[dpdk-stable] [dpdk-dev] [PATCH] net/mlx5: check meta register width for modify field

[Slava Ovsiienko]

Yes, It is palliative, it is not perfect, and, IMO, it is crucial - with always applying 32-bit wide values we can destroy the kernel part of reg_c0
in some extended metadata modes and this would lead to steering malfunction.

With best regards,
Slava

From: Asaf Penso <asafp at nvidia.com>
Sent: Tuesday, May 18, 2021 14:33
To: NBU-Contact-Thomas Monjalon <thomas at monjalon.net>; Alexander Kozyrev <akozyrev at nvidia.com>; Raslan Darawsheh <rasland at nvidia.com>
Cc: dev at dpdk.org; stable at dpdk.org; Raslan Darawsheh <rasland at nvidia.com>; Matan Azrad <matan at nvidia.com>; Slava Ovsiienko <viacheslavo at nvidia.com>
Subject: Re: [dpdk-dev] [PATCH] net/mlx5: check meta register width for modify field

I didn't plan to have it in this release since it's not critical and I'm afraid of such changes... I didn't mention this in the status mail today.
@Raslan Darawsheh<mailto:rasland at nvidia.com> can we check tomorrow regression result?
If not good we'll need to revert it.

Regards,
Asaf Penso
________________________________
From: Thomas Monjalon <thomas at monjalon.net<mailto:thomas at monjalon.net>>
Sent: Tuesday, May 18, 2021 12:43:34 PM
To: Alexander Kozyrev <akozyrev at nvidia.com<mailto:akozyrev at nvidia.com>>
Cc: dev at dpdk.org<mailto:dev at dpdk.org> <dev at dpdk.org<mailto:dev at dpdk.org>>; stable at dpdk.org<mailto:stable at dpdk.org> <stable at dpdk.org<mailto:stable at dpdk.org>>; Raslan Darawsheh <rasland at nvidia.com<mailto:rasland at nvidia.com>>; Matan Azrad <matan at nvidia.com<mailto:matan at nvidia.com>>; Slava Ovsiienko <viacheslavo at nvidia.com<mailto:viacheslavo at nvidia.com>>; Asaf Penso <asafp at nvidia.com<mailto:asafp at nvidia.com>>
Subject: Re: [dpdk-dev] [PATCH] net/mlx5: check meta register width for modify field

> > The modify_field Flow API assumes that the META item is 32 bits wide.
> > But the C Register that is used for Meta item can be 16 or 32 bits wide
> > depending on kernel and firmware configurations.
> > Take this into consideration and use the appropriate META width.
> >
> > Fixes: 641dbe4fb0 ("net/mlx5: support modify field flow action")
> > Cc: stable at dpdk.org<mailto:stable at dpdk.org>
> >
> > Signed-off-by: Alexander Kozyrev <akozyrev at nvidia.com<mailto:akozyrev at nvidia.com>>
> Acked-by: Viacheslav Ovsiienko <viacheslavo at nvidia.com<mailto:viacheslavo at nvidia.com>>

Applied in next-net-mlx, thanks.