* Dr. David Alan Gilbert (dgilb...@redhat.com) wrote: > Hi, > Is there any way that we could make it easier to add new migration > parameters? The current way is complicated and error prone; > as far as I can tell, to add a new parameter we need to: > > 1) qapi-schema.json > a) Add to 'MigrationParameter' enum, include comment > b) Add to migrate-set-parameters > c) Add to MigrationParameters > 2) Define the 'default' macro at the top of migration.c > 3) Add the initialisation to migrate_get_current to set the default > 4) qmp_migrate_set_parameters: > a) Add the 'has' and value arguments to qmp_migrate_set_parameters > *** Make really sure this matches the order in migrate-set-parameters! > b) Add a bounds check on the value > c) Set the value in the array if the has_ is true > 5) Fixup migrate_init to preserve the parameter around the init > 6) Add a bool and case entry to hmp_migrate_set_parameter and > pass to qmp_migrate_set_parameters > *** Make sure you get the order to qmp_migrate_set_parameters right > 7) Fixup hmp_info_migrate_parameters
oh, and don't forget to: 8) add the entries to qmp_query_migrate_parameters (I forgot). Dave > > > The three separate changes needed in the qapi-schema.json seem odd, > and the 'has'/value pairs on qmp_migrate_set_parameters is just a nightmare > because there's nothing to check the ordering, and it's just getting > a silly number of arguments to the function now (I've got 10 > parameters in one of my dev worlds, so that function has 21 arguments). > > In my ideal world there would be: > a) One thing to add to qapi-schema.json > b) qmp_migrate_set_parameters would take an array pointer indexed > by the enum > c) A way to define the bounds so that we didn't have to manually > add the bound checking. > d) Something where I defined the default value > > (I'm fairly sure earlier versions of migrate parameters patches > managed (a) and possibly (b)). > > Dave > -- > Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
