diff --git a/migration/migration.c b/migration/migration.c index 2398a9db4fce922b6b3ea60fa214d2815eeb0f88..51ccd1a4c5177fb997759ebe5322490b4e2b0bef 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -1311,6 +1311,15 @@ bool migrate_use_block(void) return s->enabled_capabilities[MIGRATION_CAPABILITY_BLOCK]; } +bool migrate_use_return_path(void) +{ + MigrationState *s; + + s = migrate_get_current(); + + return s->enabled_capabilities[MIGRATION_CAPABILITY_RETURN_PATH]; +} + bool migrate_use_block_incremental(void) { MigrationState *s; @@ -1975,10 +1984,11 @@ void migrate_fd_connect(MigrationState *s) notifier_list_notify(&migration_state_notifiers, s); /* - * Open the return path; currently for postcopy but other things might - * also want it. + * Open the return path. For postcopy, it is used exclusively. For + * precopy, only if user specified "return-path" capability would + * QEMU uses the return path. */ - if (migrate_postcopy_ram()) { + if (migrate_postcopy_ram() || migrate_use_return_path()) { if (open_return_path_on_source(s)) { error_report("Unable to open return-path for postcopy"); migrate_set_state(&s->state, MIGRATION_STATUS_SETUP, diff --git a/migration/migration.h b/migration/migration.h index 994b01701503d336d6e0a0277ce407e0b1a05fb5..148c9facbce9a25218a2b611385461edaf48e5ef 100644 --- a/migration/migration.h +++ b/migration/migration.h @@ -177,6 +177,7 @@ bool migrate_colo_enabled(void); bool migrate_use_block(void); bool migrate_use_block_incremental(void); +bool migrate_use_return_path(void); bool migrate_use_compression(void); int migrate_compress_level(void); diff --git a/qapi-schema.json b/qapi-schema.json index 4b50b652d3edfadb92537d6012f22d2e741c377b..9e34cf71f37fd5d57503a4eefc898e8fbbfcafd1 100644 --- a/qapi-schema.json +++ b/qapi-schema.json @@ -900,12 +900,15 @@ # offers more flexibility. # (Since 2.10) # +# @return-path: If enabled, migration will use the return path even +# for precopy. (since 2.10) +# # Since: 1.2 ## { 'enum': 'MigrationCapability', 'data': ['xbzrle', 'rdma-pin-all', 'auto-converge', 'zero-blocks', 'compress', 'events', 'postcopy-ram', 'x-colo', 'release-ram', - 'block' ] } + 'block', 'return-path' ] } ## # @MigrationCapabilityStatus: