Re: [PATCH 4/4][RFC] kvm: eoi_eventfd

From: Alex Williamson
Date: Sun Jun 24 2012 - 11:02:37 EST


On Sun, 2012-06-24 at 15:56 +0300, Avi Kivity wrote:
> On 06/23/2012 01:16 AM, Alex Williamson wrote:
> > I think we're probably also going to need something like this.
> > When running in non-accelerated qemu, we're going to have to
> > create some kind of EOI notifier for drivers. VFIO can make
> > additional improvements when running on KVM so it will probably
> > make use of the KVM_IRQFD_LEVEL_EOI interface, but we don't
> > want to have a generic EOI notifier in qemu that just stops
> > working when kvm-ioapic is enabled.
>
> Why?

Hmm, I must be missing something or not describing it correctly, because
it seems obvious. If we create a dependency in qemu of needing to know
when an eoi occurs and notifier a driver and have no way to fulfill that
dependency when running on kvm... that'd be bad, right? I don't want to
assume that every consumer of such an interface would prefer to make use
of an irqfd. Not sure if that answers your question though. Thanks,

Alex

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/