On Thu, Aug 09, 2012 at 05:20:11PM +0300, Avi Kivity wrote: > On 08/09/2012 05:18 PM, Gerd Hoffmann wrote: > > Hi, > > > >>> So what do you suggest? The options I see are: > >>> > >>> (1) Use this patch (with alignment issue fixed of course). > >>> (2) Do a full kvmclock implementation. Feels a bit like overkill. > >>> (3) SeaBIOS can fallback to the PIT for timing on machines which > >>> have no TSC. We could do that too in case we detect kvm ... > >> > >> What sort of timeouts are these? If seconds, maybe the rtc would be best. > > > > All sorts of timeouts, from a few miliseconds to seconds. > > > > The problematic ones are the longer timeouts, which wait for I/O stuff > > like disk reads complete. The stuff with smaller timeouts (like waiting > > for AHCI link become ready) tend to finish instantly in kvm. > > That's not guaranteed. The AHCI adapter might be real hardware. Or the > emulation may change. > > What's wrong with having a full kvmclock implementation? Instead of > issuing rdtsc call a function pointer. Its not necessary (someone is going to maintain the kvmclock frequency retrieve, which patch is already here, versus maintainance of full kvmclock). Frequency scaling (or the software equivalent: TSC trapping) are required for other reasons anyway. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
