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

[Hal Rosenstock]

On Tue, Jul 14, 2009 at 9:38 AM, Eli Cohen<eli at dev.mellanox.co.il> wrote:
> 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.

So opensm, ibdiagnet, and smpquery fail (error out) ?

> For example, something that uses only QP1. Are
> the any in ibutils?

In infiniband-diags, there are perfquery, saquery, vendstat, ibping,
and ibssystat which only use QP1. The latter two run are client/server
and can take GUID (not GID) as an argument.

-- Hal

>>
>> >> 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
>