[PATCH 0/5] migration: Fix migration state reference counting

[Fabiano Rosas]

We currently have a bug when running migration code in bottom
halves. The issue has already been reported in Gitlab[1] and it
started happening very frequently on my machine for some reason.

The issue is that we're dropping the last reference to the
MigrationState object while the cleanup bottom half is still running
and it leads to an use after free. More details on the commit message.

This series fixes the issue and does a refactoring around the
migration BH scheduling aiming to consolidate some code so that it is
less error prone.

1- https://gitlab.com/qemu-project/qemu/-/issues/1969

CI run: https://gitlab.com/farosas/qemu/-/pipelines/1144927625

Fabiano Rosas (5):
  migration: Fix use-after-free of migration state object
  migration: Take reference to migration state around
    bg_migration_vm_start_bh
  migration: Reference migration state around
    loadvm_postcopy_handle_run_bh
  migration: Add a wrapper to qemu_bh_schedule
  migration: Centralize BH creation and dispatch

 migration/migration.c | 82 +++++++++++++++++++++++++------------------
 migration/migration.h |  5 +--
 migration/savevm.c    |  5 +--
 3 files changed, 49 insertions(+), 43 deletions(-)

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2.35.3