On 25/01/2017 13:27, Pavel Dovgalyuk wrote: >> From: Paolo Bonzini [mailto:[email protected]] >> On 25/01/2017 12:33, Pavel Dovgalyuk wrote: >>>> From: Paolo Bonzini [mailto:[email protected]] >>>> On 25/01/2017 12:12, Pavel Dovgalyuk wrote: >>>>>> From: Paolo Bonzini [mailto:[email protected]] >>>>>> On 24/01/2017 08:17, Pavel Dovgalyuk wrote: >>>>>>> @@ -451,6 +451,10 @@ static inline bool cpu_handle_exception(CPUState >>>>>>> *cpu, int *ret) >>>>>>> #ifndef CONFIG_USER_ONLY >>>>>>> } else if (replay_has_exception() >>>>>>> && cpu->icount_decr.u16.low + cpu->icount_extra == 0) { >>>>>>> + /* Break the execution loop in case of running out of TB cache. >>>>>>> + This is needed to make flushing of the TB cache, because >>>>>>> + real flush is queued to be executed outside the cpu loop. */ >>>>>>> + cpu->exception_index = EXCP_INTERRUPT; >>>>>>> /* try to cause an exception pending in the log */ >>>>>>> cpu_exec_nocache(cpu, 1, tb_find(cpu, NULL, 0), true); >>>>>>> *ret = -1; >>>>>> >>>>>> Why is replay_has_exception() related to be running out of TB cache? >>>>> >>>>> It doesn't. >>>>> Calling tb_find when there is not space in cache causes tb_flush and >>>>> cpu_loop_exit. >>>>> But execution loop will continue, because there is no reason to break it >>>>> (like setting exception_index). >>>> >>>> What about setting cpu->exit_request? queue_work_on_cpu calls >>>> qemu_cpu_kick. >>> >>> cpu->exit_request does not checked in this loop. >>> We have to add this checking somewhere then? >> >> It's checked by cpu_handle_interrupt. Are you not reaching >> cpu_handle_interrupt then? Why? > > Execution doesn't reach cpu_handle_interrupt, because tb_find > calls cpu_loop_exit. And the execution loop enters cpu_handle_exception again > and again.
Perhaps tb_gen_code should set cpu->exception_index before calling cpu_loop_exit. Paolo > Pavel Dovgalyuk >
