Re: [PATCH 0/4] RFC: ovmf: Add support for TPM Physical Presence interface

[Laszlo Ersek <lersek@redhat.com>]

On 05/15/18 14:30, marcandre.lureau@redhat.com wrote:
> From: Marc-André Lureau <marcandre.lureau@redhat.com>
> 
> Hi,
> 
> The following series adds basic TPM PPI 1.3 support for OVMF-on-QEMU
> with TPM2 (I haven't tested TPM1, for lack of interest).
> 
> PPI test runs successfully with Windows 10 WHLK, despite the limited
> number of supported funcions (tpm2_ppi_funcs table, in particular, no
> function allows to manipulate Tcg2PhysicalPresenceFlags)
> 
> The way it works is relatively simple: a memory region is allocated by
> QEMU to save PPI related variables. An ACPI interface is exposed by
> QEMU to let the guest manipulate those. At boot, ovmf processes and
> updates the PPI qemu region and request variables.
> 
> I build edk2 with:
> 
> $ build -DTPM2_ENABLE -DSECURE_BOOT_ENABLE

Is -DSECURE_BOOT_ENABLE necessary for *building* with -DTPM2_ENABLE? If
that's the case, we should update the DSC files; users building OVMF
from source shouldn't have to care about "-D" inter-dependencies, if we
can manage that somehow.

If -DSECURE_BOOT_ENABLE is only there because otherwise a guest OS
doesn't really make use of -DTPM2_ENABLE either, that's different. In
that case, it's fine to allow building OVMF with TPM2 support but
without SB support.

Thanks!
Laszlo