Re: Clock stops working on OpenBSD qemu/kvm guest

On Friday, January 26th, 2024 at 13:40, Dave Voutila <dv@sisu.io> wrote:
>
> Lévai, Dániel leva@ecentrum.hu writes:
>
> > Hi all!
> >
> > I have this OpenBSD 7.4 qemu/kvm VM managed by libvirt on an Ubuntu 22.04 host.
[...]
> > Anyway, the symptoms are funny, it always involves the clock stopping/not working after some period of time.
>
> What is your Linux kernel version?

It's at 6.5.0-15-generic atm, like the upgrade log showed, that was the latest update to date.

> > This has been set on the guest, though (defaults):
> > kern.timecounter.tick=1
> > kern.timecounter.timestepwarnings=0
> > kern.timecounter.hardware=pvclock0
> > kern.timecounter.choice=i8254(0) pvclock0(1500) acpitimer0(1000)
>
>
> So pvclock should be relying on KVM to properly deal with TSC
> paravirtualzation. Do you see this issue with Linux guests using
> kvmclock? (Or do your Linux guests decide on a different clocksource?)

Nowhere else, and even this has been working fine until I think the beginning of this January.
There's a bunch of OSs running there, Fedora, Ubuntu, Arch, all using 'kvm-clock' as their clock source, they work fine.
No problem with FreeBSD (using kvmclock0) and Win11 (no clue what it's using) either.