From dd3dd4ba7b949662d2c67a4c041549b3d79c4b0e Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Thu, 23 Feb 2017 09:51:30 +0100
Subject: [PATCH] virtio: check for vring setup in virtio_queue_empty

If the vring has not been set up, there is nothing in the virtqueue.
virtio_queue_host_notifier_aio_poll calls virtio_queue_empty even in
this case; we have to filter it out just like virtio_queue_notify_aio_vq.

Reported-by: Gerd Hoffmann <kraxel@redhat.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---
 hw/virtio/virtio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 23483c752f..e487e36cda 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -2291,7 +2291,7 @@ static bool virtio_queue_host_notifier_aio_poll(void *opaque)
     VirtQueue *vq = container_of(n, VirtQueue, host_notifier);
     bool progress;
 
-    if (virtio_queue_empty(vq)) {
+    if (!vq->vring.desc || virtio_queue_empty(vq)) {
         return false;
     }
 
-- 
2.39.2