Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull virtio fixes from Michael Tsirkin:
 "This includes a bugfix for virtio 9p fs. It also fixes hybernation for
  s390 guests with virtio devices"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  virtio/s390: implement PM operations for virtio_ccw
  9p/trans_virtio: discard zero-length reply

net/9p/trans_virtio.c

@@ -160,7 +160,8 @@ static void req_done(struct virtqueue *vq)
 		spin_unlock_irqrestore(&chan->lock, flags);
 		/* Wakeup if anyone waiting for VirtIO ring space. */
 		wake_up(chan->vc_wq);
-		p9_client_cb(chan->client, req, REQ_STATUS_RCVD);
+		if (len)
+			p9_client_cb(chan->client, req, REQ_STATUS_RCVD);
 	}
 }