[ewg] [PATCH 2/8 v3] ib_core: RDMAoE support only QP1

[Eli Cohen]

On Tue, Jul 14, 2009 at 07:15:44AM -0400, Hal Rosenstock wrote:
> On Tue, Jul 14, 2009 at 3:46 AM, Eli Cohen<eli at dev.mellanox.co.il> wrote:
> > On Mon, Jul 13, 2009 at 03:26:34PM -0400, Hal Rosenstock wrote:
> >> On Mon, Jul 13, 2009 at 2:14 PM, Eli Cohen<eli at mellanox.co.il> wrote:
> >> > Since RDMAoE is using Ethernet as its link layer, there is no need for QP0. QP1
> >> > is still needed since it handles communications between CM agents. This patch
> >> > will create only QP1 for RDMAoE ports.
> >>
> >> What happens with other QP1 traffic (other than CM and SA) ?
> > I think it should work but I haven't tried that.
> 
> Would you ? You could try tools from infiniband-diags or ibdiagnet.
Yes I would try that. But I need something that will not fail because
it could not open QP0. For example, something that uses only QP1. Are
the any in ibutils?

> 
> >> Userspace
> >> can access QP1 (and QP0).
> > QP0 is not accessible since ib_register_mad_agent() will fail for QP0
> > becuase of this:
> >
> >        if (!port_priv->qp_info[qp_type].qp)
> >                return NULL;
> >
> > QP1 should work in the same way
> 
> So what happens with things like PerfMgt class ? I think it ends up
> timing out if no receiver consumer is present.
> 
> >> Does QP0 error out ? What about QP1 ? Does
> >> it just timeout ? If so, a direct error would be better.
> >>
> >
> > See above - you can't access QP0. Do you know of a utility from
> > userspace which sends/receives MADs on QP0 or QP1?
> 
> Yes, opensm, infiniband-diags (various), and ibutils (ibdiagnet, etc).
> 
> -- Hal