[Qemu-devel] [PATCH 3/4] runstate: introduce suspended state

[Luiz Capitulino <lcapitulino@redhat.com>]

QEMU enters in this state when the guest suspends to ram (S3).

This is important so that HMP users and QMP clients can know that
the guest is suspended. QMP also has an event for this, but events
are not reliable and are limited (ie. a client can connect to QEMU
after the event has been emitted).

Having a different state for S3 brings a new issue, though. Every
device that doesn't run when the VM is stopped but wants to run
when the VM is suspended has to check for RUN_STATE_SUSPENDED
explicitly. This is the case for the keyboard and mouse devices,
for example.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
 input.c          |    4 ++--
 qapi-schema.json |    4 +++-
 qmp.c            |    2 ++
 vl.c             |    7 +++++++
 4 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/input.c b/input.c
index 6b5c2c3..6968b31 100644
--- a/input.c
+++ b/input.c
@@ -130,7 +130,7 @@ void qemu_remove_led_event_handler(QEMUPutLEDEntry *entry)
 
 void kbd_put_keycode(int keycode)
 {
-    if (!runstate_is_running()) {
+    if (!runstate_is_running() && !runstate_check(RUN_STATE_SUSPENDED)) {
         return;
     }
     if (qemu_put_kbd_event) {
@@ -154,7 +154,7 @@ void kbd_mouse_event(int dx, int dy, int dz, int buttons_state)
     void *mouse_event_opaque;
     int width, height;
 
-    if (!runstate_is_running()) {
+    if (!runstate_is_running() && !runstate_check(RUN_STATE_SUSPENDED)) {
         return;
     }
     if (QTAILQ_EMPTY(&mouse_handlers)) {
diff --git a/qapi-schema.json b/qapi-schema.json
index 0166ec2..4dbcb26 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -116,12 +116,14 @@
 #
 # @shutdown: guest is shut down (and -no-shutdown is in use)
 #
+# @suspended: guest is suspended (ACPI S3)
+#
 # @watchdog: the watchdog action is configured to pause and has been triggered
 ##
 { 'enum': 'RunState',
   'data': [ 'debug', 'inmigrate', 'internal-error', 'io-error', 'paused',
             'postmigrate', 'prelaunch', 'finish-migrate', 'restore-vm',
-            'running', 'save-vm', 'shutdown', 'watchdog' ] }
+            'running', 'save-vm', 'shutdown', 'suspended', 'watchdog' ] }
 
 ##
 # @StatusInfo:
diff --git a/qmp.c b/qmp.c
index a182b51..fee9fb2 100644
--- a/qmp.c
+++ b/qmp.c
@@ -151,6 +151,8 @@ void qmp_cont(Error **errp)
                runstate_check(RUN_STATE_SHUTDOWN)) {
         error_set(errp, QERR_RESET_REQUIRED);
         return;
+    } else if (runstate_check(RUN_STATE_SUSPENDED)) {
+        return;
     }
 
     bdrv_iterate(iostatus_bdrv_it, NULL);
diff --git a/vl.c b/vl.c
index ae91a8a..a7afc79 100644
--- a/vl.c
+++ b/vl.c
@@ -366,6 +366,11 @@ static const RunStateTransition runstate_transitions_def[] = {
     { RUN_STATE_SHUTDOWN, RUN_STATE_PAUSED },
     { RUN_STATE_SHUTDOWN, RUN_STATE_FINISH_MIGRATE },
 
+    { 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_WATCHDOG, RUN_STATE_RUNNING },
     { RUN_STATE_WATCHDOG, RUN_STATE_FINISH_MIGRATE },
 
@@ -1420,6 +1425,7 @@ static void qemu_system_suspend(void)
 {
     pause_all_vcpus();
     notifier_list_notify(&suspend_notifiers, NULL);
+    runstate_set(RUN_STATE_SUSPENDED);
     monitor_protocol_event(QEVENT_SUSPEND, NULL);
     is_suspended = true;
 }
@@ -1447,6 +1453,7 @@ void qemu_system_wakeup_request(WakeupReason reason)
     if (!(wakeup_reason_mask & (1 << reason))) {
         return;
     }
+    runstate_set(RUN_STATE_RUNNING);
     monitor_protocol_event(QEVENT_WAKEUP, NULL);
     notifier_list_notify(&wakeup_notifiers, &reason);
     reset_requested = 1;
-- 
1.7.9.2.384.g4a92a