Re: [patch 0/2] x86/cpu/amd: Fixup the topology rework fallout

From: Laura Nao
Date: Thu Apr 11 2024 - 07:28:24 EST


Hi Thomas,

On 4/10/24 21:45, Thomas Gleixner wrote:
> Testing at Collabora unearthed two issues in the new AMD topology parser
> code:
>
> 1) The CPUID 0x80000008 parser initializes the wrong topology domain
> level.
>
> 2) The NODEID_MSR parser uses bitfields in a union wrongly which results
> in reading out the wrong value and finally in a division by zero.
>
> Many thanks to Laura for helping to debug this issue.
>
> tglx
>
>

Thanks a lot for investigating and solving the issue!

I confirm that with this series applied the kernel boots correctly on
all three AMD Stoney Ridge Chromebooks that were affected by the
regression.

I tested the patches on top of c749ce39 (culprit commit identified by
the bisection) - reference test job:
https://lava.collabora.dev/scheduler/job/13339645

The series doesn't apply directly to next, but I manually applied the
changes on top of next-20240411 and can confirm the kernel boots
correctly with this revision too - reference test job:
https://lava.collabora.dev/scheduler/job/13340321

The regression was originally reported by KernelCI, so:

Reported-by: "kernelci.org bot" <bot@xxxxxxxxxxxx>
Tested-by: Laura Nao <laura.nao@xxxxxxxxxxxxx>

I'll make sure to update the Regzbot tag when the series is merged.

Best,

Laura