> 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. Pavel Dovgalyuk
