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

[Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>]

On Thu, May 04, 2017 at 07:14:27AM -0400, Stefan Berger wrote:
> 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?

What if we later on want to pass something else than locality to the
backend? How that will work out?

/Jarkko