[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-discuss] [Qemu-devel] live migration between amd fam15h-fam10h

From: Markus Kovero
Subject: Re: [Qemu-discuss] [Qemu-devel] live migration between amd fam15h-fam10h
Date: Mon, 03 Feb 2014 11:15:17 +0200
User-agent: RoundCube Webmail/0.8.0

On 01.02.2014 19:45, Brian Jackson wrote:
On 01/27/2014 08:20 AM, Markus Kovero wrote:

I am getting a frozen guest when migrating from an Opteron 6274 host
fam15h) to
an Opteron 6174 host (amd fam10h). The live migration completes
succesfully, but
the guest is frozen: vcn screen is still there, but no input is
possible and
no kernel output is seen. Trying "c" on the qemu-monitor does not help.
I am using "-cpu Opteron_G3" which I assumed would be ok for both
host cpus.

In the opposite direction (migrating from an amd fam10h host to an
host) the guest continues to run on the destination. However, on most
of these
successfull live migrations, I notice a "clocksource unstable"
message on the
guest kernel (using the default kvm-clock clocksource) e.g.
Clocksource tsc unstable (delta = -1500533439 ns)
Same situation (guest runs on destination with clocksource unstable
happens when migrating between fam15h hosts (I have not tried between

Changing the clocksource (tsc, acpi_pm, hpet) does not solve the issue.
Also tried with "-cpu kvm64" with same result.

qemu-kvm version: 0.15.1, 1.0 or qemu-kvm/master
Host kernel: 3.0.15 (on both hosts)
Guest kernel: 3.0.6 or 3.2

this is the qemu-kvm command line used on the source host:

kvm -enable-kvm -m 1024 -smp 1 -cpu Opteron_G3,check -drive \




-monitor stdio -vnc -vga std -chardev pty,id=charserial0
isa-serial,chardev=charserial0,id=serial0 -usb -device

The destination host has the same command line with an added "-incoming
tcp:4444". I have mainly tested this with non-shared storage (but
also shared
storage has the same result). Migration is triggered with "migrate -b

Do the TSC microarchitecture changes in amdfam15h (see AMD SW
guide for fam15h, 47414 Rev 3.02 Appendix E) affect pvclock stability on
migration in same family or across families?

cpuid information follows in case it's helpful.

Hi, I can confirm this problem still exists in live migrations between
Opteron 6128HE and Opteron 6274.
Live migration from 6100-series to 6200-series work, but never from
6200 to 6100.
Issue is reproducible and symptoms are identical with previous poster.
I have tested with 3.10.5 host-kernel and 1.7 qemu, also with 3.1.4
and >1.0 qemu, guest kernel seems to be irrelevant at this point (as
it crashes any OS).

I would say this needs attention, and I'm willing to help to get this
sorted out.

Did it ever work? If so, I'd start by git bisecting to find out where it

Hi, as far as I understood, Vasilis never got it to work, and neither have I. Migration seems to work under same set of cpus fine, but problem lies migrations between these two.

Thanks for response.

Markus Kovero

reply via email to

[Prev in Thread] Current Thread [Next in Thread]