vdpa: introduce config operations for associating ASID to a virtqueue group

This patch introduces a new bus operation to allow the vDPA bus driver
to associate an ASID to a virtqueue group.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Gautam Dawar <gdawar@xilinx.com>
Message-Id: <20220330180436.24644-8-gdawar@xilinx.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

include/linux/vdpa.h

@@ -240,6 +240,12 @@ struct vdpa_map_file {
  *				@vdev: vdpa device
  *				Returns the iova range supported by
  *				the device.
+ * @set_group_asid:		Set address space identifier for a
+ *				virtqueue group
+ *				@vdev: vdpa device
+ *				@group: virtqueue group
+ *				@asid: address space id for this group
+ *				Returns integer: success (0) or error (< 0)
  * @set_map:			Set device memory mapping (optional)
  *				Needed for device that using device
  *				specific DMA translation (on-chip IOMMU)
@@ -325,6 +331,8 @@ struct vdpa_config_ops {
 		       u64 iova, u64 size, u64 pa, u32 perm, void *opaque);
 	int (*dma_unmap)(struct vdpa_device *vdev, unsigned int asid,
 			 u64 iova, u64 size);
+	int (*set_group_asid)(struct vdpa_device *vdev, unsigned int group,
+			      unsigned int asid);
 
 	/* Free device resources */
 	void (*free)(struct vdpa_device *vdev);