qapi: add dirty-bitmaps migration capability

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20180313180320.339796-7-vsementsov@virtuozzo.com

migration/migration.c

@@ -1565,6 +1565,15 @@ int migrate_decompress_threads(void)
     return s->parameters.decompress_threads;
 }
 
+bool migrate_dirty_bitmaps(void)
+{
+    MigrationState *s;
+
+    s = migrate_get_current();
+
+    return s->enabled_capabilities[MIGRATION_CAPABILITY_DIRTY_BITMAPS];
+}
+
 bool migrate_use_events(void)
 {
     MigrationState *s;

migration/migration.h

@@ -205,6 +205,7 @@ bool migrate_postcopy(void);
 bool migrate_release_ram(void);
 bool migrate_postcopy_ram(void);
 bool migrate_zero_blocks(void);
+bool migrate_dirty_bitmaps(void);
 
 bool migrate_auto_converge(void);
 bool migrate_use_multifd(void);

qapi/migration.json

@@ -354,12 +354,16 @@
 #
 # @x-multifd: Use more than one fd for migration (since 2.11)
 #
+# @dirty-bitmaps: If enabled, QEMU will migrate named dirty bitmaps.
+#                 (since 2.12)
+#
 # Since: 1.2
 ##
 { 'enum': 'MigrationCapability',
   'data': ['xbzrle', 'rdma-pin-all', 'auto-converge', 'zero-blocks',
            'compress', 'events', 'postcopy-ram', 'x-colo', 'release-ram',
-           'block', 'return-path', 'pause-before-switchover', 'x-multifd' ] }
+           'block', 'return-path', 'pause-before-switchover', 'x-multifd',
+           'dirty-bitmaps' ] }
 
 ##
 # @MigrationCapabilityStatus: