Commit 209b71b6 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

cpu-exec: avoid cpu_loop_exit in cpu_handle_interrupt 



The siglongjmp goes straight back to the beginning of cpu_exec's
outermost loop.  We do not need a siglongjmp, we can simply
leave the inner TB execution loop.

Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent a70fe14b

cpu-exec.c

+12 −11
Original line number Diff line number Diff line
@@ -461,7 +461,7 @@ static inline bool cpu_handle_exception(CPUState *cpu, int *ret) 
    return false;

}



static inline void cpu_handle_interrupt(CPUState *cpu,

static inline bool cpu_handle_interrupt(CPUState *cpu,

                                        TranslationBlock **last_tb)

{

    CPUClass *cc = CPU_GET_CLASS(cpu);
@@ -475,7 +475,7 @@ static inline void cpu_handle_interrupt(CPUState *cpu, 
        if (interrupt_request & CPU_INTERRUPT_DEBUG) {

            cpu->interrupt_request &= ~CPU_INTERRUPT_DEBUG;

            cpu->exception_index = EXCP_DEBUG;

            cpu_loop_exit(cpu);

            return true;

        }

        if (replay_mode == REPLAY_MODE_PLAY && !replay_has_interrupt()) {

            /* Do nothing */
@@ -484,7 +484,7 @@ static inline void cpu_handle_interrupt(CPUState *cpu, 
            cpu->interrupt_request &= ~CPU_INTERRUPT_HALT;

            cpu->halted = 1;

            cpu->exception_index = EXCP_HLT;

            cpu_loop_exit(cpu);

            return true;

        }

#if defined(TARGET_I386)

        else if (interrupt_request & CPU_INTERRUPT_INIT) {
@@ -494,13 +494,13 @@ static inline void cpu_handle_interrupt(CPUState *cpu, 
            cpu_svm_check_intercept_param(env, SVM_EXIT_INIT, 0);

            do_cpu_init(x86_cpu);

            cpu->exception_index = EXCP_HALTED;

            cpu_loop_exit(cpu);

            return true;

        }

#else

        else if (interrupt_request & CPU_INTERRUPT_RESET) {

            replay_interrupt();

            cpu_reset(cpu);

            cpu_loop_exit(cpu);

            return true;

        }

#endif

        /* The target hook has 3 exit conditions:
@@ -526,8 +526,10 @@ static inline void cpu_handle_interrupt(CPUState *cpu, 
    if (unlikely(atomic_read(&cpu->exit_request) || replay_has_interrupt())) {

        atomic_set(&cpu->exit_request, 0);

        cpu->exception_index = EXCP_INTERRUPT;

        cpu_loop_exit(cpu);

        return true;

    }



    return false;

}



static inline void cpu_loop_exec_tb(CPUState *cpu, TranslationBlock *tb,
@@ -625,7 +627,7 @@ int cpu_exec(CPUState *cpu) 
    for(;;) {

        /* prepare setjmp context for exception handling */

        if (sigsetjmp(cpu->jmp_env, 0) == 0) {

            TranslationBlock *tb, *last_tb = NULL;

            TranslationBlock *last_tb = NULL;

            int tb_exit = 0;



            /* if an exception is pending, we execute it here */
@@ -633,14 +635,13 @@ int cpu_exec(CPUState *cpu) 
                break;

            }



            for(;;) {

                cpu_handle_interrupt(cpu, &last_tb);

                tb = tb_find(cpu, last_tb, tb_exit);

            while (!cpu_handle_interrupt(cpu, &last_tb)) {

                TranslationBlock *tb = tb_find(cpu, last_tb, tb_exit);

                cpu_loop_exec_tb(cpu, tb, &last_tb, &tb_exit, &sc);

                /* Try to align the host and virtual clocks

                   if the guest is in advance */

                align_clocks(&sc, cpu);

            } /* for(;;) */

            }

        } else {

#if defined(__clang__) || !QEMU_GNUC_PREREQ(4, 6)

            /* Some compilers wrongly smash all local variables after