[Qemu-devel] [PATCH] Rework vm_state_change notifiers

[Jan Kiszka <jan.kiszka@web.de>]

[ Now tested and found working. ]

Enhance the vm_state_change notifier API to pass also a change reason.
This allows for replacing the vm_stop_cb with it and drop related code.

Converting gdb_vm_stopped to gdb_vm_state_change also includes that this
callback will now officially only handle EXCP_DEBUG and EXCP_INTERRUPT
stop reasons. That allows to define and use new (non-zero) stop reasons
without disturbing the gdbstub.
---

 audio/audio.c |    3 ++-
 gdbstub.c     |   11 +++++------
 sysemu.h      |    6 +-----
 vl.c          |   29 ++++-------------------------
 4 files changed, 12 insertions(+), 37 deletions(-)

diff --git a/audio/audio.c b/audio/audio.c
index 762c2e3..e2635c0 100644
--- a/audio/audio.c
+++ b/audio/audio.c
@@ -1622,7 +1622,8 @@ static int audio_driver_init (AudioState *s, struct audio_driver *drv)
     }
 }
 
-static void audio_vm_change_state_handler (void *opaque, int running)
+static void audio_vm_change_state_handler (void *opaque, int running,
+                                           int reason)
 {
     AudioState *s = opaque;
     HWVoiceOut *hwo = NULL;
diff --git a/gdbstub.c b/gdbstub.c
index 99a4772..bb9b405 100644
--- a/gdbstub.c
+++ b/gdbstub.c
@@ -1867,7 +1867,7 @@ void gdb_set_stop_cpu(CPUState *env)
 }
 
 #ifndef CONFIG_USER_ONLY
-static void gdb_vm_stopped(void *opaque, int reason)
+static void gdb_vm_state_change(void *opaque, int running, int reason)
 {
     GDBState *s = gdbserver_state;
     CPUState *env = s->c_cpu;
@@ -1875,7 +1875,8 @@ static void gdb_vm_stopped(void *opaque, int reason)
     const char *type;
     int ret;
 
-    if (s->state == RS_SYSCALL)
+    if (running || (reason != EXCP_DEBUG && reason != EXCP_INTERRUPT) ||
+        s->state == RS_SYSCALL)
         return;
 
     /* disable single step if it was enable */
@@ -1904,10 +1905,8 @@ static void gdb_vm_stopped(void *opaque, int reason)
         }
 	tb_flush(env);
         ret = GDB_SIGNAL_TRAP;
-    } else if (reason == EXCP_INTERRUPT) {
-        ret = GDB_SIGNAL_INT;
     } else {
-        ret = 0;
+        ret = GDB_SIGNAL_INT;
     }
     snprintf(buf, sizeof(buf), "T%02xthread:%02x;", ret, env->cpu_index+1);
     put_packet(s, buf);
@@ -2300,7 +2299,7 @@ int gdbserver_start(const char *port)
     gdbserver_state = s;
     qemu_chr_add_handlers(chr, gdb_chr_can_receive, gdb_chr_receive,
                           gdb_chr_event, NULL);
-    qemu_add_vm_stop_handler(gdb_vm_stopped, NULL);
+    qemu_add_vm_change_state_handler(gdb_vm_state_change, NULL);
     return 0;
 }
 #endif
diff --git a/sysemu.h b/sysemu.h
index 56eb9b3..abd8e81 100644
--- a/sysemu.h
+++ b/sysemu.h
@@ -12,16 +12,12 @@ extern uint8_t qemu_uuid[];
 #define UUID_FMT "%02hhx%02hhx%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx"
 
 typedef struct vm_change_state_entry VMChangeStateEntry;
-typedef void VMChangeStateHandler(void *opaque, int running);
-typedef void VMStopHandler(void *opaque, int reason);
+typedef void VMChangeStateHandler(void *opaque, int running, int reason);
 
 VMChangeStateEntry *qemu_add_vm_change_state_handler(VMChangeStateHandler *cb,
                                                      void *opaque);
 void qemu_del_vm_change_state_handler(VMChangeStateEntry *e);
 
-int qemu_add_vm_stop_handler(VMStopHandler *cb, void *opaque);
-void qemu_del_vm_stop_handler(VMStopHandler *cb, void *opaque);
-
 void vm_start(void);
 void vm_stop(int reason);
 
diff --git a/vl.c b/vl.c
index 34ddc07..77f7234 100644
--- a/vl.c
+++ b/vl.c
@@ -3420,37 +3420,21 @@ void qemu_del_vm_change_state_handler(VMChangeStateEntry *e)
     qemu_free (e);
 }
 
-static void vm_state_notify(int running)
+static void vm_state_notify(int running, int reason)
 {
     VMChangeStateEntry *e;
 
     for (e = vm_change_state_head.lh_first; e; e = e->entries.le_next) {
-        e->cb(e->opaque, running);
+        e->cb(e->opaque, running, reason);
     }
 }
 
-/* XXX: support several handlers */
-static VMStopHandler *vm_stop_cb;
-static void *vm_stop_opaque;
-
-int qemu_add_vm_stop_handler(VMStopHandler *cb, void *opaque)
-{
-    vm_stop_cb = cb;
-    vm_stop_opaque = opaque;
-    return 0;
-}
-
-void qemu_del_vm_stop_handler(VMStopHandler *cb, void *opaque)
-{
-    vm_stop_cb = NULL;
-}
-
 void vm_start(void)
 {
     if (!vm_running) {
         cpu_enable_ticks();
         vm_running = 1;
-        vm_state_notify(1);
+        vm_state_notify(1, 0);
         qemu_rearm_alarm_timer(alarm_timer);
     }
 }
@@ -3460,12 +3444,7 @@ void vm_stop(int reason)
     if (vm_running) {
         cpu_disable_ticks();
         vm_running = 0;
-        if (reason != 0) {
-            if (vm_stop_cb) {
-                vm_stop_cb(vm_stop_opaque, reason);
-            }
-        }
-        vm_state_notify(0);
+        vm_state_notify(0, reason);
     }
 }