On Mon, Sep 12, 2022 at 1:22 AM Kangjie Xu <kangjie...@linux.alibaba.com> wrote:
>
> Introduce vhost_virtqueue_reset(), which can reset the specific
> virtqueue in the device. Then it will unmap vrings and the desc
> of the virtqueue.
>
> Here we do not reuse the vhost_net_stop_one() or vhost_dev_stop(),
> because they work at queue pair level. We do not use
> vhost_virtqueue_stop() because it may stop the device in the
> backend.
>
> This patch only considers the case of vhost-kernel, when
> NetClientDriver is NET_CLIENT_DRIVER_TAP.
>
> Furthermore, we do not need net->nc->info->poll() because
> it enables userspace datapath and we want to stop all
> datapaths for this reset virtqueue here.
>
> Signed-off-by: Kangjie Xu <kangjie...@linux.alibaba.com>
> Signed-off-by: Xuan Zhuo <xuanz...@linux.alibaba.com>
Acked-by: Jason Wang <jasow...@redhat.com>
> ---
> hw/net/vhost_net.c | 25 +++++++++++++++++++++++++
> include/net/vhost_net.h | 2 ++
> 2 files changed, 27 insertions(+)
>
> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
> index d28f8b974b..8beecb4d22 100644
> --- a/hw/net/vhost_net.c
> +++ b/hw/net/vhost_net.c
> @@ -531,3 +531,28 @@ int vhost_net_set_mtu(struct vhost_net *net, uint16_t
> mtu)
>
> return vhost_ops->vhost_net_set_mtu(&net->dev, mtu);
> }
> +
> +void vhost_net_virtqueue_reset(VirtIODevice *vdev, NetClientState *nc,
> + int vq_index)
> +{
> + VHostNetState *net = get_vhost_net(nc->peer);
> + const VhostOps *vhost_ops = net->dev.vhost_ops;
> + struct vhost_vring_file file = { .fd = -1 };
> + int idx;
> +
> + /* should only be called after backend is connected */
> + assert(vhost_ops);
> +
> + idx = vhost_ops->vhost_get_vq_index(&net->dev, vq_index);
> +
> + if (net->nc->info->type == NET_CLIENT_DRIVER_TAP) {
> + file.index = idx;
> + int r = vhost_net_set_backend(&net->dev, &file);
> + assert(r >= 0);
> + }
> +
> + vhost_virtqueue_stop(&net->dev,
> + vdev,
> + net->dev.vqs + idx,
> + net->dev.vq_index + idx);
> +}
> diff --git a/include/net/vhost_net.h b/include/net/vhost_net.h
> index 387e913e4e..85d85a4957 100644
> --- a/include/net/vhost_net.h
> +++ b/include/net/vhost_net.h
> @@ -48,4 +48,6 @@ uint64_t vhost_net_get_acked_features(VHostNetState *net);
>
> int vhost_net_set_mtu(struct vhost_net *net, uint16_t mtu);
>
> +void vhost_net_virtqueue_reset(VirtIODevice *vdev, NetClientState *nc,
> + int vq_index);
> #endif
> --
> 2.32.0
>
