On Mon, Oct 05, 2015 at 11:28:03AM +0300, Avi Kivity wrote:
Eventfd is a natural enough representation of an interrupt; both kvm andeventfd without kernel intervention sounds unlikely.
vfio use it, and are also able to share the eventfd, allowing a vfio
interrupt to generate a kvm interrupt, without userspace intervention, and
one day without even kernel intervention.
kvm might configure the cpu such that an interrupt will not trigger a
vmexit. eventfd seems like an unlikely interface to do that: with the
eventfd, device triggering it has no info about the interrupt so it
can't send it to the correct VM.