Re: [Qemu-devel] [patch 01/10] qemu: create helper for event notification

[Marcelo Tosatti]

On Wed, Mar 25, 2009 at 08:18:58PM -0300, Glauber Costa wrote:
> > +void qemu_notify_event(void)
> > +{
> > +    CPUState *env = cpu_single_env;
> > +
> > +    if (env) {
> > +        cpu_exit(env);
> > +#ifdef USE_KQEMU
> > +        if (env->kqemu_enabled)
> > +            kqemu_cpu_interrupt(env);
> > +#endif
> > +     }
> >  }
> 
> Have you tested this with kqemu? 

Nope.

> It will fire kqemu interrupts in a lot of circunstances it didn't
> before. That said, I don't even think kqemu is that important, but if
> it's in the tree, we don't want to introduce regressions. I'd suggest
> passing a flag indicating the type of event we're notifying. It's easy
> to foresee other uses for that as well.

qemu_notify_event() basically means "process events handled by
main_loop_wait ASAP". Maybe it needs a better name.

I'll make sure there's no serious regression with kqemu.

There are things like

                /* reset soft MMU for next block (it can currently
                   only be set by a memory fault) */
#if defined(USE_KQEMU)
#define MIN_CYCLE_BEFORE_SWITCH (100 * 1000)
                if (kqemu_is_ok(env) &&
                    (cpu_get_time_fast() - env->last_io_time) >=
MIN_CYCLE_BEFORE_SWITCH) {
                    cpu_loop_exit();
                }
#endif

Which needs some rethinking.