Re: [GIT PULL] x86/urgent for v5.13-rc5

From: Linus Torvalds
Date: Sun Jun 06 2021 - 15:39:52 EST


On Sun, Jun 6, 2021 at 12:55 AM Borislav Petkov <bp@xxxxxxx> wrote:
>
> - Do away with all the wankery of reserving X amount of memory in
> the first megabyte to prevent BIOS corrupting it and simply and
> unconditionally reserve the whole first megabyte.

This seems a bit draconic.

How does this work at all under Windows? There must be some windows
knowledge about what the BIOS updates that we're not aware of.

I've pulled it, but it does seem like something odd is going on.

And that

Fixes: a799c2bd29d1 ("x86/setup: Consolidate early memory reservations")

makes me go "Umm.." too. What did a799c2bd29d1 actually break? It
looks like it was meant to be a no-op consolidation - if somebody
bisected to it, I think that is a sign that there's something odd
there.

Linus