Re: [PATCH for-next 6/7] IB/mlx4: Create and use another QP1 for RoCEv2

[Matan Barak <matanb-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>]

On 12/29/2015 4:42 PM, Or Gerlitz wrote:
> On 12/29/2015 3:24 PM, Matan Barak wrote:
>> The mlx4 driver uses a special QP to implement the GSI QP. This kind
>> of QP allows to build the InfiniBand headers in SW to be put before
>> the payload that comes in with the WR. The mlx4 HW builds the packet,
>> calculates the ICRC and puts it at the end of the payload. This ICRC
>> calculation however depends on the QP configuration which is
>> determined when QP is modified (roce_mode during INIT->RTR).
>> On the other hand, ICRC verification when packet is received does to
>> depend on this configuration.
>
> I don't understand the part of the sentence saying "when packet is
> received does to depend on this configuration"
> maybe some typo/s there?
>

I'll rephrase Moni's commit message for V2:

The mlx4 driver uses a special QP to implement the GSI QP. This kind of 
QP allows to build the InfiniBand headers in software.
When mlx4 hadware builds the packet, it calculates the ICRC and puts it 
at the end of the payload. However, this ICRC calculation depends
on the QP configuration, which is determined when the QP is modified 
(roce_mode during INIT->RTR).
When receiving a packet, the ICRC verification doesn't depend on this 
configuration.
Therefore, using two GSI QPs for send (one for each RoCE version) and 
one GSI QP for receive are required.

>> Therefore, using 2 GSI QPs for send (one for each RoCE version) and 1
>> GSI QP for receive are required.
>
> s/2/two/ and s/1/one/ please
>

No problem

> Or.
>

Matan
--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html