Re: [PATCH v2 4/7] tpm: infrastructure for TPM spaces

[Jarkko Sakkinen <jarkko.sakkinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>]

On Tue, Feb 21, 2017 at 11:54:50PM +0530, Nayna wrote:
> 
> 
> On 02/17/2017 12:55 AM, Jarkko Sakkinen wrote:
> > Added an ability to virtualize TPM commands into an isolated context
> > that we call a TPM space because the word context is already heavily
> > used in the TPM specification. Both the handle areas and bodies (where
> > necessary) are virtualized.
> > 
> > The mechanism works by adding a new parameter struct tpm_space to the
> > tpm_transmit() function. This new structure contains the list of virtual
> > handles and a buffer of page size (currently) for backing storage.
> > 
> > When tpm_transmit() is called with a struct tpm_space instance it will
> > execute the following sequence:
> > 
> > 1. Take locks.
> > 2. Load transient objects from the backing storage by using ContextLoad
> >     and map virtual handles to physical handles.
> > 3. Perform the transaction.
> > 4. Save transient objects to backing storage by using ContextSave and
> >     map resulting physical handle to virtual handle if there is such.
> > 
> > This commit does not implement virtualization support for hmac and
> > policy sessions.
> > 
> 
> If I have understood discussions correctly, I assume, that kernel TPM
> operations will also be routed via RM. And I think that is not happening now
> with these patches.
> 
> Am I missing something ?
> 
> Thanks & Regards,
>    - Nayna

Nope. It's not in the scope of this patch set and there are not
kernel use cases at the moment that would require it.

/Jarkko

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