Re: [Qemu-devel] [PATCH RFC 0/3] basic support for composing sysbus devices

[Anthony Liguori]

On 06/10/2011 09:18 AM, Jan Kiszka wrote:
> On 2011-06-10 16:12, Anthony Liguori wrote:
> > On 06/10/2011 08:43 AM, Jan Kiszka wrote:
> >    -device piix3,id=piix3 -device
> > isa-serial,id=serial,irq[3]=piix3.irq[3],irq[4]=piix3.irq[4],...
> >
> > But I don't think we benefit from modelling it this correctly.  The
> > point is that the infrastructure could handle it though.
>
> I don't see the point of 'piix3.' in your IRQ assignment, though. It is
> redundant to the bus assignment

Bus assignment is the problem.

IRQ routing cannot be tied strictly to buses if we want to be able to do 
composition.

You could do clever things syntactically but the general mechanism is 
needed is the ability to wire things in an arbitrary fashion.

Regards,

Anthony Liguori

 - as the ISA bus also routes interrupts.
> There are surely also buses that don't. Still, interrupt routing via the
> bus should be possible (as it avoids boilerplate code or configuration
> redundancy).
>
> Jan