Merge remote-tracking branch 'remotes/dgilbert/tags/pull-migration-20200601a' into...

Migration/virtio/hmp pull 2020-06-01

A mixed pull with:
  - RDMA migration fix (CID 1428762)
  - HMP qom-get addition and qom-set cleanup
  - a virtiofsd fix
  - COLO fixes

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
# gpg: Signature made Mon 01 Jun 2020 19:37:15 BST
# gpg:                using RSA key 45F5C71B4A0CB7FB977A9FA90516331EBC5BFDE7
# gpg: Good signature from "Dr. David Alan Gilbert (RH2) <dgilbert@redhat.com>" [full]
# Primary key fingerprint: 45F5 C71B 4A0C B7FB 977A  9FA9 0516 331E BC5B FDE7

* remotes/dgilbert/tags/pull-migration-20200601a:
  migration/migration.c: Fix hang in ram_save_host_page
  migration/colo.c: Move colo_notify_compares_event to the right place
  migration/colo.c: Relaunch failover even if there was an error
  migration/colo.c: Flush ram cache only after receiving device state
  migration/colo.c: Use cpu_synchronize_all_states()
  migration/colo.c: Use event instead of semaphore
  migration/vmstate: Remove unnecessary MemoryRegion forward declaration
  virtiofsd: remove symlink fallbacks
  hmp: Simplify qom-set
  hmp: Implement qom-get HMP command
  migration/rdma: cleanup rdma context before g_free to avoid memleaks
  migration/rdma: fix potential nullptr access in rdma_start_incoming_migration

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