[openib-general] CMA issue: SDP login compliancy

[Steve Wise]

On Mon, 2006-12-04 at 18:57 +0200, Michael S. Tsirkin wrote:
> > Subject: CMA issue: SDP login compliancy
> > 
> > Hi!
> > SDP compliance statement *requires* that a consumer checks the
> > Responder Resources field in the connection Request/Response,
> > verifying that it is > 0. This is part of CA 4-41 in the spec.
> > 
> > However Responder Resources field does not seem to be exposed by the CMA API.  I
> > think knowing this value (at least in REQ, but preferably in REP is well) is
> > also important for any ULP that does RDMA reads.
> > 
> > Should/can CMA/UCMA be extended to pass this to the user? This might be
> > something we need to address before UCMA merge to avoid ABI breakage later.
> 
> Steve, could you please comment on the iWarp side of things?
> Does iwarp connection get the number of RDMA read requests remote side
> can support during connection setup?
> Or is this IB-specific?
> 

I believe Sean's latest CMA patches under consideration for 2.6.20
support this from a CMA perspective. 

See http://thread.gmane.org/gmane.linux.drivers.openib/33576/focus=33580

iWARP (MPA protocol) currently doesn't exchange this information across
the wire at connection setup, but there are proposals in the works to
support this (It requires a wire protocol change).  So eventually, iWARP
will provide the remote peer's responder resources in the connection
events.

Steve.