Re: [Qemu-devel] [PATCH 1/7] Introduce a new bus "ICC" to connect APIC

[Paolo Bonzini <pbonzini@redhat.com>]

On 02/24/2012 02:30 PM, Andreas Färber wrote:
> SysBus is supposed to go away in Anthony's upcoming 4th QOM series, so
> I'd rather not base a new series on that.

Not sure about that.  I haven't understood well the scope of the series,
but I think it only converted buses to QOM, it didn't kill them.
Perhaps SysBus was special, in which case it would become automatically
hotpluggable: just create a new QOM object.

> The issue with TYPE_DEVICE is that we don't want to leak that into the
> user emulators (would break the build), and any infrastructure only
> available to qdev should gradually be made accessible to all objects
> (Paolo has done some work in that direction wrt properties).

I haven't, but it would be next on the list of things to do.

> So the main remaining difference between Object and Device is the
> GPIO IRQ support. Anthony wanted to introduce Pin objects to replace
> qemu_irq.

Aiming at "replacing" is a bad idea unless you can do it fast and
painlessly.  Adding gpio_in and gpio_out property types would be more
useful and would let you expose qemu_irq as QOM.  You can then change
the existing qdev.c functions to operate on those new property types.

Paolo