Merge remote-tracking branch 'remotes/dgilbert/tags/pull-migration-20190306a' into...

Migation pull 2019-03-06

(This replaces the pull sent yesterday)

   a) 4 small fixes including the cancel problem
     that caused the ahci migration test to fail
     intermittently
   b) Yury's ignore-shared feature
   c) Juan's extra tests
   d) Wei Wang's free page hinting
   e) Some Colo fixes from Zhang Chen

Diff from yesterdays pull:
  1) A missing fix of mine (cleanup during exit)
  2) Changes from Eric/Markus on 'Create socket-address parameter'

# gpg: Signature made Wed 06 Mar 2019 11:39:53 GMT
# gpg:                using RSA key 0516331EBC5BFDE7
# 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-20190306a: (22 commits)
  qapi/migration.json: Remove a variable that doesn't exist in example
  Migration/colo.c: Make COLO node running after failover
  Migration/colo.c: Fix double close bug when occur COLO failover
  virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT
  migration/ram.c: add the free page optimization enable flag
  migration/ram.c: add a notifier chain for precopy
  migration: API to clear bits of guest free pages from the dirty bitmap
  migration: use bitmap_mutex in migration_bitmap_clear_dirty
  bitmap: bitmap_count_one_with_offset
  bitmap: fix bitmap_count_one
  tests: Add basic migration precopy tcp test
  migration: Create socket-address parameter
  tests: Add migration xbzrle test
  migration: Add capabilities validation
  tests/migration-test: Add a test for ignore-shared capability
  migration: Add an ability to ignore shared RAM blocks
  migration: Introduce ignore-shared capability
  exec: Change RAMBlockIterFunc definition
  migration/rdma: clang compilation fix
  migration: Cleanup during exit
  ...

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