Re: [PATCH net-next v6 09/10] virtio_net: xsk: rx: support recv merge mode

[Paolo Abeni <pabeni@redhat.com>]

On Tue, 2024-06-18 at 15:56 +0800, Xuan Zhuo wrote:
> Support AF-XDP for merge mode.
> 
> Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> ---
>  drivers/net/virtio_net.c | 139 +++++++++++++++++++++++++++++++++++++++
>  1 file changed, 139 insertions(+)
> 
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 06608d696e2e..cfa106aa8039 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -504,6 +504,10 @@ static int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp,
>  			       struct net_device *dev,
>  			       unsigned int *xdp_xmit,
>  			       struct virtnet_rq_stats *stats);
> +static struct sk_buff *virtnet_skb_append_frag(struct sk_buff *head_skb,
> +					       struct sk_buff *curr_skb,
> +					       struct page *page, void *buf,
> +					       int len, int truesize);
>  
>  static bool is_xdp_frame(void *ptr)
>  {
> @@ -1128,6 +1132,139 @@ static struct sk_buff *virtnet_receive_xsk_small(struct net_device *dev, struct
>  	}
>  }
>  
> +static void xsk_drop_follow_bufs(struct net_device *dev,
> +				 struct receive_queue *rq,
> +				 u32 num_buf,
> +				 struct virtnet_rq_stats *stats)
> +{
> +	struct xdp_buff *xdp;
> +	u32 len;
> +
> +	while (num_buf-- > 1) {

Why do you skip the last buffer? I thought it should be dropped, too?!?

Thanks!

Paolo