Re: [PATCH] x86/boot/64: Initialize 5-level paging variables earlier

From: Kirill A. Shutemov
Date: Mon Oct 12 2020 - 10:08:50 EST


On Sat, Oct 10, 2020 at 03:26:24PM -0400, Arvind Sankar wrote:
> On Sat, Oct 10, 2020 at 03:11:10PM -0400, Arvind Sankar wrote:
> > Commit
> > ca0e22d4f011 ("x86/boot/compressed/64: Always switch to own page table")
> > started using a new set of pagetables even without KASLR.
> >
> > After that commit, initialize_identity_maps() is called before the
> > 5-level paging variables are setup in choose_random_location(), which
> > will not work if 5-level paging is actually enabled.
>
> Note that I don't have hardware that supports 5-level paging, so this
> is not actually tested with 5-level, but based on code inspection, it
> shouldn't work.

qemu supports it. -cpu "qemu64,+la57"

--
Kirill A. Shutemov