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

[Jiri Pirko]

Mon, Oct 19, 2026 at 06:10:31PM +0200, drdeeglaze@xxxxxxxxx wrote:
>On Mon, Oct 19, 2026 at 5:08 AM Jiri Pirko <jiri@xxxxxxxxxxx> wrote:
>>
>> Yeah, I was thinking about this and went back and forth. In the end, the
>> only reason for leaving it unbounded is to allow multiple independent
>> users of the same register. For example, IMA and systemd could share a
>> TDX RTMR. The systemd side would read the journal through the
>> attestation device and the IMA side through securityfs, but both are
>> views of the same journal. If one side truncated it, the other could no
>> longer replay the RTMR. Isn't this the valid usecase? Do you see how to
>> resolve this?
>>
>
>Bright minds have spent a significant amount of time working on this.
>
>+Roberto Sassu, +Mimi Zohar
>IMA logs and systemd logs are both system level concerns that are
>relevant to the OS construction, not individual users,
>so I would just say to reroute IMA to use ctlv using a kernel config
>setting, then make systemd the new system manager of the holistic log.

Yeah, isn't there a valid usecase for 2 separete userspace consumers
though? It could be a limitation, perhaps configurable :S


>The securityfs log contents can simply say, "log managed by ctlv" in
>this setting, in the form of the template identifier.

Yeah, I just wanted the existing userspace IMA ecosystem *just work*
without any distruption.


>For policy violations, only the 0... extend needs to go to ctlv.
>IMA can still keep its violation log as a ring buffer when it's not a
>1-to-1 violation to extension
>https://www.youtube.com/watch?v=gyYUYbdiN_4