Re: [Qemu-devel] Re: [Bug 599958] Re: Timedrift problems with Win7: hpet missing time drift fixups

[Avi Kivity]

On 07/05/2010 03:16 PM, Jan Kiszka wrote:
> > It's also architecturally cleaner.  Masks and acks are architectural
> > events.  Injections are not - there's the edge on the LINT0 or INTI2
> > pins, generation of an APIC message, receipt of the APIC message, and
> > assertion of the APIC-to-core interrupt interface.  I'm not sure how the
> > proposed interface maps to that.
> >      
> Our emulation does not reflect every architectural detail of the
> delivery path anyway.

Usually, when that happens, we get an obscure bug.

So if we add a facility, especially across the user/kernel boundary, 
it's better to have it conform to the architecture.  That reduces the 
chance it has a serious hidden bug.

> The abstraction is always an IRQ line which can be
> high or low (sometimes it is only high, but this is a bug).
>    

That's a bug in the use of qemu_irq, not qemu_irq itself.

But qemu_irq needs to remember its state, otherwise when an irq 
controller unmasks a level-triggered line, it won't see the interrupt.

--
error compiling committee.c: too many arguments to function