Re: qemu-x86: kernel panic when host is loaded

From: Thomas Gleixner
Date: Thu Apr 02 2020 - 05:58:01 EST


Corentin Labbe <clabbe.montjoie@xxxxxxxxx> writes:
> On our kernelci lab, each qemu worker pass an healtcheck job each day and after each job failure, so it is heavily used.
> The healtcheck job is a Linux boot with a stable release.
> Since we upgraded our worker to buster, the qemu x86_64 healthcheck randomly panic with:
> <0>[ 0.009000] Kernel panic - not syncing: IO-APIC + timer doesn't work! Boot with apic=debug and send a report. Then try booting with the 'noapic' option.
> After some test I found the source of this kernel panic, the host is
> loaded and qemu run "slower". Simply renicing all qemu removed this
> behavour.
> So now what can I do ?
> Appart renicing qemu process, does something could be done ?

As the qemu timer/ioapic routing is actually sane, you might try to add
"no_timer_check" to the kernel command line.