Re: [Qemu-devel] [PATCH 1/5] Add TPM 1.2 device interface

[Stefan Berger]

On 02/18/2011 12:37 PM, Andreas Niederl wrote:
> On 02/18/2011 05:37 PM, Stefan Berger wrote:
> > On 02/18/2011 10:33 AM, Andreas Niederl wrote:
> > > This implementation is based on the TPM 1.2 interface for virtualized TPM
> > > devices from the Xen-4.0.0 ioemu-qemu-xen fork.
> > >
> > > A backend driver infrastructure is provided to be able to use different
> > > device backends.
> [...]
> > I have a tpm_tis.c with major changes in it getting rid of the polling,
> > closer to specs that passes a test suite and a registerable backend as
> > well that has several more interface functions, due to support for
> > snapshotting etc. Unfortunately it doesn't make much sense for me to
> > post it since the backend is based on a library that's currently in the
> > Fedora review process and nobody else could build or test it  -- unless
> > there really was interest in reviewing at least some part of it.
> So I'm guessing that this library is not publicly available right now?
Not via the fedora repository at least. So yum install does not work, yet.
> Is this backend meant for integration into QEMU or does it run as
> separate process?
The backend is meant for integration in Qemu. It runs as a thread.
> How/Where could I integrate a passthrough backend like the one in this
> patch series?
It's possible via similar mechanisms as you have, just the interface is 
bigger and main code calls into the interface at different times. I'd 
need to share the code with you.
> The polling code isn't really necessary for the host backend, I left it
> there just in case it would be needed by such a socket interface as is
> used in the Xen fork.
I don't think it's necessary to have it all. In the new code, the  
frontend delivers a request to the backend and provides a callback 
function for delivering the response back once received.

> > It would certainly be desirable if your backend and mine could be
> > accommodate.
> Of course.
Let's see how we do this.

  Stefan

> Regards,
> Andreas