Re: [PATCH 0/8] multi-target: remove qmp_query_cpu_definitions duplication

["Daniel P. Berrangé" <berrange@redhat.com>]

On Thu, Oct 15, 2026 at 10:57:50AM -0700, Pierrick Bouvier wrote:
> On 10/15/2026 12:57 AM, Daniel P. Berrangé wrote:
> > On Thu, Oct 15, 2026 at 07:58:29AM +0200, Markus Armbruster wrote:
> >> Pierrick Bouvier <pierrick.bouvier@oss.qualcomm.com> writes:
> >>
> >>> This series allows to link multiple targets that define
> >>> qmp_query_cpu_definitions. It simply replaces the duplicated definitions with
> >>> target-specific ones and a single dispatcher. We didn't use yet the dispatcher
> >>> pattern, and it's the first situation where it appears to be a good fit.
> >>>
> >>> A possible alternative would be to introduce this callback directly at
> >>> target-info level, which I think is a less desirable solution, since it would
> >>> ties this API to monitor.
> >>
> >> I'm curious... why would such a tie be undesirable?
> > 
> > I don't think target-info should be involved at all, it is a problem
> > to solve in the CPU type system. The CPU definitions are introspecting
> > sub-classes of TYPE_CPU.
> > 
> > IMHO the right way to solve this is for CPUClass to gain a callback for
> > introspection, and for each target to provide an impl of that callback.
> > 
> > There should only be a single qmp_query_cpu_definitions method that
> > introspects all registered TYPE_CPU subclasses. That way in a
> > multi-target binary, the introspection will return info for all
> > CPUs for all compiled in targets.
> >
> 
> I was wondering if what we would like to expose is all targets, or only
> the ones that have a cpu active.

Introspection commands such as this one generally should report on
everything that is built-in to the binary.

> > That would need refactoring of the current qmp_query_cpu_definitions
> > methods which is a bigger job. This series as is, is a reasonable
> > small initial stepping stone to make it possible to link the binaries,
> > before a later followup patch to do the full refactoring to get the
> > desirable API semantics.
> >
> 
> That was the goal 👍.
> 

With regards,
Daniel
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