> From: Paolo Bonzini [mailto:[email protected]] > 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.
Maybe it would be better, because tb_gen_code is called in many other paths. I'll fix the patch. Pavel Dovgalyuk
