From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753345AbdEJNU3 (ORCPT ); Wed, 10 May 2017 09:20:29 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:36684 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753049AbdEJNU1 (ORCPT ); Wed, 10 May 2017 09:20:27 -0400 Subject: Re: [PATCH v2 3/3] tpm: vtpm_proxy: Add ioctl to request locality prepended to command To: Jarkko Sakkinen References: <1493384538-27883-1-git-send-email-stefanb@linux.vnet.ibm.com> <1493384538-27883-4-git-send-email-stefanb@linux.vnet.ibm.com> <20170503223747.zefh76m4youqlgje@intel.com> <40cd7d48-f6d1-39f4-99a3-916c7cdbb636@linux.vnet.ibm.com> <20170504091738.rxl77hjzf6vnpuda@intel.com> <20170504184007.46efvqyqwxjkzwuq@intel.com> <20170508234328.iydmoverh5z4nwco@intel.com> <20170510124745.lmqvonrkjmjes7ep@intel.com> Cc: tpmdd-devel@lists.sourceforge.net, LSM List , jgunthorpe@obsidianresearch.com, linux-kernel@vger.kernel.org From: Stefan Berger Date: Wed, 10 May 2017 09:20:14 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <20170510124745.lmqvonrkjmjes7ep@intel.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 17051013-0008-0000-0000-000002180016 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007042; HX=3.00000240; KW=3.00000007; PH=3.00000004; SC=3.00000210; SDB=6.00858671; UDB=6.00425489; IPR=6.00638144; BA=6.00005342; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00015395; XFM=3.00000015; UTC=2017-05-10 13:20:17 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17051013-0009-0000-0000-00003538126E Message-Id: <2c20fc62-938a-a6da-dbb2-70711b84996d@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-05-10_10:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1703280000 definitions=main-1705100093 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/10/2017 08:47 AM, Jarkko Sakkinen wrote: > On Tue, May 09, 2017 at 11:49:05AM -0400, Stefan Berger wrote: >> On 05/08/2017 07:43 PM, Jarkko Sakkinen wrote: >>> On Thu, May 04, 2017 at 04:03:18PM -0400, Stefan Berger wrote: >>>> On 05/04/2017 02:40 PM, Jarkko Sakkinen wrote: >>>>> On Thu, May 04, 2017 at 07:14:27AM -0400, Stefan Berger wrote: >>>>>> On 05/04/2017 05:17 AM, Jarkko Sakkinen wrote: >>>>>>> On Wed, May 03, 2017 at 07:40:48PM -0400, Stefan Berger wrote: >>>>>>>> On 05/03/2017 06:37 PM, Jarkko Sakkinen wrote: >>>>>>>>> On Fri, Apr 28, 2017 at 09:02:18AM -0400, Stefan Berger wrote: >>>>>>>>>> Add an ioctl to request that the locality be prepended to every TPM >>>>>>>>>> command. >>>>>>>>> Don't really understand this change. Why locality is prenpended? >>>>>>>> Commands can be executed under locality 0-3 and for some commands it is >>>>>>>> important to know which locality a user may have chosen. How else should we >>>>>>>> convey that locality to the TPM emulator ? >>>>>>> Why this is not in the commit message? >>>>>>> >>>>>>> More scalable way to do this would be to have a set of vtpm proxy >>>>>>> commands. There could be a command for requesting and releasing >>>>>>> locality. That would be more clean. >>>>>> I would think that if someone wanted to use locality it's the client using >>>>>> /dev/tpm(rm)0 calling an ioctl or so and the vtpm proxy then merely passing >>>>>> that locality to the backend (TPM emulator). I suppose the intention is to >>>>>> support something like that following the addition of the new functions >>>>>> request_locality and release_locality? >>>>> What if we later on want to pass something else than locality to the >>>>> backend? How that will work out? >>>> 'push' more data in front. 'pop' off by recipient. We could wrap the command >>>> in some form. >>>> >>>> Stefan >>> I would find having a set of special commands cleaner. Prepending sounds >>> like a quick hack to me, not really something that should exist in the >>> mainline. >> Along the lines of this here? >> >> uint32_2 command >> uint32_2 totlength >> uint8_t locality >> uint8_t buffer[] <- the actual TPM command >> >> >> With a command code like VTPM_PROXY_CMD_TPM_CMD = 1. >> >> Stefan > That would break binary compability. That's why I am adding that additional flag that allows a client to choose whether it wants the TPM command wrapped (or locality prepended) so that it knows what to expect from the driver. I don't think that breaks compatibility. > > I would suggest allocating CC's backwards starting from 0xFFFFFFFF for > these control messages and send them in regular TPM command layout. A > bit similar idea as we have in the RM. > > /Jarkko >