Re: [RFC PATCH v3 11/11] tests: add plugin asserting correctness of discon event's to_pc

[Julian Ganz]

Hi Richard,

December 6, 2024 at 8:42 PM, "Richard Henderson" wrote:
> On 12/6/24 13:02, Pierrick Bouvier wrote:
> > On 12/6/24 00:42, Julian Ganz wrote:
> > > IIUC qemu will schedule interrupts "opportunistically" between tb
> > >  executions. If that's the case we'll observe interrupts exclusively
> > >  after the last instruction in a tb. That strikes me as a serious
> > >  limitation.
> > > 
> >  To reuse fancy vocabulary, maybe we should have a distinction between 
> > inferable > interruptions (interrupt instruction) and uninferable 
> > interrupts, triggered by an external > event.
> >  In the latter, it *might* be acceptable to not provide a from_pc (let's 
> > say a value 0), > because there is no useful information in itself, except 
> > creating random edges in the > control flow graph, which we don't want to 
> > do.
> >  What do you think of it?
> > 
> I think you both are over-complicating things.
> 
> Always, env->pc (or whatever) within cc->cpu_exec_interrupt *is* where the 
> interrupt is recognized, and *is* where the discontinuity occurs. Report that.

Glad to hear. This means what I naïvely did for most targets should be
correct at least in this regard.

Regards,
Julian