Re: [PATCH v3 4/6] migration: Set migration status early in incoming side

[Peter Xu]

On Fri, Jun 30, 2023 at 06:29:00PM -0300, Fabiano Rosas wrote:
> We are sending a migration event of MIGRATION_STATUS_SETUP at
> qemu_start_incoming_migration but never actually setting the state.
> 
> This creates a window between qmp_migrate_incoming and
> process_incoming_migration_co where the migration status is still
> MIGRATION_STATUS_NONE. Calling query-migrate during this time will
> return an empty response even though the incoming migration command
> has already been issued.
> 
> Commit 7cf1fe6d68 ("migration: Add migration events on target side")
> has added support to the 'events' capability to the incoming part of
> migration, but chose to send the SETUP event without setting the
> state. I'm assuming this was a mistake.
> 
> This introduces a change in behavior, any QMP client waiting for the
> SETUP event will hang, unless it has previously enabled the 'events'
> capability. Having the capability enabled is sufficient to continue to
> receive the event.
> 
> Signed-off-by: Fabiano Rosas <farosas@suse.de>

Reviewed-by: Peter Xu <peterx@redhat.com>

-- 
Peter Xu