cpu-exec: reset exception_index correctly

Exception index is reset at every entry at every entry into cpu_exec()
function. This may cause missing the exceptions while replaying them.
This patch moves exception_index reset to the locations where they are
processed.

Signed-off-by: Pavel Dovgalyuk <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

cpu-exec.c

@@ -358,7 +358,6 @@ int cpu_exec(CPUArchState *env)
     }
 
     cc->cpu_exec_enter(cpu);
-    cpu->exception_index = -1;
 
     /* Calculate difference between guest clock and host clock.
      * This delay includes the delay of the last cycle, so
@@ -378,6 +377,7 @@ int cpu_exec(CPUArchState *env)
                     if (ret == EXCP_DEBUG) {
                         cpu_handle_debug_exception(env);
                     }
+                    cpu->exception_index = -1;
                     break;
                 } else {
 #if defined(CONFIG_USER_ONLY)
@@ -388,6 +388,7 @@ int cpu_exec(CPUArchState *env)
                     cc->do_interrupt(cpu);
 #endif
                     ret = cpu->exception_index;
+                    cpu->exception_index = -1;
                     break;
 #else
                     cc->do_interrupt(cpu);

cpus.c

@@ -934,6 +934,7 @@ static void *qemu_kvm_cpu_thread_fn(void *arg)
     qemu_mutex_lock(&qemu_global_mutex);
     qemu_thread_get_self(cpu->thread);
     cpu->thread_id = qemu_get_thread_id();
+    cpu->exception_index = -1;
     current_cpu = cpu;
 
     r = kvm_init_vcpu(cpu);
@@ -974,6 +975,7 @@ static void *qemu_dummy_cpu_thread_fn(void *arg)
     qemu_mutex_lock_iothread();
     qemu_thread_get_self(cpu->thread);
     cpu->thread_id = qemu_get_thread_id();
+    cpu->exception_index = -1;
 
     sigemptyset(&waitset);
     sigaddset(&waitset, SIG_IPI);
@@ -1016,6 +1018,7 @@ static void *qemu_tcg_cpu_thread_fn(void *arg)
     CPU_FOREACH(cpu) {
         cpu->thread_id = qemu_get_thread_id();
         cpu->created = true;
+        cpu->exception_index = -1;
     }
     qemu_cond_signal(&qemu_cpu_cond);