Re: [PATCH 0/5] Extend TPM PPI interface to support revision 1.3

From: Stefan Berger <stefanb@linux.ibm.com>
To: "Safford, David (GE Global Research)" <david.safford@ge.com>,
	Stefan Berger <stefanb@linux.vnet.ibm.com>,
	"linux-integrity@vger.kernel.org"
	<linux-integrity@vger.kernel.org>,
	"jarkko.sakkinen@linux.intel.com"
	<jarkko.sakkinen@linux.intel.com>
Cc: "linux-security-module@vger.kernel.org" 
	<linux-security-module@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 0/5] Extend TPM PPI interface to support revision 1.3
Date: Mon, 14 Jan 2019 14:51:48 -0500	[thread overview]
Message-ID: <268c3238-b4fe-ef9f-d656-4d34479ec481@linux.ibm.com> (raw)
In-Reply-To: <BCA04D5D9A3B764C9B7405BBA4D4A3C0151A3125@ALPMBAPA12.e2k.ad.ge.com>

On 1/11/19 3:28 PM, Safford, David (GE Global Research) wrote:
>> -----Original Message-----
>> From: linux-integrity-owner@vger.kernel.org <linux-integrity-
>> owner@vger.kernel.org> On Behalf Of Stefan Berger
>> Sent: Wednesday, January 09, 2019 5:11 PM
>> To: linux-integrity@vger.kernel.org; jarkko.sakkinen@linux.intel.com
>> Cc: linux-security-module@vger.kernel.org; linux-kernel@vger.kernel.org;
>> Stefan Berger <stefanb@linux.vnet.ibm.com>
>> Subject: EXT: [PATCH 0/5] Extend TPM PPI interface to support revision 1.3
>>
>> This series of patches extends the TPM subsystem's PPI support to support
>> TPM PPI revision 1.3 where more commands are supported (up to 101) and
>> the TPM 2 command code '23' takes an additional parameter.
>>
>> For the command code '23' see this document here on document page 39:
>> https://trustedcomputinggroup.org/wp-content/uploads/Physical-
>> Presence-Interface_1-30_0-52.pdf
>>
>>     Stefan
> You might mention that this is an important feature, as on at least some
> systems, ppi function 23 is the only way to enable/disable PCR banks.

'The only way' depends on how good or bad the firmware support for this 
is. SeaBIOS will have a menu item that lets one toggle the activation of 
the PCR banks in the firmware menu -- assuming my patch makes it 
upstream :-)

>
> I have tested this patch set on my HP Spectre laptop, and I am finally
> able to turn the sha-1 bank on and off. Much appreciated!
>
> Tested-by: David Safford <david.safford@ge.com>

Thanks.

     Stefan

>
>> Stefan Berger (5):
>>    tpm: ppi: pass function revision ID to tpm_eval_dsm()
>>    tpm: ppi: rename TPM_PPI_REVISION_ID to TPM_PPI_REVISION_1
>>    tpm: ppi: Display up to 101 operations as define for version 1.3
>>    tpm: ppi: Possibly show command parameter if TPM PPI 1.3 is used
>>    tpm: ppi: Enable submission of optional command parameter for PPI 1.3
>>
>>   drivers/char/tpm/tpm_ppi.c | 78 ++++++++++++++++++++++++++++--------
>> --
>>   1 file changed, 58 insertions(+), 20 deletions(-)
>>
>> --
>> 2.17.1