pci, pc, virtio: features, fixes, cleanups

intel-iommu scalable option
pcie acs emulation
beginning for vhost-user-blk reconnect and of vhost-user backend work
misc fixes and cleanups

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

# gpg: Signature made Wed 13 Mar 2019 02:52:02 GMT
# gpg:                using RSA key 281F0DB8D28D5469
# gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>" [full]
# gpg:                 aka "Michael S. Tsirkin <mst@redhat.com>" [full]
# Primary key fingerprint: 0270 606B 6F3C DF3D 0B17  0970 C350 3912 AFBE 8E67
#      Subkey fingerprint: 5D09 FD08 71C8 F85B 94CA  8A0D 281F 0DB8 D28D 5469

* remotes/mst/tags/for_upstream: (26 commits)
  i386, acpi: check acpi_memory_hotplug capacity in pre_plug
  gen_pcie_root_port: Add ACS (Access Control Services) capability
  pcie: Add a simple PCIe ACS (Access Control Services) helper function
  vhost-user-blk: Add support to get/set inflight buffer
  libvhost-user: Support tracking inflight I/O in shared memory
  libvhost-user: Introduce vu_queue_map_desc()
  libvhost-user: Remove unnecessary FD flag check for event file descriptors
  vhost-user: Support transferring inflight buffer between qemu and backend
  nvdimm: use NVDIMM_ACPI_IO_LEN for the proper IO size
  nvdimm: use *function* directly instead of allocating it again
  nvdimm: fix typo in nvdimm_build_nvdimm_devices argument
  intel_iommu: add scalable-mode option to make scalable mode work
  intel_iommu: add 256 bits qi_desc support
  intel_iommu: scalable mode emulation
  libvhost-user: add vu_queue_unpop()
  libvhost-user-glib: export vug_source_new()
  vhost-user: split vhost_user_read()
  vhost-user: wrap some read/write with retry handling
  libvhost-user: exit by default on VHOST_USER_NONE
  vhost-user: simplify vhost_user_init/vhost_user_cleanup
  ...

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