Re: [Qemu-devel] [QEMU PATCH] kvmclock: advance clock by time window between vm_stop and pre_save

[Marcelo Tosatti]

On Fri, Nov 04, 2016 at 04:25:23PM +0100, Radim Krčmář wrote:
> > +        /*
> > +         * Transition from VM-running to VM-stopped via migration?
> > +         * Record when the VM was stopped.
> > +         */
> > +
> > +        if (state == RUN_STATE_FINISH_MIGRATE &&
> > +            !migration_in_postcopy(migrate_get_current())) {
> > +            clock_gettime(CLOCK_MONOTONIC, &s->t_aftervmstop);
> 
> How big (more like small) was the clock delta between here and
> kvmclock_pre_save with postcopy?
> 
> Thanks.

qemu-system-x86_64: postcopy_ram_supported_by_host: userfaultfd not
available: Function not implemented

But should be about the same as precopy+this patch (guess as i don't 
know the postcopy path).