migration: migration_stop_vm() helper

Provide a helper for non-COLO use case of migration to stop a VM.  This
prepares for adding some downtime relevant tracepoints to migration, where
they may or may not apply to COLO.

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231030163346.765724-5-peterx@redhat.com>

migration/migration.c

@@ -149,6 +149,11 @@ static gint page_request_addr_cmp(gconstpointer ap, gconstpointer bp)
     return (a > b) - (a < b);
 }
 
+int migration_stop_vm(RunState state)
+{
+    return vm_stop_force_state(state);
+}
+
 void migration_object_init(void)
 {
     /* This can only be called once. */
@@ -2169,7 +2174,7 @@ static int postcopy_start(MigrationState *ms, Error **errp)
 
     qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER, NULL);
     global_state_store();
-    ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
+    ret = migration_stop_vm(RUN_STATE_FINISH_MIGRATE);
     if (ret < 0) {
         goto fail;
     }
@@ -2371,7 +2376,7 @@ static int migration_completion_precopy(MigrationState *s,
     s->vm_old_state = runstate_get();
     global_state_store();
 
-    ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
+    ret = migration_stop_vm(RUN_STATE_FINISH_MIGRATE);
     trace_migration_completion_vm_stop(ret);
     if (ret < 0) {
         goto out_unlock;
@@ -3222,7 +3227,7 @@ static void *bg_migration_thread(void *opaque)
 
     global_state_store();
     /* Forcibly stop VM before saving state of vCPUs and devices */
-    if (vm_stop_force_state(RUN_STATE_PAUSED)) {
+    if (migration_stop_vm(RUN_STATE_PAUSED)) {
         goto fail;
     }
     /*

migration/migration.h

@@ -544,4 +544,6 @@ void migration_rp_wait(MigrationState *s);
  */
 void migration_rp_kick(MigrationState *s);
 
+int migration_stop_vm(RunState state);
+
 #endif