libvirt users - Nov 2014 - Cannot find suitable CPU model for given data

Hello all,
I have a new Sun fire X4140 server with two amd opteron 2435 CPUs running
debian jessie, libvirt 1.2.9-3, virtinst 1.0.1-3, qemu/kvm 2.1. When
attempting to create virtual machines (with --debug), I receive this:

[Thu, 20 Nov 2014 13:56:36 virt-install 1842] DEBUG (cli:234)   File
"/usr/share/virt-manager/virt-install", line 876, in <module>
    sys.exit(main())
  File "/usr/share/virt-manager/virt-install", line 870, in main
    start_install(guest, continue_inst, options)
  File "/usr/share/virt-manager/virt-install", line 588, in
start_install
    fail(e, do_exit=False)
  File "/usr/share/virt-manager/virtinst/cli.py", line 234, in fail
    logging.debug("".join(traceback.format_stack()))

[Thu, 20 Nov 2014 13:56:36 virt-install 1842] ERROR (cli:235) internal
error: Cannot find suitable CPU model for given data
[Thu, 20 Nov 2014 13:56:36 virt-install 1842] DEBUG (cli:237)
Traceback (most recent call last):
  File "/usr/share/virt-manager/virt-install", line 560, in
start_install
    dom = guest.start_install(meter=meter, noboot=options.noreboot)
  File "/usr/share/virt-manager/virtinst/guest.py", line 403, in
start_install
    noboot)
  File "/usr/share/virt-manager/virtinst/guest.py", line 467, in
_create_guest
    dom = self.conn.createLinux(start_xml or final_xml, 0)
  File "/usr/lib/python2.7/dist-packages/libvirt.py", line 3440, in
createLinux
    if ret is None:raise libvirtError('virDomainCreateLinux() failed',
conn=self)
libvirtError: internal error: Cannot find suitable CPU model for given data
[Thu, 20 Nov 2014 13:56:36 virt-install 1842] DEBUG (cli:248) Domain
installation does not appear to have been successful.


svm and svm_lock are present in /proc/cpuinfo, in the initial output of
virt-install with --debug, it says it will use the proper cpu:

  <cpu mode="custom" match="exact">
    <model>Opteron_G3</model>
  </cpu>


I've tried using --cpu host, --cpu best, --cpu Opteron_G3, all fail with
the same error. Anyone know what I can do here? I'd like to stick with KVM,
but maybe Xen would work? I'm not sure if this error is coming from
libvirt, or KVM itself.

Thanks!


mb