QMP: query-status: Introduce 'status' key

This new key reports the current VM status to clients. Please, check
the documentation being added in this commit for more details.
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>

monitor.c

@@ -2636,8 +2636,7 @@ static void do_info_status_print(Monitor *mon, const QObject *data)
 
 static void do_info_status(Monitor *mon, QObject **ret_data)
 {
-    *ret_data = qobject_from_jsonf("{ 'running': %i, 'singlestep': %i }",
-                                    runstate_is_running(), singlestep);
+    *ret_data = qobject_from_jsonf("{ 'running': %i, 'singlestep': %i, 'status': %s }", runstate_is_running(), singlestep, runstate_as_string());
 }
 
 static qemu_acl *find_acl(Monitor *mon, const char *name)

qmp-commands.hx

@@ -1573,11 +1573,28 @@ Return a json-object with the following information:
 - "running": true if the VM is running, or false if it is paused (json-bool)
 - "singlestep": true if the VM is in single step mode,
                 false otherwise (json-bool)
+- "status": one of the following values (json-string)
+    "debug" - QEMU is running on a debugger
+    "inmigrate" - guest is paused waiting for an incoming migration
+    "internal-error" - An internal error that prevents further guest
+    execution has occurred
+    "io-error" - the last IOP has failed and the device is configured
+    to pause on I/O errors
+    "paused" - guest has been paused via the 'stop' command
+    "postmigrate" - guest is paused following a successful 'migrate'
+    "prelaunch" - QEMU was started with -S and guest has not started
+    "finish-migrate" - guest is paused to finish the migration process
+    "restore-vm" - guest is paused to restore VM state
+    "running" - guest is actively running
+    "save-vm" - guest is paused to save the VM state
+    "shutdown" - guest is shut down (and -no-shutdown is in use)
+    "watchdog" - the watchdog action is configured to pause and
+     has been triggered
 
 Example:
 
 -> { "execute": "query-status" }
-<- { "return": { "running": true, "singlestep": false } }
+<- { "return": { "running": true, "singlestep": false, "status": "running" } }
 
 EQMP
 

sysemu.h

@@ -39,6 +39,7 @@ void runstate_init(void);
 bool runstate_check(RunState state);
 void runstate_set(RunState new_state);
 int runstate_is_running(void);
+const char *runstate_as_string(void);
 typedef struct vm_change_state_entry VMChangeStateEntry;
 typedef void VMChangeStateHandler(void *opaque, int running, RunState state);
 

vl.c

@@ -378,6 +378,22 @@ static const RunStateTransition runstate_transitions_def[] = {
 
 static bool runstate_valid_transitions[RSTATE_MAX][RSTATE_MAX];
 
+static const char *const runstate_name_tbl[RSTATE_MAX] = {
+    [RSTATE_DEBUG] = "debug",
+    [RSTATE_IN_MIGRATE] = "incoming-migration",
+    [RSTATE_PANICKED] = "internal-error",
+    [RSTATE_IO_ERROR] = "io-error",
+    [RSTATE_PAUSED] = "paused",
+    [RSTATE_POST_MIGRATE] = "post-migrate",
+    [RSTATE_PRE_LAUNCH] = "prelaunch",
+    [RSTATE_PRE_MIGRATE] = "finish-migrate",
+    [RSTATE_RESTORE] = "restore-vm",
+    [RSTATE_RUNNING] = "running",
+    [RSTATE_SAVEVM] = "save-vm",
+    [RSTATE_SHUTDOWN] = "shutdown",
+    [RSTATE_WATCHDOG] = "watchdog",
+};
+
 bool runstate_check(RunState state)
 {
     return current_run_state == state;
@@ -406,6 +422,13 @@ void runstate_set(RunState new_state)
     current_run_state = new_state;
 }
 
+const char *runstate_as_string(void)
+{
+    assert(current_run_state > RSTATE_NO_STATE &&
+           current_run_state < RSTATE_MAX);
+    return runstate_name_tbl[current_run_state];
+}
+
 int runstate_is_running(void)
 {
     return runstate_check(RSTATE_RUNNING);