Re: [PATCH net-next v3 14/15] virtio_net: introduce receive_small_build_xdp

[Jason Wang <jasowang@xxxxxxxxxx>]

在 2023/4/23 18:57, Xuan Zhuo 写道:
> Simplifying receive_small() function. Bringing the logic relating to
> build_skb together.
>
> Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>


Acked-by: Jason Wang <jasowang@xxxxxxxxxx>

Thanks


> ---
>   drivers/net/virtio_net.c | 48 ++++++++++++++++++++++++++--------------
>   1 file changed, 31 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index d2973c8fa48c..811cf1046df2 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -931,6 +931,34 @@ static struct page *xdp_linearize_page(struct receive_queue *rq,
>   	return NULL;
>   }
>   
> +static struct sk_buff *receive_small_build_skb(struct virtnet_info *vi,
> +					       unsigned int xdp_headroom,
> +					       void *buf,
> +					       unsigned int len)
> +{
> +	unsigned int header_offset;
> +	unsigned int headroom;
> +	unsigned int buflen;
> +	struct sk_buff *skb;
> +
> +	header_offset = VIRTNET_RX_PAD + xdp_headroom;
> +	headroom = vi->hdr_len + header_offset;
> +	buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
> +		SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
> +
> +	skb = build_skb(buf, buflen);
> +	if (!skb)
> +		return NULL;
> +
> +	skb_reserve(skb, headroom);
> +	skb_put(skb, len);
> +
> +	buf += header_offset;
> +	memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len);
> +
> +	return skb;
> +}
> +
>   static struct sk_buff *receive_small_xdp(struct net_device *dev,
>   					 struct virtnet_info *vi,
>   					 struct receive_queue *rq,
> @@ -1030,9 +1058,6 @@ static struct sk_buff *receive_small(struct net_device *dev,
>   {
>   	unsigned int xdp_headroom = (unsigned long)ctx;
>   	struct page *page = virt_to_head_page(buf);
> -	unsigned int header_offset;
> -	unsigned int headroom;
> -	unsigned int buflen;
>   	struct sk_buff *skb;
>   
>   	len -= vi->hdr_len;
> @@ -1060,20 +1085,9 @@ static struct sk_buff *receive_small(struct net_device *dev,
>   		rcu_read_unlock();
>   	}
>   
> -	header_offset = VIRTNET_RX_PAD + xdp_headroom;
> -	headroom = vi->hdr_len + header_offset;
> -	buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) +
> -		SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
> -
> -	skb = build_skb(buf, buflen);
> -	if (!skb)
> -		goto err;
> -	skb_reserve(skb, headroom);
> -	skb_put(skb, len);
> -
> -	buf += header_offset;
> -	memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len);
> -	return skb;
> +	skb = receive_small_build_skb(vi, xdp_headroom, buf, len);
> +	if (likely(skb))
> +		return skb;
>   
>   err:
>   	stats->drops++;