Re: [PATCH] x86: Construct 32 bit boot time page tables in nativeformat.

[H. Peter Anvin]

Jeremy Fitzhardinge wrote:
> H. Peter Anvin wrote:
> > In other words, reusing the early page tables isn't all that 
> > straightforward.  It may easily be that it's better to build a new set 
> > of page tables from scratch, however, it would *still* be beneficial 
> > to have the early page tables be in the same format as the later one, 
> > since it lets us use the fixmap area, and therefore 
> > {bt,early}_ioremap() much sooner.
>
> Yes, and it simplifies Xen as it always starts guest domains in the 
> appropriate pagetable mode and doesn't let the guest change it on the 
> fly.  If early_ioremap depends on non-PAE early pagetables in an 
> otherwise PAE kernel, we'd need to go to some effort to make sure all 
> the early_ioremap stuff is skipped (which would be possible but 
> unpleasant for domU, but very bad in dom0).

Yeah, and it's ugly for the kernel proper, so that bit is a no-brainer. 
 It's just a matter of hammering out the details.

It doesn't sound from the above that you have any opinion either way 
about reusing the initial page tables or creating a new set, as long as 
they're in the same format.

	-hpa
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