Re: [QEMU PATCH v2] kvmclock: advance clock by time window between vm_stop and pre_save

Juan Quintela
2016-11-04T18:58:06Z

Marcelo Tosatti <mtosatti@redhat.com> wrote:
> This patch, relative to pre-copy migration codepath,
> measures the time between vm_stop() and pre_save(),
> which includes copying the remaining RAM to destination,
> and advances the clock by that amount.
>
> In a VM with 5 seconds downtime, this reduces the guest
> clock difference on destination from 5s to 0.2s.
>
> Tested with Linux and Windows 2012 R2 guests with -cpu XXX,+hv-time.
>
> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
>
> ---
>
> v2: use subsection (Juan Quintela)
> fix older machine types support
>

Reviewed-by: Juan Quintela <quintela@redhat.com>