Re: [PATCH 0/3] arm64/virt: Add Arm CCA measurement register support

[Sami Mujawar]

Hi Jason,

> On Tue, Apr 14, 2026 at 02:26:58PM +0100, Suzuki K Poulose wrote:
> > On 14/04/2026 13:29, Jason Gunthorpe wrote:
> > > On Tue, Apr 14, 2026 at 11:10:51AM +0100, Suzuki K Poulose wrote:
> > >
> > > > > Isn't this also sort of incomplete?  Doesn't anything serious need
> > > > > signed measurements? Isnt't there alot more data that comes out of RMM
> > > > > than just a few measurement registers?
> > > > As mentioned above, this series adds the support for Runtime Extendible
> > > > Measurements (REM in CCA, RTMR on TDX). The RIM+Platform Attestation is
> > > > already provided via the TSM_REPORT
> > >
> > > Okay, but what actual use is this?
> > >
> >
> > Good point. This REMs are planned to be used for EFI_CC_MEASUREMENT_PROTOCOL
> > as described below:
> >
> > https://github.com/tianocore/edk2/issues/11383
> 
> So this is tying it to the same FW event log that TPM uses.
> 
> I think that strengthens my point this should all be uninform. TPM
> drivers are directly exposing the event log today, but I guess that
> needs generalization if non-TPM drivers are going to present it as
> well.
> 
> How do you imagine getting and manipulating the EFI event log to use
> with this?

The event logs from UEFI will be handed off to the OS using CCEL ACPI table. The CCEL table spec update can be seen at  https://github.com/tianocore/edk2/issues/11384 

Regards,

Sami Mujawar
> Jason
>