Re: [PATCH 0/1] qom: fix setting of qdev array properties

[Daniel P . Berrangé]

On Thu, Sep 07, 2023 at 10:35:22AM +0100, Peter Maydell wrote:
> On Thu, 7 Sept 2023 at 10:33, Markus Armbruster <armbru@redhat.com> wrote:
> >
> > Kevin Wolf <kwolf@redhat.com> writes:
> >
> > > Am 04.09.2023 um 18:25 hat Daniel P. Berrangé geschrieben:
> > >> By the time of the 8.2.0 release, it will have been 2 years and 6
> > >> releases since we accidentally broke setting of array properties
> > >> for user creatable devices:
> > >>
> > >>   https://gitlab.com/qemu-project/qemu/-/issues/1090
> > >
> > > Oh, nice!
> >
> > Nice?  *Awesome*!
> >
> > > Well, maybe that sounds a bit wrong, but the syntax that was broken was
> > > problematic and more of a hack,
> >
> > A monstrosity, in my opinion.  I tried to strangle it in the crib, but
> > its guardians wouldn't let me.  Can dig up references for the morbidly
> > curious.
> 
> I don't care about the syntax on the command line much (AFAIK that's
> just the rocker device). But the actual feature is used more widely
> within QEMU itself for devices created in C code, which is what it
> was intended for. If you want to get rid of it you need to provide
> an adequate replacement.

I wonder if we can poison  DEFINE_PROP_ARRAY somewhere such that
it fails if DeviceClass user_creatable == true.

That would let internal code carry on using it, while ensuring
anyone creating a new user creatable device will quickly fnid
out it doesn't allow these arrays. Rocker would need fixing
of course.


With regards,
Daniel
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