Re: [Qemu-devel] [RFC 02/19] s390: Add FIXME for unexplained user_creatable=false line

[Eduardo Habkost]

On Mon, Apr 03, 2017 at 10:55:38AM +0200, Cornelia Huck wrote:
> On Fri, 31 Mar 2017 21:46:07 -0300
> Eduardo Habkost <address@hidden> wrote:
> 
> > TYPE_S390_PCI_HOST_BRIDGE has user_creatable=false but has
> > no comment explaining why. Add a FIXME to document that.
> > 
> > Cc: Frank Blaschka <address@hidden>
> > Cc: Cornelia Huck <address@hidden>
> > Cc: Christian Borntraeger <address@hidden>
> > Cc: Alexander Graf <address@hidden>
> > Cc: Richard Henderson <address@hidden>
> > Signed-off-by: Eduardo Habkost <address@hidden>
> > ---
> >  hw/s390x/s390-pci-bus.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/hw/s390x/s390-pci-bus.c b/hw/s390x/s390-pci-bus.c
> > index 1ec30c45ce..2c3b960bdf 100644
> > --- a/hw/s390x/s390-pci-bus.c
> > +++ b/hw/s390x/s390-pci-bus.c
> > @@ -867,7 +867,7 @@ static void s390_pcihost_class_init(ObjectClass *klass, 
> > void *data)
> >      DeviceClass *dc = DEVICE_CLASS(klass);
> >      HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
> >  
> > -    dc->user_creatable = false;
> > +    dc->user_creatable = false; /*FIXME: explain why */
> >      dc->reset = s390_pcihost_reset;
> >      k->init = s390_pcihost_init;
> >      hc->plug = s390_pcihost_hot_plug;
> 
> (adding some more possibly interested parties)
> 
> We currently have one master s390 phb (and it's been that way since
> s390 pci was introduced). Recently, there has been some remodelling
> going on to make this more similar to what sPAPR does. I think we could
> make this even more similar to sPAPR and have this user createable; but
> I'm currently not sure it's worth the effort. Opinions?

It looks -device s390-pcihost was never possible, anyway, because
no s390x machine has has_dynamic_sysbus=1, and TYPE_PCI_HOST_BRIDGE
is a sys-bus-device.

Also, patch 03/19 on this series would make the explicit
user_creatable=false assignment in s390_pcihost_class_init()
unnecessary.

I don't think it is worth the effort to change that, unless you
have a specific use case that would benefit from it.

-- 
Eduardo