Re: unhandled wrmsr

[Dave Young <hidave.darkstar@gmail.com>]

On Thu, Jun 3, 2010 at 10:23 AM, Dave Young <hidave.darkstar@gmail.com> wrote:
> On Thu, Jun 3, 2010 at 9:34 AM, Dave Young <hidave.darkstar@gmail.com> wrote:
>> On Wed, Jun 2, 2010 at 8:45 PM, Andre Przywara <andre.przywara@amd.com> wrote:
>>> Dave Young wrote:
>>>>
>>>> Hi,
>>>>
>>>> With today's git version (qemu-kvm), I got following message in kernel
>>>> dmesg
>>>>
>>>> [168344.215605] kvm: 27289: cpu0 unhandled wrmsr: 0x198 data 0
>>>
>>> Are you sure about that?
>>
>> Sure
>>
>> 0x198 is an Intel architectural perfmon MSR and it
>>> is read-only. The Linux kernel source I grep'ed obeys this and does only
>>> rdmsr.
>>> You can work around this by changing the error to a warning with:
>>> # modprobe kvm ignore_msrs=1
>>
>> with this param, appear following warning:
>> kvm: 28520: cpu0 ignored wrmsr: 0x198 data 0
>>
>>>
>>> I'd like to see more details about the guest Linux kernel, at least the
>>> version you used to see why there is a wrmsr on this address. Best is you
>>> provide the kernel (just the vmlinuz file) somewhere so that we can
>>> reproduce this. Also the qemu-kvm command line would be interesting.
>>
>> Actually I tried different guest image, recreate this problem is easy.
>>
>> one of them is slackware 13.0 kernel version 2.6.29.6, you can download from:
>> http://www.slackware.at/data/slackware64-13.0/kernels/huge.s/
>>
>> kvm cmdline:
>> qemu-system-x86_64 -net nic -net tap,ifname=tap0,script=no slack64.img
>>
>>>
>>> Regards,
>>> Andre.
>>>
>>>>
>>>> bash-3.1$ /home/dave/tmp/qemu-system-x86_64 --version
>>>> QEMU emulator version 0.12.50 (qemu-kvm-devel), Copyright (c)
>>>> 2003-2008 Fabrice Bellard
>
> Another problem with this build is I can not boot from virtio-blk, cmdline:
> qemu-system-x86_64 -boot c -drive file=slack64.img,if-virtio,boot=on
typo, if=virtio
>
> qemu just complain about:
> Could not read the boot disk
>
> Anything missing by me?
>
>>>>
>>>>
>>>> bash-3.1$ uname -a
>>>> Linux darkstar 2.6.35-rc1 #35 SMP Mon May 31 16:50:15 CST 2010 x86_64
>>>> Intel(R) Core(TM)2 Duo CPU     E7500  @ 2.93GHz GenuineIntel GNU/Linux
>>>>
>>>> host distribution is slackware64-13.0
>>>>
>>>> 0.12.3 works well
>>>>
>>>> BTW the guest is a tiny core linux image
>>>>
>>>
>>> --
>>> Andre Przywara
>>> AMD-Operating System Research Center (OSRC), Dresden, Germany
>>> Tel: +49 351 448-3567-12
>>>
>>> --
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>>>
>>
>>
>>
>> --
>> Regards
>> dave
>>
>
>
>
> --
> Regards
> dave
>



-- 
Regards
dave