8.10.5. Examples Using Clock Synchronization

Example 8.5. Clock synchronizing to local time with RTC and PIT timers

In this example. the clock is synchronized to local time with RTC and PIT timers
<clock offset="localtime">
	<timer name="rtc" tickpolicy="catchup" track="guest virtual machine" />
	<timer name="pit" tickpolicy="delay" />
	
</clock>

Note

The PIT clocksource can be used with a 32-bit guest running under a 64-bit host (which cannot use PIT), with the following conditions:
  • Guest virtual machine may have only one CPU
  • APIC timer must be disabled (use the "noapictimer" command line option)
  • NoHZ mode must be disabled in the guest (use the "nohz=off" command line option)
  • High resolution timer mode must be disabled in the guest (use the "highres=off" command line option)
  • The PIT clocksource is not compatible with either high resolution timer mode, or NoHz mode.