Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging

Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging

pc, pci, virtio: fixes for rc3

A bunch of fixes all over the place.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
# gpg: Signature made Fri 01 Dec 2017 17:06:33 GMT
# gpg:                using RSA key 0x281F0DB8D28D5469
# gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>"
# gpg:                 aka "Michael S. Tsirkin <mst@redhat.com>"
# 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:
  pc: fix crash on attempted cpu unplug
  virtio: check VirtQueue Vring object is set
  vhost: fix error check in vhost_verify_ring_mappings()
  dump-guest-memory.py: fix No symbol "vmcoreinfo_find"
  vhost: restore avail index from vring used index on disconnection
  virtio: Add queue interface to restore avail index from vring used index
  i386/msi: Correct mask of destination ID in MSI address

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