vl: change QEMU state machine for system reset

This patch implements proposal from Paolo to handle system reset when
the guest is not running.

"After a reset, main_loop_should_exit should actually transition
to VM_STATE_PRELAUNCH (*not* RUN_STATE_PAUSED) for *all* states except
RUN_STATE_INMIGRATE, RUN_STATE_SAVE_VM (which I think cannot happen
there) and (of course) RUN_STATE_RUNNING."

Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1455369986-20353-1-git-send-email-den@openvz.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/vl.c b/vl.c
index 175ebccb813b2570a144c855620eafe055e5ab98..76dfb54bcf5c99e3b53f7dfd17b747e8da8ddf89 100644 (file)
--- a/vl.c
+++ b/vl.c
@@ -579,6 +579,7 @@ static const RunStateTransition runstate_transitions_def[] = {
     /*     from      ->     to      */
     { RUN_STATE_DEBUG, RUN_STATE_RUNNING },
     { RUN_STATE_DEBUG, RUN_STATE_FINISH_MIGRATE },
+    { RUN_STATE_DEBUG, RUN_STATE_PRELAUNCH },
 
     { RUN_STATE_INMIGRATE, RUN_STATE_INTERNAL_ERROR },
     { RUN_STATE_INMIGRATE, RUN_STATE_IO_ERROR },
@@ -592,15 +593,19 @@ static const RunStateTransition runstate_transitions_def[] = {
 
     { RUN_STATE_INTERNAL_ERROR, RUN_STATE_PAUSED },
     { RUN_STATE_INTERNAL_ERROR, RUN_STATE_FINISH_MIGRATE },
+    { RUN_STATE_INTERNAL_ERROR, RUN_STATE_PRELAUNCH },
 
     { RUN_STATE_IO_ERROR, RUN_STATE_RUNNING },
     { RUN_STATE_IO_ERROR, RUN_STATE_FINISH_MIGRATE },
+    { RUN_STATE_IO_ERROR, RUN_STATE_PRELAUNCH },
 
     { RUN_STATE_PAUSED, RUN_STATE_RUNNING },
     { RUN_STATE_PAUSED, RUN_STATE_FINISH_MIGRATE },
+    { RUN_STATE_PAUSED, RUN_STATE_PRELAUNCH },
 
     { RUN_STATE_POSTMIGRATE, RUN_STATE_RUNNING },
     { RUN_STATE_POSTMIGRATE, RUN_STATE_FINISH_MIGRATE },
+    { RUN_STATE_POSTMIGRATE, RUN_STATE_PRELAUNCH },
 
     { RUN_STATE_PRELAUNCH, RUN_STATE_RUNNING },
     { RUN_STATE_PRELAUNCH, RUN_STATE_FINISH_MIGRATE },
@@ -608,8 +613,10 @@ static const RunStateTransition runstate_transitions_def[] = {
 
     { RUN_STATE_FINISH_MIGRATE, RUN_STATE_RUNNING },
     { RUN_STATE_FINISH_MIGRATE, RUN_STATE_POSTMIGRATE },
+    { RUN_STATE_FINISH_MIGRATE, RUN_STATE_PRELAUNCH },
 
     { RUN_STATE_RESTORE_VM, RUN_STATE_RUNNING },
+    { RUN_STATE_RESTORE_VM, RUN_STATE_PRELAUNCH },
 
     { RUN_STATE_RUNNING, RUN_STATE_DEBUG },
     { RUN_STATE_RUNNING, RUN_STATE_INTERNAL_ERROR },
@@ -626,17 +633,21 @@ static const RunStateTransition runstate_transitions_def[] = {
 
     { RUN_STATE_SHUTDOWN, RUN_STATE_PAUSED },
     { RUN_STATE_SHUTDOWN, RUN_STATE_FINISH_MIGRATE },
+    { RUN_STATE_SHUTDOWN, RUN_STATE_PRELAUNCH },
 
     { RUN_STATE_DEBUG, RUN_STATE_SUSPENDED },
     { RUN_STATE_RUNNING, RUN_STATE_SUSPENDED },
     { RUN_STATE_SUSPENDED, RUN_STATE_RUNNING },
     { RUN_STATE_SUSPENDED, RUN_STATE_FINISH_MIGRATE },
+    { RUN_STATE_SUSPENDED, RUN_STATE_PRELAUNCH },
 
     { RUN_STATE_WATCHDOG, RUN_STATE_RUNNING },
     { RUN_STATE_WATCHDOG, RUN_STATE_FINISH_MIGRATE },
+    { RUN_STATE_WATCHDOG, RUN_STATE_PRELAUNCH },
 
     { RUN_STATE_GUEST_PANICKED, RUN_STATE_RUNNING },
     { RUN_STATE_GUEST_PANICKED, RUN_STATE_FINISH_MIGRATE },
+    { RUN_STATE_GUEST_PANICKED, RUN_STATE_PRELAUNCH },
 
     { RUN_STATE__MAX, RUN_STATE__MAX },
 };
@@ -1881,8 +1892,9 @@ static bool main_loop_should_exit(void)
         cpu_synchronize_all_states();
         qemu_system_reset(VMRESET_REPORT);
         resume_all_vcpus();
-        if (runstate_needs_reset()) {
-            runstate_set(RUN_STATE_PAUSED);
+        if (!runstate_check(RUN_STATE_RUNNING) &&
+                !runstate_check(RUN_STATE_INMIGRATE)) {
+            runstate_set(RUN_STATE_PRELAUNCH);
         }
     }
     if (qemu_wakeup_requested()) {