pc,pci,vhost,virtio: fixes

Lots of fixes all over the place.
virtio-mem and virtio-iommu patches are kind of fixes but
it seems better to just make them behave sanely than
try to educate users about the limitations ...

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

# gpg: Signature made Wed 04 Nov 2020 18:40:03 GMT
# gpg:                using RSA key 5D09FD0871C8F85B94CA8A0D281F0DB8D28D5469
# gpg:                issuer "mst@redhat.com"
# 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: (31 commits)
  contrib/vhost-user-blk: fix get_config() information leak
  block/export: fix vhost-user-blk get_config() information leak
  block/export: make vhost-user-blk config space little-endian
  configure: introduce --enable-vhost-user-blk-server
  libvhost-user: follow QEMU comment style
  vhost-blk: set features before setting inflight feature
  Revert "vhost-blk: set features before setting inflight feature"
  net: Add vhost-vdpa in show_netdevs()
  vhost-vdpa: Add qemu_close in vhost_vdpa_cleanup
  vfio: Don't issue full 2^64 unmap
  virtio-iommu: Set supported page size mask
  vfio: Set IOMMU page size as per host supported page size
  memory: Add interface to set iommu page size mask
  virtio-iommu: Add notify_flag_changed() memory region callback
  virtio-iommu: Add replay() memory region callback
  virtio-iommu: Call memory notifiers in attach/detach
  virtio-iommu: Add memory notifiers for map/unmap
  virtio-iommu: Store memory region in endpoint struct
  virtio-iommu: Fix virtio_iommu_mr()
  hw/smbios: Fix leaked fd in save_opt_one() error path
  ...

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