[v1,1/8] qapi/migration: Introduce x-vcpu-dirty-limit-period parameter

diff --git a/migration/migration.c b/migration/migration.c
index bb8bbdd..a8a8065 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -116,6 +116,8 @@ 
 #define DEFAULT_MIGRATE_ANNOUNCE_ROUNDS    5
 #define DEFAULT_MIGRATE_ANNOUNCE_STEP    100
 
+#define DEFAULT_MIGRATE_VCPU_DIRTY_LIMIT_PERIOD     500     /* ms */
+
 static NotifierList migration_state_notifiers =
     NOTIFIER_LIST_INITIALIZER(migration_state_notifiers);
 
@@ -962,6 +964,9 @@  MigrationParameters *qmp_query_migrate_parameters(Error **errp)
                        s->parameters.block_bitmap_mapping);
     }
 
+    params->has_x_vcpu_dirty_limit_period = true;
+    params->x_vcpu_dirty_limit_period = s->parameters.x_vcpu_dirty_limit_period;
+
     return params;
 }
 
@@ -1662,6 +1667,10 @@  static void migrate_params_test_apply(MigrateSetParameters *params,
         dest->has_block_bitmap_mapping = true;
         dest->block_bitmap_mapping = params->block_bitmap_mapping;
     }
+
+    if (params->has_x_vcpu_dirty_limit_period) {
+        dest->x_vcpu_dirty_limit_period = params->x_vcpu_dirty_limit_period;
+    }
 }
 
 static void migrate_params_apply(MigrateSetParameters *params, Error **errp)
@@ -1784,6 +1793,10 @@  static void migrate_params_apply(MigrateSetParameters *params, Error **errp)
             QAPI_CLONE(BitmapMigrationNodeAliasList,
                        params->block_bitmap_mapping);
     }
+    if (params->has_x_vcpu_dirty_limit_period) {
+        s->parameters.x_vcpu_dirty_limit_period =
+            params->x_vcpu_dirty_limit_period;
+    }
 }
 
 void qmp_migrate_set_parameters(MigrateSetParameters *params, Error **errp)
@@ -4385,6 +4398,9 @@  static Property migration_properties[] = {
     DEFINE_PROP_STRING("tls-creds", MigrationState, parameters.tls_creds),
     DEFINE_PROP_STRING("tls-hostname", MigrationState, parameters.tls_hostname),
     DEFINE_PROP_STRING("tls-authz", MigrationState, parameters.tls_authz),
+    DEFINE_PROP_UINT64("x-vcpu-dirty-limit-period", MigrationState,
+                       parameters.x_vcpu_dirty_limit_period,
+                       DEFAULT_MIGRATE_VCPU_DIRTY_LIMIT_PERIOD),
 
     /* Migration capabilities */
     DEFINE_PROP_MIG_CAP("x-xbzrle", MIGRATION_CAPABILITY_XBZRLE),
diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
index c6cd6f9..7569859 100644
--- a/monitor/hmp-cmds.c
+++ b/monitor/hmp-cmds.c
@@ -532,6 +532,10 @@  void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict)
                 }
             }
         }
+
+        monitor_printf(mon, "%s: %" PRIu64 " ms\n",
+        MigrationParameter_str(MIGRATION_PARAMETER_X_VCPU_DIRTY_LIMIT_PERIOD),
+        params->x_vcpu_dirty_limit_period);
     }
 
     qapi_free_MigrationParameters(params);
@@ -1351,6 +1355,10 @@  void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
         error_setg(&err, "The block-bitmap-mapping parameter can only be set "
                    "through QMP");
         break;
+    case MIGRATION_PARAMETER_X_VCPU_DIRTY_LIMIT_PERIOD:
+        p->has_x_vcpu_dirty_limit_period = true;
+        visit_type_size(v, param, &p->x_vcpu_dirty_limit_period, &err);
+        break;
     default:
         assert(0);
     }
diff --git a/qapi/migration.json b/qapi/migration.json
index 81185d4..332c087 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -776,8 +776,12 @@ 
 #                        block device name if there is one, and to their node name
 #                        otherwise. (Since 5.2)
 #
+# @x-vcpu-dirty-limit-period: Periodic time (ms) of dirty limit during live migration.
+#                             Defaults to 500ms. (Since 7.1)
+#
 # Features:
-# @unstable: Member @x-checkpoint-delay is experimental.
+# @unstable: Member @x-checkpoint-delay and @x-vcpu-dirty-limit-period
+#            are experimental.
 #
 # Since: 2.4
 ##
@@ -795,8 +799,9 @@ 
            'multifd-channels',
            'xbzrle-cache-size', 'max-postcopy-bandwidth',
            'max-cpu-throttle', 'multifd-compression',
-           'multifd-zlib-level' ,'multifd-zstd-level',
-           'block-bitmap-mapping' ] }
+           'multifd-zlib-level', 'multifd-zstd-level',
+           'block-bitmap-mapping',
+           { 'name': 'x-vcpu-dirty-limit-period', 'features': ['unstable'] } ] }
 
 ##
 # @MigrateSetParameters:
@@ -941,8 +946,12 @@ 
 #                        block device name if there is one, and to their node name
 #                        otherwise. (Since 5.2)
 #
+# @x-vcpu-dirty-limit-period: Periodic time (ms) of dirty limit during live migration.
+#                             Defaults to 500ms. (Since 7.1)
+#
 # Features:
-# @unstable: Member @x-checkpoint-delay is experimental.
+# @unstable: Member @x-checkpoint-delay and @x-vcpu-dirty-limit-period
+#            are experimental.
 #
 # Since: 2.4
 ##
@@ -976,7 +985,9 @@ 
             '*multifd-compression': 'MultiFDCompression',
             '*multifd-zlib-level': 'uint8',
             '*multifd-zstd-level': 'uint8',
-            '*block-bitmap-mapping': [ 'BitmapMigrationNodeAlias' ] } }
+            '*block-bitmap-mapping': [ 'BitmapMigrationNodeAlias' ],
+            '*x-vcpu-dirty-limit-period': { 'type': 'uint64',
+                                            'features': [ 'unstable' ] } } }
 
 ##
 # @migrate-set-parameters:
@@ -1141,8 +1152,12 @@ 
 #                        block device name if there is one, and to their node name
 #                        otherwise. (Since 5.2)
 #
+# @x-vcpu-dirty-limit-period: Periodic time (ms) of dirty limit during live migration.
+#                             Defaults to 500ms. (Since 7.1)
+#
 # Features:
-# @unstable: Member @x-checkpoint-delay is experimental.
+# @unstable: Member @x-checkpoint-delay and @x-vcpu-dirty-limit-period
+#            are experimental.
 #
 # Since: 2.4
 ##
@@ -1174,7 +1189,9 @@ 
             '*multifd-compression': 'MultiFDCompression',
             '*multifd-zlib-level': 'uint8',
             '*multifd-zstd-level': 'uint8',
-            '*block-bitmap-mapping': [ 'BitmapMigrationNodeAlias' ] } }
+            '*block-bitmap-mapping': [ 'BitmapMigrationNodeAlias' ],
+            '*x-vcpu-dirty-limit-period': { 'type': 'uint64',
+                                            'features': [ 'unstable' ] } } }
 
 ##
 # @query-migrate-parameters: