Re: [Qemu-devel] [PATCH 11/22] i8259: Update IRQ state after reset

[Avi Kivity]

> > 
> > The way to fix it is two-phase reset:
> > 
> > phase 1: reset internal state (-> move all outputs to reset
> > values),
> > don't sample inputs yet
> > phase 2: allow sampling inputs
> 
> As far as I understood Anthony's QOM plans, phase 1 will correspond
> to
> "unrealize", phase 2 to "realize".

That smells of abusing mechanism used for construction for reset purposes.

Why not use an ordinary qemu_irq?  It reresents a pin; 0->1 edge (assert) 
enters phase 1, 1->0 edge (deassert) enters phase 2.  Exactly like real 
hardware.

> 
> However, we do not depend on two phases in this particular case
> (i8259)
> and can live with a coalescing both for now.
> 

Agree.