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Date:   Mon, 22 Aug 2022 14:44:19 -0700
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Subject: Re: [PATCH v9 1/6] x86/tdx: Add TDX Guest attestation interface
 driver
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To:     Borislav Petkov <bp@alien8.de>
Cc:     Kuppuswamy Sathyanarayanan 
        <sathyanarayanan.kuppuswamy@linux.intel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>,
        Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org,
        "H . Peter Anvin" <hpa@zytor.com>,
        "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
        Tony Luck <tony.luck@intel.com>,
        Andi Kleen <ak@linux.intel.com>,
        Kai Huang <kai.huang@intel.com>,
        Wander Lairson Costa <wander@redhat.com>,
        Isaku Yamahata <isaku.yamahata@gmail.com>,
        marcelo.cerri@canonical.com, tim.gardner@canonical.com,
        khalid.elmously@canonical.com, philip.cox@canonical.com,
        linux-kernel@vger.kernel.org
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From:   Dave Hansen <dave.hansen@intel.com>
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On 8/22/22 14:36, Borislav Petkov wrote:
> Which makes my initial suggestion of calling this whole guest
> functionality a "tdx" driver not such a bad idea... Depends on
> whether there will be a split at all or it'll continue gaining more
> functionality.

Yep, let's get the crystal ball out.

TDX folks:

What other ioctl()s are in the pipeline for the guest side?

What ioctl()s are in the pipeline for the host side?  Are they all part
of /dev/kvm, or are there any TDX-specific "drivers" for the host?

We want to avoid both:

 1. A driver called /dev/tdx (or "tdx-guest) which is only and will only
    ever do TDX guest attestation.
 2. A driver called /dev/tdx-guest-attest which shares a ton of
    functionality with some future TDX guest feature like
    /dev/tdx-guest-snazzy-feature-foo.  Then, a new driver every time
    a new snazzy TDX feature shows up.