target/xtensa: hold BQL for interrupt processing

Make sure we have the BQL held when processing interrupts.
Reported-by: NThomas Huth <thuth@redhat.com>
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Acked-by: NMax Filippov <jcmvbkbc@gmail.com>

target/xtensa/helper.c

@@ -217,6 +217,7 @@ static void handle_interrupt(CPUXtensaState *env)
     }
 }
 
+/* Called from cpu_handle_interrupt with BQL held */
 void xtensa_cpu_do_interrupt(CPUState *cs)
 {
     XtensaCPU *cpu = XTENSA_CPU(cs);

target/xtensa/op_helper.c

@@ -26,6 +26,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu/main-loop.h"
 #include "cpu.h"
 #include "exec/helper-proto.h"
 #include "qemu/host-utils.h"
@@ -381,7 +382,11 @@ void HELPER(waiti)(CPUXtensaState *env, uint32_t pc, uint32_t intlevel)
     env->pc = pc;
     env->sregs[PS] = (env->sregs[PS] & ~PS_INTLEVEL) |
         (intlevel << PS_INTLEVEL_SHIFT);
+
+    qemu_mutex_lock_iothread();
     check_interrupts(env);
+    qemu_mutex_unlock_iothread();
+
     if (env->pending_irq_level) {
         cpu_loop_exit(CPU(xtensa_env_get_cpu(env)));
         return;
@@ -426,7 +431,9 @@ void HELPER(update_ccompare)(CPUXtensaState *env, uint32_t i)
 
 void HELPER(check_interrupts)(CPUXtensaState *env)
 {
+    qemu_mutex_lock_iothread();
     check_interrupts(env);
+    qemu_mutex_unlock_iothread();
 }
 
 void HELPER(itlb_hit_test)(CPUXtensaState *env, uint32_t vaddr)