[PATCH QEMU v5 3/8] qapi/migration: Introduce vcpu-dirty-limit parameters

[~hyman]

From: Hyman Huang(黄勇) <yong.huang@smartx.com>

Introduce "vcpu-dirty-limit" migration parameter used
to limit dirty page rate during live migration.

"vcpu-dirty-limit" and "x-vcpu-dirty-limit-period" are
two dirty-limit-related migration parameters, which can
be set before and during live migration by qmp
migrate-set-parameters.

This two parameters are used to help implement the dirty
page rate limit algo of migration.

Signed-off-by: Hyman Huang(黄勇) <yong.huang@smartx.com>
Acked-by: Peter Xu <peterx@redhat.com>
---
 migration/migration-hmp-cmds.c |  8 ++++++++
 migration/options.c            | 21 +++++++++++++++++++++
 qapi/migration.json            | 18 +++++++++++++++---
 3 files changed, 44 insertions(+), 3 deletions(-)

diff --git a/migration/migration-hmp-cmds.c b/migration/migration-hmp-cmds.c
index 352e9ec716..35e8020bbf 100644
--- a/migration/migration-hmp-cmds.c
+++ b/migration/migration-hmp-cmds.c
@@ -368,6 +368,10 @@ 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);
+
+        monitor_printf(mon, "%s: %" PRIu64 " MB/s\n",
+            MigrationParameter_str(MIGRATION_PARAMETER_VCPU_DIRTY_LIMIT),
+            params->vcpu_dirty_limit);
     }
 
     qapi_free_MigrationParameters(params);
@@ -628,6 +632,10 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict 
*qdict)
         p->has_x_vcpu_dirty_limit_period = true;
         visit_type_size(v, param, &p->x_vcpu_dirty_limit_period, &err);
         break;
+    case MIGRATION_PARAMETER_VCPU_DIRTY_LIMIT:
+        p->has_vcpu_dirty_limit = true;
+        visit_type_size(v, param, &p->vcpu_dirty_limit, &err);
+        break;
     default:
         assert(0);
     }
diff --git a/migration/options.c b/migration/options.c
index 1cb735e35f..8dc1ab10e1 100644
--- a/migration/options.c
+++ b/migration/options.c
@@ -81,6 +81,7 @@
     DEFINE_PROP_BOOL(name, MigrationState, capabilities[x], false)
 
 #define DEFAULT_MIGRATE_VCPU_DIRTY_LIMIT_PERIOD     1000    /* microsecond */
+#define DEFAULT_MIGRATE_VCPU_DIRTY_LIMIT            1       /* MB/s */
 
 Property migration_properties[] = {
     DEFINE_PROP_BOOL("store-global-state", MigrationState,
@@ -168,6 +169,9 @@ Property migration_properties[] = {
     DEFINE_PROP_UINT64("x-vcpu-dirty-limit-period", MigrationState,
                        parameters.x_vcpu_dirty_limit_period,
                        DEFAULT_MIGRATE_VCPU_DIRTY_LIMIT_PERIOD),
+    DEFINE_PROP_UINT64("vcpu-dirty-limit", MigrationState,
+                       parameters.vcpu_dirty_limit,
+                       DEFAULT_MIGRATE_VCPU_DIRTY_LIMIT),
 
     /* Migration capabilities */
     DEFINE_PROP_MIG_CAP("x-xbzrle", MIGRATION_CAPABILITY_XBZRLE),
@@ -898,6 +902,8 @@ MigrationParameters *qmp_query_migrate_parameters(Error 
**errp)
 
     params->has_x_vcpu_dirty_limit_period = true;
     params->x_vcpu_dirty_limit_period = 
s->parameters.x_vcpu_dirty_limit_period;
+    params->has_vcpu_dirty_limit = true;
+    params->vcpu_dirty_limit = s->parameters.vcpu_dirty_limit;
 
     return params;
 }
@@ -932,6 +938,7 @@ void migrate_params_init(MigrationParameters *params)
     params->has_announce_rounds = true;
     params->has_announce_step = true;
     params->has_x_vcpu_dirty_limit_period = true;
+    params->has_vcpu_dirty_limit = true;
 }
 
