How to enable and use Tag matching offload using OpenMPI

HI, I have a Mellanox CX5 , ibv_devinfo says tag matching is not supported, but product documentation says otherwise.
my question is their any nvram setting or specific firmware that enables tag matching offload and once enable
how to configure openmpi to use tag matching.

Got the Information , Since my CX5 is configured in ROCE mode its not supported.