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.

Backports commit 209b71b60ef3341246038e1c926c3b704969cdd3 from qemu
This commit is contained in:
Paolo Bonzini 2018-03-02 08:03:17 -05:00 committed by Lioncash
parent b39acfc3c6
commit 28b615a8b7
No known key found for this signature in database
GPG key ID: 4E3C3CC1031BA9C7

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@ -321,7 +321,7 @@ static inline bool cpu_handle_exception(struct uc_struct *uc, CPUState *cpu, int
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->uc, cpu);
@ -335,13 +335,13 @@ 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 (interrupt_request & CPU_INTERRUPT_HALT) {
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) {
@ -350,7 +350,7 @@ static inline void cpu_handle_interrupt(CPUState *cpu,
cpu_svm_check_intercept_param(env, SVM_EXIT_INIT, 0, 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) {
@ -380,8 +380,9 @@ static inline void cpu_handle_interrupt(CPUState *cpu,
if (unlikely(cpu->exit_request)) {
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,
@ -502,7 +503,7 @@ int cpu_exec(struct uc_struct *uc, CPUState *cpu)
env->invalid_error = UC_ERR_OK;
for(;;) {
TranslationBlock *tb, *last_tb;
TranslationBlock *last_tb = NULL;
int tb_exit = 0;
/* prepare setjmp context for exception handling */
@ -518,16 +519,15 @@ int cpu_exec(struct uc_struct *uc, CPUState *cpu)
last_tb = NULL; /* forget the last executed TB after exception */
atomic_mb_set(&cpu->tb_flushed, false); /* reset before first TB lookup */
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);
if (!tb) { // invalid TB due to invalid code?
uc->invalid_error = UC_ERR_FETCH_UNMAPPED;
ret = EXCP_HLT;
break;
}
cpu_loop_exec_tb(cpu, tb, &last_tb, &tb_exit);
} /* for(;;) */
}
} else {
#if defined(__clang__) || !QEMU_GNUC_PREREQ(4, 6)
/* Some compilers wrongly smash all local variables after