Re: [Qemu-devel] [PATCH] vhost_net: cleanup recovery

[Jason Wang <jasowang@redhat.com>]

On 09/03/2014 05:10 PM, Michael S. Tsirkin wrote:
> commit aad4dce934649b3a398396fc2a76f215bb194ea4
>     vhost_net: start/stop guest notifiers properly
>
> changed the order of calls for guest notifiers,
> but did not recover in the correct (reverse) order.
> Fix it up.
>
> Cc: qemu-stable@nongnu.org
> Cc: Andrey Korolyov <andrey@xdel.ru>
> Cc: Jason Wang <jasowang@redhat.com>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  hw/net/vhost_net.c | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
> index ba5d544..1fe18c7 100644
> --- a/hw/net/vhost_net.c
> +++ b/hw/net/vhost_net.c
> @@ -289,7 +289,7 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
>      BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
>      VirtioBusState *vbus = VIRTIO_BUS(qbus);
>      VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
> -    int r, i = 0;
> +    int r, i;
>  
>      if (!vhost_net_device_endian_ok(dev)) {
>          error_report("vhost-net does not support cross-endian");
> @@ -317,16 +317,22 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
>          r = vhost_net_start_one(get_vhost_net(ncs[i].peer), dev);
>  
>          if (r < 0) {
> -            goto err;
> +            goto err_start;
>          }
>      }
>  
>      return 0;
>  
> -err:
> +err_start:
>      while (--i >= 0) {
>          vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
>      }
> +err:
> +    r = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
> +    if (r < 0) {
> +        fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
> +        fflush(stderr);
> +    }

We probably need a new label, since we only want to do this when guest
notifiers has been set.
>      return r;
>  }
>