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

[Avi Kivity]

> >
> >
> > Would not this corruption also happen on real hardware?  If reset
> > to the disk controller is delayed by a slow gate or extra
> > capacitance on a line?
>
> Maybe, but the delays are probably too short on real HW before any
> packets are sent or disk gets written. On QEMU, I/O can be
> instantaneous.
>

Right, this is a real difference.  If any hardware actually depends on this, we 
can model it by launching a timer instead of issuing the I/O.  When the reset 
arrives to the disk controller, it will cancel the timer.

This is expensive both to code and in run-time performance, but we can afford 
the expense since we don't have such a case, yes?