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Message-ID: <82d4c654ce78416ba3635bad15f8bb21c3a42a4f.camel@intel.com>
Subject: Re: [PATCH v8 1/5] x86/tdx: Add TDX Guest attestation interface
 driver
From:   Kai Huang <kai.huang@intel.com>
To:     Sathyanarayanan Kuppuswamy 
        <sathyanarayanan.kuppuswamy@linux.intel.com>,
        Dave Hansen <dave.hansen@intel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org
Cc:     "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>,
        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
Date:   Thu, 07 Jul 2022 10:59:28 +1200
In-Reply-To: <e92c570e-29c0-e6d1-88e8-cb6344c01859@linux.intel.com>
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On Wed, 2022-07-06 at 15:27 -0700, Sathyanarayanan Kuppuswamy wrote:
>=20
> On 7/5/22 3:31 PM, Kai Huang wrote:
> > On Tue, 2022-07-05 at 14:21 -0700, Sathyanarayanan Kuppuswamy wrote:
> > > SGX is a related feature. It also uses IOCTL approach for enclave pro=
visioning.
> > >=20
> > > arch/x86/kernel/cpu/sgx/ioctl.c
> >=20
> > SGX isn't a good example here.  The IOCTLs are used to create enclaves,=
 but not
> > for attestation.  SGX attestation relies on enclave itself to get/verif=
y the
> > report, etc, so has no interaction with the kernel.
>=20
> If you are looking for an attestation specific example, you can only chec=
k the AMD
> code.
>=20
> https://patchwork.kernel.org/project/linux-mm/patch/20220307213356.279720=
5-44-brijesh.singh@amd.com/
>=20
> Also, sev_get_attestation_report() in arch/x86/kvm/svm/sev.c also impleme=
nts attestation
> IOCTL specific to KVM.
>=20

I think we only need to look at how attestation is implemented in kernel fo=
r
other vendors, so yes it would be helpful to look at AMD's implementation. =
=20
I'll probably also look at it when I have some time.

--=20
Thanks,
-Kai