Re: [PATCH] xive: Make some device types not user creatable

[Greg Kurz <groug@kaod.org>]

On Fri, 4 Oct 2019 11:17:30 +0200
Philippe Mathieu-Daudé <philmd@redhat.com> wrote:

> Hi Greg,
> 
> On 10/4/19 9:38 AM, Greg Kurz wrote:
> > Some device types of the XIVE model are exposed to the QEMU command
> > line:
> > 
> > $ ppc64-softmmu/qemu-system-ppc64 -device help | grep xive
> > name "xive-end-source", desc "XIVE END Source"
> > name "xive-source", desc "XIVE Interrupt Source"
> > name "xive-tctx", desc "XIVE Interrupt Thread Context"
> > 
> > These are internal devices that shouldn't be instantiable by the
> > user. By the way, they can't be because their respective realize
> > functions expect link properties that can't be set from the command
> > line:
> > 
> > qemu-system-ppc64: -device xive-source: required link 'xive' not found:
> >   Property '.xive' not found
> > qemu-system-ppc64: -device xive-end-source: required link 'xive' not found:
> >   Property '.xive' not found
> > qemu-system-ppc64: -device xive-tctx: required link 'cpu' not found:
> >   Property '.cpu' not found
> 
> Why do you have to test that manually, isn't it what 
> tests/device-introspect-test.c::test_one_device does?
> 

Heh probably because I wasn't aware of it :)

And BTW, test_one_device() can't help here since it only cares
about 'device_add foo,help' not crashing QEMU:

    help = qtest_hmp(qts, "device_add \"%s,help\"", type);

as explained in a comment at the beginning of the file.

/*
 * Covers QMP device-list-properties and HMP device_add help.  We
 * currently don't check that their output makes sense, only that QEMU
 * survives.  Useful since we've had an astounding number of crash
 * bugs around here.
 */

> > Hide them by setting dc->user_creatable to false in their respective
> > class init functions.
> > 
> > Signed-off-by: Greg Kurz <groug@kaod.org>
> > ---
> >   hw/intc/xive.c |    3 +++
> >   1 file changed, 3 insertions(+)
> > 
> > diff --git a/hw/intc/xive.c b/hw/intc/xive.c
> > index 29df06df1136..6c54a35fd4bb 100644
> > --- a/hw/intc/xive.c
> > +++ b/hw/intc/xive.c
> > @@ -670,6 +670,7 @@ static void xive_tctx_class_init(ObjectClass *klass, void *data)
> >       dc->realize = xive_tctx_realize;
> >       dc->unrealize = xive_tctx_unrealize;
> >       dc->vmsd = &vmstate_xive_tctx;
> > +    dc->user_creatable = false;
> >   }
> >   
> >   static const TypeInfo xive_tctx_info = {
> > @@ -1118,6 +1119,7 @@ static void xive_source_class_init(ObjectClass *klass, void *data)
> >       dc->props   = xive_source_properties;
> >       dc->realize = xive_source_realize;
> >       dc->vmsd    = &vmstate_xive_source;
> > +    dc->user_creatable = false;
> >   }
> >   
> >   static const TypeInfo xive_source_info = {
> > @@ -1853,6 +1855,7 @@ static void xive_end_source_class_init(ObjectClass *klass, void *data)
> >       dc->desc    = "XIVE END Source";
> >       dc->props   = xive_end_source_properties;
> >       dc->realize = xive_end_source_realize;
> > +    dc->user_creatable = false;
> >   }
> >   
> >   static const TypeInfo xive_end_source_info = {
> > 
> >