Re: Missing boot related measurements at TPM 2.0 PCRs 0-7 with OVMF

["Zhang, Chao B" <chao.b.zhang@intel.com>]

Hi Ricardo
   I double checked OVMF Debug Build. All the 2 PCDs are already built as Dynamic PCD. There should be no problem
Setting & Getting these PCD as Dynamic. We also verified this feature on several real hardware platforms with same configuration.
No issue reported.
   Can you share me the boot log?

From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of Laszlo Ersek
Sent: Friday, August 3, 2018 10:46 PM
To: Ricardo Araújo <ricardo@lsd.ufcg.edu.br>; Zhang, Chao B <chao.b.zhang@intel.com>
Cc: edk2-devel@lists.01.org; Zeng, Star <star.zeng@intel.com>; Gao, Liming <liming.gao@intel.com>
Subject: Re: [edk2] Missing boot related measurements at TPM 2.0 PCRs 0-7 with OVMF

On 08/03/18 15:39, Ricardo Araújo wrote:
> Hi folks, sorry for the delay!
>
> I've just applied the patch and got the same error message and empty PCRs.

Thanks for the feedback -- although it's not the kind I had hoped for :)

I have now filed "[regression] SecurityPkg commit f15cb995bb38 breaks
TPM2_ENABLE in OvmfPkg":

  https://bugzilla.tianocore.org/show_bug.cgi?id=1075

Ricardo, please consider registering in the TianoCore Bugzilla, and
adding yourself to the CC list of BZ#1075.

For now, I have assigned the BZ to Marc-André, for triaging / analysis.
swtpm is not set up on my end, and the TPM2 enablement for OvmfPkg was
contributed by Marc-André. Marc-André, are you OK with this? The BZ
assignment is about root-causing the issue, at the moment.

Once we know more closely what the problem is, we can decide what to do.
If it's hard to fix, my argument will be that we should roll back
SecurityPkg commit f15cb995bb38 first (it's a regression after all), and
re-apply it only when it no longer breaks OVMF. If the issue is not hard
to fix and we can commit the solution quickly, then I'll be fine with
leaving f15cb995bb38 applied.

