Re: [PATCH V4 9/9] IB/mlx4: Enable mlx4_ib support for MODIFY_QP_EX

[Or Gerlitz <ogerlitz-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>]

On 12/09/2013 14:31, Devesh Sharma wrote:
> On Thu, Sep 12, 2013 at 4:15 PM, Or Gerlitz <ogerlitz-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org> wrote:
>> We've posted the kernel patches, that should be enough for the review. If you have any specific questions re user space aspects of this series, feel free to send them now.
> Yes! for kenel space I see the above set of patches will work fine
> without any issues. On the other hand, if from user space some
> application tries to establish a connection using RDMACM, the Driver
> will receive dmac and vlanid fields as Zeros because
> libibverbs/librdmacm still does not call _EX versions of UVERBS/UCM
> commands, which are introduced in these set of patches (7/9, 8/9). So,
> for example if I try to run ib_send_bw with -R, traffice will not run!!
>
> So what are the plans to add these changes in libibverbs/librdmacm libraries.
>                   OR
> there is some flaw in my understanding that librdmacm/libibverbs needs
> changes in order to uses newly proposed scheme. Please clarify.
>

Let me clarify this. The idea is that current RoCE applications will run 
as is after they update "their"
librdmacm, since its this library that works with the new uverbs entries.

Note that the RoCE stack assumes existence of Ethernet device for the 
specific vendor along with
their IB driver and this series does another tiny step assuming this 
device has IP address configured
and hence RoCE applications are expected to use librdmacm.

If the underlying device/port run IB, biz as usual, the patches / 
extended commands need not come into play and
the related non-extended  uverbs commands are all working as they did 
before the patches. This is per port, that
is if port1 is IB and port2 is Eth, QPs on port1 can be worked out with 
the older uverbs commands.

As for your question, ib_send_bw -R uses the rdma-cm and hence will not 
need to change, since the rdma-cm
is doing the qp modifications.

Or.
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