[ofa-general] Re: [PATCH] core/cm: improve requestmessage interpretation of subnet local fields

[Sean Hefty]

>I'm with Hal on this - why does this cause a problem? There is no IB
>packet verification check that tests if a GRH is present, only if it
>is presen it must be valid - so how can an extra correctly filled in
>GRH cause anything but degraded performance?

ib_init_ah_from_path() uses the hop_limit in the path record to determine if a
GRH should be used.  It sets the address handle attributes (used to configure
the QP) based on hop_limit > 1.  If hop_limit is set incorrectly in the CM REQ,
the path record formed by the CM based on data carried in the REQ could have
invalid GRH values.

It's possible that this is an active side CM issue, but that's not clear to me.

- Sean