On Wed, Jul 31, 2019 at 1:26 PM Sumit Garg [off-list ref] wrote:

quoted

Interesting, I wrote something similar and posted it to the lists a while back:
https://github.com/jkrh/linux/commit/d77ea03afedcb5fd42234cd834da8f8a0809f6a6

Since there are no generic 'TEEs' available,

There is already a generic TEE interface driver available in kernel.
Have a look here: "Documentation/tee.txt".

I guess my wording was wrong, tried to say that physical TEEs in the
wild vary massively hardware wise. Generalizing these things is rough.

quoted

I implemented the same
thing as a generic protocol translator. The shared memory binding for
instance already assumes fair amount about the TEE and how that is
physically present in the system. Besides, the help from usage of shm
is pretty limited due to the size of the keydata.

If you look at patch #1 and #2, they add support to register kernel
memory buffer (keydata buffer in this case) with TEE to operate on. So
there isn't any limitation due to the size of the keydata.

Ah, didn't mean that. Meant that the keydata is typically pretty small
in size, so there is limited benefit from passing that in via shm if
that complicates anything.


-- 
Janne