On Tue, Apr 18, 2023 at 2:53 PM Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx> wrote: > > Avoid the problem that some variables(headroom and so on) will repeat > the calculation when process xdp. While at it, if we agree to use separate code paths for building skbs. It would be better to have a helper for building skb for non XDP cases, then we can hide those calculation there. Thanks > > Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx> > --- > drivers/net/virtio_net.c | 12 ++++++++---- > 1 file changed, 8 insertions(+), 4 deletions(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index f6f5903face2..5a5636178bd3 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -1040,11 +1040,10 @@ static struct sk_buff *receive_small(struct net_device *dev, > struct sk_buff *skb; > struct bpf_prog *xdp_prog; > unsigned int xdp_headroom = (unsigned long)ctx; > - unsigned int header_offset = VIRTNET_RX_PAD + xdp_headroom; > - unsigned int headroom = vi->hdr_len + header_offset; > - unsigned int buflen = SKB_DATA_ALIGN(GOOD_PACKET_LEN + headroom) + > - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); > struct page *page = virt_to_head_page(buf); > + unsigned int header_offset; > + unsigned int headroom; > + unsigned int buflen; > > len -= vi->hdr_len; > stats->bytes += len; > @@ -1072,6 +1071,11 @@ static struct sk_buff *receive_small(struct net_device *dev, > rcu_read_unlock(); > > skip_xdp: > + 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; > -- > 2.32.0.3.g01195cf9f >
