Re: [PATCH v2 3/3] tpm: vtpm_proxy: Add ioctl to request locality prepended to command

From: Stefan Berger
Date: Thu May 04 2017 - 07:14:48 EST


On 05/04/2017 05:17 AM, Jarkko Sakkinen wrote:
On Wed, May 03, 2017 at 07:40:48PM -0400, Stefan Berger wrote:
On 05/03/2017 06:37 PM, Jarkko Sakkinen wrote:
On Fri, Apr 28, 2017 at 09:02:18AM -0400, Stefan Berger wrote:
Add an ioctl to request that the locality be prepended to every TPM
command.
Don't really understand this change. Why locality is prenpended?
Commands can be executed under locality 0-3 and for some commands it is
important to know which locality a user may have chosen. How else should we
convey that locality to the TPM emulator ?
Why this is not in the commit message?

More scalable way to do this would be to have a set of vtpm proxy
commands. There could be a command for requesting and releasing
locality. That would be more clean.

I would think that if someone wanted to use locality it's the client using /dev/tpm(rm)0 calling an ioctl or so and the vtpm proxy then merely passing that locality to the backend (TPM emulator). I suppose the intention is to support something like that following the addition of the new functions request_locality and release_locality?