Re: [PATCH 1/3] x86: increase precision of x86_platform.get/set_wallclock()

From: John Stultz
Date: Tue May 14 2013 - 13:53:01 EST


On 05/13/2013 10:56 AM, David Vrabel wrote:
From: David Vrabel <david.vrabel@xxxxxxxxxx>

All the virtualized platforms (KVM, lguest and Xen) have persistent
wallclocks that have more than one second of precision.

read_persistent_wallclock() and update_persistent_wallclock() allow
for nanosecond precision but their implementation on x86 with
x86_platform.get/set_wallclock() only allows for one second precision.
This means guests may see a wallclock time that is off by up to 1
second.

Make set_wallclock() and get_wallclock() take a struct timespec
parameter (which allows for nanosecond precision) so KVM and Xen
guests may start with a more accurate wallclock time and a Xen dom0
can maintain a more accurate wallclock for guests.

Signed-off-by: David Vrabel <david.vrabel@xxxxxxxxxx>

I've gone ahead and queued this one for 3.11

thanks
-john

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