The purpose of commit 703eec1b2422 ("virtio_net: fixing XDP for fully checksummed packets handling") is to record the flags in advance, as their value may be overwritten in the XDP case. However, the flags recorded under big mode are incorrect, because in big mode, the passed buf does not point to the rx buffer, but rather to the page of the submitted buffer. This commit fixes this issue. For the small mode, the commit c11a49d58ad2 ("virtio_net: Fix mismatched buf address when unmapping for small packets") fixed it. Fixes: 703eec1b2422 ("virtio_net: fixing XDP for fully checksummed packets handling") Signed-off-by: Xuan Zhuo --- drivers/net/virtio_net.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 975bdc5dab84..b4d1c09ff488 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -2621,22 +2621,28 @@ static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq, return; } - /* 1. Save the flags early, as the XDP program might overwrite them. + /* About the flags below: + * 1. Save the flags early, as the XDP program might overwrite them. * These flags ensure packets marked as VIRTIO_NET_HDR_F_DATA_VALID * stay valid after XDP processing. * 2. XDP doesn't work with partially checksummed packets (refer to * virtnet_xdp_set()), so packets marked as * VIRTIO_NET_HDR_F_NEEDS_CSUM get dropped during XDP processing. */ - flags = ((struct virtio_net_common_hdr *)buf)->hdr.flags; - if (vi->mergeable_rx_bufs) + if (vi->mergeable_rx_bufs) { + flags = ((struct virtio_net_common_hdr *)buf)->hdr.flags; skb = receive_mergeable(dev, vi, rq, buf, ctx, len, xdp_xmit, stats); - else if (vi->big_packets) + } else if (vi->big_packets) { + void *p = page_address((struct page *)buf); + + flags = ((struct virtio_net_common_hdr *)p)->hdr.flags; skb = receive_big(dev, vi, rq, buf, len, stats); - else + } else { + flags = ((struct virtio_net_common_hdr *)buf)->hdr.flags; skb = receive_small(dev, vi, rq, buf, ctx, len, xdp_xmit, stats); + } if (unlikely(!skb)) return; -- 2.32.0.3.g01195cf9f The commit be50da3e9d4a ("net: virtio_net: implement exact header length guest feature") introduces support for the VIRTIO_NET_F_GUEST_HDRLEN feature in virtio-net. This feature requires virtio-net to set hdr_len to the actual header length of the packet when transmitting, the number of bytes from the start of the packet to the beginning of the transport-layer payload. However, in practice, hdr_len was being set using skb_headlen(skb), which is clearly incorrect. This commit fixes that issue. Fixes: be50da3e9d4a ("net: virtio_net: implement exact header length guest feature") Signed-off-by: Xuan Zhuo --- include/linux/virtio_net.h | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h index 20e0584db1dd..4273420a9ff9 100644 --- a/include/linux/virtio_net.h +++ b/include/linux/virtio_net.h @@ -217,20 +217,25 @@ static inline int virtio_net_hdr_from_skb(const struct sk_buff *skb, if (skb_is_gso(skb)) { struct skb_shared_info *sinfo = skb_shinfo(skb); + u16 hdr_len; - /* This is a hint as to how much should be linear. */ - hdr->hdr_len = __cpu_to_virtio16(little_endian, - skb_headlen(skb)); + hdr_len = skb_transport_offset(skb); hdr->gso_size = __cpu_to_virtio16(little_endian, sinfo->gso_size); - if (sinfo->gso_type & SKB_GSO_TCPV4) + if (sinfo->gso_type & SKB_GSO_TCPV4) { hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4; - else if (sinfo->gso_type & SKB_GSO_TCPV6) + hdr_len += tcp_hdrlen(skb); + } else if (sinfo->gso_type & SKB_GSO_TCPV6) { hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6; - else if (sinfo->gso_type & SKB_GSO_UDP_L4) + hdr_len += tcp_hdrlen(skb); + } else if (sinfo->gso_type & SKB_GSO_UDP_L4) { hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP_L4; - else + hdr_len += sizeof(struct udphdr); + } else { return -EINVAL; + } + + hdr->hdr_len = __cpu_to_virtio16(little_endian, hdr_len); if (sinfo->gso_type & SKB_GSO_TCP_ECN) hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN; } else -- 2.32.0.3.g01195cf9f