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

[Lu, Wenzhuo]

> -----Original Message-----
> From: Michal Schmidt <mschmidt at redhat.com>
> Sent: Thursday, December 8, 2022 8:19 PM
> To: dev at dpdk.org
> Cc: Richardson, Bruce <bruce.richardson at intel.com>; Wu, Jingjing
> <jingjing.wu at intel.com>; Xing, Beilei <beilei.xing at intel.com>; Wang, Haiyue
> <haiyue.wang at intel.com>
> Subject: [PATCH] net/iavf: fix mbuf VLAN offload flags in the L2TAG2 path with
> AVX2
> 
> 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")
> 
> Signed-off-by: Michal Schmidt <mschmidt at redhat.com>
Acked-by: Wenzhuo Lu <wenzhuo.lu at intel.com>