The vector Tx path does not support VLAN insertion via the L2TAG2 field,
but the scalar path supports. The earlier commit was to force to select
scalar path as soon as kernel driver requests to use L2TAG2. That logic is
incorrect. Because other case like VLAN offloading not required but scalar
path selected would have a significant performance drop.
Therefore the following commit was reverted accordingly.
commit 0d58caa7d6 ("net/iavf: fix VLAN insertion")
After reverting this commit, the AVX512 Tx path would insert the VLAN tag
into the wrong location(inner of QinQ) when the kernel driver requested
L2TAG2. This is inconsistent with the behavior of PF(outer of QinQ).
It is currently known that ice kernel drivers newer than 1.8.9 will request
the use of L2TAG2. User can set parameter '--force-max-simd-bitwidth' to
64/128/256 to avoid this issue.
Fixes: 0d58caa7d6 ("net/iavf: fix VLAN insertion")
Cc: stable@dpdk.org
Signed-off-by: Yiding Zhou <yidingx.zhou@intel.com>
Acked-by: Qi Zhang <qi.z.zhang@intel.com>
d048a0aaae