[openib-general] Problem is routing CM REQ

[Sean Hefty]

> I have a follow up question to this.. With CM how is the SL for each
> side determined? I'm looking through the code here and it looks like
> the SL of the active side is passed in the REQ to the passive side (ie
> both sides are the same) But cma_query_ib_route does not set the
> reversible bit when it asks for the path. If you don't set the
> reversible bit isn't it necessary to make a 2nd path query to get the
> reverse path's SL? [Path responses without the reversible bit set
> are actually simplex paths and reversing them probably will run into
> SL2VL mapping tables that cause the packets to be dropped ie o7-8]

Complete support for non-reversible paths is missing.  It would take some 
additional work to add this in, and would likely require API changes. 
(Personally, I would like to keep ignoring this until it becomes an issue.)  For 
now, the CMA should at least set the reversible bit for its query.

I don't know that the reversible bit in a path record can really apply across 
subnets.

- Sean