Re: [PATCH] hw/ppc/mac_newworld: Check for the availability of pci-ohci before using it

[Thomas Huth]

On 26/05/2023 19.24, Mark Cave-Ayland wrote:
> On 26/05/2023 14:30, BALATON Zoltan wrote:
>
> > On Fri, 26 May 2023, Thomas Huth wrote:
> > > pci-ohci might habe been disabled in the QEMU binary (e.g. when "configure"
> > > has been run with "--without-default-devices"). Thus we should check
> > > for its availability before blindly using it.
> > >
> > > Signed-off-by: Thomas Huth <thuth@redhat.com>
> > > ---
> > > hw/ppc/mac_newworld.c | 3 ++-
> > > 1 file changed, 2 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/hw/ppc/mac_newworld.c b/hw/ppc/mac_newworld.c
> > > index 535710314a..c7cca430e1 100644
> > > --- a/hw/ppc/mac_newworld.c
> > > +++ b/hw/ppc/mac_newworld.c
> > > @@ -349,7 +349,8 @@ static void ppc_core99_init(MachineState *machine)
> > >                                     sysbus_mmio_get_region(s, 3));
> > >     }
> > >
> > > -    machine->usb |= defaults_enabled() && !machine->usb_disabled;
> > > +    machine->usb |= defaults_enabled() && !machine->usb_disabled &&
> > > +                    module_object_class_by_name("pci-ohci") != 0;
> >
> > Considering that PowerMacs have an OHCI controller built in soldered to 
> > the motherboard should this depend on it instead and not rely on pulling 
> > it in with PCI_DEVICES and --without-default-devices disabling it?
> >
> > Currently it's not quite emulating a real Mac but I think we should aim 
> > for going that way rather than to keep emulating random Mac hardware.
>
> Indeed that's correct: New World Macs should always have USB ports built-in. 
> I guess the problem here is that this isn't being indicated correctly via 
> Kconfig and/or the machine->usb_disabled logic?

Yes, the other solution to the problem is to add a proper "select" statement 
to the Kconfig file. I can also send a patch for that instead.

The other question is whether the OHCI device should always be instantiated, 
even if QEMU had been started with "--nodefaults"? ... otherwise you could 
not hot-plug USB devices to this machine during runtime...

 Thomas