[Qemu-devel] [PULL] Net patches

[Qemu-devel] [PULL] Net patches

[Jason Wang]

The following changes since commit 5e19aed59ab48ca3c7f1e2da203eed27b91bef2d:

  Merge remote-tracking branch 'remotes/dgibson/tags/ppc-for-2.11-20171127' into staging (2017-11-27 11:16:20 +0000)

are available in the git repository at:

  https://github.com/jasowang/qemu.git tags/net-pull-request

for you to fetch changes up to 70e53e6e4da3db4b2c31981191753a7e974936d0:

  virtio-net: don't touch virtqueue if vm is stopped (2017-11-28 11:54:50 +0800)

----------------------------------------------------------------

----------------------------------------------------------------
Jason Wang (1):
      virtio-net: don't touch virtqueue if vm is stopped

 hw/net/virtio-net.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

[Qemu-devel] [PULL] virtio-net: don't touch virtqueue if vm is stopped

[Jason Wang]

Guest state should not be touched if VM is stopped, unfortunately we
didn't check running state and tried to drain tx queue unconditionally
in virtio_net_set_status(). A crash was then noticed as a migration
destination when user type quit after virtqueue state is loaded but
before region cache is initialized. In this case,
virtio_net_drop_tx_queue_data() tries to access the uninitialized
region cache.

Fix this by only dropping tx queue data when vm is running.

Fixes: 283e2c2adcb80 ("net: virtio-net discards TX data after link down")
Cc: Yuri Benditovich <yuri.benditovich@daynix.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: qemu-stable@nongnu.org
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 hw/net/virtio-net.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 150fd07..38674b0 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -288,7 +288,8 @@ static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
                 qemu_bh_cancel(q->tx_bh);
             }
             if ((n->status & VIRTIO_NET_S_LINK_UP) == 0 &&
-                (queue_status & VIRTIO_CONFIG_S_DRIVER_OK)) {
+                (queue_status & VIRTIO_CONFIG_S_DRIVER_OK) &&
+                vdev->vm_running) {
                 /* if tx is waiting we are likely have some packets in tx queue
                  * and disabled notification */
                 q->tx_waiting = 0;
-- 
2.7.4

Re: [Qemu-devel] [PULL] Net patches

[Peter Maydell]

On 28 November 2017 at 04:01, Jason Wang <jasowang@redhat.com> wrote:
> The following changes since commit 5e19aed59ab48ca3c7f1e2da203eed27b91bef2d:
>
>   Merge remote-tracking branch 'remotes/dgibson/tags/ppc-for-2.11-20171127' into staging (2017-11-27 11:16:20 +0000)
>
> are available in the git repository at:
>
>   https://github.com/jasowang/qemu.git tags/net-pull-request
>
> for you to fetch changes up to 70e53e6e4da3db4b2c31981191753a7e974936d0:
>
>   virtio-net: don't touch virtqueue if vm is stopped (2017-11-28 11:54:50 +0800)
>
> ----------------------------------------------------------------
>
> ----------------------------------------------------------------
> Jason Wang (1):
>       virtio-net: don't touch virtqueue if vm is stopped
>
>  hw/net/virtio-net.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Applied, thanks.

-- PMM