[PATCH v4 09/14] virtio: queue_reset: struct virtio_config_ops add callbacks for queue_reset

[Xuan Zhuo]

Performing reset on a queue is divided into four steps:

1. reset_vq: reset one vq
2. recycle the buffer from vq by virtqueue_detach_unused_buf()
3. release the ring of the vq by vring_release_virtqueue()
4. enable_reset_vq: re-enable the reset queue

So add two callbacks reset_vq, enable_reset_vq to struct
virtio_config_ops.

Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
---
 include/linux/virtio_config.h | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index 4d107ad31149..0d01a64f2576 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -74,6 +74,17 @@ struct virtio_shm_region {
  * @set_vq_affinity: set the affinity for a virtqueue (optional).
  * @get_vq_affinity: get the affinity for a virtqueue (optional).
  * @get_shm_region: get a shared memory region based on the index.
+ * @reset_vq: reset a queue individually
+ *	vq: the virtqueue
+ *	Returns 0 on success or error status
+ *	After successfully calling this, be sure to call
+ *	virtqueue_detach_unused_buf() to recycle the buffer in the ring, and
+ *	then call vring_release_virtqueue() to release the vq ring.
+ * @enable_reset_vq: enable a reset queue
+ *	vq: the virtqueue
+ *	ring_num: specify ring num for the vq to be re-enabled. 0 means use the
+ *	          default value. MUST be a power of 2.
+ *	Returns 0 on success or error status
  */
 typedef void vq_callback_t(struct virtqueue *);
 struct virtio_config_ops {
@@ -100,6 +111,8 @@ struct virtio_config_ops {
 			int index);
 	bool (*get_shm_region)(struct virtio_device *vdev,
 			       struct virtio_shm_region *region, u8 id);
+	int (*reset_vq)(struct virtqueue *vq);
+	int (*enable_reset_vq)(struct virtqueue *vq, u16 ring_num);
 };
 
 /* If driver didn't advertise the feature, it will never appear. */
-- 
2.31.0