vm won't start if host cpus are different steppings

Bug #1093292 reported by Peter Hurley
8
This bug affects 1 person
Affects Status Importance Assigned to Milestone
qemu-kvm (Ubuntu)
Confirmed
Medium
Unassigned
virt-manager (Ubuntu)
Triaged
Medium
Unassigned

Bug Description

On a machine with multiple processors, different steppings may have different cpu features. So when the 'host cpu configuration' is copied, required cpu features may not be supported on the other cpu's cores.

On the test machine, dual Intel Xeon E5420s have steppings 6 and 10. Stepping 6 does not support 'xsave' (/proc/cpuinfo attached).

Perhaps the host cpu configuration should be per-physical id and vcpus pinned to their respective host?

Revision history for this message
Peter Hurley (phurley) wrote :
Revision history for this message
Karma Dorje (taaroa) wrote :

If you need support, post the output of 'lsb_release -rd; cat /proc/version; apt-cache policy libc-bin'

Changed in virt-manager (Ubuntu):
status: New → Incomplete
Revision history for this message
Dave Gilbert (ubuntu-treblig) wrote :

Triaged: Because the reporter describes the problem exactly
Medium: I was thinking originally low since It's got an easy work around and I think this is a very unusual situation,
    however to someone not experienced it's going to be hard to understand and I actually don't know how unusual the situation is.

(Frankly I'm surprised your machine booted at all, but Intel's site does seem to suggest it might be supported, and the kernels check seems to be based on whether the boot CPU has the feature, which yours doesn't).

I'm also going to add qemu-kvm since I think they should at least be aware of this if they aren't already

Changed in virt-manager (Ubuntu):
importance: Undecided → Medium
status: Incomplete → Triaged
Revision history for this message
Dave Gilbert (ubuntu-treblig) wrote :

Peter; could you state the OS install version, and package version of the virt-manager and qemu-kvm you've got.

Revision history for this message
Peter Hurley (phurley) wrote :

OS: Ubuntu 12.10 (quantal)
Kernel: from ubuntu mainline 3.7.0-030700-generic
virt-manager: 0.9.3-1ubuntu2
qemu-kvm: 1.2.0+noroms-0ubuntu2

Changed in qemu-kvm (Ubuntu):
status: New → Confirmed
importance: Undecided → Medium
To post a comment you must log in.
This report contains Public information  
Everyone can see this information.

Other bug subscribers

Remote bug watches

Bug watches keep track of this bug in other bug trackers.