doc: fix some statements for ice vector PMD

1. Add descriptions for how to select avx512 datapath.
2. Add explanation for "P" in ice.ini.

Fixes: 7f85d5ebcfe1 ("net/ice: add AVX512 vector path")
Fixes: 271cc8c5028a ("doc: update ice features list")
Cc: stable@dpdk.org
Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
Acked-by: Leyi Rong <leyi.rong@intel.com>

diff --git a/doc/guides/nics/ice.rst b/doc/guides/nics/ice.rst
index a0887f1..ccda26f 100644 (file)
--- a/doc/guides/nics/ice.rst
+++ b/doc/guides/nics/ice.rst
@@ -211,9 +211,12 @@ are chosen based on 2 conditions.
 - ``CPU``
   On the X86 platform, the driver checks if the CPU supports AVX2.
   If it's supported, AVX2 paths will be chosen. If not, SSE is chosen.
 - ``CPU``
   On the X86 platform, the driver checks if the CPU supports AVX2.
   If it's supported, AVX2 paths will be chosen. If not, SSE is chosen.

+  If the CPU supports AVX512 and EAL argument ``--force-max-simd-bitwidth``
+  is set to 512, AVX512 paths will be chosen.

 
 - ``Offload features``
 
 - ``Offload features``

-  The supported HW offload features are described in the document ice_vec.ini.
+  The supported HW offload features are described in the document ice.ini,
+  A value "P" means the offload feature is not supported by vector path.

   If any not supported features are used, ICE vector PMD is disabled and the
   normal paths are chosen.
 
   If any not supported features are used, ICE vector PMD is disabled and the
   normal paths are chosen.