[openib-general] semantics of process_mad?

[Roland Dreier]

    Hal> Are you saying to just make sure SM class is QP0 and all GS
    Hal> classes are not QP0 (QP1 is insufficient when redirection is
    Hal> supported) ? Because of redirection, it seems adding QP
    Hal> number as a parameter is a better solution.

Actually I think redirection is a great argument for putting the
filtering outside the low-level driver.  How can the low-level driver
know whether or not to respond to PMA requests on QP5?

So I think the right answer is to put the tests for SM on QP0, GS on
non-QP0 etc outside the low-level driver and in particular outside
process_mad.

    Hal> I think the only difference with OpenIB right now is that a
    Hal> MAD right now cannot be multiply consumed as it can in the
    Hal> Topspin implementation.

If the low-level driver returns IB_MAD_RESULT_CONSUMED that's the end
of it in the Tospin driver (the multiple consumers come after the
low-level driver has its shot at the MAD).