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 <jan.kiszka@siemens.com>
CC: TeLeMan <geleman@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/cpus.c b/cpus.c
index 26e5bba..975a6ce 100644
--- a/cpus.c
+++ b/cpus.c
@@ -166,29 +166,8 @@
     return true;
 }
 
-static CPUDebugExcpHandler *debug_excp_handler;
-
-CPUDebugExcpHandler *cpu_set_debug_excp_handler(CPUDebugExcpHandler *handler)
+static void cpu_handle_guest_debug(CPUState *env)
 {
-    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);
-    }
-
     gdb_set_stop_cpu(env);
     qemu_system_debug_request();
 #ifdef CONFIG_IOTHREAD
@@ -818,7 +797,7 @@
         if (cpu_can_run(env)) {
             r = kvm_cpu_exec(env);
             if (r == EXCP_DEBUG) {
-                cpu_handle_debug_exception(env);
+                cpu_handle_guest_debug(env);
             }
         }
         qemu_kvm_wait_io_event(env);
@@ -1110,7 +1089,7 @@
                 r = tcg_cpu_exec(env);
             }
             if (r == EXCP_DEBUG) {
-                cpu_handle_debug_exception(env);
+                cpu_handle_guest_debug(env);
                 break;
             }
         } else if (env->stop || env->stopped) {