Re: hyper-v support in KVM

[Vadim Rozenfeld <vrozenfe@redhat.com>]

On Mon, 2014-02-24 at 08:35 +0000, Zhang, Yang Z wrote:
> Vadim Rozenfeld wrote on 2014-02-24:
> > On Mon, 2014-02-24 at 03:01 +0000, Zhang, Yang Z wrote:
> >> Vadim Rozenfeld wrote on 2014-02-14:
> >>> On Fri, 2014-02-14 at 02:35 +0000, Liu, RongrongX wrote:
> >>>> Vadim Rozenfeld wrote on 2014-02-12:
> >>>>> 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/ff539
> >>>>>>> 08
> >>>>>>> 1%
> >>>>>>> 28v=vs.85%29.aspx
> >>>>>>> 
> >>>>>>> Local APIC MSR Accesses
> >>>>>>> http://msdn.microsoft.com/en-us/library/windows/hardware/ff542
> >>>>>>> 39
> >>>>>>> 6%
> >>>>>>> 28v=vs.85%29.aspx
> >>>>>>> 
> >>>>>>> Reference Time Counter
> >>>>>>> http://msdn.microsoft.com/en-us/library/windows/hardware/ff542
> >>>>>>> 63
> >>>>>>> 7%
> >>>>>>> 28v=vs.85%29.aspx
> >>>>>>> 
> >>>>>>> We are going to add: Reference TSC Page
> >>>>>>> http://msdn.microsoft.com/en-us/library/windows/hardware/ff542
> >>>>>>> 64
> >>>>>>> 3%
> >>>>>>> 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
> >>> 
> >>> something like this: -cpu qemu64,
> >>> +x2apic,family=0xf,hv_vapic,hv_spinlocks=0xfff,hv_relaxed,hv_time
> >>> 
> >>> (for hv_vapic we also need x2apic to be enabled)
> >> 
> >> I saw the win8.1 guest boot up fail with error code 0x0000005c after
> >> enabling
> > hv_vapic on my ivy bridge-EP box. But it works well on my Sandy
> > bridge-EP. Any thought?
> >> 
> > What are the bug check parameters coming with
> > HAL_INITIALIZATION_FAILED bug check? Is your guest 32 or 64-bit? How does it work with Win8?
> > 
> Parameters:
> 0x110, 0xffffffffffd11000, 0x19, 0xffffffffc0000001
> 
> Also saw this issue with Win8.
> 

Thanks, 
I'll try to find Ivy Bridge-EP system and check why it doesn't work.

Cheers,
Vadim.

> 
> > Thanks,
> > Vadim.
> > 
> >> 
> >>> 
> >>> Best regards,
> >>> Vadim.
> >>> 
> >>>> 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.
> >>>>> pd
> >>>>> f
> >>>>> 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@vger.kernel.org More
> >>>>>>>> majordomo info at  http://vger.kernel.org/majordomo-info.html
> >>>>>>> 
> >>>>>>> 
> >>>>>> 
> >>>>>> 
> >>>>>> Best regards,
> >>>>>> Yang
> >>>>>> 
> >>>>>> 
> >>>>> 
> >>>> 
> >>> 
> >> 
> >> 
> >> Best regards,
> >> Yang
> >> 
> >> 
> >
> 
> 
> Best regards,
> Yang
> 
>