Re: [PATCH v5 06/22] coco/tdx-host: Expose P-SEAMLDR information via sysfs
From: Chao Gao
Date: Wed Mar 18 2026 - 05:10:53 EST
On Wed, Mar 18, 2026 at 04:20:54PM +0800, Xiaoyao Li wrote:
>On 3/18/2026 2:54 PM, Chao Gao wrote:
>> > > +
>> > > +What: /sys/devices/faux/tdx_host/seamldr/version
>> > > +Contact: linux-coco@xxxxxxxxxxxxxxx
>> > > +Description: (RO) Report the version of the loaded SEAM loader. The SEAM
>> > > + loader version is formatted as x.y.z, where "x" is the major
>> > > + version, "y" is the minor version and "z" is the update version.
>> > > + Versions are used for bug reporting and compatibility checks.
>> > > +
>> > > +What: /sys/devices/faux/tdx_host/seamldr/num_remaining_updates
>> > > +Contact: linux-coco@xxxxxxxxxxxxxxx
>> > > +Description: (RO) Report the number of remaining updates. TDX maintains a
>> > > + log about each TDX module that has been loaded. This log has
>> > > + a finite size, which limits the number of TDX module updates
>> > > + that can be performed.
>> > > +
>> > > + After each successful update, the number reduces by one. Once it
>> > > + reaches zero, further updates will fail until next reboot. The
>> > > + number is always zero if the P-SEAMLDR doesn't support updates.
>> > > +
>> > > + See Intel® Trust Domain Extensions - SEAM Loader (SEAMLDR)
>> > > + Interface Specification, Revision 343755-003, Chapter 3.3
>> > > + "SEAMLDR_INFO" and Chapter 4.2 "SEAMLDR.INSTALL" for more
>> > > + information.
>> >
>> > Do you think revision and chapter numbers useful here?
>>
>> I think it's nice-to-have. Without specific references, people would need to
>> read the entire 26-page spec. But I can drop them if they make it too verbose.
>
>I have some concerns about the "revision". The good thing is that it can tell
>what the attribute was built against while the bad thing is that it might not
>be easy for people to find an old revision years later.
I'm okay with dropping the revision number.
The intent is not to require readers to find the exact same revision. If they
can find that exact revision, great. If not, the chapter numbers may differ
in newer revisions.
Kirill, do you mean dropping the numbers but keeping the chapter titles:
See Intel® Trust Domain Extensions - SEAM Loader (SEAMLDR)
Interface Specification, Chapter "SEAMLDR_INFO" and Chapter
"SEAMLDR.INSTALL" for more information.
This keeps a targeted reference so readers do not need to scan the entire spec.