Merge remote-tracking branch 'remotes/dgilbert-gitlab/tags/pull-migration-20220302b...

Migration/HMP/Virtio pull 2022-03-02

A bit of a mix this time:
  * Minor fixes from myself, Hanna, and Jack
  * VNC password rework by Stefan and Fabian
  * Postcopy changes from Peter X that are
    the start of a larger series to come
  * Removing the prehistoic load_state_old
    code from Peter M

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
# gpg: Signature made Wed 02 Mar 2022 18:25:12 GMT
# 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-gitlab/tags/pull-migration-20220302b:
  migration: Remove load_state_old and minimum_version_id_old
  tests: Pass in MigrateStart** into test_migrate_start()
  migration: Add migration_incoming_transport_cleanup()
  migration: postcopy_pause_fault_thread() never fails
  migration: Enlarge postcopy recovery to capture !-EIO too
  migration: Move static var in ram_block_from_stream() into global
  migration: Add postcopy_thread_create()
  migration: Dump ramblock and offset too when non-same-page detected
  migration: Introduce postcopy channels on dest node
  migration: Tracepoint change in postcopy-run bottom half
  migration: Finer grained tracepoints for POSTCOPY_LISTEN
  migration: Dump sub-cmd name in loadvm_process_command tp
  migration/rdma: set the REUSEADDR option for destination
  qapi/monitor: allow VNC display id in set/expire_password
  qapi/monitor: refactor set/expire_password with enums
  monitor/hmp: add support for flag argument with value
  virtiofsd: Let meson check for statx.stx_mnt_id
  clock-vmstate: Add missing END_OF_LIST

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