Migration pull request

- Avihai's fix to allow vmstate iterators to not starve for VFIO
 - Maksim's fix on additional check on precopy load error
 - Fabiano's fix on fdatasync() hang in mapped-ram
 - Jonathan's fix on vring cached access over MMIO regions
 - Cedric's cleanup patches 1-4 out of his error report series
 - Yu's fix for RDMA migration (which used to be broken even for 8.2)
 - Anthony's small cleanup/fix on err message
 - Steve's patches on privatize migration.h
 - Xiang's patchset to enable zero page detections in multifd threads
 -----BEGIN PGP SIGNATURE-----
 
 iIgEABYKADAWIQS5GE3CDMRX2s990ak7X8zN86vXBgUCZe9+uBIccGV0ZXJ4QHJl
 ZGhhdC5jb20ACgkQO1/MzfOr1wamaQD/SvmpMEcuRndT9LPSxzXowAGDZTBpYUfv
 5XAbx80dS9IBAO8PJJgQJIBHBeacyLBjHP9CsdVtgw5/VW+wCsbfV4AB
 =xavb
 -----END PGP SIGNATURE-----

Merge tag 'migration-20240311-pull-request' of https://gitlab.com/peterx/qemu into staging

Migration pull request

- Avihai's fix to allow vmstate iterators to not starve for VFIO
- Maksim's fix on additional check on precopy load error
- Fabiano's fix on fdatasync() hang in mapped-ram
- Jonathan's fix on vring cached access over MMIO regions
- Cedric's cleanup patches 1-4 out of his error report series
- Yu's fix for RDMA migration (which used to be broken even for 8.2)
- Anthony's small cleanup/fix on err message
- Steve's patches on privatize migration.h
- Xiang's patchset to enable zero page detections in multifd threads

# -----BEGIN PGP SIGNATURE-----
#
# iIgEABYKADAWIQS5GE3CDMRX2s990ak7X8zN86vXBgUCZe9+uBIccGV0ZXJ4QHJl
# ZGhhdC5jb20ACgkQO1/MzfOr1wamaQD/SvmpMEcuRndT9LPSxzXowAGDZTBpYUfv
# 5XAbx80dS9IBAO8PJJgQJIBHBeacyLBjHP9CsdVtgw5/VW+wCsbfV4AB
# =xavb
# -----END PGP SIGNATURE-----
# gpg: Signature made Mon 11 Mar 2024 21:59:20 GMT
# gpg:                using EDDSA key B9184DC20CC457DACF7DD1A93B5FCCCDF3ABD706
# gpg:                issuer "peterx@redhat.com"
# gpg: Good signature from "Peter Xu <xzpeter@gmail.com>" [marginal]
# gpg:                 aka "Peter Xu <peterx@redhat.com>" [marginal]
# gpg: WARNING: This key is not certified with sufficiently trusted signatures!
# gpg:          It is not certain that the signature belongs to the owner.
# Primary key fingerprint: B918 4DC2 0CC4 57DA CF7D  D1A9 3B5F CCCD F3AB D706

* tag 'migration-20240311-pull-request' of https://gitlab.com/peterx/qemu: (34 commits)
  migration/multifd: Add new migration test cases for legacy zero page checking.
  migration/multifd: Enable multifd zero page checking by default.
  migration/multifd: Implement ram_save_target_page_multifd to handle multifd version of MigrationOps::ram_save_target_page.
  migration/multifd: Implement zero page transmission on the multifd thread.
  migration/multifd: Add new migration option zero-page-detection.
  migration/multifd: Allow clearing of the file_bmap from multifd
  migration/multifd: Allow zero pages in file migration
  migration: purge MigrationState from public interface
  migration: delete unused accessors
  migration: privatize colo interfaces
  migration: migration_file_set_error
  migration: migration_is_device
  migration: migration_thread_is_self
  migration: export vcpu_dirty_limit_period
  migration: export migration_is_running
  migration: export migration_is_active
  migration: export migration_is_setup_or_active
  migration: remove migration.h references
  migration: export fewer options
  migration: Fix format in error message
  ...

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

docs/devel/migration/main.rst

@@ -44,7 +44,8 @@ over any transport.
 - file migration: do the migration using a file that is passed to QEMU
   by path. A file offset option is supported to allow a management
   application to add its own metadata to the start of the file without
-  QEMU interference.
+  QEMU interference. Note that QEMU does not flush cached file
+  data/metadata at the end of migration.
 
 In addition, support is included for migration using RDMA, which
 transports the page data using ``RDMA``, where the hardware takes care of