Re: [PATCH RFC 3/3] tsm: Add TVM Measurement Sample Code
From: James Bottomley
Date: Thu Sep 12 2024 - 08:28:17 EST
On Sat, 2024-09-07 at 23:56 -0500, Cedric Xing wrote:
> This sample kernel module demonstrates how to make MRs accessible to
> user mode
> through TSM.
>
> Once loaded, this module registers a virtual measurement provider
> with the TSM
> core and will result in the directory tree below.
>
> /sys/kernel/tsm/
> └── measurement-example
> ├── config_mr
> ├── full_report
> ├── report_digest
> ├── rtmr0
> │ ├── append_event
> │ ├── digest
> │ ├── event_log
> │ └── hash_algo
> ├── rtmr1
> │ ├── append_event
> │ ├── digest
> │ ├── event_log
> │ └── hash_algo
> ├── static_mr
> └── user_data
I'm not sure this is the best structure to apply to logs with multiple
banks (hash algorithms). There needs to be a way to get the same
registers measurement for each bank, but the log should sit above that
(appending should extend all active banks)
How about
/sys/kernel/tsm/
└──<measurement type>
├──reg0
│ ├── <log format>
│ │ ├── append_event
│ │ └── event_log
│ ├── <hash algo>
│ ... └── digest
...
That way it supports multiple log formats (would be the job of the log
extender to ensure compatibility) and multiple banks.
James