linux-kernel - Re: [PATCH] x86/sev: Make SEV

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: <20250305111251.GBZ8gxs_6O7g3gLVEh@fat_crate.local>
Date: Wed, 5 Mar 2025 12:12:51 +0100
From: Borislav Petkov <bp@...en8.de>
To: Joerg Roedel <joro@...tes.org>
Cc: x86@...nel.org, hpa@...or.com, Tom Lendacky <thomas.lendacky@....com>,
	Nikunj A Dadhania <nikunj@....com>, linux-kernel@...r.kernel.org,
	Larry.Dewey@....com, Joerg Roedel <jroedel@...e.de>
Subject: Re: [PATCH] x86/sev: Make SEV_STATUS available via SYSFS

On Wed, Mar 05, 2025 at 11:52:34AM +0100, Joerg Roedel wrote:
> From: Joerg Roedel <jroedel@...e.de>
> 
> Current user-space tooling which needs access to the SEV_STATUS MSR is
> using the MSR module. The use of this module poses a security risk in
> any trusted execution environment and is generally discouraged.
> 
> Instead, provide an file in SYSFS in the already existing
> /sys/devices/system/cpu/sev/ directory to provide the value of the
> SEV_STATUS MSR to user-space.

Right, to continue this discussion on the ML, like we said yesterday, I think
that dumping a raw MSR value is not really user-friendly.

We could stick a

Coco:

line in /proc/cpuinfo and simply dump SEV_STATUS there and TDX can put the
respective TDX-specific feature flags of what is enabled there and then we
have a good tested and well-known interface to communicate such things to
userspace through.

I'd say...

-- 
Regards/Gruss,
    Boris.

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