> -----Original Message----- > From: Vadim Rozenfeld [mailto:vrozenfe@xxxxxxxxxx] > Sent: Wednesday, February 12, 2014 3:42 PM > To: Zhang, Yang Z > Cc: kvm@xxxxxxxxxxxxxxx; Liu, RongrongX > Subject: Re: hyper-v support in KVM > > 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 Hi Vadim, in QEMU command line, how to enable these feature? I try it with 1. [root@vt-snb9 ]#qemu-system-x86_64 -enable-kvm -m 2048 -smp 2 -net none win8.1.img -cpu feature hv_vapic,+hv_spinlocks,+hv_time,+hv_relaxed qemu-system-x86_64: -cpu feature: drive with bus=0, unit=0 (index=0) exists 2. [root@vt-snb9]# qemu-system-x86_64 -enable-kvm -m 2048 -smp 2 -net none win8.1.img -cpu qemu64,+hv_vapic,+hv_spinlocks,+hv_time,+hv_relaxed CPU feature hv_vapic not found CPU feature hv_spinlocks not found CPU feature hv_time not found CPU feature hv_relaxed not found CPU feature hv_vapic not found CPU feature hv_spinlocks not found CPU feature hv_time not found CPU feature hv_relaxed not found VNC server running on `::1:5900' > > 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 > > > > > ��.n��������+%������w��{.n�����o�^n�r������&��z�ޗ�zf���h���~����������_��+v���)ߣ�
