[PATCH 04/12] kvm: qemu: Disable recv notifications until avail buffers exhausted

[Mark McLoughlin <markmc@redhat.com>]

Once we know we have buffers available on the receive ring, we can
safely disable notifications.

Signed-off-by: Mark McLoughlin <markmc@redhat.com>
---
 qemu/hw/virtio-net.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/qemu/hw/virtio-net.c b/qemu/hw/virtio-net.c
index b001475..47349ce 100644
--- a/qemu/hw/virtio-net.c
+++ b/qemu/hw/virtio-net.c
@@ -106,9 +106,12 @@ static int virtio_net_can_receive(void *opaque)
 	!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
 	return 0;
 
-    if (n->rx_vq->vring.avail->idx == n->rx_vq->last_avail_idx)
+    if (n->rx_vq->vring.avail->idx == n->rx_vq->last_avail_idx) {
+	n->rx_vq->vring.used->flags &= ~VRING_USED_F_NO_NOTIFY;
 	return 0;
+    }
 
+    n->rx_vq->vring.used->flags |= VRING_USED_F_NO_NOTIFY;
     return 1;
 }
 
-- 
1.5.4.1