[PATCH v2] migration: Drop redundant query-migrate result @blocked

[Markus Armbruster <armbru@redhat.com>]

Result @blocked is true when and only when result @blocked-reasons is
present.  It's always non-empty when present.  @blocked is redundant.
It was introduced in commit 3af8554bd0 "migration: Add blocker
information", and has not been released.  This gives us a chance to
fix the interface with minimal fuss: drop @blocked.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
---
This is alternative to "[PATCH] migration: Deprecate redundant
query-migrate result @blocked".

 qapi/migration.json   |  7 +++----
 migration/migration.c | 29 +++++++++++++----------------
 monitor/hmp-cmds.c    |  2 +-
 3 files changed, 17 insertions(+), 21 deletions(-)

diff --git a/qapi/migration.json b/qapi/migration.json
index 9bf0bc4d25..7a5bdf9a0d 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -224,9 +224,9 @@
 #        only returned if VFIO device is present, migration is supported by all
 #        VFIO devices and status is 'active' or 'completed' (since 5.2)
 #
-# @blocked: True if outgoing migration is blocked (since 6.0)
-#
-# @blocked-reasons: A list of reasons an outgoing migration is blocked (since 6.0)
+# @blocked-reasons: A list of reasons an outgoing migration is blocked.
+#                   Present and non-empty when migration is blocked.
+#                   (since 6.0)
 #
 # Since: 0.14
 ##
@@ -241,7 +241,6 @@
            '*setup-time': 'int',
            '*cpu-throttle-percentage': 'int',
            '*error-desc': 'str',
-           'blocked': 'bool',
            '*blocked-reasons': ['str'],
            '*postcopy-blocktime' : 'uint32',
            '*postcopy-vcpu-blocktime': ['uint32'],
diff --git a/migration/migration.c b/migration/migration.c
index 8ca034136b..fdadee290e 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1073,27 +1073,24 @@ static void populate_vfio_info(MigrationInfo *info)
 static void fill_source_migration_info(MigrationInfo *info)
 {
     MigrationState *s = migrate_get_current();
+    GSList *cur_blocker = migration_blockers;
 
-    info->blocked = migration_is_blocked(NULL);
-    info->has_blocked_reasons = info->blocked;
     info->blocked_reasons = NULL;
-    if (info->blocked) {
-        GSList *cur_blocker = migration_blockers;
 
-        /*
-         * There are two types of reasons a migration might be blocked;
-         * a) devices marked in VMState as non-migratable, and
-         * b) Explicit migration blockers
-         * We need to add both of them here.
-         */
-        qemu_savevm_non_migratable_list(&info->blocked_reasons);
+    /*
+     * There are two types of reasons a migration might be blocked;
+     * a) devices marked in VMState as non-migratable, and
+     * b) Explicit migration blockers
+     * We need to add both of them here.
+     */
+    qemu_savevm_non_migratable_list(&info->blocked_reasons);
 
-        while (cur_blocker) {
-            QAPI_LIST_PREPEND(info->blocked_reasons,
-                              g_strdup(error_get_pretty(cur_blocker->data)));
-            cur_blocker = g_slist_next(cur_blocker);
-        }
+    while (cur_blocker) {
+        QAPI_LIST_PREPEND(info->blocked_reasons,
+                          g_strdup(error_get_pretty(cur_blocker->data)));
+        cur_blocker = g_slist_next(cur_blocker);
     }
+    info->has_blocked_reasons = info->blocked_reasons != NULL;
 
     switch (s->state) {
     case MIGRATION_STATUS_NONE:
diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
index 0ad5b77477..d9bef63373 100644
--- a/monitor/hmp-cmds.c
+++ b/monitor/hmp-cmds.c
@@ -224,7 +224,7 @@ void hmp_info_migrate(Monitor *mon, const QDict *qdict)
 
     migration_global_dump(mon);
 
-    if (info->blocked) {
+    if (info->blocked_reasons) {
         strList *reasons = info->blocked_reasons;
         monitor_printf(mon, "Outgoing migration blocked:\n");
         while (reasons) {
-- 
2.26.3