Re: [PATCH v10 48/50] KVM: SEV: Provide support for SNP_GUEST_REQUEST NAE event

[Dan Williams]

[ add Ard for the SBOM sysfs ABI commentary ]

Dionna Amalie Glaze wrote:
[..]
> > > My own plan for SEV-SNP was to have a bespoke signed measurement of
> > > the UEFI in the GUID table, but that doesn't extend to TDX. If we're
> > > looking more at an industry alignment on coRIM for SBOM formats (yes
> > > please), then it'd be great to start getting that kind of info plumbed
> > > to the user in a uniform way that doesn't have to rely on servers
> > > providing the endorsements.
> > >
> > > [1] https://uefi.org/blog/firmware-sbom-proposal
> >
> > Honestly my first reaction for this ABI would be for a new file under
> > /sys/firmware/efi/efivars or similar.
> 
> For UEFI specifically that could make sense, yes. Not everyone has
> been mounting efivars, so it's been a bit of an uphill battle for that
> one.

I wonder what the concern is with mounting efivarfs vs configfs? In any
event this seems distinct enough to be its own /sys/firmware/efi/sbom
file. I would defer to Ard, but I think SBOM is a generally useful
concept that would be out of place as a blob returned from configfs-tsm.

> Still there's the matter of cached TDI RIMs. NVIDIA would have

I am not immediatly sure what a "TDI RIM" is?

> everyone send attestation requests to their servers every quote
> request in the NRAS architecture, but we're looking at other ways to

"NRAS" does not parse for me either.

> provide reliable attestation without a third party service, albeit
> with slightly different security properties.

Setting the above confusion aside, I would just say that in general yes,
the kernel needs to understand its role in an end-to-end attestation
architecture that is not beholden to a single vendor, but also allows
the kernel to enforce ABI stability / mitigate regressions based on
binary format changes.