Thanks,
Laszlo

>
> De: "Zhang, Chao B" <chao.b.zhang@intel.com<mailto:chao.b.zhang@intel.com>>
> Para: "Laszlo Ersek" <lersek@redhat.com<mailto:lersek@redhat.com>>, "Ricardo Araújo" <ricardo@lsd.ufcg.edu.br<mailto:ricardo@lsd.ufcg.edu.br>>, "Marc-André Lureau" <marcandre.lureau@redhat.com<mailto:marcandre.lureau@redhat.com>>
> Cc: edk2-devel@lists.01.org<mailto:edk2-devel@lists.01.org>, "Gao, Liming" <liming.gao@intel.com<mailto:liming.gao@intel.com>>, "Zeng, Star" <star.zeng@intel.com<mailto:star.zeng@intel.com>>
> Enviadas: Quinta-feira, 2 de agosto de 2018 21:22:18
> Assunto: RE: [edk2] Missing boot related measurements at TPM 2.0 PCRs 0-7 with OVMF
>
>
>
> Tks Lazslo. And please make sure PcdLib is correctly lined in OVMF
>
>
>
>
> From: Laszlo Ersek [mailto:lersek@redhat.com]
> Sent: Thursday, August 2, 2018 9:14 PM
> To: Zhang, Chao B <chao.b.zhang@intel.com<mailto:chao.b.zhang@intel.com>>; Ricardo Araújo <ricardo@lsd.ufcg.edu.br<mailto:ricardo@lsd.ufcg.edu.br>>; Marc-André Lureau <marcandre.lureau@redhat.com<mailto:marcandre.lureau@redhat.com>>
> Cc: edk2-devel@lists.01.org<mailto:edk2-devel@lists.01.org>; Gao, Liming <liming.gao@intel.com<mailto:liming.gao@intel.com>>; Zeng, Star <star.zeng@intel.com<mailto:star.zeng@intel.com>>
> Subject: Re: [edk2] Missing boot related measurements at TPM 2.0 PCRs 0-7 with OVMF
>
>
>
>
> On 08/02/18 04:04, Zhang, Chao B wrote:
>> Hi Laszlo & Ricardo
>> The patch was intended to reduce the time to read TPM interface ID register. The interface type should not change within boot cycle according to PTP spec.
>> I agree to add some ASSERT after PCDSetxxsS.
>> But It is a core solution without platform change as PCD has been configured as DYN, DYNEx in DEC. I don’t know why you meet Set Failure
>> In OVMF. Here, I include PCD expert to explain this.
>
> As far as I recall, dynamic PCDs have never behaved as actually settable
> for me unless I added dynamic defaults for them in the OVMF DSC files.
>
> I never really researched why this was the case, I just accepted that
> the dynamic defaults were apparently necessary.
>
> Let's wait for Ricardo's response. Perhaps my analysis / suspicion were
> incorrect and it's not actually the "dynamism" of the PCD that's missing
> for OVMF. Ricardo's answer will tell us if there's another issue.
>
> Thanks
> Laszlo
>
>> From: Laszlo Ersek [ mailto:lersek@redhat.com ]
>> Sent: Thursday, August 2, 2018 5:49 AM
>> To: Ricardo Araújo < ricardo@lsd.ufcg.edu.br<mailto:ricardo@lsd.ufcg.edu.br> >; Zhang, Chao B < chao.b.zhang@intel.com<mailto:chao.b.zhang@intel.com> >; Marc-André Lureau < marcandre.lureau@redhat.com<mailto:marcandre.lureau@redhat.com> >
>> Cc: edk2-devel@lists.01.org<mailto:edk2-devel@lists.01.org>
>> Subject: Re: [edk2] Missing boot related measurements at TPM 2.0 PCRs 0-7 with OVMF
>>
>> On 08/01/18 19:50, Ricardo Araújo wrote:
>>> The commit I was referring to is:
>>> https://github.com/tianocore/edk2/commit/f15cb995bb3880b77e15afe6facd3da05e599a17
>>>
>>> Regards,
>>>
>>> Ricardo Araujo -
>>> www.lsd.ufcg.edu.br/~ricardo<http://www.lsd.ufcg.edu.br/~ricardo<http://www.lsd.ufcg.edu.br/~ricardo%3chttp:/www.lsd.ufcg.edu.br/~ricardo> >
>>>
>>> ----- Mensagem original -----
>>> De: "Ricardo Araújo" < ricardo@lsd.ufcg.edu.br<mailto:ricardo@lsd.ufcg.edu.br<mailto:ricardo@lsd.ufcg.edu.br%3cmailto:ricardo@lsd.ufcg.edu.br> >>
>>> Para: edk2-devel@lists.01.org<mailto:edk2-devel@lists.01.org<mailto:edk2-devel@lists.01.org%3cmailto:edk2-devel@lists.01.org> >
>>> Enviadas: Quarta-feira, 1 de agosto de 2018 14:33:45
>>> Assunto: [edk2] Missing boot related measurements at TPM 2.0 PCRs 0-7
>>> with OVMF
>>>
>>> Hi everyone,
>>>
>>> I'm using OVMF with a simulated TPM 2.0 (from
>>> https://github.com/stefanberger/swtpm ) and I noticed lately that PCRs
>>> 0-7 are zeroed after booting the vm (ubuntu 18.04) and the only
>>> message related to this in dmesg is:
>>>
>>> [ 2.286690] tpm_tis 00:06: 2.0 TPM (device-id 0x1, rev-id 1)
>>> [ 2.303753] tpm tpm0: A TPM error (256) occurred continue selftest
>>> [ 2.314199] tpm tpm0: starting up the TPM manually
>>>
>>> I found this started to happen after this commit , previous commits to
>>> that are showing boot time measurements on PCR 0-7 normally and the
>>> error message is gone. Has anyone experienced the same behavior? I
>>> followed the instructions here for building OVMF but I added the
>>> parameters -D TPM2_ENABLE=TRUE -D SECURE_BOOT_ENABLE=TRUE -D
>>> HTTP_BOOT_ENABLE=TRUE. Is there anything else I need to add to enable
>>> these measurements?
>>>
>>> Regards,
>>>
>>> Ricardo Araujo
>>> www.lsd.ufcg.edu.br/~ricardo<http://www.lsd.ufcg.edu.br/~ricardo<http://www.lsd.ufcg.edu.br/~ricardo%3chttp:/www.lsd.ufcg.edu.br/~ricardo> >
>>
>> Thank you for the bug report. It looks like a regression to me, but the
>> details aren't immediately clear.
>>
>> Adding Marc-André who contributed the TPM enablement for OVMF, and Chao
>> Zhang who authored the commit in question.
>>
