Merge remote-tracking branch 'remotes/sstabellini-http/tags/xen-20180531-tag' into staging

Xen 2018/05/31

# gpg: Signature made Thu 31 May 2018 20:05:49 BST
# gpg:                using RSA key 894F8F4870E1AE90
# 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-http/tags/xen-20180531-tag:
  xen-hvm: stop faking I/O to access PCI config space
  xen-hvm: try to use xenforeignmemory_map_resource() to map ioreq pages
  xen/hvm: correct reporting of modified memory under physmap during migration

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