[v3,6/9] virtio-net: handle virtio_net_receive() errors

Commit Message

Greg Kurz Sept. 26, 2016, 8:34 a.m. UTC

All these errors are caused by a buggy guest: let's switch the device to
the broken state instead of terminating QEMU. Also we detach the element
from the virtqueue and free it.

Signed-off-by: Greg Kurz <[e-mail]>
Reviewed-by: Cornelia Huck <[e-mail]>
---
v3: - detach and free element
    - updated changelog
---
 hw/net/virtio-net.c |   27 +++++++++++++++------------
 1 file changed, 15 insertions(+), 12 deletions(-)

Comments

Stefan Hajnoczi Sept. 26, 2016, 4:27 p.m. UTC | #1

On Mon, Sep 26, 2016 at 10:34:40AM +0200, Greg Kurz wrote:
> All these errors are caused by a buggy guest: let's switch the device to
> the broken state instead of terminating QEMU. Also we detach the element
> from the virtqueue and free it.
> 
> Signed-off-by: Greg Kurz <[e-mail]>
> Reviewed-by: Cornelia Huck <[e-mail]>
> ---
> v3: - detach and free element
>     - updated changelog
> ---
>  hw/net/virtio-net.c |   27 +++++++++++++++------------
>  1 file changed, 15 insertions(+), 12 deletions(-)

Reviewed-by: Stefan Hajnoczi <[e-mail]>

Patch

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 2c02ba8a70a4..10a4c745f0bd 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -1125,21 +1125,24 @@  static ssize_t virtio_net_receive(NetClientState *nc, const uint8_t *buf, size_t
 
         elem = virtqueue_pop(q->rx_vq, sizeof(VirtQueueElement));
         if (!elem) {
-            if (i == 0)
-                return -1;
-            error_report("virtio-net unexpected empty queue: "
-                         "i %zd mergeable %d offset %zd, size %zd, "
-                         "guest hdr len %zd, host hdr len %zd "
-                         "guest features 0x%" PRIx64,
-                         i, n->mergeable_rx_bufs, offset, size,
-                         n->guest_hdr_len, n->host_hdr_len,
-                         vdev->guest_features);
-            exit(1);
+            if (i) {
+                virtio_error(vdev, "virtio-net unexpected empty queue: "
+                             "i %zd mergeable %d offset %zd, size %zd, "
+                             "guest hdr len %zd, host hdr len %zd "
+                             "guest features 0x%" PRIx64,
+                             i, n->mergeable_rx_bufs, offset, size,
+                             n->guest_hdr_len, n->host_hdr_len,
+                             vdev->guest_features);
+            }
+            return -1;
         }
 
         if (elem->in_num < 1) {
-            error_report("virtio-net receive queue contains no in buffers");
-            exit(1);
+            virtio_error(vdev,
+                         "virtio-net receive queue contains no in buffers");
+            virtqueue_detach_element(q->rx_vq, elem, 0);
+            g_free(elem);
+            return -1;
         }
 
         sg = elem->in_sg;