Merge branch 'for-upstream/pvhvm' of git://xenbits.xensource.com/people/ianc/linux-2.6

* 'for-upstream/pvhvm' of git://xenbits.xensource.com/people/ianc/linux-2.6:
  xen: pvhvm: make it clearer that XEN_UNPLUG_* define bits in a bitfield
  xen: pvhvm: rename xen_emul_unplug=ignore to =unnnecessary
  xen: pvhvm: allow user to request no emulated device unplug