OvmfPkg: add customized Tcg2ConfigPei clone

The Tcg2ConfigPei module informs the firmware globally about the TPM
device type, by setting the PcdTpmInstanceGuid PCD to the appropriate
GUID value. The original module under SecurityPkg can perform device
detection, or read a cached value from a non-volatile UEFI variable.

OvmfPkg's clone of the module only performs the TPM2 hardware detection.

This is what the module does:

- Check the QEMU hardware for TPM2 availability only

- If found, set the dynamic PCD "PcdTpmInstanceGuid" to
  &gEfiTpmDeviceInstanceTpm20DtpmGuid. This is what informs the rest of
  the firmware about the TPM type.

- Install the gEfiTpmDeviceSelectedGuid PPI. This action permits the
  PEI_CORE to dispatch the Tcg2Pei module, which consumes the above PCD.
  In effect, the gEfiTpmDeviceSelectedGuid PPI serializes the setting
  and the consumption of the "TPM type" PCD.

- If no TPM2 was found, install gPeiTpmInitializationDonePpiGuid.
  (Normally this is performed by Tcg2Pei, but Tcg2Pei doesn't do it if
  no TPM2 is available. So in that case our Tcg2ConfigPei must do it.)

Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Stefan Berger <stefanb@linux.vnet.ibm.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>

2 files changed, 137 insertions, 0 deletions

diff --git a/OvmfPkg/Tcg/Tcg2Config/Tcg2ConfigPei.inf b/OvmfPkg/Tcg/Tcg2Config/Tcg2ConfigPei.inf
new file mode 100644
index 0000000000..234cdd6cb4
--- /dev/null
+++ b/OvmfPkg/Tcg/Tcg2Config/Tcg2ConfigPei.inf
@@ -0,0 +1,53 @@
+## @file

+#  Set TPM device type

+#

+#  In SecurityPkg, this module initializes the TPM device type based on

+#  a UEFI variable and/or hardware detection. In OvmfPkg, the module

+#  only performs TPM2 hardware detection.

+#

+# Copyright (c) 2015 - 2016, Intel Corporation. All rights reserved.<BR>

+# Copyright (C) 2018, Red Hat, Inc.

+#

+# This program and the accompanying materials

+# are licensed and made available under the terms and conditions of the BSD License

+# which accompanies this distribution. The full text of the license may be found at

+# http://opensource.org/licenses/bsd-license.php

+# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,

+# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

+#

+##

+

+[Defines]

+  INF_VERSION                    = 0x00010005

+  BASE_NAME                      = Tcg2ConfigPei

+  FILE_GUID                      = BF7F2B0C-9F2F-4889-AB5C-12460022BE87

+  MODULE_TYPE                    = PEIM

+  VERSION_STRING                 = 1.0

+  ENTRY_POINT                    = Tcg2ConfigPeimEntryPoint

+

+[Sources]

+  Tcg2ConfigPeim.c

+

+[Packages]

+  MdePkg/MdePkg.dec

+  MdeModulePkg/MdeModulePkg.dec

+  SecurityPkg/SecurityPkg.dec

+

+[LibraryClasses]

+  PeimEntryPoint

+  DebugLib

+  PeiServicesLib

+  Tpm2DeviceLib

+

+[Guids]

+  gEfiTpmDeviceSelectedGuid           ## PRODUCES             ## GUID    # Used as a PPI GUID

+  gEfiTpmDeviceInstanceTpm20DtpmGuid  ## SOMETIMES_CONSUMES

+

+[Ppis]

+  gPeiTpmInitializationDonePpiGuid    ## SOMETIMES_PRODUCES

+

+[Pcd]

+  gEfiSecurityPkgTokenSpaceGuid.PcdTpmInstanceGuid                 ## PRODUCES

+

+[Depex]

+  TRUE

diff --git a/OvmfPkg/Tcg/Tcg2Config/Tcg2ConfigPeim.c b/OvmfPkg/Tcg/Tcg2Config/Tcg2ConfigPeim.c
new file mode 100644
index 0000000000..8bee1926b3
--- /dev/null
+++ b/OvmfPkg/Tcg/Tcg2Config/Tcg2ConfigPeim.c
@@ -0,0 +1,84 @@
+/** @file

+  The module entry point for Tcg2 configuration module.

+

+Copyright (c) 2018, Red Hat, Inc.

+Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>

+

+This program and the accompanying materials

+are licensed and made available under the terms and conditions of the BSD License

+which accompanies this distribution.  The full text of the license may be found at

+http://opensource.org/licenses/bsd-license.php

+

+THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,

+WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

+

+**/

+

+

+#include <PiPei.h>

+

+#include <Guid/TpmInstance.h>

+#include <Library/DebugLib.h>

+#include <Library/PeiServicesLib.h>

+#include <Library/Tpm2DeviceLib.h>

+#include <Ppi/TpmInitialized.h>

+

+STATIC CONST EFI_PEI_PPI_DESCRIPTOR mTpmSelectedPpi = {

+  (EFI_PEI_PPI_DESCRIPTOR_PPI | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST),

+  &gEfiTpmDeviceSelectedGuid,

+  NULL

+};

+

+STATIC CONST EFI_PEI_PPI_DESCRIPTOR  mTpmInitializationDonePpiList = {

+  EFI_PEI_PPI_DESCRIPTOR_PPI | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST,

+  &gPeiTpmInitializationDonePpiGuid,

+  NULL

+};

+

+/**

+  The entry point for Tcg2 configuration driver.

+

+  @param  FileHandle  Handle of the file being invoked.

+  @param  PeiServices Describes the list of possible PEI Services.

+**/

+EFI_STATUS

+EFIAPI

+Tcg2ConfigPeimEntryPoint (

+  IN       EFI_PEI_FILE_HANDLE  FileHandle,

+  IN CONST EFI_PEI_SERVICES     **PeiServices

+  )

+{

+  UINTN                           Size;

+  EFI_STATUS                      Status;

+

+  DEBUG ((DEBUG_INFO, "%a\n", __FUNCTION__));

+

+  Status = Tpm2RequestUseTpm ();

+  if (!EFI_ERROR (Status)) {

+      DEBUG ((DEBUG_INFO, "%a: TPM2 detected\n", __FUNCTION__));

+      Size = sizeof(gEfiTpmDeviceInstanceTpm20DtpmGuid);

+      Status = PcdSetPtrS (

+          PcdTpmInstanceGuid,

+          &Size,

+          &gEfiTpmDeviceInstanceTpm20DtpmGuid

+          );

+      ASSERT_EFI_ERROR (Status);

+  } else {

+      DEBUG ((DEBUG_INFO, "%a: no TPM2 detected\n", __FUNCTION__));

+      // If no TPM2 was detected, we still need to install

+      // TpmInitializationDonePpi. Namely, Tcg2Pei will exit early upon

+      // seeing the default (all-bits-zero) contents of

+      // PcdTpmInstanceGuid, thus we have to install the PPI in its place,

+      // in order to unblock any dependent PEIMs.

+      Status = PeiServicesInstallPpi (&mTpmInitializationDonePpiList);

+      ASSERT_EFI_ERROR (Status);

+  }

+

+  //

+  // Selection done

+  //

+  Status = PeiServicesInstallPpi (&mTpmSelectedPpi);

+  ASSERT_EFI_ERROR (Status);

+

+  return Status;

+}