Re: v6.13-rc1: Internal error: Oops - Undefined instruction: 0000000002000000 [#1] SMP

From: Vitaly Chikunov
Date: Mon Dec 02 2024 - 17:33:56 EST


Marc,

On Mon, Dec 02, 2024 at 04:07:03PM +0000, Marc Zyngier wrote:
> On Mon, 02 Dec 2024 15:59:40 +0000,
> Vitaly Chikunov <vt@xxxxxxxxxxxx> wrote:
> >
> > Marc,
> >
> > On Mon, Dec 02, 2024 at 03:53:59PM +0000, Marc Zyngier wrote:
> > >
> > > What the log doesn't say is what the host is. Is it 6.13-rc1 as well?
> >
> > No, host is 6.6.60.
>
> Right. I wouldn't be surprised if:
>
> - this v6.6 kernel doesn't hide the MPAM feature as it should (and
> that's proably something we should backport)

How to confirm this? Currently I cannot find any (case-insensitive)
"MPAM" files in /sys, nor mpam string in /proc/cpuinfo, nor MPAM strings
in `strace -v` (as it decodes some KVM ioctls) of qemu process.

>
> - you get a nastygram in the host log telling you that the guest has
> executed something it shouldn't (you'll get the encoding of the
> instruction)

I requested admins of the box for dmesg output since I don't have root
access myself and nowadays dmesg is not accessible for a user.

>
> Can you confirm these two things?

Also, I tried to reproduce on another Kunpeng box with slightly
different HiSilicon CPU (presenting to the system as Cortex-A72) and the
problem is not reproducible there.

While things are not resolved, is it possible to workaround the problem
with some QEMU option, kernel command line, config option, or a patch?

Thanks,

>
> M.
>
> --
> Without deviation from the norm, progress is not possible.