x86: Unbreak TCG support for hardware breakpoints

Commit 83f338f73e broke x86 hardware breakpoint emulation by moving the
debug exception handling out of cpu_exec. Fix this by moving all TCG
related bits back, only leaving the generic guest debugging parts in
cpus.c.

Signed-off-by: Jan Kiszka <[email protected]>
CC: TeLeMan <[email protected]>
Signed-off-by: Marcelo Tosatti <[email protected]>
diff --git a/cpu-exec.c b/cpu-exec.c
index 34eaedc..5cc9379 100644
--- a/cpu-exec.c
+++ b/cpu-exec.c
@@ -196,6 +196,30 @@
     return tb;
 }
 
+static CPUDebugExcpHandler *debug_excp_handler;
+
+CPUDebugExcpHandler *cpu_set_debug_excp_handler(CPUDebugExcpHandler *handler)
+{
+    CPUDebugExcpHandler *old_handler = debug_excp_handler;
+
+    debug_excp_handler = handler;
+    return old_handler;
+}
+
+static void cpu_handle_debug_exception(CPUState *env)
+{
+    CPUWatchpoint *wp;
+
+    if (!env->watchpoint_hit) {
+        QTAILQ_FOREACH(wp, &env->watchpoints, entry) {
+            wp->flags &= ~BP_WATCHPOINT_HIT;
+        }
+    }
+    if (debug_excp_handler) {
+        debug_excp_handler(env);
+    }
+}
+
 /* main execution loop */
 
 volatile sig_atomic_t exit_request;
@@ -269,6 +293,9 @@
                 if (env->exception_index >= EXCP_INTERRUPT) {
                     /* exit request from the cpu execution loop */
                     ret = env->exception_index;
+                    if (ret == EXCP_DEBUG) {
+                        cpu_handle_debug_exception(env);
+                    }
                     break;
                 } else {
 #if defined(CONFIG_USER_ONLY)