user-exec: ensure interrupt_request is not used

cpu_interrupt() is not called anymore except by ARM but even there
it is dead code; disentangling the various cpregs accessors from user-mode
emulation is a work in progress.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

accel/tcg/cpu-exec.c

@@ -778,6 +778,9 @@ static inline bool cpu_handle_interrupt(CPUState *cpu,
      */
     qatomic_set_mb(&cpu->neg.icount_decr.u16.high, 0);
 
+#ifdef CONFIG_USER_ONLY
+    g_assert(!qatomic_read(&cpu->interrupt_request));
+#else
     if (unlikely(qatomic_read(&cpu->interrupt_request))) {
         int interrupt_request;
         bql_lock();
@@ -792,7 +795,6 @@ static inline bool cpu_handle_interrupt(CPUState *cpu,
             bql_unlock();
             return true;
         }
-#if !defined(CONFIG_USER_ONLY)
         if (replay_mode == REPLAY_MODE_PLAY && !replay_has_interrupt()) {
             /* Do nothing */
         } else if (interrupt_request & CPU_INTERRUPT_HALT) {
@@ -840,7 +842,6 @@ static inline bool cpu_handle_interrupt(CPUState *cpu,
              * reload the 'interrupt_request' value */
             interrupt_request = cpu->interrupt_request;
         }
-#endif /* !CONFIG_USER_ONLY */
         if (interrupt_request & CPU_INTERRUPT_EXITTB) {
             cpu->interrupt_request &= ~CPU_INTERRUPT_EXITTB;
             /* ensure that no TB jump will be modified as
@@ -851,6 +852,7 @@ static inline bool cpu_handle_interrupt(CPUState *cpu,
         /* If we exit via cpu_loop_exit/longjmp it is reset in cpu_exec */
         bql_unlock();
     }
+#endif /* !CONFIG_USER_ONLY */
 
     /* Finally, check if we need to exit to the main loop.  */
     if (unlikely(qatomic_read(&cpu->exit_request)) || icount_exit_request(cpu)) {

accel/tcg/user-exec.c

@@ -48,9 +48,7 @@ __thread uintptr_t helper_retaddr;
 
 void cpu_interrupt(CPUState *cpu, int mask)
 {
-    g_assert(bql_locked());
-    cpu->interrupt_request |= mask;
-    qatomic_set(&cpu->neg.icount_decr.u16.high, -1);
+    g_assert_not_reached();
 }
 
 /*

include/hw/core/cpu.h

@@ -423,6 +423,7 @@ struct qemu_work_item;
  * @created: Indicates whether the CPU thread has been successfully created.
  * @halt_cond: condition variable sleeping threads can wait on.
  * @interrupt_request: Indicates a pending interrupt request.
+ *   Only used by system emulation.
  * @halted: Nonzero if the CPU is in suspended state.
  * @stop: Indicates a pending stop request.
  * @stopped: Indicates the CPU has been artificially stopped.