Improve vm_stop reason declarations

Define and use dedicated constants for vm_stop reasons, they actually
have nothing to do with the EXCP_* defines used so far. At this chance,
specify more detailed reasons so that VM state change handlers can
evaluate them.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/gdbstub.c b/gdbstub.c
index d6556c9..ed51a8a 100644
--- a/gdbstub.c
+++ b/gdbstub.c
@@ -2194,14 +2194,14 @@
     const char *type;
     int ret;
 
-    if (running || (reason != EXCP_DEBUG && reason != EXCP_INTERRUPT) ||
-        s->state == RS_INACTIVE || s->state == RS_SYSCALL)
+    if (running || (reason != VMSTOP_DEBUG && reason != VMSTOP_USER) ||
+        s->state == RS_INACTIVE || s->state == RS_SYSCALL) {
         return;
-
+    }
     /* disable single step if it was enable */
     cpu_single_step(env, 0);
 
-    if (reason == EXCP_DEBUG) {
+    if (reason == VMSTOP_DEBUG) {
         if (env->watchpoint_hit) {
             switch (env->watchpoint_hit->flags & BP_MEM_ACCESS) {
             case BP_MEM_READ:
@@ -2252,7 +2252,7 @@
     gdb_current_syscall_cb = cb;
     s->state = RS_SYSCALL;
 #ifndef CONFIG_USER_ONLY
-    vm_stop(EXCP_DEBUG);
+    vm_stop(VMSTOP_DEBUG);
 #endif
     s->state = RS_IDLE;
     va_start(va, fmt);
@@ -2326,7 +2326,7 @@
     if (vm_running) {
         /* when the CPU is running, we cannot do anything except stop
            it when receiving a char */
-        vm_stop(EXCP_INTERRUPT);
+        vm_stop(VMSTOP_USER);
     } else
 #endif
     {
@@ -2588,7 +2588,7 @@
 {
     switch (event) {
     case CHR_EVENT_OPENED:
-        vm_stop(EXCP_INTERRUPT);
+        vm_stop(VMSTOP_USER);
         gdb_has_xml = 0;
         break;
     default:
@@ -2628,8 +2628,9 @@
 #ifndef _WIN32
 static void gdb_sigterm_handler(int signal)
 {
-    if (vm_running)
-        vm_stop(EXCP_INTERRUPT);
+    if (vm_running) {
+        vm_stop(VMSTOP_USER);
+    }
 }
 #endif