Re: + stupid-hack-to-make-mainline-build.patch added to -mm tree

[Jeremy Fitzhardinge <jeremy@goop.org>]

Chris Wright wrote:
> I agree with that, but I think that's esp. for things like create and launch
> new vcpu.  The IPI bit I'm not as clear on, nor running this all on native
> as well.
>   

Well, native would fall back to using the existing arch/i386 versions of
those functions, so that's reasonably straightforward.  There'll need to
be a bit of internal rearrangement so that the Xen code can call in to
do things like set up the pda/gdt and other bits of CPU state.

I don't think IPI is especially interesting in itself, is it?   It's a
necessary mechanism to implement smp_call_function(), but Xen can do IPI
without having to invoke any of the existing apic-based IPI code.  The
other main user of IPI is cross-cpu tlb shootdown, but Xen has much more
efficient mechanisms than IPI for that (so we'll need to make the tlb
pv_ops interface a little wider to pass down a cpuset).

    J