Re: [PATCH] Upgrade vtpmd to berlios version 0.7.4

[George Dunlap <george.dunlap@eu.citrix.com>]

On 26/09/12 15:39, Matthew Fioravante wrote:
> The last piece of this puzzle that I haven't figured out is the linux
> tpm frontend driver. Its not in the main linux tree. Its from the old
> 2006 vtpm code but it still works. I believe it shipped with the old xen
> 2.6.18 kernel but now I don't know whats happened to it. I still have a
> copy we have been porting to newer kernels internally.
>
> Should we try to get it in mainline linux? Or maybe provide it in the
> xen tree as an externally compilable kernel module?
>
> There also exists a linux tpm backend driver, but if were only going to
> support the domain model that is no longer needed and can go away.
We should absolutely get it into mainline Linux.  I presume it's mainly 
the front/back code, which would live in the xen/ tree, and then hooks 
to make it work with /dev/tpm?  It seems like that should be fairly 
straightforward to get upstream.

Re the backend driver: obviously you're going to be the one doing the 
work, so the final call will be up to you.  But it seems to me that if 
it's not too difficult (and from the docs I looked at, it seemed like 
not much more than a dumb pipe?), I think you might as well port it.  
That would make it easy to run vtpm and vtpmmgr in Linux stubdoms 
instead of a mini-os stubdoms, should it ever becomes necessary to do so 
(for instance, if the vtpm code ever requires more functionality than 
the mini-os libc has).

To upstream, I think the SOP is to rebase to the most recently released 
Linux kernel (3.6 now I think), and cross-post the patches to xen-devel 
and linux-kernel, CC'ing the Xen maintainer, Konrad Wilk 
<konrad.wilk@oracle.com>, and probably the TPM maintianer as well.  
(Correct me if I'm wrong, Konrad!)

  -George