<cpu mode='custom' match='exact'>
  <arch>x86_64</arch>
  <model fallback='allow'>Penryn</model>
  <feature policy='require' name='svm'/>
  <feature policy='require' name='3dnowext'/>
  <feature policy='require' name='monitor'/>
  <feature policy='require' name='pbe'/>
  <feature policy='disable' name='sse'/>
</cpu>