Re: [PATCH 1/4] net/virtio: fix dev_unplug_pending

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, Nov 14, 2019 at 03:16:10PM +0100, Jens Freimann wrote:
> .dev_unplug_pending is set up by virtio-net code indepent of whether
> failover=on was set for the device or not. This gives a wrong result when
> we check for existing primary devices in migration code.
> 
> Fix this by actually calling dev_unplug_pending() instead of just
> checking if the function pointer was set. When the feature was not
> negotiated dev_unplug_pending() will always return false. This prevents
> us from going into the wait-unplug state when there's no primary device
> present.
> 
> Fixes: 9711cd0dfc3f ("net/virtio: add failover support")
> Signed-off-by: Jens Freimann <jfreimann@redhat.com>
> Reported-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

This isn't really a series, is it?
Just a bunch of independent patches...

anyway:

Reviewed-by: Michael S. Tsirkin <mst@redhat.com>


> ---
>  hw/net/virtio-net.c | 3 +++
>  migration/savevm.c  | 3 ++-
>  2 files changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> index 97a5113f7e..946039c0dc 100644
> --- a/hw/net/virtio-net.c
> +++ b/hw/net/virtio-net.c
> @@ -3124,6 +3124,9 @@ static bool primary_unplug_pending(void *opaque)
>      VirtIODevice *vdev = VIRTIO_DEVICE(dev);
>      VirtIONet *n = VIRTIO_NET(vdev);
>  
> +    if (!virtio_vdev_has_feature(vdev, VIRTIO_NET_F_STANDBY)) {
> +        return false;
> +    }
>      return n->primary_dev ? n->primary_dev->pending_deleted_event : false;
>  }
>  
> diff --git a/migration/savevm.c b/migration/savevm.c
> index 966a9c3bdb..a71b930b91 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -1119,7 +1119,8 @@ int qemu_savevm_nr_failover_devices(void)
>      int n = 0;
>  
>      QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
> -        if (se->vmsd && se->vmsd->dev_unplug_pending) {
> +        if (se->vmsd && se->vmsd->dev_unplug_pending &&
> +            se->vmsd->dev_unplug_pending(se->opaque)) {
>              n++;
>          }
>      }
> -- 
> 2.21.0