[Qemu-devel] [PATCH] Monitor: Return before exiting with 'quit'

[Qemu-devel] [PATCH] Monitor: Return before exiting with 'quit'

[Luiz Capitulino]

The 'quit' Monitor command (implemented by do_quit()) calls
exit() directly, this is problematic under QMP because QEMU
exits before having a chance to send the ok response.

Clients don't know if QEMU exited because of a problem or
because the 'quit' command has been executed.

This commit fixes that by moving the exit() call to the main
loop, so that do_quit() requests the system to quit, instead
of calling exit() directly.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
 monitor.c |    2 +-
 sysemu.h  |    2 ++
 vl.c      |   18 ++++++++++++++++++
 3 files changed, 21 insertions(+), 1 deletions(-)

diff --git a/monitor.c b/monitor.c
index 91d7da5..4c6275e 100644
--- a/monitor.c
+++ b/monitor.c
@@ -1017,7 +1017,7 @@ static void do_info_cpu_stats(Monitor *mon)
  */
 static int do_quit(Monitor *mon, const QDict *qdict, QObject **ret_data)
 {
-    exit(0);
+    qemu_system_exit_request();
     return 0;
 }
 
diff --git a/sysemu.h b/sysemu.h
index d0effa0..fa921df 100644
--- a/sysemu.h
+++ b/sysemu.h
@@ -45,9 +45,11 @@ void cpu_disable_ticks(void);
 void qemu_system_reset_request(void);
 void qemu_system_shutdown_request(void);
 void qemu_system_powerdown_request(void);
+void qemu_system_exit_request(void);
 int qemu_shutdown_requested(void);
 int qemu_reset_requested(void);
 int qemu_powerdown_requested(void);
+int qemu_exit_requested(void);
 extern qemu_irq qemu_system_powerdown;
 void qemu_system_reset(void);
 
diff --git a/vl.c b/vl.c
index e645006..44304b2 100644
--- a/vl.c
+++ b/vl.c
@@ -1780,6 +1780,7 @@ static int shutdown_requested;
 static int powerdown_requested;
 int debug_requested;
 static int vmstop_requested;
+static int exit_requested;
 
 int qemu_shutdown_requested(void)
 {
@@ -1802,6 +1803,12 @@ int qemu_powerdown_requested(void)
     return r;
 }
 
+int qemu_exit_requested(void)
+{
+    /* just return it, we'll exit() anyway */
+    return exit_requested;
+}
+
 static int qemu_debug_requested(void)
 {
     int r = debug_requested;
@@ -1872,6 +1879,12 @@ void qemu_system_powerdown_request(void)
     qemu_notify_event();
 }
 
+void qemu_system_exit_request(void)
+{
+    exit_requested = 1;
+    qemu_notify_event();
+}
+
 #ifdef _WIN32
 static void host_main_loop_wait(int *timeout)
 {
@@ -2008,6 +2021,8 @@ static int vm_can_run(void)
         return 0;
     if (debug_requested)
         return 0;
+    if (exit_requested)
+        return 0;
     return 1;
 }
 
@@ -2063,6 +2078,9 @@ static void main_loop(void)
         if ((r = qemu_vmstop_requested())) {
             vm_stop(r);
         }
+        if (qemu_exit_requested()) {
+            exit(0);
+        }
     }
     pause_all_vcpus();
 }
-- 
1.7.0.4.297.g6555b1

Re: [Qemu-devel] [PATCH] Monitor: Return before exiting with 'quit'

[Markus Armbruster]

Luiz Capitulino <lcapitulino@redhat.com> writes:

> The 'quit' Monitor command (implemented by do_quit()) calls
> exit() directly, this is problematic under QMP because QEMU
> exits before having a chance to send the ok response.
>
> Clients don't know if QEMU exited because of a problem or
> because the 'quit' command has been executed.

Yes, that needs fixing.

> This commit fixes that by moving the exit() call to the main
> loop, so that do_quit() requests the system to quit, instead
> of calling exit() directly.

Matches how system_reset and system_powerdown work.  Looks good to me.