runstate: Allow user to migrate twice

It should be a matter of allowing the transition POSTMIGRATE ->
FINISH_MIGRATE, but it turns out that the VM won't do the
transition the second time because it's already stopped.

So this commit also adds vm_stop_force_state() which performs
the transition even if the VM is already stopped.

While there also allow other states to migrate.
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>

cpus.c

@@ -887,6 +887,17 @@ void vm_stop(RunState state)
     do_vm_stop(state);
 }
 
+/* does a state transition even if the VM is already stopped,
+   current state is forgotten forever */
+void vm_stop_force_state(RunState state)
+{
+    if (runstate_is_running()) {
+        vm_stop(state);
+    } else {
+        runstate_set(state);
+    }
+}
+
 static int tcg_cpu_exec(CPUState *env)
 {
     int ret;

migration.c

@@ -375,7 +375,7 @@ void migrate_fd_put_ready(void *opaque)
         int old_vm_running = runstate_is_running();
 
         DPRINTF("done iterating\n");
-        vm_stop(RUN_STATE_FINISH_MIGRATE);
+        vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
 
         if ((qemu_savevm_state_complete(s->mon, s->file)) < 0) {
             if (old_vm_running) {

sysemu.h

@@ -35,6 +35,7 @@ void vm_state_notify(int running, RunState state);
 
 void vm_start(void);
 void vm_stop(RunState state);
+void vm_stop_force_state(RunState state);
 
 void qemu_system_reset_request(void);
 void qemu_system_shutdown_request(void);

vl.c

@@ -337,17 +337,20 @@ static const RunStateTransition runstate_transitions_def[] = {
     { RUN_STATE_INMIGRATE, RUN_STATE_PRELAUNCH },
 
     { RUN_STATE_INTERNAL_ERROR, RUN_STATE_PAUSED },
+    { RUN_STATE_INTERNAL_ERROR, RUN_STATE_FINISH_MIGRATE },
 
     { RUN_STATE_IO_ERROR, RUN_STATE_RUNNING },
+    { RUN_STATE_IO_ERROR, RUN_STATE_FINISH_MIGRATE },
 
     { RUN_STATE_PAUSED, RUN_STATE_RUNNING },
-    { RUN_STATE_PAUSED, RUN_STATE_POSTMIGRATE },
+    { RUN_STATE_PAUSED, RUN_STATE_FINISH_MIGRATE },
 
     { RUN_STATE_POSTMIGRATE, RUN_STATE_RUNNING },
+    { RUN_STATE_POSTMIGRATE, RUN_STATE_FINISH_MIGRATE },
 
     { RUN_STATE_PRELAUNCH, RUN_STATE_RUNNING },
+    { RUN_STATE_PRELAUNCH, RUN_STATE_FINISH_MIGRATE },
     { RUN_STATE_PRELAUNCH, RUN_STATE_INMIGRATE },
-    { RUN_STATE_PRELAUNCH, RUN_STATE_POSTMIGRATE },
 
     { RUN_STATE_FINISH_MIGRATE, RUN_STATE_RUNNING },
     { RUN_STATE_FINISH_MIGRATE, RUN_STATE_POSTMIGRATE },
@@ -367,8 +370,10 @@ static const RunStateTransition runstate_transitions_def[] = {
     { RUN_STATE_SAVE_VM, RUN_STATE_RUNNING },
 
     { RUN_STATE_SHUTDOWN, RUN_STATE_PAUSED },
+    { RUN_STATE_SHUTDOWN, RUN_STATE_FINISH_MIGRATE },
 
     { RUN_STATE_WATCHDOG, RUN_STATE_RUNNING },
+    { RUN_STATE_WATCHDOG, RUN_STATE_FINISH_MIGRATE },
 
     { RUN_STATE_MAX, RUN_STATE_MAX },
 };