[Qemu-devel] [PATCH 2/2] virtio: disable notifications again after poll succeeded

[Stefan Hajnoczi <stefanha@redhat.com>]

While AioContext is in polling mode virtqueue notifications are not
necessary.  Some device virtqueue handlers enable notifications.  Make
sure they stay disabled to avoid unnecessary vmexits.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 hw/virtio/virtio.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index f04ab7a..34065c7 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -2126,6 +2126,9 @@ static bool virtio_queue_host_notifier_aio_poll(void *opaque)
     }
 
     virtio_queue_notify_aio_vq(vq);
+
+    /* In case the handler function re-enabled notifications */
+    virtio_queue_set_notification(vq, 0);
     return true;
 }
 
-- 
2.9.3