linux-kernel - Re: [PATCH v1 03/11] x86/cpufeatures: Add TDX Guest CPU feature

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: <20210610142943.uohw6nzpip5yi4no@box.shutemov.name>
Date:   Thu, 10 Jun 2021 17:29:43 +0300
From:   "Kirill A. Shutemov" <kirill@...temov.name>
To:     Borislav Petkov <bp@...en8.de>
Cc:     Kuppuswamy Sathyanarayanan 
        <sathyanarayanan.kuppuswamy@...ux.intel.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Andy Lutomirski <luto@...nel.org>,
        Peter H Anvin <hpa@...or.com>,
        Dave Hansen <dave.hansen@...el.com>,
        Tony Luck <tony.luck@...el.com>,
        Dan Williams <dan.j.williams@...el.com>,
        Andi Kleen <ak@...ux.intel.com>,
        Kirill Shutemov <kirill.shutemov@...ux.intel.com>,
        Kuppuswamy Sathyanarayanan <knsathya@...nel.org>,
        Sean Christopherson <seanjc@...gle.com>,
        linux-kernel@...r.kernel.org, x86@...nel.org
Subject: Re: [PATCH v1 03/11] x86/cpufeatures: Add TDX Guest CPU feature

On Thu, Jun 10, 2021 at 02:28:06PM +0200, Borislav Petkov wrote:
> > diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
> > index ac37830ae941..dddc3a27cc8a 100644
> > --- a/arch/x86/include/asm/cpufeatures.h
> > +++ b/arch/x86/include/asm/cpufeatures.h
> > @@ -238,6 +238,7 @@
> >  #define X86_FEATURE_VMW_VMMCALL		( 8*32+19) /* "" VMware prefers VMMCALL hypercall instruction */
> >  #define X86_FEATURE_PVUNLOCK		( 8*32+20) /* "" PV unlock function */
> >  #define X86_FEATURE_VCPUPREEMPT		( 8*32+21) /* "" PV vcpu_is_preempted function */
> > +#define X86_FEATURE_TDX_GUEST		( 8*32+22) /* Trusted Domain Extensions Guest */
> 
> What's the name of the feature bit? "TDX guest"? Why not only
> X86_FEATURE_TDX and then you can have "tdx" in cpuinfo?

No, "tdx" is host feature. It is part TDX host enabling. This feature
indicates that kernel runs within TDX guest and named accordingly.

-- 
 Kirill A. Shutemov