OvmfPkg: add Tcg2PhysicalPresenceLibQemu

Cloned "SecurityPkg/Library/DxeTcg2PhysicalPresenceLib" and:

- removed all the functions that are unreachable from
  Tcg2PhysicalPresenceLibProcessRequest() [called from platform BDS],
  or SubmitRequestToPreOSFunction() and
  ReturnOperationResponseToOsFunction() [called from Tcg2Dxe].

- replaced everything that's related to the
  TCG2_PHYSICAL_PRESENCE*_VARIABLE variables, with direct access to
  the QEMU structures.

This commit is based on initial experimental work from Stefan Berger.
In particular, he wrote most of QEMU PPI support, and designed the
qemu/firmware interaction. Initially, Stefan tried to reuse the
existing SecurityPkg code, but we eventually decided to get rid of the
variables and simplify the ovmf/qemu version.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
[lersek@redhat.com: clean up non-idiomatic coding style]
[lersek@redhat.com: null mPpi on invalid PPI address]
Reviewed-by: Laszlo Ersek <lersek@redhat.com>

OvmfPkg/Library/Tcg2PhysicalPresenceLibQemu/DxeTcg2PhysicalPresenceLib.inf

@@ -0,0 +1,76 @@
+## @file
+#  Executes TPM 2.0 requests from OS or BIOS
+#
+#  This library will check and execute TPM 2.0 request from OS or
+#  BIOS. The request may ask for user confirmation before
+#  execution. It is a clone of
+#  "SecurityPkg/Library/DxeTcg2PhysicalPresenceLib" with:
+#
+#  - removed all the functions that are unreachable from
+#    Tcg2PhysicalPresenceLibProcessRequest() [called from platform
+#    BDS], or SubmitRequestToPreOSFunction() and
+#    ReturnOperationResponseToOsFunction() [called from Tcg2Dxe].
+#
+#  - replaced everything that's related to the
+#    TCG2_PHYSICAL_PRESENCE*_VARIABLE variables, with direct access to
+#    the QEMU structures.
+#
+#  Caution: This module requires additional review when modified.
+#  This driver will have external input - variable.
+#  This external input must be validated carefully to avoid security issue.
+#
+# Copyright (C) 2018, Red Hat, Inc.
+# Copyright (c) 2013 - 2016, 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.
+#
+##
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = Tcg2PhysicalPresenceLibQemu
+  FILE_GUID                      = 41D3E698-9EEC-41FF-9CBB-5FE79A0CF326
+  MODULE_TYPE                    = DXE_DRIVER
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = Tcg2PhysicalPresenceLib|DXE_DRIVER DXE_RUNTIME_DRIVER DXE_SAL_DRIVER UEFI_APPLICATION UEFI_DRIVER
+
+#
+# The following information is for reference only and not required by the build tools.
+#
+#  VALID_ARCHITECTURES           = IA32 X64 IPF EBC
+#
+
+[Sources]
+  DxeTcg2PhysicalPresenceLib.c
+  PhysicalPresenceStrings.uni
+
+[Packages]
+  MdePkg/MdePkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+  OvmfPkg/OvmfPkg.dec
+  SecurityPkg/SecurityPkg.dec
+
+[LibraryClasses]
+  BaseMemoryLib
+  DebugLib
+  DxeServicesTableLib
+  HiiLib
+  HobLib
+  MemoryAllocationLib
+  PrintLib
+  QemuFwCfgLib
+  Tpm2CommandLib
+  UefiBootServicesTableLib
+  UefiLib
+  UefiRuntimeServicesTableLib
+
+[Protocols]
+  gEfiTcg2ProtocolGuid                 ## SOMETIMES_CONSUMES
+
+[Guids]
+  ## SOMETIMES_CONSUMES ## HII
+  gEfiTcg2PhysicalPresenceGuid