Re: [Qemu-devel] [PATCH v4 2/5] vhost: reset vhost net when virtio_net_reset happens

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

On Wed, Nov 11, 2015 at 09:24:38PM +0800, Yuanhan Liu wrote:
> When a virtio net driver is unloaded (unbind), virtio_net_reset happens.
> For vhost net, we should also send a message (RESET_OWNER) to the backend
> to do some proper reset settings.
> 
> Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>

How about we just skip RESET_OWNER completely?
After all, modern clients have VRING_ENABLE.

> ---
>  hw/net/vhost_net.c      | 20 ++++++++++++++------
>  hw/net/virtio-net.c     | 14 ++++++++++++++
>  include/net/vhost_net.h |  1 +
>  3 files changed, 29 insertions(+), 6 deletions(-)
> 
> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
> index d91b7b1..387f851 100644
> --- a/hw/net/vhost_net.c
> +++ b/hw/net/vhost_net.c
> @@ -292,12 +292,6 @@ static void vhost_net_stop_one(struct vhost_net *net,
>              int r = vhost_ops->vhost_net_set_backend(&net->dev, &file);
>              assert(r >= 0);
>          }
> -    } else if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER) {
> -        for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
> -            const VhostOps *vhost_ops = net->dev.vhost_ops;
> -            int r = vhost_ops->vhost_reset_device(&net->dev);
> -            assert(r >= 0);
> -        }
>      }
>      if (net->nc->info->poll) {
>          net->nc->info->poll(net->nc, true);
> @@ -382,6 +376,16 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
>      assert(vhost_net_set_vnet_endian(dev, ncs[0].peer, false) >= 0);
>  }
>  
> +void vhost_net_reset(VirtIODevice *vdev)
> +{
> +    VirtIONet *n = VIRTIO_NET(vdev);
> +    struct vhost_net *net = get_vhost_net(n->nic->ncs[0].peer);
> +
> +    if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER) {
> +        net->dev.vhost_ops->vhost_reset_device(&net->dev);
> +    }
> +}
> +
>  void vhost_net_cleanup(struct vhost_net *net)
>  {
>      vhost_dev_cleanup(&net->dev);
> @@ -469,6 +473,10 @@ void vhost_net_stop(VirtIODevice *dev,
>  {
>  }
>  
> +void vhost_net_reset(VirtIODevice *vdev)
> +{
> +}
> +
>  void vhost_net_cleanup(struct vhost_net *net)
>  {
>  }
> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> index a877614..75472ba 100644
> --- a/hw/net/virtio-net.c
> +++ b/hw/net/virtio-net.c
> @@ -318,10 +318,24 @@ static RxFilterInfo *virtio_net_query_rxfilter(NetClientState *nc)
>      return info;
>  }
>  
> +static void virtio_net_vhost_reset(VirtIONet *n)
> +{
> +    VirtIODevice *vdev = VIRTIO_DEVICE(n);
> +    NetClientState *nc = qemu_get_queue(n->nic);
> +
> +    if (!get_vhost_net(nc->peer)) {
> +        return;
> +    }
> +
> +    vhost_net_reset(vdev);
> +}
> +
>  static void virtio_net_reset(VirtIODevice *vdev)
>  {
>      VirtIONet *n = VIRTIO_NET(vdev);
>  
> +    virtio_net_vhost_reset(n);
> +
>      /* Reset back to compatibility mode */
>      n->promisc = 1;
>      n->allmulti = 0;
> diff --git a/include/net/vhost_net.h b/include/net/vhost_net.h
> index 3389b41..d1c1331 100644
> --- a/include/net/vhost_net.h
> +++ b/include/net/vhost_net.h
> @@ -18,6 +18,7 @@ struct vhost_net *vhost_net_init(VhostNetOptions *options);
>  
>  int vhost_net_start(VirtIODevice *dev, NetClientState *ncs, int total_queues);
>  void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs, int total_queues);
> +void vhost_net_reset(VirtIODevice *dev);
>  
>  void vhost_net_cleanup(VHostNetState *net);
>  
> -- 
> 1.9.0