Re: [RFC] Notify IRQ sources of level interrupt ack/EOI

[Michael S. Tsirkin]

On Wed, Jan 11, 2023 at 02:41:58PM +0000, David Woodhouse wrote:
> This allows drivers to register a callback on a qemu_irq, which is
> invoked when a level-triggered IRQ is acked on the irqchip.
> 
> This allows us to simulate level-triggered interrupts more efficiently,
> by resampling the state of the interrupt only when it actually matters.

I think we tried this with vfio and had to give up on this.
I don't remember the details though. Alex probably does?