migration: Convert 'status' of MigrationInfo to use an enum type

The original 'status' is an open-coded 'str' type, convert it to use an
enum type.
This conversion is backwards compatible, better documented and
more convenient for future extensibility.

In addition, Fix a typo for qapi-schema.json (just remove the typo) :
s/'completed'. 'comppleted' (since 1.2)/'completed' (since 1.2)
Signed-off-by: Nzhanghailiang <zhang.zhanghailiang@huawei.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>

hmp.c

@@ -162,7 +162,8 @@ void hmp_info_migrate(Monitor *mon, const QDict *qdict)
     }
 
     if (info->has_status) {
-        monitor_printf(mon, "Migration status: %s\n", info->status);
+        monitor_printf(mon, "Migration status: %s\n",
+                       MigrationStatus_lookup[info->status]);
         monitor_printf(mon, "total time: %" PRIu64 " milliseconds\n",
                        info->total_time);
         if (info->has_expected_downtime) {
@@ -1354,8 +1355,8 @@ static void hmp_migrate_status_cb(void *opaque)
     MigrationInfo *info;
 
     info = qmp_query_migrate(NULL);
-    if (!info->has_status || strcmp(info->status, "active") == 0 ||
-        strcmp(info->status, "setup") == 0) {
+    if (!info->has_status || info->status == MIGRATION_STATUS_ACTIVE ||
+        info->status == MIGRATION_STATUS_SETUP) {
         if (info->has_disk) {
             int progress;
 

migration/migration.c

@@ -26,16 +26,6 @@
 #include "qmp-commands.h"
 #include "trace.h"
 
-enum {
-    MIGRATION_STATUS_FAILED = -1,
-    MIGRATION_STATUS_NONE,
-    MIGRATION_STATUS_SETUP,
-    MIGRATION_STATUS_CANCELLING,
-    MIGRATION_STATUS_CANCELLED,
-    MIGRATION_STATUS_ACTIVE,
-    MIGRATION_STATUS_COMPLETED,
-};
-
 #define MAX_THROTTLE  (32 << 20)      /* Migration speed throttling */
 
 /* Amount of time to allocate to each "chunk" of bandwidth-throttled
@@ -205,13 +195,13 @@ MigrationInfo *qmp_query_migrate(Error **errp)
         break;
     case MIGRATION_STATUS_SETUP:
         info->has_status = true;
-        info->status = g_strdup("setup");
+        info->status = MIGRATION_STATUS_SETUP;
         info->has_total_time = false;
         break;
     case MIGRATION_STATUS_ACTIVE:
     case MIGRATION_STATUS_CANCELLING:
         info->has_status = true;
-        info->status = g_strdup("active");
+        info->status = MIGRATION_STATUS_ACTIVE;
         info->has_total_time = true;
         info->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME)
             - s->total_time;
@@ -247,7 +237,7 @@ MigrationInfo *qmp_query_migrate(Error **errp)
         get_xbzrle_cache_stats(info);
 
         info->has_status = true;
-        info->status = g_strdup("completed");
+        info->status = MIGRATION_STATUS_COMPLETED;
         info->has_total_time = true;
         info->total_time = s->total_time;
         info->has_downtime = true;
@@ -269,11 +259,11 @@ MigrationInfo *qmp_query_migrate(Error **errp)
         break;
     case MIGRATION_STATUS_FAILED:
         info->has_status = true;
-        info->status = g_strdup("failed");
+        info->status = MIGRATION_STATUS_FAILED;
         break;
     case MIGRATION_STATUS_CANCELLED:
         info->has_status = true;
-        info->status = g_strdup("cancelled");
+        info->status = MIGRATION_STATUS_CANCELLED;
         break;
     }
 

qapi-schema.json

@@ -410,19 +410,43 @@
            'cache-miss': 'int', 'cache-miss-rate': 'number',
            'overflow': 'int' } }
 
+# @MigrationStatus:
+#
+# An enumeration of migration status.
+#
+# @none: no migration has ever happened.
+#
+# @setup: migration process has been initiated.
+#
+# @cancelling: in the process of cancelling migration.
+#
+# @cancelled: cancelling migration is finished.
+#
+# @active: in the process of doing migration.
+#
+# @completed: migration is finished.
+#
+# @failed: some error occurred during migration process.
+#
+# Since: 2.3
+#
+##
+{ 'enum': 'MigrationStatus',
+  'data': [ 'none', 'setup', 'cancelling', 'cancelled',
+            'active', 'completed', 'failed' ] }
+
 ##
 # @MigrationInfo
 #
 # Information about current migration process.
 #
-# @status: #optional string describing the current migration status.
-#          As of 0.14.0 this can be 'setup', 'active', 'completed', 'failed' or
-#          'cancelled'. If this field is not returned, no migration process
+# @status: #optional @MigrationStatus describing the current migration status.
+#          If this field is not returned, no migration process
 #          has been initiated
 #
 # @ram: #optional @MigrationStats containing detailed migration
 #       status, only returned if status is 'active' or
-#       'completed'. 'comppleted' (since 1.2)
+#       'completed'(since 1.2)
 #
 # @disk: #optional @MigrationStats containing detailed disk migration
 #        status, only returned if status is 'active' and it is a block
@@ -453,7 +477,7 @@
 # Since: 0.14.0
 ##
 { 'type': 'MigrationInfo',
-  'data': {'*status': 'str', '*ram': 'MigrationStats',
+  'data': {'*status': 'MigrationStatus', '*ram': 'MigrationStats',
            '*disk': 'MigrationStats',
            '*xbzrle-cache': 'XBZRLECacheStats',
            '*total-time': 'int',