Re: [PATCH v8 1/5] x86/tdx: Add TDX Guest attestation interface driver

From: Kai Huang
Date: Wed Jul 06 2022 - 18:59:37 EST


On Wed, 2022-07-06 at 15:27 -0700, Sathyanarayanan Kuppuswamy wrote:
>
> 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 provisioning.
> > >
> > > arch/x86/kernel/cpu/sgx/ioctl.c
> >
> > 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/verify the
> > report, etc, so has no interaction with the kernel.
>
> If you are looking for an attestation specific example, you can only check the AMD
> code.
>
> https://patchwork.kernel.org/project/linux-mm/patch/20220307213356.2797205-44-brijesh.singh@xxxxxxx/
>
> Also, sev_get_attestation_report() in arch/x86/kvm/svm/sev.c also implements attestation
> IOCTL specific to KVM.
>

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

--
Thanks,
-Kai