[PATCH] net/iavf: fix mbuf VLAN offload flags in the L2TAG2 path with AVX2

[Maxime Coquelin]

Hi Michal,

On 12/8/22 13:19, Michal Schmidt wrote:
> It has been observed that mbufs of some received VLAN packets had the
> VLAN tag correctly set in vlan_tci, but ol_flags were missing the
> VLAN-indicating flags.
> 
> _mm256_shuffle_epi8 operates as two independent 128-bit operations,
> not as a single 256-bit operation. To have the RTE_MBUF_F_RX_VLAN* flags
> reflected in the resulting vlan_flags for all 8 rx descriptors, the
> input l2tag2_flags_shuf must contain the required pattern in both
> 128-bit halves.
> 
> Fixes: 3a1aca384d3a ("net/iavf: fix VLAN tag extraction handling")

Adding stable ML since bug was introduced in v21.05:
Cc: stable at dpdk.org

Maybe no need to resubmit and maintainer can add it when applying.

> 
> Signed-off-by: Michal Schmidt <mschmidt at redhat.com>
> ---
>   drivers/net/iavf/iavf_rxtx_vec_avx2.c | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/iavf/iavf_rxtx_vec_avx2.c b/drivers/net/iavf/iavf_rxtx_vec_avx2.c
> index 862f6eb0c0..b4ebac9d34 100644
> --- a/drivers/net/iavf/iavf_rxtx_vec_avx2.c
> +++ b/drivers/net/iavf/iavf_rxtx_vec_avx2.c
> @@ -1074,7 +1074,10 @@ _iavf_recv_raw_pkts_vec_avx2_flex_rxd(struct iavf_rx_queue *rxq,
>   					_mm256_set_epi8(0, 0, 0, 0,
>   							0, 0, 0, 0,
>   							0, 0, 0, 0,
> -							0, 0, 0, 0,
> +							0, 0,
> +							RTE_MBUF_F_RX_VLAN |
> +							RTE_MBUF_F_RX_VLAN_STRIPPED,
> +							0,
>   							/* end up 128-bits */
>   							0, 0, 0, 0,
>   							0, 0, 0, 0,

Reviewed-by: Maxime Coquelin <maxime.coquelin at redhat.com>

Thanks,
Maxime