>> If I recall correctly, in OVMF we decided to never cache the TPM type
>> but always detect it. I could be remembering wrong though. See commit
>> 6cf1880fb5b6 ("OvmfPkg: add customized Tcg2ConfigPei clone",
>> 2018-03-09).
>>
>> Chao Zhang: can you please explain what additional requirements are
>> presented for a platform by commit f15cb995bb38? In OVMF we use a
>> customized Tcg2ConfigPei module (see the commit above).
>>
>>
>> Oh wait, I suspect what's wrong. I believe there are two bugs in commit
>> f15cb995bb38 ("SecurityPkg: Cache TPM interface type info", 2018-06-25):
>>
>> * Bug#1:
>>
>> Commit f15cb995bb38 introduces a new PCD, called
>> "PcdActiveTpmInterfaceType", in section [PcdsDynamic, PcdsDynamicEx] of
>> "SecurityPkg.dec", and makes core modules from SecurityPkg dependent on
>> it.
>>
>> Obviously this means that platforms are required to provide a Dynamic
>> Default for the new PCD in their DSC files, if they include those core
>> modules from SecurityPkg, otherwise the PCD won't actually behave
>> dynamically -- "set" operations will fail, and "get" operations will
>> just return the central default from the SecurityPkg.dec file. As a
>> result, the cached TPM type will always be wrong (it will look like
>> "undetected", 0xFF).
>>
>> This could have been avoided by grepping all "*dsc*" files in the edk2
>> tree for references to the SecurityPkg module INF files that were about
>> to receive a dependency on the PCD. Such as:
>>
>> git grep -l -F \
>> -e SecurityPkg/Library/Tpm2DeviceLibDTpm/Tpm2DeviceLibDTpm.inf \
>> --or -e SecurityPkg/Library/Tpm2DeviceLibDTpm/Tpm2InstanceLibDTpm.inf \
>> --or -e SecurityPkg/Tcg/Tcg2Config/Tcg2ConfigDxe.inf \
>> --or -e SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.inf \
>> '*dsc*'
>>
>> This would have listed all platforms in-tree that were going to depend
>> on the new dynamic PCD via inclusion of the affected SecurityPkg
>> modules.
>>
>> Running this command now, I get the following output:
>>
>> OvmfPkg/OvmfPkgIa32.dsc
>> OvmfPkg/OvmfPkgIa32X64.dsc
>> OvmfPkg/OvmfPkgX64.dsc
>> SecurityPkg/SecurityPkg.dsc
>>
>> Open source hygiene dictates that modifications to infrastructure code
>> or otherwise central code be accompanied by necessary updates to *ALL*
>> in-tree subsystems that depend on said core code. (Out-of-tree
>> subsystems are a different matter.) It's OK if a single contributor
>> cannot test every single platform -- but we can still use the mailing
>> list and the bug tracker for raising the issue and expose the new
>> dependency for platforms that we can't test, but see as affected.
>>
>> Ricardo, Marc-André: does the following patch work for you guys
>> (build-tested only):
>>
>>> diff --git a/OvmfPkg/OvmfPkgIa32.dsc b/OvmfPkg/OvmfPkgIa32.dsc
>>> index a28b511d5c2f..b0153f66b710 100644
>>> --- a/OvmfPkg/OvmfPkgIa32.dsc
>>> +++ b/OvmfPkg/OvmfPkgIa32.dsc
>>> @@ -579,6 +579,7 @@ [PcdsDynamicDefault]
>>>
>>> !if $(TPM2_ENABLE) == TRUE
>>> gEfiSecurityPkgTokenSpaceGuid.PcdTpmInstanceGuid|{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}
>>> + gEfiSecurityPkgTokenSpaceGuid.PcdActiveTpmInterfaceType|0xFF
>>> !endif
>>>
>>> ################################################################################
>>> diff --git a/OvmfPkg/OvmfPkgIa32X64.dsc b/OvmfPkg/OvmfPkgIa32X64.dsc
>>> index 115d0c01ff5c..fcce846ab9a5 100644
>>> --- a/OvmfPkg/OvmfPkgIa32X64.dsc
>>> +++ b/OvmfPkg/OvmfPkgIa32X64.dsc
>>> @@ -587,6 +587,7 @@ [PcdsDynamicDefault]
>>>
>>> !if $(TPM2_ENABLE) == TRUE
>>> gEfiSecurityPkgTokenSpaceGuid.PcdTpmInstanceGuid|{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}
>>> + gEfiSecurityPkgTokenSpaceGuid.PcdActiveTpmInterfaceType|0xFF
>>> !endif
>>>
>>> ################################################################################
>>> diff --git a/OvmfPkg/OvmfPkgX64.dsc b/OvmfPkg/OvmfPkgX64.dsc
>>> index 362eb789c712..3eda1b3013f7 100644
>>> --- a/OvmfPkg/OvmfPkgX64.dsc
>>> +++ b/OvmfPkg/OvmfPkgX64.dsc
>>> @@ -586,6 +586,7 @@ [PcdsDynamicDefault]
>>>
>>> !if $(TPM2_ENABLE) == TRUE
>>> gEfiSecurityPkgTokenSpaceGuid.PcdTpmInstanceGuid|{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}
>>> + gEfiSecurityPkgTokenSpaceGuid.PcdActiveTpmInterfaceType|0xFF
>>> !endif
>>>
>>> ################################################################################
>>
>> If it works, I'll submit it later as a standalone patch.
>>
>>
>> * Bug#2:
>>
>> The PcdSet8S() calls added by commit f15cb995bb38 are not error-checked;
>> their return values are ignored.
>>
>> Honestly, if we ignore the return values of PcdSetXxxS() calls, then it
>> has been a wasted effort to introduce those "safe" APIs in the first
>> place, in commit 9a3558419509. At the bare minimum, an
>> ASSERT_RETURN_ERROR() should be added after every invocation.
>>
>> I've filed the following TianoCore BZ about Bug#2 now:
>>
>> https://bugzilla.tianocore.org/show_bug.cgi?id=1070
>>
>> Thanks
>> Laszlo
>>
>
>

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