Re: [PATCH RFC 00/20] attestation: Add a common subsystem and TDX support

[Jiri Pirko]

Wed, Oct 28, 2026 at 12:46:58AM +0100, jgg@xxxxxxxx wrote:
>On Tue, Oct 27, 2026 at 04:09:19PM -0700, Dave Jiang wrote:
>

[..]

>
>> >> 6. tdx_attestation_test's discovery_and_construction_fields expects an
>> >>    inheritance chain of 4, but the TDX family inherits ctlv-attestation
>> >>    directly, which gives 3. In a real TDX guest it fails with
>> >>    "Expected 4 (4) == ctlv_chain_len(self->dev) (3)".
>> > 
>> > I would have naively guessed this should inherent from some SPDM family?
>> 
>> The TDX family is the TD's own attestation (TD report, Quote and RTMRs), with
>> no device or SPDM in it. In wip_attestation_all_1 it inherits ctlv-attestation
>> directly, so I think the test's 4 is what's stale. Jiri would know for sure.
>
>I think TDX report/quote/rtmrs should be a different familiy from TDX device
>assignment SPDM. They are completely different things.

correct:
1) ctlv-attestation-tdx
2) ctlv-attestation-spdm

The spdm instance is backed by particular implementation/transport.