Re: [Qemu-devel] Is is possible to virtualise or share the TPM?

[Jordi Cucurull Juan <jordi.cucurull@scytl.com>]

Do you refer to the patches that add TPM support to the SeaBIOS?

If this is the case, this is just a completely virtual TPM without any 
link with the TPM of the physical machine, right?

Jordi.


On 08/30/2012 04:50 PM, Stefan Berger wrote:
> On 08/30/2012 10:21 AM, Jordi Cucurull Juan wrote:
>> Dear Stefan,
>>
>> What does it mean that the patches with the VTPM functionality exist 
>> but they are behind the regular ones? Does it mean that they are not 
>> currently updated? That they have less priority?
>
> It means that in my patch queue they are 'behind' the ones I posted 
> over the last few months.
>
>   Stefan
>
>
>>
>> Best regards,
>> Jordi.
>>
>>
>>
>> On 08/29/2012 02:57 PM, Stefan Berger wrote:
>>> On 08/23/2012 04:05 PM, Corey Bryant wrote:
>>>>
>>>>
>>>> On 08/21/2012 06:31 AM, Jordi Cucurull Juan wrote:
>>>>> Dear all,
>>>>>
>>>>> After applying the TPM patches to QEMU, I was wondering if it is
>>>>> possible to simultaneously use the TPM in more than one virtual 
>>>>> machine,
>>>>> i.e. virtualisation of the TPM.
>>>>>
>>>>> According to the paper "Stefan Berger, Ramón Cáceres, Kenneth A.
>>>>> Goldman, Ronald Perez, Reiner Sailer, Leendert van Doorn. vTPM:
>>>>> Virtualizing the Trusted Platform Module" this seems to be 
>>>>> possible in
>>>>> Xen. Is not possible in QEMU?
>>>>>
>>>>> Thanks!
>>>>> Jordi.
>>>>>
>>>>>
>>>>
>>>> I don't think the pass-through driver supports use by multiple VMs. 
>>>> Stefan Berger should be able to answer better so I'm adding him to 
>>>> the thread.
>>>>
>>>
>>> The pass-through driver cannot provide access for multiple VMs to 
>>> the single hardware TPM on the host. The usage model and the 
>>> statefulness of the TPM (SRK password, owner password, keys) 
>>> basically prevent/complicate this. The implementation for Xen was 
>>> indep. of the Qemu code base today and there we used a software 
>>> implementation of the TPM that provided a private TPm instance to 
>>> each VM. I have patches for this for Qemu but due to an IRC chat in 
>>> Sept. 2011 they are 'behind' the pass-through driver patches.
>>>
>>>    Stefan
>>>
>>
>>
>
>
>