[PATCH v2 3/3] tpm: vtpm_proxy: Add ioctl to request locality prepended to command

[Stefan Berger]

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

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