Re: [PATCH v2 8/9] virtio_net: remove xdp related info from page_to_skb()

Jason Wang
2022-12-27T07:56:42Z

在 2022/12/20 22:14, Heng Qi 写道:
> For the clear construction of xdp_buff, we remove the xdp processing
> interleaved with page_to_skb(). Now, the logic of xdp and building
> skb from xdp are separate and independent.
>
> Signed-off-by: Heng Qi <hengqi@linux.alibaba.com>
> Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>

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

Thanks

> ---
> drivers/net/virtio_net.c | 41 +++++++++-------------------------------
> 1 file changed, 9 insertions(+), 32 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 4e12196fcfd4..398ffe2a5084 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -439,9 +439,7 @@ static unsigned int mergeable_ctx_to_truesize(void *mrg_ctx)
> static struct sk_buff *page_to_skb(struct virtnet_info *vi,
> struct receive_queue *rq,
> struct page *page, unsigned int offset,
> - unsigned int len, unsigned int truesize,
> - bool hdr_valid, unsigned int metasize,
> - unsigned int headroom)
> + unsigned int len, unsigned int truesize)
> {
> struct sk_buff *skb;
> struct virtio_net_hdr_mrg_rxbuf *hdr;
> @@ -459,21 +457,11 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi,
> else
> hdr_padded_len = sizeof(struct padded_vnet_hdr);
>
> - /* If headroom is not 0, there is an offset between the beginning of the
> - * data and the allocated space, otherwise the data and the allocated
> - * space are aligned.
> - *
> - * Buffers with headroom use PAGE_SIZE as alloc size, see
> - * add_recvbuf_mergeable() + get_mergeable_buf_len()
> - */
> - truesize = headroom ? PAGE_SIZE : truesize;
> - tailroom = truesize - headroom;
> - buf = p - headroom;
> -
> + buf = p;
> len -= hdr_len;
> offset += hdr_padded_len;
> p += hdr_padded_len;
> - tailroom -= hdr_padded_len + len;
> + tailroom = truesize - hdr_padded_len - len;
>
> shinfo_size = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
>
> @@ -503,7 +491,7 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi,
> if (len <= skb_tailroom(skb))
> copy = len;
> else
> - copy = ETH_HLEN + metasize;
> + copy = ETH_HLEN;
> skb_put_data(skb, p, copy);
>
> len -= copy;
> @@ -542,19 +530,11 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi,
> give_pages(rq, page);
>
> ok:
> - /* hdr_valid means no XDP, so we can copy the vnet header */
> - if (hdr_valid) {
> - hdr = skb_vnet_hdr(skb);
> - memcpy(hdr, hdr_p, hdr_len);
> - }
> + hdr = skb_vnet_hdr(skb);
> + memcpy(hdr, hdr_p, hdr_len);
> if (page_to_free)
> put_page(page_to_free);
>
> - if (metasize) {
> - __skb_pull(skb, metasize);
> - skb_metadata_set(skb, metasize);
> - }
> -
> return skb;
> }
>
> @@ -934,7 +914,7 @@ static struct sk_buff *receive_big(struct net_device *dev,
> {
> struct page *page = buf;
> struct sk_buff *skb =
> - page_to_skb(vi, rq, page, 0, len, PAGE_SIZE, true, 0, 0);
> + page_to_skb(vi, rq, page, 0, len, PAGE_SIZE);
>
> stats->bytes += len - vi->hdr_len;
> if (unlikely(!skb))
> @@ -1222,9 +1202,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
> rcu_read_unlock();
> put_page(page);
> head_skb = page_to_skb(vi, rq, xdp_page, offset,
> - len, PAGE_SIZE, false,
> - metasize,
> - headroom);
> + len, PAGE_SIZE);
> return head_skb;
> }
> break;
> @@ -1289,8 +1267,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
> rcu_read_unlock();
>
> skip_xdp:
> - head_skb = page_to_skb(vi, rq, page, offset, len, truesize, !xdp_prog,
> - metasize, headroom);
> + head_skb = page_to_skb(vi, rq, page, offset, len, truesize);
> curr_skb = head_skb;
>
> if (unlikely(!curr_skb))