister itself with the core driver:
* Register::
- extern int mdev_register_driver(struct mdev_driver *drv,
- struct module *owner);
+ extern int mdev_register_driver(struct mdev_driver *drv);
* Unregister::
diff --git a/Documentation/driver-api/vfio.rst b/Documentation/driver-api/vfio.rst
index f1a4d3c3ba0b..decc68cb8114 100644
--- a/Documentation/driver-api/vfio.rst
+++ b/Documentation/driver-api/vfio.rst
@@ -249,35 +249,41 @@ VFIO bus driver API
VFIO bus drivers, such as vfio-pci make use of only a few interfaces
into VFIO core. When devices are bound and unbound to the driver,
-the driver should call vfio_add_group_dev() and vfio_del_group_dev()
- extern int vfio_add_group_dev(struct device *dev,
- const struct vfio_device_ops *ops,
- void *device_data);
- extern void *vfio_del_group_dev(struct device *dev);
-vfio_add_group_dev() indicates to the core to begin tracking the
-iommu_group of the specified dev and register the dev as owned by
-a VFIO bus driver. The driver provides an ops structure for callbacks
+the driver should call vfio_register_group_dev() and
+vfio_unregister_group_dev() respectively::
+ void vfio_init_group_dev(struct vfio_device *device,
+ struct device *dev,
+ const struct vfio_device_ops *ops);
+ int vfio_register_group_dev(struct vfio_device *device);
+ void vfio_unregister_group_dev(struct vfio_device *device);
+The driver should embed the vfio_device in its own structure and call
+vfio_init_group_dev() to pre-configure it before going to registration.
+vfio_register_group_dev() indicates to the core to begin tracking the
+iommu_group of the specified dev and register the dev as owned by a VFIO bus
+driver. Once vfio_register_group_dev() returns it is possible for userspace to
+start accessing the driver, thus the driver should ensure it is completely
+ready before calling it. The driver provides an ops structure for callbacks
similar to a file operations structure::
struct vfio_device_ops {
- int (*open)(void *device_data);
- void (*release)(void *device_data);
- ssize_t (*read)(void *device_data, char __user *buf,
+ int (*open)(struct vfio_device *vdev);
+ void (*release)(struct vfio_device *vdev);
+ ssize_t (*read)(struct vfio_device *vdev, char __user *buf,
size_t count, loff_t *ppos);
- ssize_t (*write)(void *device_data, const char __user *buf,
+ ssize_t (*write)(struct vfio_device *vdev,
+ const char __user *buf,
size_t size, loff_t *ppos);
- long (*ioctl)(void *device_data, unsigned int cmd,
+ long (*ioctl)(struct vfio_device *vdev, unsigned int cmd,
unsigned long arg);
- int (*mmap)(void *device_data, struct vm_area_struct *vma);
+ int (*mmap)(struct vfio_device *vdev,
+ struct vm_area_struct *vma);
-Each function is passed the device_data that was originally registered
-in the vfio_add_group_dev() call above. This allows the bus driver
-an easy place to store its opaque, private data. The open/release
+Each function is passed the vdev that was originally registered
+in the vfio_register_group_dev() call above. This allows the bus driver
+to obtain its private data using container_of(). The open/release
callbacks are issued when a new file descriptor is created for a
device (via VFIO_GROUP_GET_DEVICE_FD). The ioctl interface provides
a direct pass through for VFIO_DEVICE_* ioctls. The read/write/mmap