On Wed, 2014-02-12 at 01:33 +0000, Zhang, Yang Z wrote: > Vadim Rozenfeld wrote on 2014-02-10: > > On Mon, 2014-02-10 at 08:21 +0000, Zhang, Yang Z wrote: > >> Hi Vadim, > >> > >> Do you know the latest status of Hyper-v Enlightenments supporting in KVM? > > Like how many Hyper-v interfaces are supported in KVM? > > > > Hi Yang, > > > > There is no many at the moment. KVM currently supports the following > > Hyper-V features: > > > > Guest Spinlocks > > http://msdn.microsoft.com/en-us/library/windows/hardware/ff539081% > > 28v=vs.85%29.aspx > > > > Local APIC MSR Accesses > > http://msdn.microsoft.com/en-us/library/windows/hardware/ff542396% > > 28v=vs.85%29.aspx > > > > Reference Time Counter > > http://msdn.microsoft.com/en-us/library/windows/hardware/ff542637% > > 28v=vs.85%29.aspx > > > > We are going to add: Reference TSC Page > > http://msdn.microsoft.com/en-us/library/windows/hardware/ff542643% > > 28v=vs.85%29.aspx > > > > Lazy EOI support, maybe more. > > > > Thanks for your update. More questions: > I want to measure the performance improvement with hyper-v features enabled. So I want to know: > Are those features enabled by default in KVM? In KVM - yes, but you also need to specify them in QEMU command line. They can be enabled by -cpu features hv_vapic, hv_spinlocks, hv_time, and hv_relaxed > How to turn off/on it manually? Yes. From the QEMU command line. > And how can I know whether guest is using it really? There are two options - printk from the KVM side or WinDbg from the guest side. But in case of hv_time you can check the value returned by QueryPerformanceFrequency http://msdn.microsoft.com/en-us/library/windows/desktop/ms644905% 28v=vs.85%29.aspx it should be 10MHz > Also, Do you have any performance data? http://www.linux-kvm.org/wiki/images/0/0a/2012-forum-kvm_hyperv.pdf pp 16, 18 I compared DPC and ISR times with xperf for two cases - with and without enlightenment. I also have seen reports mentioned around 5-10 percent CPU usage drop on the host side, when loading guest with some disk-stress tests. > > > Kind regards. > > Vadim. > > > >> > >> best regards > >> yang > >> > >> -- > >> 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 > > > > > > > Best regards, > Yang > > -- 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
