linux-kernel - Re: [REGRESSION] Too-low frequency limit for AMD GPU PCI-passed-through to Windows VM

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <d541b534-8b83-b566-56eb-ea8baa7c998e@leemhuis.info>
Date:   Thu, 17 Mar 2022 13:54:11 +0100
From:   Thorsten Leemhuis <regressions@...mhuis.info>
To:     James Turner <linuxkernel.foss@...rc-none.turner.link>
Cc:     Alex Deucher <alexdeucher@...il.com>,
        "Lazar, Lijo" <lijo.lazar@....com>,
        "Deucher, Alexander" <Alexander.Deucher@....com>,
        "regressions@...ts.linux.dev" <regressions@...ts.linux.dev>,
        "kvm@...r.kernel.org" <kvm@...r.kernel.org>,
        Greg KH <gregkh@...uxfoundation.org>,
        "Pan, Xinhui" <Xinhui.Pan@....com>,
        LKML <linux-kernel@...r.kernel.org>,
        "amd-gfx@...ts.freedesktop.org" <amd-gfx@...ts.freedesktop.org>,
        Alex Williamson <alex.williamson@...hat.com>,
        "Koenig, Christian" <Christian.Koenig@....com>
Subject: Re: [REGRESSION] Too-low frequency limit for AMD GPU
 PCI-passed-through to Windows VM

On 13.03.22 19:33, James Turner wrote:
>
>> My understanding at this point is that the root problem is probably
>> not in the Linux kernel but rather something else (e.g. the machine
>> firmware or AMD Windows driver) and that the change in f9b7f3703ff9
>> ("drm/amdgpu/acpi: make ATPX/ATCS structures global (v2)") simply
>> exposed the underlying problem.

FWIW: that in the end is irrelevant when it comes to the Linux kernel's
'no regressions' rule. For details see:

https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/Documentation/admin-guide/reporting-regressions.rst
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/Documentation/process/handling-regressions.rst

That being said: sometimes for the greater good it's better to not
insist on that. And I guess that might be the case here.

> I'm not sure where to go from here. This issue isn't much of a concern> for me anymore, since blacklisting `amdgpu` works for my machine. At>
this point, my understanding is that the root problem needs to be fixed>
in AMD's Windows GPU driver or Dell's firmware, not the Linux kernel.
If> any of the AMD developers on this thread would like to forward it to
the> AMD Windows driver team, I'd be happy to work with AMD to fix the
issue> properly.
In that case I'll drop it from the list of regressions, unless what I
wrote above makes you change your mind.

#regzbot invalid: firmware issue exposed by kernel change, user seems to
be happy with a workaround

Thx everyone who participated in handling this.

Ciao, Thorsten