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

[Stefan Berger <stefanb@linux.vnet.ibm.com>]

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
>