migration: Add qmp commands to set and query parameters

Add the qmp commands to tune and query the parameters used in live
migration.

Signed-off-by: Liang Li <liang.z.li@intel.com>
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

migration/migration.c

@@ -188,6 +188,21 @@ MigrationCapabilityStatusList *qmp_query_migrate_capabilities(Error **errp)
     return head;
 }
 
+MigrationParameters *qmp_query_migrate_parameters(Error **errp)
+{
+    MigrationParameters *params;
+    MigrationState *s = migrate_get_current();
+
+    params = g_malloc0(sizeof(*params));
+    params->compress_level = s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL];
+    params->compress_threads =
+            s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS];
+    params->decompress_threads =
+            s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS];
+
+    return params;
+}
+
 static void get_xbzrle_cache_stats(MigrationInfo *info)
 {
     if (migrate_use_xbzrle()) {
@@ -301,6 +316,47 @@ void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params,
     }
 }
 
+void qmp_migrate_set_parameters(bool has_compress_level,
+                                int64_t compress_level,
+                                bool has_compress_threads,
+                                int64_t compress_threads,
+                                bool has_decompress_threads,
+                                int64_t decompress_threads, Error **errp)
+{
+    MigrationState *s = migrate_get_current();
+
+    if (has_compress_level && (compress_level < 0 || compress_level > 9)) {
+        error_set(errp, QERR_INVALID_PARAMETER_VALUE, "compress_level",
+                  "is invalid, it should be in the range of 0 to 9");
+        return;
+    }
+    if (has_compress_threads &&
+            (compress_threads < 1 || compress_threads > 255)) {
+        error_set(errp, QERR_INVALID_PARAMETER_VALUE,
+                  "compress_threads",
+                  "is invalid, it should be in the range of 1 to 255");
+        return;
+    }
+    if (has_decompress_threads &&
+            (decompress_threads < 1 || decompress_threads > 255)) {
+        error_set(errp, QERR_INVALID_PARAMETER_VALUE,
+                  "decompress_threads",
+                  "is invalid, it should be in the range of 1 to 255");
+        return;
+    }
+
+    if (has_compress_level) {
+        s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL] = compress_level;
+    }
+    if (has_compress_threads) {
+        s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS] = compress_threads;
+    }
+    if (has_decompress_threads) {
+        s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS] =
+                                                    decompress_threads;
+    }
+}
+
 /* shared migration helpers */
 
 static void migrate_set_state(MigrationState *s, int old_state, int new_state)

qapi-schema.json

@@ -592,6 +592,51 @@
 { 'enum': 'MigrationParameter',
   'data': ['compress-level', 'compress-threads', 'decompress-threads'] }
 
+#
+# @migrate-set-parameters
+#
+# Set the following migration parameters
+#
+# @compress-level: compression level
+#
+# @compress-threads: compression thread count
+#
+# @decompress-threads: decompression thread count
+#
+# Since: 2.4
+##
+{ 'command': 'migrate-set-parameters',
+  'data': { '*compress-level': 'int',
+            '*compress-threads': 'int',
+            '*decompress-threads': 'int'} }
+
+#
+# @MigrationParameters
+#
+# @compress-level: compression level
+#
+# @compress-threads: compression thread count
+#
+# @decompress-threads: decompression thread count
+#
+# Since: 2.4
+##
+{ 'struct': 'MigrationParameters',
+  'data': { 'compress-level': 'int',
+            'compress-threads': 'int',
+            'decompress-threads': 'int'} }
+##
+# @query-migrate-parameters
+#
+# Returns information about the current migration parameters
+#
+# Returns: @MigrationParameters
+#
+# Since: 2.4
+##
+{ 'command': 'query-migrate-parameters',
+  'returns': 'MigrationParameters' }
+
 ##
 # @MouseInfo:
 #

qmp-commands.hx

@@ -3442,6 +3442,63 @@ EQMP
         .mhandler.cmd_new = qmp_marshal_input_query_migrate_capabilities,
     },
 
+SQMP
+migrate-set-parameters
+----------------------
+
+Set migration parameters
+
+- "compress-level": set compression level during migration (json-int)
+- "compress-threads": set compression thread count for migration (json-int)
+- "decompress-threads": set decompression thread count for migration (json-int)
+
+Arguments:
+
+Example:
+
+-> { "execute": "migrate-set-parameters" , "arguments":
+      { "compress-level": 1 } }
+
+EQMP
+
+    {
+        .name       = "migrate-set-parameters",
+        .args_type  =
+            "compress-level:i?,compress-threads:i?,decompress-threads:i?",
+	.mhandler.cmd_new = qmp_marshal_input_migrate_set_parameters,
+    },
+SQMP
+query-migrate-parameters
+------------------------
+
+Query current migration parameters
+
+- "parameters": migration parameters value
+         - "compress-level" : compression level value (json-int)
+         - "compress-threads" : compression thread count value (json-int)
+         - "decompress-threads" : decompression thread count value (json-int)
+
+Arguments:
+
+Example:
+
+-> { "execute": "query-migrate-parameters" }
+<- {
+      "return": {
+         "decompress-threads", 2,
+         "compress-threads", 8,
+         "compress-level", 1
+      }
+   }
+
+EQMP
+
+    {
+        .name       = "query-migrate-parameters",
+        .args_type  = "",
+        .mhandler.cmd_new = qmp_marshal_input_query_migrate_parameters,
+    },
+
 SQMP
 query-balloon
 -------------