linux-kernel - Re: [PATCH v15 22/23] x86/mce: Improve error log of kernel space TDX #MC due to erratum

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20231205204132.GLZW+K/Ix5sngfmcsY@fat_crate.local>
Date:   Tue, 5 Dec 2023 21:41:32 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     "Huang, Kai" <kai.huang@...el.com>
Cc:     "kvm@...r.kernel.org" <kvm@...r.kernel.org>,
        "Brown, Len" <len.brown@...el.com>,
        "Hansen, Dave" <dave.hansen@...el.com>,
        "david@...hat.com" <david@...hat.com>,
        "bagasdotme@...il.com" <bagasdotme@...il.com>,
        "ak@...ux.intel.com" <ak@...ux.intel.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "kirill.shutemov@...ux.intel.com" <kirill.shutemov@...ux.intel.com>,
        "mingo@...hat.com" <mingo@...hat.com>,
        "pbonzini@...hat.com" <pbonzini@...hat.com>,
        "seanjc@...gle.com" <seanjc@...gle.com>,
        "Yamahata, Isaku" <isaku.yamahata@...el.com>,
        "nik.borisov@...e.com" <nik.borisov@...e.com>,
        "tglx@...utronix.de" <tglx@...utronix.de>,
        "Luck, Tony" <tony.luck@...el.com>,
        "hpa@...or.com" <hpa@...or.com>,
        "peterz@...radead.org" <peterz@...radead.org>,
        "imammedo@...hat.com" <imammedo@...hat.com>,
        "sagis@...gle.com" <sagis@...gle.com>,
        "Gao, Chao" <chao.gao@...el.com>,
        "rafael@...nel.org" <rafael@...nel.org>,
        "sathyanarayanan.kuppuswamy@...ux.intel.com" 
        <sathyanarayanan.kuppuswamy@...ux.intel.com>,
        "Huang, Ying" <ying.huang@...el.com>,
        "x86@...nel.org" <x86@...nel.org>,
        "Williams, Dan J" <dan.j.williams@...el.com>
Subject: Re: [PATCH v15 22/23] x86/mce: Improve error log of kernel space TDX
 #MC due to erratum

On Tue, Dec 05, 2023 at 08:33:14PM +0000, Huang, Kai wrote:
> Yes I understand what you said.  My point is X86_FEATURE_TDX doesn't suit
> because when it is set, the kernel actually hasn't done any enabling work yet
> thus TDX is not available albeit the X86_FEATURE_TDX is set.

You define a X86_FEATURE flag. You set it *when* TDX is available and
enabled. Then you query that flag. This is how synthetic flags work.

In your patchset, when do you know that TDX is enabled? Point me to the
code place pls.

-- 
Regards/Gruss,
    Boris.

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