RE: [PATCH v5 05/16] x86/cpu: Defer CR pinning setup until after EFI initialization

[Luck, Tony]

>> Yeah, I was talking about 64-bit only.  On 32-bit PAE a PGD maps 1/4 of
>> the address space which is totally unworkable for stealing.
>
> But it is also not necessary.

So maybe we could make the 64-bit version of use_temporary_mm()
use some reserved address mapping to a reserved PGD in the upper
half of address space, and the 32-bit version continue to use "user"
addresses. It's unclear to me whether adding complexity here would be
worth it to remove the 64-bit STAC/CLAC text patching issues.

-Tony