[openib-general] IB mcast question

[Sean Hefty]

>>     Steve> I was able to create a mcast group with the mc
>>     Steve> qkey==0xe00a0a0a, and 3 apps joined this group, but their
>>     Steve> qp qkeys were 0 (I changed ucma_init_ud_qp() to set the qp
>>     Steve> qkey to 0).  One app sent to the mcgroup ah/qkey/qpn and
>>     Steve> the other two received the packet.  Does that make sense?
>>
>> In theory the Q_Key of a multicast group record is the Q_Key you're
>> supposed to use when sending to the group.  Of course nothing enforces
>> this but I don't really like abusing things this way.
>>
>
>I _did_ send the message to the qkey of the mcg.

I didn't think that this was supposed to work.

Is the QKey going out on the wire the QKey from the send WR, or that associated
with the QP?  I think the QKey going out on the wire is the latter, which just
happens to make it work.

- Sean