On Mon, 2018-08-20 at 14:48 -0700, Linus Torvalds wrote:
> 
> Of course, after the long (and entirely unrelated) discussion about
> the TLB flushing bug we had, I'm starting to worry about my own
> competence, and maybe I'm missing something really fundamental, and
> the XPFO patches do something else than what I think they do, or my
> "hey, let's use our Meltdown code" idea has some fundamental weakness
> that I'm missing.

The interesting part is taking the user (and other) pages out of the
kernel's 1:1 physmap.

It's the *kernel* we don't want being able to access those pages,
because of the multitude of unfixable cache load gadgets.