Re: [RFC 0/9] Linear Address Masking enabling

From: Kirill A. Shutemov
Date: Fri Feb 05 2021 - 17:46:26 EST


On Fri, Feb 05, 2021 at 04:49:05PM +0100, Peter Zijlstra wrote:
> On Fri, Feb 05, 2021 at 06:16:20PM +0300, Kirill A. Shutemov wrote:
> > The feature competes for bits with 5-level paging: LAM_U48 makes it
> > impossible to map anything about 47-bits. The patchset made these
> > capability mutually exclusive: whatever used first wins. LAM_U57 can be
> > combined with mappings above 47-bits.
>
> And I suppose we still can't switch between 4 and 5 level at runtime,
> using a CR3 bit?

No. And I can't imagine how would it work with 5-level on kernel side.

--
Kirill A. Shutemov