Users register async copy device when vhost queue is enabled.
However, if VHOST_USER_F_PROTOCOL_FEATURES is not supported,
a deadlock occurs inside rte_vhost_async_channel_register(),
as vhost_user_msg_handler() already takes vq->access_lock
before processing VHOST_USER_SET_VRING_KICK message.

This patch removes calling vring_state_changed() in
vhost_user_set_vring_kick() to avoid deadlock on async register.

Signed-off-by: Jiayu Hu <redacted>
---
 lib/librte_vhost/vhost_user.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 399675c..a319c1c 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c

@@ -1919,9 +1919,6 @@ vhost_user_set_vring_kick(struct virtio_net **pdev, struct VhostUserMsg *msg,
 	 */
 	if (!(dev->features & (1ULL << VHOST_USER_F_PROTOCOL_FEATURES))) {
 		vq->enabled = 1;
-		if (dev->notify_ops->vring_state_changed)
-			dev->notify_ops->vring_state_changed(
-				dev->vid, file.index, 1);
 	}
 
 	if (vq->ready) {

-- 
2.7.4