Re: [PATCH v5 0/8] In-kernel XICS interrupt controller emulation

Paul Mackerras
2013-04-27T08:36:21Z

On Fri, Apr 26, 2013 at 04:30:37PM +0200, Alexander Graf wrote:
> Very nice patch set. I've applie 1-7 of it to kvm-ppc-queue. So they will hopefully make it to 3.10.
>
> Please check for 8/8 whether
>
> a) You want to have a released kernel version without irq routing (irqfd) support. It makes user space's life harder, because you need to maintain backwards compatibility.

If we do a version without irq routing and later add it, old userspace
should still work, since KVM_IRQ_LINE still works, right? New
userspace on an old kernel can test the KVM_CAP_IRQ_ROUTING capability
to see if it can use irqfd. So on the whole, I would like to get it
in, provided of course I can get it tested and sent out before the
window closes.

> b) Please rebase on top of the current state of things, especially the changed lifecycle assumptions. Devices should now just live until the vm gets destroyed. It gives me way less headaches.

OK, I've done that, but I need to grab David Gibson to get a qemu that
knows about the new API so I can test it.

Regards,
Paul.