On Mon, Jun 19, 2023 at 06:57:37PM +0800, Heng Qi wrote:
> We are now re-probing the csum related fields and trying
> to have XDP and RX hw checksum capabilities coexist on the
> XDP path. For the benefit of:
> 1. RX hw checksum capability can be used if XDP is loaded.
> 2. Avoid packet loss when loading XDP in the vm-vm scenario.
>
> Signed-off-by: Heng Qi <hengqi@xxxxxxxxxxxxxxxxx>
> Reviewed-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
> ---
> drivers/net/virtio_net.c | 36 ++++++++++++++++++++++++------------
> 1 file changed, 24 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 07b4801d689c..25b486ab74db 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -1709,6 +1709,7 @@ static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
> struct net_device *dev = vi->dev;
> struct sk_buff *skb;
> struct virtio_net_hdr_mrg_rxbuf *hdr;
> + __u8 flags;
>
> if (unlikely(len < vi->hdr_len + ETH_HLEN)) {
> pr_debug("%s: short packet %i\n", dev->name, len);
> @@ -1717,6 +1718,8 @@ static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
> return;
> }
>
> + flags = ((struct virtio_net_hdr_mrg_rxbuf *)buf)->hdr.flags;
> +
> if (vi->mergeable_rx_bufs)
> skb = receive_mergeable(dev, vi, rq, buf, ctx, len, xdp_xmit,
> stats);
what's going on here?
> @@ -1728,19 +1731,28 @@ static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
> if (unlikely(!skb))
> return;
>
> - hdr = skb_vnet_hdr(skb);
> - if (dev->features & NETIF_F_RXHASH && vi->has_rss_hash_report)
> - virtio_skb_set_hash((const struct virtio_net_hdr_v1_hash *)hdr, skb);
> -
> - if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID)
> - skb->ip_summed = CHECKSUM_UNNECESSARY;
> + if (unlikely(vi->xdp_enabled)) {
> + if (virtnet_set_csum_after_xdp(vi, skb, flags) < 0) {
> + pr_debug("%s: errors occurred in flow dissector setting csum",
> + dev->name);
> + goto frame_err;
> + }
>
> - if (virtio_net_hdr_to_skb(skb, &hdr->hdr,
> - virtio_is_little_endian(vi->vdev))) {
> - net_warn_ratelimited("%s: bad gso: type: %u, size: %u\n",
> - dev->name, hdr->hdr.gso_type,
> - hdr->hdr.gso_size);
> - goto frame_err;
> + } else {
> + hdr = skb_vnet_hdr(skb);
> + if (dev->features & NETIF_F_RXHASH && vi->has_rss_hash_report)
> + virtio_skb_set_hash((const struct virtio_net_hdr_v1_hash *)hdr, skb);
> +
> + if (hdr->hdr.flags & VIRTIO_NET_HDR_F_DATA_VALID)
> + skb->ip_summed = CHECKSUM_UNNECESSARY;
> +
> + if (virtio_net_hdr_to_skb(skb, &hdr->hdr,
> + virtio_is_little_endian(vi->vdev))) {
> + net_warn_ratelimited("%s: bad gso: type: %u, size: %u\n",
> + dev->name, hdr->hdr.gso_type,
> + hdr->hdr.gso_size);
> + goto frame_err;
> + }
> }
>
> skb_record_rx_queue(skb, vq2rxq(rq->vq));
> --
> 2.19.1.6.gb485710b
