Re: [patch 00/21] Xen-paravirt: Xen guest implementation for paravirt_ops interface

Andi Kleen
2007-02-17T13:51:16Z

On Fri, Feb 16, 2007 at 01:59:44PM -0800, Christoph Lameter wrote:
> On Fri, 16 Feb 2007, Zachary Amsden wrote:
>
> > Yes, but that is just because the Xen hooks happens to be near the last part
> > of the merge. VMI required some special hooks, as do both Xen and lhype (I
> > think ... Rusty can correct me if lhype's puppy's have precluded the addition
> > of new hooks). Xen page table handling is very different, mostly it is trap
> > and emulate so writable page tables can work, which means they don't always
> > issue hypercalls for PTE updates, although they do have that option, should
> > the hypervisor MMU model change, or performance concerns prompt a different
> > model (or perhaps, migration?)
>
> Well looks like there are still some major design issues to be ironed out.
> What is proposed here is to make paravirt_ops a fake generic
> API and then tunnel through it to vendor specific kernel mods.

That was always its intention. It's not a direct interface to a hypervisor,
but an somewhat abstracted interface to a "hypervisor driver"

But you're right that there are currently still quite a lot of hooks
being added. I plan to be much more strict on that in the future.

-Andi