On Mon, Jun 02, 2014 at 11:13:15AM +0200, Michal Privoznik wrote:
> On 30.05.2014 16:05, Marcelo Tosatti wrote:
> >It is necessary to reset RTC interrupt backlog if guest time is
> >synchronized via a different mechanism, such as QGA's guest-set-time
> >command.
> >
> >Failing to do so causes both corrections to be applied (summed),
> >resulting in an incorrect guest time.
> >
> >
>
> Marcelo,
>
> what happens if quest is synchronized via NTP? Does this command
> still need to be executed after 'cont'?
>
> Michal
Yes because NTP will either take time to adjust by slewing or step the
clock (which renders guest-set-time() unuseable). During that time,
guest clock will be ahead of realtime.
Algorithm should be:
- ret = guest-set-time()
- if (ret = success)
- rtc-reset-reinjection()
That leaves a window where RTC interrupts are reinjected, but i
see no better option.
