linux-kernel - Re: [PATCH v2 2/8] x86/mtrr: support setting MTRR state for software defined MTRRs

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: <Y+pTDFQlX9qNL35z@zn.tnic>
Date:   Mon, 13 Feb 2023 16:11:08 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     Juergen Gross <jgross@...e.com>
Cc:     linux-kernel@...r.kernel.org, x86@...nel.org,
        lists@...dbynature.de, mikelley@...rosoft.com,
        torvalds@...ux-foundation.org,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        "H. Peter Anvin" <hpa@...or.com>
Subject: Re: [PATCH v2 2/8] x86/mtrr: support setting MTRR state for software
 defined MTRRs

On Mon, Feb 13, 2023 at 04:03:07PM +0100, Borislav Petkov wrote:
> > Wouldn't !cpu_feature_enabled(X86_FEATURE_HYPERVISOR) be enough?
> >
> > I'm not sure we won't need that for TDX guests, too.
>
> See, that's the problem. I wanna have it simple too. Lemme check with
> dhansen.

He says MTRRs are enabled in TDX guests: "X86_FEATURE_MTRR is fixed to
1 in TDX guests."

So we will have to do the more finer-grained check I guess.

-- 
Regards/Gruss,
    Boris.

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