Re: Hypercall interface changes for PAE

[Gerd Knorr <kraxel@suse.de>]

On Tue, May 31, 2005 at 07:26:51PM +0100, Keir Fraser wrote:
> 
> On 31 May 2005, at 19:21, Keir Fraser wrote:
> 
> >The downside of this approach is that the C declarations of 
> >mmu_update_t, update_va_mapping, etc are different on 32-bit PAE 
> >builds. But only low-level guest code will touch those interfaces 
> >anyway, and there is unlikely to be code sharing between PAE and 
> >non-PAE at that level.
> >
> >What do you think?
> 
> Actually, we could export intpte_t and physaddr_t at the guest 
> interface and declare mmu_update_t and friends in terms of those 
> typedefs. This would also avoid needing different wrapper 
> implementations of those hypercalls within Xen itself. Neat. :-)

That certainly would be the way to go if we want to have
different interfaces for PAE and non-PAE.  I'm not sure it
is a good idea to have different hypercall interfaces for
PAE and non-PAE cases in the first place.

What does this mean for the tools?  Would these also be
either PAE or non-PAE then?

What about the option to maybe run non-PAE guests in PAE-xen
in some translated shadow mode?  That wouldn't work then.
I don't think this would be a big problem though ...

  Gerd

-- 
-mm seems unusually stable at present.
	-- akpm about 2.6.12-rc3-mm3