linux-kernel - Re: [PATCH 0/3] Resolve problems with kexec identity mapping

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240708195810.GKZoxE0pRWHEUljjnQ@fat_crate.local>
Date: Mon, 8 Jul 2024 21:58:10 +0200
From: Borislav Petkov <bp@...en8.de>
To: Steve Wahl <steve.wahl@....com>
Cc: Ard Biesheuvel <ardb@...nel.org>, Ashish Kalra <ashish.kalra@....com>,
	Dave Hansen <dave.hansen@...ux.intel.com>,
	Andy Lutomirski <luto@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>, x86@...nel.org,
	"H. Peter Anvin" <hpa@...or.com>, linux-kernel@...r.kernel.org,
	Pavin Joseph <me@...injoseph.com>,
	Eric Hagberg <ehagberg@...il.com>,
	Simon Horman <horms@...ge.net.au>,
	Eric Biederman <ebiederm@...ssion.com>,
	Dave Young <dyoung@...hat.com>, Sarah Brofeldt <srhb@....dk>,
	Russ Anderson <rja@....com>, Dimitri Sivanich <sivanich@....com>,
	Hou Wenlong <houwenlong.hwl@...group.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Baoquan He <bhe@...hat.com>, Yuntao Wang <ytcoode@...il.com>,
	Bjorn Helgaas <bhelgaas@...gle.com>, Joerg Roedel <jroedel@...e.de>,
	Michael Roth <michael.roth@....com>
Subject: Re: [PATCH 0/3] Resolve problems with kexec identity mapping

On Mon, Jul 08, 2024 at 02:29:05PM -0500, Steve Wahl wrote:
> Yes, this is about AMD machines which support SEV, running bare metal.
> ("Server" is in question, one of my testers is known to be using a
> laptop, so the facilities must be present in non-servers as well.)

No, they can't be. SEV is supported only on server, not on client. This laptop
has a different problem it seems.

> As far as I can see it, the effort you're putting into finding a
> different solution must mean you find something less than desirable
> about the solution I have offered.  But at this point, I don't
> understand why;

Why would we parse the CC blob which is destined *solely* for a SEV- *guest*,
when booting the baremetal kernel which is *not* a guest?

This is the solution I'm chasing - don't do something you're not supposed to
or needed to do.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette