On Tue, Jan 17, 2017 at 06:13:51PM +0000, Rolf Neugebauer wrote:
> This patch part reverts fd2a0437dc33 and e858fae2b0b8 which introduced a
> subtle change in how the virtio_net flags are derived from the SKBs
> ip_summed field.
>
> With the above commits, the flags are set to VIRTIO_NET_HDR_F_DATA_VALID
> when ip_summed == CHECKSUM_UNNECESSARY, thus treating it differently to
> ip_summed == CHECKSUM_NONE, which should be the same.
>
> Further, the virtio spec 1.0 / CS04 explicitly says that
> VIRTIO_NET_HDR_F_DATA_VALID must not be set by the driver.
>
> Signed-off-by: Rolf Neugebauer <rolf.neugeba...@docker.com>
Fixes: fd2a0437dc33 ("virtio_net: introduce virtio_net_hdr_{from,to}_skb")
Fixes: e858fae2b0b8 (" virtio_net: use common code for virtio_net_hdr and skb
GSO conversion")
Acked-by: Michael S. Tsirkin <m...@redhat.com>
Should be backported into stable as well.
> ---
> include/linux/virtio_net.h | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h
> index 66204007d7ac..56436472ccc7 100644
> --- a/include/linux/virtio_net.h
> +++ b/include/linux/virtio_net.h
> @@ -91,8 +91,6 @@ static inline int virtio_net_hdr_from_skb(const struct
> sk_buff *skb,
> skb_checksum_start_offset(skb));
> hdr->csum_offset = __cpu_to_virtio16(little_endian,
> skb->csum_offset);
> - } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
> - hdr->flags = VIRTIO_NET_HDR_F_DATA_VALID;
> } /* else everything is zero */
>
> return 0;
> --
> 2.11.0
