[SLOF] [PATCH v2 00/20] Add vTPM support to SLOF

Thomas Huth thuth at redhat.com
Fri Nov 20 03:11:06 AEDT 2015

On 19/11/15 16:47, Stefan Berger wrote:
> On 11/19/2015 06:52 AM, Thomas Huth wrote:
>> - In the second half of the patch series, you add a lot of functions
>>    (or rather one function and two wrappers) three times: One time in
>>    vio-vtpm-cdriver.fs, one time in tpm-static.fs and one time in
>>    vtpm-sml.fs. Is it really necessary to have those functions in both
>>    device tree nodes, /vdevice/vtpm and /ibm,vtpm ? What does the spec
>>    say?
>>    Anyway, I think you should at least get rid of the functions
>>    in tpm-static.fs and implement the stuff only in /ibm,vtpm instead.
> Here is what the spec  (V1.2) says in section 1.3.2:
> "This /vdevice/vtpm node is provided for use by the client – it simply
> passes commands on to the real /ibm,vtpm node."

That's a strange design. But ok, if it's already in the spec this way,
you likely can hardly do anything against this.

>> - Also for the other functions in tpm-static.fs, I think it would be
>>    nicer if you would move them to /ibm,vtpm instead to get rid of
>>    tpm-static.fs completely.
> See above. I do not think we can.

Why not? The functions in tpm-static.fs aren't mandated by the spec, are
they? I'd expect that only the device tree nodes are defined by the
spec, so it should be fine to remove tpm-static.fs and keep all
functions in the device tree node instead.

For example vtpm-measure-hdd-mbr - if you move that function to
/ibm,vtpm you could do something like this in disk-label instead:

 : load-from-boot-partition ( addr -- size )
    debug-disk-label? IF ." Trying DOS boot " .s cr THEN
    dup load-from-dos-boot-partition ?dup 0 <> IF
       block s" /ibm,vtpm" find-node dup IF
          s" vtpm-measure-hdd-mbr" rot $call-static

That way you also do not have to worry about including a wrapper for
board-js2x anymore.


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