On Wed, 31 Jul 2019 at 16:33, Janne Karhunen <janne.karhu...@gmail.com> wrote: > > On Wed, Jul 31, 2019 at 1:26 PM Sumit Garg <sumit.g...@linaro.org> wrote: > > > > 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. >
There are already well defined GlobalPlatform Standards to generalize the TEE interface. One of them is GlobalPlatform TEE Client API [1] which provides the basis for this TEE interface. > > > > 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. > Ah, ok. Do you think of any better approach rather than to use SHM? [1] https://globalplatform.org/specs-library/tee-client-api-specification/ -Sumit > > -- > Janne
