Commit a2fb4bc4e2a6 ("net: implement virtio helpers to handle UDP
GSO tunneling.") inadvertently altered checksum offload behavior
for guests not using UDP GSO tunneling.Before, tun_put_user called tun_vnet_hdr_from_skb, which passed has_data_valid = true to virtio_net_hdr_from_skb. After, tun_put_user began calling tun_vnet_hdr_tnl_from_skb instead, which passes has_data_valid = false into both call sites. This caused virtio hdr flags to not include VIRTIO_NET_HDR_F_DATA_VALID for SKBs where skb->ip_summed == CHECKSUM_UNNECESSARY. As a result, guests are forced to recalculate checksums unnecessarily. Restore the previous behavior by ensuring has_data_valid = true is passed in the !tnl_gso_type case. Cc: Paolo Abeni <[email protected]> Fixes: a2fb4bc4e2a6 ("net: implement virtio helpers to handle UDP GSO tunneling.") Signed-off-by: Jon Kohler <[email protected]> --- include/linux/virtio_net.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h index b673c31569f3..570c6dd1666d 100644 --- a/include/linux/virtio_net.h +++ b/include/linux/virtio_net.h @@ -394,7 +394,7 @@ virtio_net_hdr_tnl_from_skb(const struct sk_buff *skb, tnl_gso_type = skb_shinfo(skb)->gso_type & (SKB_GSO_UDP_TUNNEL | SKB_GSO_UDP_TUNNEL_CSUM); if (!tnl_gso_type) - return virtio_net_hdr_from_skb(skb, hdr, little_endian, false, + return virtio_net_hdr_from_skb(skb, hdr, little_endian, true, vlan_hlen); /* Tunnel support not negotiated but skb ask for it. */ -- 2.43.0

