Merge remote-tracking branch 'remotes/juanquintela/tags/migration-pull-pull-request' into staging

Migration pull request

# gpg: Signature made Mon 20 Jan 2020 10:29:53 GMT
# gpg:                using RSA key 1899FF8EDEBF58CCEE034B82F487EF185872D723
# gpg: Good signature from "Juan Quintela <quintela@redhat.com>" [full]
# gpg:                 aka "Juan Quintela <quintela@trasno.org>" [full]
# Primary key fingerprint: 1899 FF8E DEBF 58CC EE03  4B82 F487 EF18 5872 D723

* remotes/juanquintela/tags/migration-pull-pull-request: (29 commits)
  multifd: Be consistent about using uint64_t
  migration: Support QLIST migration
  apic: Use 32bit APIC ID for migration instance ID
  migration: Change SaveStateEntry.instance_id into uint32_t
  migration: Define VMSTATE_INSTANCE_ID_ANY
  Bug #1829242 correction.
  migration/multifd: fix destroyed mutex access in terminating multifd threads
  migration/multifd: fix nullptr access in terminating multifd threads
  migration/multifd: not use multifd during postcopy
  migration/multifd: clean pages after filling packet
  migration/postcopy: enable compress during postcopy
  migration/postcopy: enable random order target page arrival
  migration/postcopy: set all_zero to true on the first target page
  migration/postcopy: count target page number to decide the place_needed
  migration/postcopy: wait for decompress thread in precopy
  migration/postcopy: reduce memset when it is zero page and matches_target_page_size
  migration/ram: Yield periodically to the main loop
  migration: savevm_state_handler_insert: constant-time element insertion
  migration: add savevm_state_handler_remove()
  misc: use QEMU_IS_ALIGNED
  ...

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