docs: vfio: Update vfio.rst per latest interfaces

this imports the latest vfio_device_ops definition to vfio.rst.

Signed-off-by: Yi Liu <yi.l.liu@intel.com>

Documentation/driver-api/vfio.rst

@@ -249,19 +249,21 @@ 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_register_group_dev() and
-vfio_unregister_group_dev() respectively::
+Following interfaces are called when devices are bound to and
+unbound from the driver::
 
-	void vfio_init_group_dev(struct vfio_device *device,
-				struct device *dev,
-				const struct vfio_device_ops *ops);
-	void vfio_uninit_group_dev(struct vfio_device *device);
 	int vfio_register_group_dev(struct vfio_device *device);
+	int vfio_register_emulated_iommu_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
-and call vfio_uninit_group_dev() after completing the un-registration.
+vfio_alloc_device() to allocate the structure, and can register
+@init/@release callbacks to manage any private state wrapping the
+vfio_device.
+
+	vfio_alloc_device(dev_struct, member, dev, ops);
+	void vfio_put_device(struct vfio_device *device);
+
 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
@@ -270,28 +272,50 @@ ready before calling it. The driver provides an ops structure for callbacks
 similar to a file operations structure::
 
 	struct vfio_device_ops {
-		int	(*open)(struct vfio_device *vdev);
+		char	*name;
+		int	(*init)(struct vfio_device *vdev);
 		void	(*release)(struct vfio_device *vdev);
+		int	(*bind_iommufd)(struct vfio_device *vdev,
+					struct iommufd_ctx *ictx, u32 *out_device_id);
+		void	(*unbind_iommufd)(struct vfio_device *vdev);
+		int	(*attach_ioas)(struct vfio_device *vdev, u32 *pt_id);
+		int	(*open_device)(struct vfio_device *vdev);
+		void	(*close_device)(struct vfio_device *vdev);
 		ssize_t	(*read)(struct vfio_device *vdev, char __user *buf,
 				size_t count, loff_t *ppos);
-		ssize_t	(*write)(struct vfio_device *vdev,
-				 const char __user *buf,
-				 size_t size, loff_t *ppos);
+		ssize_t	(*write)(struct vfio_device *vdev, const char __user *buf,
+			 size_t count, loff_t *size);
 		long	(*ioctl)(struct vfio_device *vdev, unsigned int cmd,
 				 unsigned long arg);
-		int	(*mmap)(struct vfio_device *vdev,
-				struct vm_area_struct *vma);
-	};
+		int	(*mmap)(struct vfio_device *vdev, struct vm_area_struct *vma);
+		void	(*request)(struct vfio_device *vdev, unsigned int count);
+		int	(*match)(struct vfio_device *vdev, char *buf);
+		void	(*dma_unmap)(struct vfio_device *vdev, u64 iova, u64 length);
+		int	(*device_feature)(struct vfio_device *device, u32 flags,
+					  void __user *arg, size_t argsz);
+};
 
 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
-interfaces implement the device region access defined by the device's
-own VFIO_DEVICE_GET_REGION_INFO ioctl.
-
+in the vfio_register_group_dev() or vfio_register_emulated_iommu_dev()
+call above.  This allows the bus driver to obtain its private data using
+container_of().
+- The init/release callbacks are issued when vfio_device is initialized
+- and released.
+- The open/close_device 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 [un]bind_iommufd callbacks are issued when the device is bound to
+- and unbound from iommufd.
+- The attach_ioas callback is issued when the device is attached to an IOAS
+  managed by the bound iommufd. The attached IOAS is automatically detached
+  when the device is unbound from the iommufd.
+- The read/write/mmap interfaces implement the device region access defined by
+  the device's own VFIO_DEVICE_GET_REGION_INFO ioctl.
+- The request callback is issued when device is going to be unregistered.
+- The dma_unmap callback is issued when a range of iova's are unmapped in
+  the container or IOAS attached by the device. Drivers which care about
+  DMA unmap can implement this callback and must tolerate receiving unmap
+  notifications before the device is opened.
 
 PPC64 sPAPR implementation note
 -------------------------------