1 files changed, 16 insertions, 12 deletions

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 5635620a31..08aa0b65e3 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -1641,24 +1641,28 @@ static bool virtio_net_can_receive(NetClientState *nc)
 
 static int virtio_net_has_buffers(VirtIONetQueue *q, int bufsize)
 {
+    int opaque;
+    unsigned int in_bytes;
     VirtIONet *n = q->n;
-    if (virtio_queue_empty(q->rx_vq) ||
-        (n->mergeable_rx_bufs &&
-         !virtqueue_avail_bytes(q->rx_vq, bufsize, 0))) {
-        virtio_queue_set_notification(q->rx_vq, 1);
-
-        /* To avoid a race condition where the guest has made some buffers
-         * available after the above check but before notification was
-         * enabled, check for available buffers again.
-         */
-        if (virtio_queue_empty(q->rx_vq) ||
-            (n->mergeable_rx_bufs &&
-             !virtqueue_avail_bytes(q->rx_vq, bufsize, 0))) {
+
+    while (virtio_queue_empty(q->rx_vq) || n->mergeable_rx_bufs) {
+        opaque = virtqueue_get_avail_bytes(q->rx_vq, &in_bytes, NULL,
+                                           bufsize, 0);
+        /* Buffer is enough, disable notifiaction */
+        if (bufsize <= in_bytes) {
+            break;
+        }
+
+        if (virtio_queue_enable_notification_and_check(q->rx_vq, opaque)) {
+            /* Guest has added some buffers, try again */
+            continue;
+        } else {
             return 0;
         }
     }
 
     virtio_queue_set_notification(q->rx_vq, 0);
+
     return 1;
 }