linux-kernel - Re: [RFC PATCH] x86/bugs: Remove 'force' options for retbleed/ITS

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Message-ID: <20250626145543.GEaF1fb95lZXESXkl1@fat_crate.local>
Date: Thu, 26 Jun 2025 16:55:43 +0200
From: Borislav Petkov <bp@...en8.de>
To: Peter Zijlstra <peterz@...radead.org>
Cc: David Kaplan <david.kaplan@....com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Josh Poimboeuf <jpoimboe@...nel.org>,
	Pawan Gupta <pawan.kumar.gupta@...ux.intel.com>,
	Ingo Molnar <mingo@...hat.com>,
	Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org,
	"H. Peter Anvin" <hpa@...or.com>, linux-kernel@...r.kernel.org
Subject: Re: [RFC PATCH] x86/bugs: Remove 'force' options for retbleed/ITS

On Thu, Jun 26, 2025 at 04:40:47PM +0200, Peter Zijlstra wrote:
> Testing; I use these things for testing. Makes I don't have to run on
> affected hardware, I can just force the feature on and inspect the code
> and ensures it runs.
> 
> If you use force, you get to keep all pieces -- no warranties.

Right, I don't have a good feeling when "force" makes a machine unmitigated
all of a sudden.

And we're not screaming nearly as loud as possible when =force is supplied and
for such a thing we probably should even taint the kernel.

I'd prefer if we don't expose =force options to the general public but make
them depend on CONFIG_DEBUG_KERNEL perhaps.

IOW, too dangerous.

-- 
Regards/Gruss,
    Boris.

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