Merge remote-tracking branch 'remotes/sstabellini/xen-2014-10-30' into staging

* remotes/sstabellini/xen-2014-10-30:
  fix off-by-one error in pci_piix3_xen_ide_unplug
  xen-hvm.c: Add support for Xen access to vmport

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>