Re: [Qemu-devel] [PATCH v3 0/3] TPM NVRAM persistent storage

[Stefan Berger]

On 06/14/2013 11:38 AM, Anthony Liguori wrote:
> Corey Bryant <address@hidden> writes:
>
> > On 06/14/2013 10:01 AM, Anthony Liguori wrote:
> > > Corey Bryant <address@hidden> writes:
> > >
> > > > This patch series provides persistent storage support that a TPM
> > > > can use to store NVRAM data.  It uses QEMU's block driver to store
> > > > data on a drive image.  The libtpms TPM 1.2 backend will be the
> > > > initial user of this functionality to store data that must persist
> > > > through a reboot or migration.  A sample command line may look like
> > > > this:
> > > This should be folded into the libtpms backend series.
> > >
> > > There are no users for this so this would just be untestable code in the
> > > tree subject to bitrot.
> > >
> > > Regards,
> > >
> > > Anthony Liguori
> > Fair enough.  I assume you're ok with this code though?
> I don't understand why it's needed to be honest.  I suspect this has to
> do with the fact that the libtpms implementation will need significant
> reworking.

libtpms does not implement a file storage layer. It neither writes data 
into a FILE * nor into a QEMU BDRV. Instead it provides callbacks for 
users to implement the file storage layer. Is there a problem with that?

   Regards,
      Stefan

> Regards,
>
> Anthony Liguori
>
> > --
> > Regards,
> > Corey Bryant
> >
> > > > qemu-system-x86_64 ...
> > > > -drive file=/path/to/nvram.qcow2,id=drive-nvram0-0-0
> > > > -tpmdev libtpms,id=tpm-tpm0
> > > > -device tpm-tis,tpmdev=tpm-tpm0,id=tpm0,drive=drive-nvram0-0-0
> > > >
> > > > Thanks,
> > > > Corey
> > > >
> > > > Corey Bryant (3):
> > > >     nvram: Add TPM NVRAM implementation
> > > >     nvram: Add tpm-tis drive support
> > > >     TPM NVRAM test
> > > >
> > > >    hw/tpm/Makefile.objs     |    1 +
> > > >    hw/tpm/tpm_int.h         |    2 +
> > > >    hw/tpm/tpm_nvram.c       |  324 
> > > > ++++++++++++++++++++++++++++++++++++++++++++++
> > > >    hw/tpm/tpm_nvram.h       |   25 ++++
> > > >    hw/tpm/tpm_passthrough.c |   85 ++++++++++++
> > > >    hw/tpm/tpm_tis.c         |    8 +
> > > >    6 files changed, 445 insertions(+), 0 deletions(-)
> > > >    create mode 100644 hw/tpm/tpm_nvram.c
> > > >    create mode 100644 hw/tpm/tpm_nvram.h