KVM host freezing

Marc Haber
2011-06-02T08:54:37Z

Hi,

I have just started deploying a host doing virtualization with KVM.
The box has an Athlon 64 X2, 4 GB RAM and is running Debian squeeze
with a locally built 2.6,39 kernel and backported versions of qemu-kvm
(0.14.0) and libvirt (0.9.0) from Debian sid. The box is currently
hosting five VMs, all of them Debian systems as well and rather
unloaded. The only time when there is significant load is when all VMs
are simultaneously starting up their cron jobs.

When the host starts up, it immediately spews the following lines to
the console:

kvm: 2865: cpu0 unhandled rdmsr: 0xc0010048
kvm: 2865: cpu0 unhandled wrmsr: 0xc0010048 data 2100000401
kvm: 2865: cpu0 unhandled rdmsr: 0xc0010001
kvm: 2849: cpu0 unhandled rdmsr: 0xc0010048
kvm: 2849: cpu0 unhandled wrmsr: 0xc0010048 data c0579f7cc0010448
kvm: 2849: cpu0 unhandled rdmsr: 0xc0010001
kvm: 2950: cpu0 unhandled rdmsr: 0xc0010048
kvm: 2950: cpu0 unhandled wrmsr: 0xc0010048 data c0579f7cc0010448
kvm: 2849: cpu1 unhandled rdmsr: 0xc0010048
kvm: 2963: cpu0 unhandled rdmsr: 0xc0010112
kvm: 2963: cpu0 unhandled rdmsr: 0xc0010048
kvm: 2963: cpu0 unhandled wrmsr: 0xc0010048 data 2100000401
kvm: 2963: cpu0 unhandled rdmsr: 0xc0010001
kvm: 2963: cpu1 unhandled rdmsr: 0xc0010048
kvm: 2963: cpu1 unhandled wrmsr: 0xc0010048 data 2100000401

Every few days, the system stops dead in its tracks and needs a hard
reset to be revived. I have a serial console, which unfortunately
disconnects me after a few minutes of inactivity, and only caches the
last few lines of activity. Whenever I connect to the serial console
of the frozen system, I have a few lines of the same "unhandled
(rd|wr)msr" messages.

The syslog doesn't show anything strange. The system just stops dead
in its tracks.

Is there any possibility that the freezes have to do with the
"unhandles (rd|wr)msr" messages? When else could be the cause?

In the mean time, I have taken the box offline and am running memtest.
Up to now, everything seems to be fine.

Any hints will be appreciated.

Greetings
Marc

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Marc Haber | "I don't trust Computers. They | Mailadresse im Header
Mannheim, Germany | lose things." Winona Ryder | Fon: *49 621 72739834
Nordisch by Nature | How to make an American Quilt | Fax: *49 3221 2323190