Re: Windows7 crashes inside the VM when starting a certain program

From: Gleb Natapov <gleb@redhat.com>
To: Avi Kivity <avi@redhat.com>
Cc: "André Weidemann" <Andre.Weidemann@web.de>, kvm@vger.kernel.org
Subject: Re: Windows7 crashes inside the VM when starting a certain program
Date: Sun, 31 Jul 2011 11:34:02 +0300	[thread overview]
Message-ID: <20110731083402.GW4404@redhat.com> (raw)
In-Reply-To: <4E350F40.2010508@redhat.com>

On Sun, Jul 31, 2011 at 11:16:00AM +0300, Avi Kivity wrote:
> On 07/30/2011 03:29 PM, André Weidemann wrote:
> >>Looks like it tries to read MSR_LASTBRANCH_TOS MSR which kvm does not
> >>support. Do you see something interesting in dmesg? I wonder how
> >>availability of the MSR should be checked.
> >
> >
> >You are right about the MSR. The log file from the time of
> >occurrence shows the following:
> >
> >Jul  4 18:55:12 server kernel: [ 1528.618647] kvm: 3123: cpu1
> >kvm_set_msr_common: MSR_IA32_DEBUGCTLMSR 0x1, nop
> >Jul  4 18:55:12 server kernel: [ 1528.619444] kvm: 3123: cpu1
> >unhandled rdmsr: 0x1c9
> >
> 
> You can try
> 
> $ rmmod kvm-intel kvm
> $ modprobe kvm ignore_msrs=1
> $ modprobe kvm-intel
> 
> (or kvm-amd, as the case may be)
> 
> This will work around the issue, but the application may not
> function correctly.
> 
I wonder why Windows tries to use this MSR with -cpu host, but not with -cpu
Nehalem. Both cpus have this MSR (it is supported back to P4 it seams). 

--
			Gleb.