doc: add metadata limitation in mlx5 guide

The metadata limitation is described.

Signed-off-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>

diff --git a/doc/guides/nics/mlx5.rst b/doc/guides/nics/mlx5.rst
index 7fac9d1..76a2ca8 100644 (file)
--- a/doc/guides/nics/mlx5.rst
+++ b/doc/guides/nics/mlx5.rst
@@ -162,6 +162,9 @@ Limitations
      - msg_type
      - teid
 
+- No Tx metadata go to the E-Switch steering domain for the Flow group 0.
+  The flows within group 0 and set metadata action are rejected by hardware.
+
 .. note::
 
    MAC addresses not already present in the bridge table of the associated