If you use hwclock in guest os ,you will find the result of hwclock isn't changed after changing host os's clock. I find this issue is generated in this patch:
http://lists.gnu.org/archive/html/qemu-devel/2013-08/msg03353.html Before this patch,the result will be changed if you change host's clock. It makes use of the following codes in qemu-timer.c: if (now < last) { notifier_list_notify(&clock->reset_notifiers, &now); } It is useless if you register a QEMU_CLOCK_REALTIME's clock_reset_notifier, --- hw/timer/mc146818rtc.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/hw/timer/mc146818rtc.c b/hw/timer/mc146818rtc.c index df54546..821c27e 100644 --- a/hw/timer/mc146818rtc.c +++ b/hw/timer/mc146818rtc.c @@ -879,7 +879,7 @@ static void rtc_realizefn(DeviceState *dev, Error **errp) check_update_timer(s); s->clock_reset_notifier.notify = rtc_notify_clock_reset; - qemu_clock_register_reset_notifier(QEMU_CLOCK_REALTIME, + qemu_clock_register_reset_notifier(rtc_clock, &s->clock_reset_notifier); s->suspend_notifier.notify = rtc_notify_suspend; --
