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

From: John Stultz
Date: Tue May 14 2013 - 12:17:33 EST


On 05/14/2013 09:14 AM, Jan Beulich wrote:
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).

Ok, I appreciate the explanation. Still waiting for acks on this one.

thanks
-john
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