Re: RDMA/CM and multiple QPs

[Bart Van Assche <bart.vanassche-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>]

On 09/08/2015 06:57 AM, Tom Talpey wrote:
> On 9/6/2015 11:15 AM, Bart Van Assche wrote:
>> On 09/06/15 00:50, Christoph Hellwig wrote:
>>> Note that the SRP driver already in tree is a good example for this,
>>> although it doesn't use RDMA/CM and thus already operates on a
>>> per-ib_device level.
>>
>> The challenges with regard to adding RDMA/CM support to the SRP
>> initiator and target drivers are:
>> - IANA has not yet assigned a port number to the SRP protocol (see e.g.
>>
>> http://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml).
>
> IANA doesn't do this automatically. Has anyone made the request?
>
> You might want to think through why it needs a dedicated port number
> though. iSER reuses the iSCSI port, by negotiating RDMA during login.

iSER is an iSCSI transport and that is why iSER reuses the iSCSI port 
number. SRP is a SCSI transport protocol by itself and that is why a new 
port number is needed for the SRP protocol.

>> - The login request (struct srp_login_req) is too large for the RDMA/CM.
>>     A format for the login parameters for the RDMA/CM has not yet been
>>     standardized.
>
> Are you suggesting that RDMA/CM perform the login? That seems
> like a layering issue.

Sorry but I don't see why this would be a layering issue.

Bart.
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