linux-kernel - Re: [RFT PATCH v3 00/21] x86: strict separation of startup code

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Message-ID: <20250514185316.GJaCTmnPdcK9goOFWc@fat_crate.local>
Date: Wed, 14 May 2025 20:53:16 +0200
From: Borislav Petkov <bp@...en8.de>
To: Ard Biesheuvel <ardb@...nel.org>
Cc: Ard Biesheuvel <ardb+git@...gle.com>, linux-kernel@...r.kernel.org,
	linux-efi@...r.kernel.org, x86@...nel.org,
	Ingo Molnar <mingo@...nel.org>,
	Dionna Amalie Glaze <dionnaglaze@...gle.com>,
	Kevin Loughlin <kevinloughlin@...gle.com>,
	Tom Lendacky <thomas.lendacky@....com>
Subject: Re: [RFT PATCH v3 00/21] x86: strict separation of startup code

On Wed, May 14, 2025 at 06:37:14PM +0100, Ard Biesheuvel wrote:
> The rule is really that you can no longer randomly call other code
> without being forced to consider carefully what else gets pulled in,
> and whether or not that code is guaranteed to behave correctly when
> being called via the 1:1 mapping.

I like "consider carefully". Right now, the decompressor is a mess and
untangling it is a losing game.

> Basically, the first order of business when calling the kernel via the
> 1:1 mapping is to create the kernel virtual mapping in the page
> tables. It is just really unfortunate that SEV-SNP requires so much
> prep work before we can even map the kernel.
> 
> I don't anticipate that this code will grow a lot after I'm done with it.

Right, ok.

Lemme keep looking.

Thx.

-- 
Regards/Gruss,
    Boris.

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