[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [Qemu-devel] [PATCH 1/4] xen: introduce mc146818rtcxen
On 11/20/2011 08:53 AM, Avi Kivity wrote: On 11/18/2011 04:54 PM, Anthony Liguori wrote:Thinking more about it, I think this entire line of thinking is wrong (including mine) :-) The problem you're trying to solve is that the RTC fires two 1 second timers regardless of whether the guest is reading the wall clock time, right? And since wall clock time is never read from the QEMU RTC in Xen, it's a huge waste? The Right Solution would be to modify the RTC emulation such that it did a qemu_get_clock() during read of the CMOS registers in order to ensure the time was up to date (instead of using 1 second timers). Then the timers wouldn't even exist anymore.That would make host time adjustments (suspend/resume) be reflected in the guest. qemu_get_clock(rtc_clock)It depends on what clock rtc_clock is tied too. If it's tied to vm_clock, it won't be affected. Not sure if that's good or bad, but it's different. Doing this wouldn't change the behavior. I presume you were confusing qemu_get_clock() with qemu_get_timedate(). But our current default behavior has the characteristic that you're concerned about. It's was a conscious decision. See: commit 6875204c782e7c9aa5c28f96b2583fd31c50468f Author: Jan Kiszka <jan.kiszka@xxxxxxxxxxx> Date: Tue Sep 15 13:36:04 2009 +0200 Enable host-clock-based RTC Regards, Anthony Liguori _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel
|
Lists.xenproject.org is hosted with RackSpace, monitoring our |