Messages in this thread | | | Date | Thu, 24 Jan 2008 14:39:54 -0800 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH] x86: Construct 32 bit boot time page tables in native format. |
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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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