Re: [Qemu-trivial] [Qemu-ppc] [Qemu-devel] [PATCH] RFC kvm irqfd: add directly mapped MSI IRQ support

[Benjamin Herrenschmidt]

On Sun, 2013-06-23 at 10:02 -0500, Anthony Liguori wrote:
> It doesn't make a lot of sense to have Power do MSI decoding in
> userspace while x86 does it in the kernel.  I assume the kernel
> doesn't have enough information to do the translation on Power?

Well, it would need the host bridge which it doesn't have and it
would need a concept of mapping that to interrupt numbers which
we don't want in the kernel.

We can keep the kernel side a LOT simpler (completely avoiding
the whole route bloatware) by sticking to our "simple" direct map kernel
stuff and doing the mapping from address/data to interrupts in qemu, so
we'll stick to that.

Cheers,
Ben.