Re: [Xen-devel] [PATCH 3/3] x86/xen: sync the CMOS RTC as wellas the Xen wallclock

[Jan Beulich]

>>> On 14.05.13 at 17:59, John Stultz <john.stultz@xxxxxxxxxx> wrote:
> On 05/14/2013 12:57 AM, Jan Beulich wrote:
>>>>> On 14.05.13 at 02:52, John Stultz <john.stultz@xxxxxxxxxx> wrote:
>>> Honestly, it seems a little strange to me. If you're running as dom0,
>>> why does HYPERVISOR_dom0_op() not cause the hypervisor to set the cmos
>>> its virtualizing? This seems to mess with the proper virtualization
>>> layering.
>> Thy hypervisor tries to control as little system and peripheral devices
>> as possible, and the CMOS (including the clock) is among those not
>> controlled by it, but by Dom0.
> 
> Huh. So what does calling HYPERVISOR_dom0_op do then?

Here it merely tells the hypervisor that the wall clock changed (so
it can propagate this on to DomU-s).

Jan

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