BSOD while installing Windows 2011 SBS

[TomTomGo]

Hi there,

We've installed a Windows SBS 2011 in a VM with cpu type Nehalem, an encountered some problems with kvm / qemu 1.0.50 since 2.0.
All was fine with Proxmox 1.9 / kvm / qemu 0.15 but with a fresh install of Proxmox 2.0 and new W2K11SBS vm, we've got a BSOD during the installation.
In kern.log, while BSOD happening we've got :

Apr 24 14:03:46 host kernel: kvm: 30866: cpu0 kvm_set_msr_common: MSR_IA32_DEBUGCTLMSR 0x1, nop
Apr 24 14:03:46 host kernel: kvm: 30866: cpu0 unhandled rdmsr: 0x1c9
Apr 24 14:51:27 host kernel: kvm: 43711: cpu0 unhandled wrmsr: 0x188 data 0
Apr 24 14:53:12 host kernel: kvm: 44125: cpu0 unhandled wrmsr: 0x188 data 0

We tried some different -cpu type in vm configuration (host, Nehalem, core2duo, Conroe ...) with the same result.
Workaround is :

rmmod kvm-intel kvm
modprobe kvm ignore_msrs=1
modprobe kvm-intel

and now we've got :

Apr 25 09:54:31 host kernel: kvm: 51326: cpu0 kvm_set_msr_common: MSR_IA32_DEBUGCTLMSR 0x1, nop
Apr 25 09:54:31 host kernel: kvm: 51326: cpu0 ignored rdmsr: 0x1c9
Apr 25 09:54:31 host kernel: kvm: 51326: cpu0 ignored rdmsr: 0x680
Apr 25 09:54:31 host kernel: kvm: 51326: cpu0 ignored rdmsr: 0x6c0

and no more BSOD while installing the SBS ...

Physical host are Dell PE T410 / Xeon E5606 cpu / 16 Gb RAM and Dell PE T310 / Xeon X3430 / 16 Gb RAM

Are there any planed solutions for this problem ?

Thanks and great job for this nice 2.0 !!!

Thomas

 

[spirit]

Hi, did you have try with other cpu models in your vm ? (like rhel6)

 

[TomTomGo]

Hi, and thanks for your post,

No, i didn't try with rhel6 cpu model because it talk about AMD cpu type, and msr is present in the "feature_edx" cpu definition ...
Maybe should i remove the msr capability from Nehalem cpu definition , or is it possible to make our own cpu defnition in /etc/kvm/target-x86_64.conf ?
Is the msr capability mandatory ?

Regards,

Thomas

 

[spirit]

mmm..msr should be supported without problem but maybe it's a kvm bug or something in sbs2011 not supported in kvm.
(I'll try to install sbs2011 today).

for rhel6 cpu model, it's more like qemu64 with compatibility between intel/amd between live migration.

You can change the target-x86_64.conf but It can be updated with next pve-qemu-kvm package version, so be carefull.

Does It hang only at installation ? or also after in normal windows boot ?

 

[TomTomGo]

mmm..msr should be supported without problem but maybe it's a kvm bug or something in sbs2011 not supported in kvm.
(I'll try to install sbs2011 today).

Yes, it should be, and it was working fine with Proxmox 1.9 / kvm qemu v 0.15 so it looks like a regression ...

You can change the target-x86_64.conf but It can be updated with next pve-qemu-kvm package version, so be carefull.

Yes of course, i was thinking about this for tests purpose only ...

Does It hang only at installation ? or also after in normal windows boot ?

No, it hangs belong installation, after the first reboot step (copying, extracting installation files ...) and then, at each reboot of the VM, there are a few output sequence of lines below on the server console :

Apr 25 09:54:31 host kernel: kvm: 51326: cpu0 kvm_set_msr_common: MSR_IA32_DEBUGCTLMSR 0x1, nop
Apr 25 09:54:31 host kernel: kvm: 51326: cpu0 ignored rdmsr: 0x1c9
Apr 25 09:54:31 host kernel: kvm: 51326: cpu0 ignored rdmsr: 0x680
Apr 25 09:54:31 host kernel: kvm: 51326: cpu0 ignored rdmsr: 0x6c0

And of course before loading kvm module with "modprobe kvm ignore_msrs=1", BSOD and simultaneously on the console :

Apr 24 14:03:46 host kernel: kvm: 30866: cpu0 kvm_set_msr_common: MSR_IA32_DEBUGCTLMSR 0x1, nop
Apr 24 14:03:46 host kernel: kvm: 30866: cpu0 unhandled rdmsr: 0x1c9
Apr 24 14:51:27 host kernel: kvm: 43711: cpu0 unhandled wrmsr: 0x188 data 0
Apr 24 14:53:12 host kernel: kvm: 44125: cpu0 unhandled wrmsr: 0x188 data 0

After the BSOD, SBS says to restart the installation completely !!!

 

[e100]

there are a few output sequence of lines below on the server console :

Apr 25 09:54:31 host kernel: kvm: 51326: cpu0 kvm_set_msr_common: MSR_IA32_DEBUGCTLMSR 0x1, nop
Apr 25 09:54:31 host kernel: kvm: 51326: cpu0 ignored rdmsr: 0x1c9
Apr 25 09:54:31 host kernel: kvm: 51326: cpu0 ignored rdmsr: 0x680
Apr 25 09:54:31 host kernel: kvm: 51326: cpu0 ignored rdmsr: 0x6c0

And of course before loading kvm module with "modprobe kvm ignore_msrs=1", BSOD and simultaneously on the console :

Apr 24 14:03:46 host kernel: kvm: 30866: cpu0 kvm_set_msr_common: MSR_IA32_DEBUGCTLMSR 0x1, nop
Apr 24 14:03:46 host kernel: kvm: 30866: cpu0 unhandled rdmsr: 0x1c9
Apr 24 14:51:27 host kernel: kvm: 43711: cpu0 unhandled wrmsr: 0x188 data 0
Apr 24 14:53:12 host kernel: kvm: 44125: cpu0 unhandled wrmsr: 0x188 data 0

I am not sure if what I am about to say is accurate or applicable to this situation or not.....

I've noticed similar messages starting Windows VMs, even ones that work just fine and researched this well over a year ago.
My understanding is that these errors happen because Windows is probing the CPU to see if certain instructions/registers exist so it knows what features are available.
When it probes something that is not available those unhandled wrmsr/rdmsr errors get thrown from KVM.
So in most cases these errors mean nothing.