Re: [PATCH 3/3] OvmfPkg/Tcg2ConfigPei: skip TPM-1.2 detection when building for ARM/AARCH64

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 5/21/20 12:58 AM, Laszlo Ersek wrote:
> Dating back to commits f5cb3767038e and ddd34a818315d, the
> "ArmVirtPkg/ArmVirtQemu.dsc" platform includes the
> "OvmfPkg/Tcg/Tcg2Config/Tcg2ConfigPei.inf" module when the TPM2_ENABLE
> build flag is defined.
> 
> This was regressed in commit 89236992913f, which added a Tpm12DeviceLib
> dependency to Tcg2ConfigPei. "ArmVirtQemu.dsc" does not resolve that class
> to any instance, so now we get a build failure:
> 
>> build.py...
>> ArmVirtPkg/ArmVirtQemu.dsc(...): error 4000: Instance of library class
>> [Tpm12DeviceLib] is not found
>>          in [OvmfPkg/Tcg/Tcg2Config/Tcg2ConfigPei.inf] [AARCH64]
>>          consumed by module [OvmfPkg/Tcg/Tcg2Config/Tcg2ConfigPei.inf]
> 
> The TPM-1.2 code in OvmfPkg/Tcg2ConfigPei is limited to a special use case
> (a kind of physical TPM-1.2 assignment), and that has never applied to
> "ArmVirtQemu.dsc".
> 
> Short-circuit the TPM-1.2 detection in the ARM/AARCH64 builds of
> OvmfPkg/Tcg2ConfigPei, removing the Tpm12DeviceLib dependency.
> 
> Functionally, this patch is a no-op on IA32 / X64.
> 
> Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
> Cc: Eric Auger <eric.auger@redhat.com>
> Cc: Jordan Justen <jordan.l.justen@intel.com>
> Cc: Marc-André Lureau <marcandre.lureau@redhat.com>
> Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
> Cc: Simon Hardy <simon.hardy@itdev.co.uk>
> Cc: Stefan Berger <stefanb@linux.ibm.com>
> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=2728
> Signed-off-by: Laszlo Ersek <lersek@redhat.com>
> ---
>   OvmfPkg/Tcg/Tcg2Config/Tcg2ConfigPei.inf  | 11 +++++++--
>   OvmfPkg/Tcg/Tcg2Config/Tpm12Support.h     |  4 ++++
>   OvmfPkg/Tcg/Tcg2Config/Tpm12SupportNull.c | 25 ++++++++++++++++++++
>   3 files changed, 38 insertions(+), 2 deletions(-)
> 
> diff --git a/OvmfPkg/Tcg/Tcg2Config/Tcg2ConfigPei.inf b/OvmfPkg/Tcg/Tcg2Config/Tcg2ConfigPei.inf
> index aa996b7da778..194ebfba6409 100644
> --- a/OvmfPkg/Tcg/Tcg2Config/Tcg2ConfigPei.inf
> +++ b/OvmfPkg/Tcg/Tcg2Config/Tcg2ConfigPei.inf
> @@ -21,9 +21,14 @@ [Defines]
>   
>   [Sources]
>     Tcg2ConfigPeim.c
> -  Tpm12Support.c
>     Tpm12Support.h
>   
> +[Sources.IA32, Sources.X64]
> +  Tpm12Support.c
> +
> +[Sources.ARM, Sources.AARCH64]
> +  Tpm12SupportNull.c
> +
>   [Packages]
>     MdePkg/MdePkg.dec
>     MdeModulePkg/MdeModulePkg.dec
> @@ -35,9 +40,11 @@ [LibraryClasses]
>     BaseLib
>     DebugLib
>     PeiServicesLib
> -  Tpm12DeviceLib
>     Tpm2DeviceLib
>   
> +[LibraryClasses.IA32, LibraryClasses.X64]
> +  Tpm12DeviceLib
> +
>   [Guids]
>     gEfiTpmDeviceSelectedGuid           ## PRODUCES ## GUID # Used as a PPI GUID
>     gEfiTpmDeviceInstanceTpm20DtpmGuid  ## SOMETIMES_CONSUMES
> diff --git a/OvmfPkg/Tcg/Tcg2Config/Tpm12Support.h b/OvmfPkg/Tcg/Tcg2Config/Tpm12Support.h
> index c739775d2353..d92c43253081 100644
> --- a/OvmfPkg/Tcg/Tcg2Config/Tpm12Support.h
> +++ b/OvmfPkg/Tcg/Tcg2Config/Tpm12Support.h
> @@ -15,6 +15,10 @@
>   /**
>     Detect the presence of a TPM with interface version 1.2.
>   
> +  @retval EFI_UNSUPPORTED  The platform that includes this particular
> +                           implementation of the function does not support
> +                           TPM-1.2.
> +
>     @retval EFI_SUCCESS      TPM-1.2 available. The Tpm12RequestUseTpm() and
>                              Tpm12SubmitCommand(TPM_ORD_GetTicks) operations
>                              (from the Tpm12DeviceLib class) have succeeded.
> diff --git a/OvmfPkg/Tcg/Tcg2Config/Tpm12SupportNull.c b/OvmfPkg/Tcg/Tcg2Config/Tpm12SupportNull.c
> new file mode 100644
> index 000000000000..7bb377b9b9b0
> --- /dev/null
> +++ b/OvmfPkg/Tcg/Tcg2Config/Tpm12SupportNull.c
> @@ -0,0 +1,25 @@
> +/** @file
> +  Null implementation of InternalTpm12Detect(), always returning
> +  EFI_UNSUPPORTED.
> +
> +  Copyright (C) 2020, Red Hat, Inc.
> +
> +  SPDX-License-Identifier: BSD-2-Clause-Patent
> +**/
> +
> +#include "Tpm12Support.h"
> +
> +/**
> +  Detect the presence of a TPM with interface version 1.2.
> +
> +  @retval EFI_UNSUPPORTED  The platform that includes this particular
> +                           implementation of the function does not support
> +                           TPM-1.2.
> +**/
> +EFI_STATUS
> +InternalTpm12Detect (
> +  VOID
> +  )
> +{
> +  return EFI_UNSUPPORTED;
> +}
> 

Reviewed-by: Philippe Mathieu-Daude <philmd@redhat.com>