Re: [Qemu-devel] [PULL 24/28] migration: Make events a capability

[Juan Quintela]

Wen Congyang <address@hidden> wrote:
> At 2015/7/7 21:09, Juan Quintela Wrote:
>> Make check fails with events.  THis is due to the parser/lexer that it
>> uses.  Just in case that they are more broken parsers, just only send
>> events when there are capabilities.
>> 
>> Signed-off-by: Juan Quintela <address@hidden>
>> Reviewed-by: Dr. David Alan Gilbert <address@hidden>
>> ---
>>   include/migration/migration.h |  1 +
>>   migration/migration.c         | 20 ++++++++++++++++++--
>>   qapi-schema.json              |  5 ++++-
>>   3 files changed, 23 insertions(+), 3 deletions(-)
>> 
>> diff --git a/include/migration/migration.h b/include/migration/migration.h
>> index a308ecc..b2711ef 100644
>> --- a/include/migration/migration.h
>> +++ b/include/migration/migration.h
>> @@ -177,6 +177,7 @@ bool migrate_use_compression(void);
>>   int migrate_compress_level(void);
>>   int migrate_compress_threads(void);
>>   int migrate_decompress_threads(void);
>> +bool migrate_use_events(void);
>> 
>>   void ram_control_before_iterate(QEMUFile *f, uint64_t flags);
>>   void ram_control_after_iterate(QEMUFile *f, uint64_t flags);
>> diff --git a/migration/migration.c b/migration/migration.c
>> index d8415c4..cd32eac 100644
>> --- a/migration/migration.c
>> +++ b/migration/migration.c
>> @@ -205,6 +205,14 @@ void register_global_state(void)
>>       vmstate_register(NULL, 0, &vmstate_globalstate, &global_state);
>>   }
>> 
>> +static void migrate_generate_event(int new_state)
>> +{
>> +    if (migrate_use_events()) {
>> +        qapi_event_send_migration(new_state, &error_abort);
>> +        trace_migrate_set_state(new_state);
>> +    }
>> +}
>> +
>>   /*
>>    * Called on -incoming with a defer: uri.
>>    * The migration can be started later after any parameters have been
>> @@ -511,8 +519,7 @@ void qmp_migrate_set_parameters(bool has_compress_level,
>>   static void migrate_set_state(MigrationState *s, int old_state, int 
>> new_state)
>>   {
>>       if (atomic_cmpxchg(&s->state, old_state, new_state) == old_state) {
>> -        qapi_event_send_migration(new_state, &error_abort);
>> -        trace_migrate_set_state(new_state);
>> +        migrate_generate_event(new_state);
>
> Why moving trace_* to migrate_generate_event()? trace event should be
> controlled
> by the monitor command trace-event xxx on/off. It is very strange if the
> user turns
> the trace event on, but gets no output.

Ok, will send another patch with one line change.

I put the set_state event as migrate_event one, but can accept the other
meanining.

Thanks, Juan.

>
> Thanks
> Wen Congyang
>
>>       }
>>   }
>> 
>> @@ -862,6 +869,15 @@ int migrate_decompress_threads(void)
>>       return s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS];
>>   }
>> 
>> +bool migrate_use_events(void)
>> +{
>> +    MigrationState *s;
>> +
>> +    s = migrate_get_current();
>> +
>> +    return s->enabled_capabilities[MIGRATION_CAPABILITY_EVENTS];
>> +}
>> +
>>   int migrate_use_xbzrle(void)
>>   {
>>       MigrationState *s;
>> diff --git a/qapi-schema.json b/qapi-schema.json
>> index 106008c..1285b8c 100644
>> --- a/qapi-schema.json
>> +++ b/qapi-schema.json
>> @@ -523,6 +523,9 @@
>>   #          minimize migration traffic. The feature is disabled by default.
>>   #          (since 2.4 )
>>   #
>> +# @events: generate events for each migration state change
>> +#          (since 2.4 )
>> +#
>>   # @auto-converge: If enabled, QEMU will automatically throttle down the 
>> guest
>>   #          to speed up convergence of RAM migration. (since 1.6)
>>   #
>> @@ -530,7 +533,7 @@
>>   ##
>>   { 'enum': 'MigrationCapability',
>>     'data': ['xbzrle', 'rdma-pin-all', 'auto-converge', 'zero-blocks',
>> -           'compress'] }
>> +           'compress', 'events'] }
>> 
>>   ##
>>   # @MigrationCapabilityStatus
>>