Re: [edk2-devel] [PATCH v2 5/5] ArmVirtPkg/ArmVirtQemu: add optional support for TPM2 measured boot

["Ard Biesheuvel" <ard.biesheuvel@linaro.org>]

On Wed, 26 Feb 2020 at 01:40, Laszlo Ersek <lersek@redhat.com> wrote:
>
> On 02/25/20 11:44, Ard Biesheuvel wrote:
> > Duplicate the TPM2_ENABLE and TPM2_CONFIG_ENABLE build time flags that
> > already exist in OvmfPkg, and wire them up in the .DSC and .FDF so
> > that setting those flags produces a ArmVirtQemu build that implements
> > measured boot using a TPM provided by QEMU and described in the device
> > tree.
> >
> > Note that the TPM2 driver stack relies on a PEI phase being implemented,
> > so there is no point in enabling this for ArmVirtQemuKernel or ArmVirtXen.
> >
> > Also note that, despite ArmVirtQemuKernel being unaffected by this patch,
> > ArmVirtPkg/ArmVirtQemuFvMain.fdf.inc is being modified, for keeping the
> > contexts of the referring !include directives simple.
> >
> > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> > ---
> >  ArmVirtPkg/ArmVirtQemu.dsc           | 75 ++++++++++++++++++++
> >  ArmVirtPkg/ArmVirtQemu.fdf           |  6 ++
> >  ArmVirtPkg/ArmVirtQemuFvMain.fdf.inc | 10 +++
> >  3 files changed, 91 insertions(+)
>
> Under a similar, recent patch from Marc-André (which proposes enabling
> TPM-1.2 in OvmfPkg), I asked Marc-André to build up the work in small
> steps, practically mirroring the gradual TPM2.0 stuff from OvmfPkg:
>
> * [edk2-devel] [PATCH v2 3/3] Ovmf: enable TPM 1.2 support
>
> http://mid.mail-archive.com/bbf8cf87-9c90-5507-82b3-ae8534555a54@redhat.com
>
> https://edk2.groups.io/g/devel/message/54473
>
> I'd like to be consistent as a review (and I indeed prefer that
> approach), so I'd like to ask you for the same.
>
> Now if you and Marc-André agree that I'm being unreasonable, I guess I
> could be convinced... I don't want to annoy patch authors needlessly (I
> just find small gradual steps easier to understand, later).
>
> (Extra apologies if my current request contradicts something I asked for
> in the v1 review -- please do point it out, if that's the case. I'd like
> to be responsive and consistent, but there's just too much to re-review,
> even incrementally. I can easily see myself making process mistakes
> here, due to fatigue.)
>

I don't mind per se, but I'm not sure I understand how you want this
to be split.

- library classes first, then PCDs, then components.
- PEI modules first, then DXE modules
- TPM2_ENABLE pieces first, then TPM2_CONFIG_ENABLE.