Re: [dpdk-dev] [PATCH v3] net/mlx5: fix loopback for DV queue

[Bing Zhao <bingz@nvidia.com>]

Thanks a lot, Thomas.

> -----Original Message-----
> From: Thomas Monjalon <thomas@monjalon.net>
> Sent: Tuesday, May 18, 2021 4:33 PM
> To: Bing Zhao <bingz@nvidia.com>
> Cc: Slava Ovsiienko <viacheslavo@nvidia.com>; Matan Azrad
> <matan@nvidia.com>; dev@dpdk.org; Ori Kam <orika@nvidia.com>; Raslan
> Darawsheh <rasland@nvidia.com>; stable@dpdk.org; Tal Shnaiderman
> <talshn@nvidia.com>
> Subject: Re: [dpdk-dev] [PATCH v3] net/mlx5: fix loopback for DV
> queue
> 
> External email: Use caution opening links or attachments
> 
> 
> 17/05/2021 17:18, Bing Zhao:
> > In the past, all the queues and other hardware objects were
> created
> > through Verbs interface. Currently, most of the objects creation
> are
> > migrated to Devx interface by default, including queues. Only when
> the
> > DV is disabled by device arg or eswitch is enabled, all or some of
> the
> > objects are created through Verbs interface.
> >
> > When using Devx interface to create queues, the kernel driver
> behavior
> > is different from the case using Verbs. The Tx loopback cannot
> work
> > properly even if the Tx and Rx queues are configured with loopback
> > attribute. To fix the support self loopback for Tx, a Verbs dummy
> > queue pair needs to be created to trigger the kernel to enable the
> > global loopback capability.
> >
> > This is only required when TIR is created for Rx and loopback is
> > needed. Only CQ and QP are needed for this case, no WQ(RQ) needs
> to be
> > created.
> >
> > This requirement comes from bugzilla 645, more details can be
> found in
> > the bugzilla link.
> >
> > Bugzilla ID: 645
> >
> > Fixes: 6deb19e1b2d2 ("net/mlx5: separate Rx queue object
> creations")
> > Cc: stable@dpdk.org
> >
> > Signed-off-by: Bing Zhao <bingz@nvidia.com>
> > Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
> 
> Applied to next-net-mlx, thanks.
> 
>