 /*
@@ -1101,6 +1108,14 @@ bool migrate_params_check(MigrationParameters *params, 
Error **errp)
         return false;
     }
 
+    if (params->has_vcpu_dirty_limit &&
+        (params->vcpu_dirty_limit < 1)) {
+        error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
+                   "vcpu_dirty_limit",
+                   "is invalid, it must greater then 1 MB/s");
+        return false;
+    }
+
     return true;
 }
 
@@ -1205,6 +1220,9 @@ static void 
migrate_params_test_apply(MigrateSetParameters *params,
         dest->x_vcpu_dirty_limit_period =
             params->x_vcpu_dirty_limit_period;
     }
+    if (params->has_vcpu_dirty_limit) {
+        dest->vcpu_dirty_limit = params->vcpu_dirty_limit;
+    }
 }
 
 static void migrate_params_apply(MigrateSetParameters *params, Error **errp)
@@ -1328,6 +1346,9 @@ static void migrate_params_apply(MigrateSetParameters 
*params, Error **errp)
         s->parameters.x_vcpu_dirty_limit_period =
             params->x_vcpu_dirty_limit_period;
     }
+    if (params->has_vcpu_dirty_limit) {
+        s->parameters.vcpu_dirty_limit = params->vcpu_dirty_limit;
+    }
 }
 
 void qmp_migrate_set_parameters(MigrateSetParameters *params, Error **errp)
diff --git a/qapi/migration.json b/qapi/migration.json
index 8d491ee121..b970b68672 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -783,6 +783,9 @@
 #                             live migration. Should be in the range 1 to 
1000ms,
 #                             defaults to 1000ms. (Since 8.1)
 #
+# @vcpu-dirty-limit: Dirtyrate limit (MB/s) during live migration.
+#                    Defaults to 1. (Since 8.1)
+#
 # Features:
 #
 # @unstable: Members @x-checkpoint-delay and @x-vcpu-dirty-limit-period
@@ -806,7 +809,8 @@
            'max-cpu-throttle', 'multifd-compression',
            'multifd-zlib-level', 'multifd-zstd-level',
            'block-bitmap-mapping',
-           { 'name': 'x-vcpu-dirty-limit-period', 'features': ['unstable'] } ] 
}
+           { 'name': 'x-vcpu-dirty-limit-period', 'features': ['unstable'] },
+           'vcpu-dirty-limit'] }
 
 ##
 # @MigrateSetParameters:
@@ -945,6 +949,9 @@
 #                             live migration. Should be in the range 1 to 
1000ms,
 #                             defaults to 1000ms. (Since 8.1)
 #
+# @vcpu-dirty-limit: Dirtyrate limit (MB/s) during live migration.
+#                    Defaults to 1. (Since 8.1)
+#
 # Features:
 #
 # @unstable: Members @x-checkpoint-delay and @x-vcpu-dirty-limit-period
@@ -985,7 +992,8 @@
             '*multifd-zstd-level': 'uint8',
             '*block-bitmap-mapping': [ 'BitmapMigrationNodeAlias' ],
             '*x-vcpu-dirty-limit-period': { 'type': 'uint64',
-                                            'features': [ 'unstable' ] } } }
+                                            'features': [ 'unstable' ] },
+            '*vcpu-dirty-limit': 'uint64'} }
 
 ##
 # @migrate-set-parameters:
@@ -1144,6 +1152,9 @@
 #                             live migration. Should be in the range 1 to 
1000ms,
 #                             defaults to 1000ms. (Since 8.1)
 #
+# @vcpu-dirty-limit: Dirtyrate limit (MB/s) during live migration.
+#                    Defaults to 1. (Since 8.1)
+#
 # Features:
 #
 # @unstable: Members @x-checkpoint-delay and @x-vcpu-dirty-limit-period
@@ -1181,7 +1192,8 @@
             '*multifd-zstd-level': 'uint8',
             '*block-bitmap-mapping': [ 'BitmapMigrationNodeAlias' ],
             '*x-vcpu-dirty-limit-period': { 'type': 'uint64',
-                                            'features': [ 'unstable' ] } } }
+                                            'features': [ 'unstable' ] },
+            '*vcpu-dirty-limit': 'uint64'} }
 
 ##
 # @query-migrate-parameters:
-- 
2.38.5