vdpa: Add resume operation

Add a new operation to allow a vDPA device to be resumed after it has
been suspended. Trying to resume a device that wasn't suspended will
result in a no-op.

This operation is optional. If it's not implemented, the associated
backend feature bit will not be exposed. And if the feature bit is not
exposed, invoking this operation will return an error.

Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Message-Id: <6e05c4b31b47f3e29cb2bd7ebd56c81f84b8f48a.1672742878.git.sebastien.boeuf@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>

diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
index 6d0f5e4e82c252285f68f339bfae43fbe53a91a4..96d308cbf97bd5fcb794f16cd4ec2d7bec1825dd 100644 (file)
--- a/include/linux/vdpa.h
+++ b/include/linux/vdpa.h
@@ -219,7 +219,10 @@ struct vdpa_map_file {
  * @reset:                     Reset device
  *                             @vdev: vdpa device
  *                             Returns integer: success (0) or error (< 0)
- * @suspend:                   Suspend or resume the device (optional)
+ * @suspend:                   Suspend the device (optional)
+ *                             @vdev: vdpa device
+ *                             Returns integer: success (0) or error (< 0)
+ * @resume:                    Resume the device (optional)
  *                             @vdev: vdpa device
  *                             Returns integer: success (0) or error (< 0)
  * @get_config_size:           Get the size of the configuration space includes
@@ -324,6 +327,7 @@ struct vdpa_config_ops {
        void (*set_status)(struct vdpa_device *vdev, u8 status);
        int (*reset)(struct vdpa_device *vdev);
        int (*suspend)(struct vdpa_device *vdev);
+       int (*resume)(struct vdpa_device *vdev);
        size_t (*get_config_size)(struct vdpa_device *vdev);
        void (*get_config)(struct vdpa_device *vdev, unsigned int offset,
                           void *buf, unsigned int len);