linux-kernel - Re: [PATCH] x86/srso: Disable the mitigation on unaffected configurations

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Date:   Mon, 14 Aug 2023 23:17:27 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     Josh Poimboeuf <jpoimboe@...nel.org>
Cc:     Nikolay Borisov <nik.borisov@...e.com>, X86 ML <x86@...nel.org>,
        Josh Poimboeuf <jpoimboe@...hat.com>,
        LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] x86/srso: Disable the mitigation on unaffected
 configurations

On Mon, Aug 14, 2023 at 01:53:00PM -0700, Josh Poimboeuf wrote:
> cpu_smt_possible() already does that.

Ok.

> 2. ENUMERATION OF NEW CAPABILITIES

Yes, exactly. On the next page: "Hypervisor software should
synthesize... " I got confused initially too.

> Since technically the CPU is affected, I'm thinking it should say
> "Mitigation: SMT disabled" or such, instead of "Not affected".

Lemme see how ugly it becomes tomorrow.

> Hm?  You mean the *_NO ones that determine whether the BUG bits get set
> in the first place?  How do they print "Not affected"?

If SMT is disabled on those configurations, it is not affected. But ok,
"SMT disabled".

-- 
Regards/Gruss,
    Boris.

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