Re: [PATCH for-next] RDMA/usnic: Remove the query_pkey callback

[Gal Pressman <galpress@amazon.com>]

On 27/08/2020 16:55, Jason Gunthorpe wrote:
> On Thu, Aug 27, 2020 at 04:10:27PM +0300, Gal Pressman wrote:
>> On 27/08/2020 16:01, Jason Gunthorpe wrote:
>>> On Thu, Aug 27, 2020 at 03:58:23PM +0300, Gal Pressman wrote:
>>>> On 27/08/2020 15:20, Håkon Bugge wrote:
>>>>>> On 27 Aug 2020, at 14:01, Jason Gunthorpe <jgg@ziepe.ca> wrote:
>>>>>> On Thu, Aug 27, 2020 at 11:20:16AM +0300, Gal Pressman wrote:
>>>>>>> On 27/08/2020 10:53, Kamal Heib wrote:
>>>>>>>> On Thu, Aug 20, 2020 at 04:53:38PM +0300, Kamal Heib wrote:
>>>>>>>>> On Thu, Aug 20, 2020 at 04:11:23PM +0300, Gal Pressman wrote:
>>>>>>>>>> On 20/08/2020 15:53, Kamal Heib wrote:
>>>>>>>>>>> Now that the query_pkey() isn't mandatory by the RDMA core, this
>>>>>>>>>>> callback can be removed from the usnic provider.
>>>>>>>>>>
>>>>>>>>>> Not directly related to this patch, but pyverbs has a test which verifies that
>>>>>>>>>> max_pkeys > 0, maybe this check should be removed.
>>>>>>>>>
>>>>>>>>> Or changed to work only for node_type == e.IBV_NODE_CA?
>>>>>>>>>
>>>>>>>>> Thanks,
>>>>>>>>> Kamal
>>>>>>>>
>>>>>>>> BTW, do the efa care about pkey?
>>>>>>>
>>>>>>> Depends.. We only support the default pkey so it doesn't do much in terms of
>>>>>>> functionality, but we still need to support it as part of the QP state machine
>>>>>>> for modify QP.
>>>>>>
>>>>>> Does the pkey appear on the wire, or is it just some cruft for API sake?
>>>>>
>>>>> On the wire. Included in the BTH (Base Transfer Header).
>>>>
>>>> He was probably asking specifically about EFA.
>>>> I can't share any details about the wire protocol, does it matter?
>>>
>>> If it isn't actually used for anything then the driver shouldn't
>>> expose PKEY at all, if you do use it then leave it.
>>
>> How would that work? How can you not expose pkeys and still have ibv_ud_pingpong
>> work?
>> You mean remove query_pkey, but still support IBV_QP_PKEY_INDEX in modify_qp?
> 
> iWarp doesn't use PKEY at all, so you'd have to follow their
> model. Some of the userspace that assumes IB would probably need
> fixing (eg ud pingpong does not support iwarp)

Thanks, I'd rather keep supporting the default pkey only.