ram_postcopy_send_discard_bitmap() performs the final RAM dirty bitmap
sync at postcopy switchover, before sending discard bitmap to the
destination. Unlike the precopy switchover path, it currently calls the
raw migration_bitmap_sync() helper and passes last_stage=false.
Postcopy switchover is also a stopped-VM final sync point, so use
migration_bitmap_sync_precopy(true). This keeps RAM final bitmap sync
handling consistent across precopy and postcopy switchover, including
the precopy bitmap-sync notifier wrapper. Current notifier users are
safe in postcopy: virtio-balloon free-page hinting already opts out when
postcopy-ram is enabled [1].
This prepares for moving the final sync out of RAM completion/discard
paths and into migration_switchover_start(), where the migration core
can run a final save_query_pending pass for all modules uniformly.
[1] fd51e54fa1 ("virtio-balloon: don't start free page hinting if postcopy is possible")
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Link: https://lore.kernel.org/qemu-devel/20260706085211.13905-3-avihaih@nvidia.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>
ce0b9fa9e7