Re: system time goes weird in kvm guest after host suspend/resume

From: Miklos Szeredi
Date: Fri May 29 2020 - 05:51:46 EST


On Thu, May 28, 2020 at 10:43 PM Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
>
> Miklos Szeredi <miklos@xxxxxxxxxx> writes:
> > Bisected it to:
> >
> > b95a8a27c300 ("x86/vdso: Use generic VDSO clock mode storage")
> >
> > The effect observed is that after the host is resumed, the clock in
> > the guest is somewhat in the future and is stopped. I.e. repeated
> > date(1) invocations show the same time.
>
> TBH, the bisect does not make any sense at all. It's renaming the
> constants and moving the storage space and I just read it line for line
> again that the result is equivalent. I'll have a look once the merge
> window dust settles a bit.

Yet, reverting just that single commit against latest linus tree fixes
the issue. Which I think is a pretty good indication that that commit
*is* doing something.

The jump forward is around 35 minutes; that seems to be consistent as well.

Thanks,
Miklos