Re: [PATCH net-next v1 10/19] virtio_net: xsk: prevent disable tx napi

[Jason Wang <jasowang@redhat.com>]

On Mon, Oct 16, 2023 at 8:01 PM Xuan Zhuo <xuanzhuo@linux.alibaba.com> wrote:
>
> Since xsk's TX queue is consumed by TX NAPI, if sq is bound to xsk, then
> we must stop tx napi from being disabled.
>
> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>

Acked-by: Jason Wang <jasowang@redhat.com>

Thanks


> ---
>  drivers/net/virtio/main.c | 10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/virtio/main.c b/drivers/net/virtio/main.c
> index 38733a782f12..b320770e5f4e 100644
> --- a/drivers/net/virtio/main.c
> +++ b/drivers/net/virtio/main.c
> @@ -3203,7 +3203,7 @@ static int virtnet_set_coalesce(struct net_device *dev,
>                                 struct netlink_ext_ack *extack)
>  {
>         struct virtnet_info *vi = netdev_priv(dev);
> -       int ret, queue_number, napi_weight;
> +       int ret, queue_number, napi_weight, i;
>         bool update_napi = false;
>
>         /* Can't change NAPI weight if the link is up */
> @@ -3232,6 +3232,14 @@ static int virtnet_set_coalesce(struct net_device *dev,
>                 return ret;
>
>         if (update_napi) {
> +               /* xsk xmit depends on the tx napi. So if xsk is active,
> +                * prevent modifications to tx napi.
> +                */
> +               for (i = queue_number; i < vi->max_queue_pairs; i++) {
> +                       if (rtnl_dereference(vi->sq[i].xsk.pool))
> +                               return -EBUSY;
> +               }
> +
>                 for (; queue_number < vi->max_queue_pairs; queue_number++)
>                         vi->sq[queue_number].napi.weight = napi_weight;
>         }
> --
> 2.32.0.3.g01195cf9f
>