Re: [Qemu-devel] [PATCH v7 03/14] replay: exception replay fix

["Pavel Dovgalyuk" <dovgaluk@ispras.ru>]

> From: Paolo Bonzini [mailto:pbonzini@redhat.com]
> 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).

Pavel Dovgalyuk