[openib-general] race in mthca_cq.c?

[Michael S. Tsirkin]

Roland, I think I see a race in mthca: let's assume that
a QP is destroyed. We remove the qpn from qp_table.

Before we have the chance to cleanup the CQ, another QP is created
and put in the same slot in table. If the user now polls the CQ he'll see a
completion for a wrong QP, since poll CQ does:

               *cur_qp = mthca_array_get(&dev->qp_table.qp,
                                          be32_to_cpu(cqe->my_qpn) &
                                          (dev->limits.num_qps - 1));

Is this analysis right?
If yes, I think we can fix this by testing (*cur_qp)->qpn ==
be32_to_cpu(cqe->my_qpn), does this make sense?

Same for userspace I guess?

It seems a similiar issue exists for CQs, does it not?
And I think it can be solved in a similiar way, checking the CQN?

-- 
MST