Merge remote-tracking branch 'remotes/sstabellini/tags/xen-20170718-tag' into staging

Xen 2017/07/18

# gpg: Signature made Tue 18 Jul 2017 23:18:16 BST
# gpg:                using RSA key 0x894F8F4870E1AE90
# gpg: Good signature from "Stefano Stabellini <stefano.stabellini@eu.citrix.com>"
# gpg:                 aka "Stefano Stabellini <sstabellini@kernel.org>"
# Primary key fingerprint: D04E 33AB A51F 67BA 07D3  0AEA 894F 8F48 70E1 AE90

* remotes/sstabellini/tags/xen-20170718-tag:
  xen: don't use xenstore to save/restore physmap anymore
  xen/mapcache: introduce xen_replace_cache_entry()
  xen/mapcache: add an ability to create dummy mappings
  xen: move physmap saving into a separate function
  xen-platform: separate unplugging of NVMe disks
  xen_pt_msi.c: Check for xen_host_pci_get_* failures in xen_pt_msix_init()
  hw/xen: Set emu_mask for igd_opregion register

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