Re: [PATCH for-rc v1 0/4] RDMA/providers: Set max_pkey attribute

[Kamal Heib <kamalheib1@gmail.com>]

On Tue, Jul 07, 2020 at 01:12:47PM -0300, Jason Gunthorpe wrote:
> On Mon, Jul 06, 2020 at 12:11:15PM +0300, Kamal Heib wrote:
> > This patch set makes sure to set the max_pkeys attribute to the providers
> > that aren't setting it or not setting it correctly.
> > 
> > v1: Drop the efa patch and target for-rc.
> > 
> > Kamal Heib (4):
> >   RDMA/siw: Set max_pkeys attribute
> >   RDMA/cxgb4: Set max_pkeys attribute
> >   RDMA/i40iw: Set max_pkeys attribute
> >   RDMA/usnic: Fix reported max_pkeys attribute
> 
> Why should iwarp have a 1 pkey value?
> 
> Jason

That is a good question :-)

My Idea in this patchset was to match between the reported pkey_tbl_len and
the max_pkeys attribute that the providers expose.

But after taking a deeper look now, I see that the RDMA core requires
from all providers to implement the query_pkey() callback, which before
[1] commit that will cause the provider driver not to load. For IB
providers the requirement make sense, also for RoCE providers, because
there is a requirement by the RoCE Spec to support the default PKey, For
iwarp providers, This doesn't make sense and I think that they decided to
do the same as RoCE and to avoid the driver load failure.

Probably, The requirement from the RDMA core needs to be changed and
the query_pkey() callback needs to be removed from the iwarp providers,
Thoughts?

------>8------
git grep -n IB_MANDATORY_FUNC drivers/infiniband/ | grep pkey
drivers/infiniband/core/device.c:275:		IB_MANDATORY_FUNC(query_pkey),
------>8------

[1] - 6780c4fa9d6e ("RDMA: Add indication for in kernel API support to IB device")

Thanks,
Kamal