Comment 8 for bug 1086255

I suggest the following, rather than using an 'exec' command (exec is baaad, mm'kay?'). It uses the service libvirt that nova creates.

  if $enabled {
    $service_ensure = "running"
  } else {
    $service_ensure = "stopped"
  }

  # If you're using ethernet KVM connections then we need to change the qemu default settings
  # They're recommended against, hence not being turned on in qemu by default, but they're
  # needed by some VIF plugging code.
  file { "/etc/libvirt/qemu.conf":
     ensure => present,
     notify => Service['libvirt'], # from nova::compute - beware the cross-dependency
     source => 'puppet:///modules/quantum/qemu.conf',
  }