Re: [Qemu-devel] BSOD when using Hyper-V extensions with Win2k8R2 guests

[Vadim Rozenfeld <vrozenfe@redhat.com>]

On Thursday, March 15, 2012 10:00:11 PM Anthony Liguori wrote:
> On 03/15/2012 02:54 PM, Vadim Rozenfeld wrote:
> > On Thursday, March 15, 2012 09:14:39 PM Michael Roth wrote:
> >> Hi Vadim,
> >> 
> >> I've been trying to use -cpu qemu64,hv_relaxed as a workaround for a
> >> CLOCK_WATCHDOG_TIMEOUT BSOD on Windows 2008 R2 guests when a vcpu's
> >> execution is delayed for an extended period. When I do this however I
> >> get the following the BSOD:
> >> 
> >> http://msdn.microsoft.com/en-us/library/windows/hardware/ff559206(v=vs.8
> >> 5). aspx
> >> 
> >> I've also tried -cpu qemu64,hv_spinlocks=4 and -cpu qemu64,hv_vapic as a
> >> sanity check and this results in the same error being thrown.
> >> 
> >> Host is RHEL6.1 using latest qemu.git, guests are win2k8 server r2 (same
> > 
> > I'm pretty much sure that hyper-v support was not backported into RHEL
> > 6.1 KVM.
> 
> So is there a hyper-v capability for KVM then?  Or a CPUID feature?
KVM_CAP_HYPERV, but we don't use it at the moment.
> 
> Should QEMU refuse to enable hv_relaxed if the capability isn't present?
Yes. I will submit a patch.
Best regards,
Vadim.
> 
> Regards,
> 
> Anthony Liguori
> 
> > Best regards,
> > Vadim.
> > 
> >> behavior for both SP0 and SP1). Here's the full command-line:
> >> 
> >> qemu-upstream -L ../qemu-build/pc-bios -cpu qemu64,hv_relaxed
> >> --enable-kvm \ -M pc-1.1 -enable-kvm -m 4096 -smp
> >> 4,sockets=4,cores=1,threads=1 \ -name ichigo-dom45 -nodefconfig
> >> -nodefaults -rtc base=utc,driftfix=slew \ -drive
> >> file=/scratch/mdroth/win2k8r2sp1.raw,if=none,id=drive0,format=raw,cache
> >> =wr itethrough,snapshot=on \ -device
> >> virtio-blk-pci,bus=pci.0,drive=drive0,id=disk0,bootindex=1 \ -netdev
> >> tap,id=hostnet0,script=/etc/qemu-ifup \
> >> 
> >>      -device
> >> 
> >> virtio-net-pci,netdev=hostnet0,id=net0,mac=00:FF:FE:00:00:2d,bus=pci.0 \
> >> -device virtio-balloon-pci,id=balloon0,bus=pci.0 \
> >> 
> >>      -usb -device usb-tablet,id=input0 -vnc 0.0.0.0:45 -vga cirrus
> >> 
> >> Unfortunately the BSOD is too early to get a kernel dump, but here are
> >> the error params in case that's useful:
> >> 
> >> 0xFC0000096, 0xF800027F6200, 0x0, 0x0
> >> 
> >> Let me know if you need any other details.
> >> 
> >> Thanks!