Re: [RFC PATCH 1/2] migration: Report error in incoming migration

[Fabiano Rosas <farosas@suse.de>]

Peter Xu <peterx@redhat.com> writes:

> On Thu, Nov 09, 2023 at 01:58:55PM -0300, Fabiano Rosas wrote:
>> We're not currently reporting the errors set with migrate_set_error()
>> when incoming migration fails.
>> 
>> Signed-off-by: Fabiano Rosas <farosas@suse.de>
>> ---
>>  migration/migration.c | 7 +++++++
>>  1 file changed, 7 insertions(+)
>> 
>> diff --git a/migration/migration.c b/migration/migration.c
>> index 28a34c9068..cca32c553c 100644
>> --- a/migration/migration.c
>> +++ b/migration/migration.c
>> @@ -698,6 +698,13 @@ process_incoming_migration_co(void *opaque)
>>      }
>>  
>>      if (ret < 0) {
>> +        MigrationState *s = migrate_get_current();
>> +
>> +        if (migrate_has_error(s)) {
>> +            WITH_QEMU_LOCK_GUARD(&s->error_mutex) {
>> +                error_report_err(s->error);
>> +            }
>> +        }
>
> What's the major benefit of dumping this explicitly?

This is incoming migration, so there's no centralized error reporting
aside from the useless "load of migration failed: -5". If the code has
not called error_report we just never see the error message.

> And this is not relevant to the multifd problem, correct?

Yes, I'm being sneaky.