[PATCH V5 03/13] OvmfPkg/IntelTdx: Add SecTdxHelperLib


Gerd Hoffmann
 

On Sat, Jan 28, 2023 at 09:58:32PM +0800, Min Xu wrote:
From: Min M Xu <min.m.xu@...>

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4243

TdxHelperLib provides below helper functions for a td-guest.
- TdxHelperProcessTdHob
- TdxHelperMeasureTdHob
- TdxHelperMeasureCfvImage
- TdxHelperBuildGuidHobForTdxMeasurement

SecTdxHelperLib is the SEC instance of TdxHelperLib. It implements 4
functions for tdx in SEC phase:
- TdxHelperProcessTdHob consumes TdHob to accept un-accepted memories.
Before the TdHob is consumed, it is first validated.

- TdxHelperMeasureTdHob measure/extend TdHob and store the measurement
value in workarea.

- TdxHelperMeasureCfvImage measure/extend the Configuration FV image and
store the measurement value in workarea.

- TdxHelperBuildGuidHobForTdxMeasurement builds GuidHob for tdx
measurement.

This patch implements the stubs of the functions. The actual
implementations are in the following patches. Because they are moved from
other files.

Cc: Erdem Aktas <erdemaktas@...>
Cc: James Bottomley <jejb@...>
Cc: Jiewen Yao <jiewen.yao@...>
Cc: Gerd Hoffmann <kraxel@...>
Cc: Tom Lendacky <thomas.lendacky@...>
Cc: Michael Roth <michael.roth@...>
Signed-off-by: Min Xu <min.m.xu@...>
Acked-by: Gerd Hoffmann <kraxel@...>


Min Xu
 

From: Min M Xu <min.m.xu@...>

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4243

TdxHelperLib provides below helper functions for a td-guest.
- TdxHelperProcessTdHob
- TdxHelperMeasureTdHob
- TdxHelperMeasureCfvImage
- TdxHelperBuildGuidHobForTdxMeasurement

SecTdxHelperLib is the SEC instance of TdxHelperLib. It implements 4
functions for tdx in SEC phase:
- TdxHelperProcessTdHob consumes TdHob to accept un-accepted memories.
Before the TdHob is consumed, it is first validated.

- TdxHelperMeasureTdHob measure/extend TdHob and store the measurement
value in workarea.

- TdxHelperMeasureCfvImage measure/extend the Configuration FV image and
store the measurement value in workarea.

- TdxHelperBuildGuidHobForTdxMeasurement builds GuidHob for tdx
measurement.

This patch implements the stubs of the functions. The actual
implementations are in the following patches. Because they are moved from
other files.

Cc: Erdem Aktas <erdemaktas@...>
Cc: James Bottomley <jejb@...>
Cc: Jiewen Yao <jiewen.yao@...>
Cc: Gerd Hoffmann <kraxel@...>
Cc: Tom Lendacky <thomas.lendacky@...>
Cc: Michael Roth <michael.roth@...>
Signed-off-by: Min Xu <min.m.xu@...>
---
OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelper.c | 78 +++++++++++++++++++
.../IntelTdx/TdxHelperLib/SecTdxHelperLib.inf | 52 +++++++++++++
2 files changed, 130 insertions(+)
create mode 100644 OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelper.c
create mode 100644 OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelperLib.inf

diff --git a/OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelper.c b/OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelper.c
new file mode 100644
index 000000000000..ef958b335940
--- /dev/null
+++ b/OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelper.c
@@ -0,0 +1,78 @@
+/** @file
+ TdxHelper Functions which are used in SEC phase
+
+ Copyright (c) 2022 - 2023, Intel Corporation. All rights reserved.<BR>
+
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <PiPei.h>
+
+/**
+ In Tdx guest, some information need to be passed from host VMM to guest
+ firmware. For example, the memory resource, etc. These information are
+ prepared by host VMM and put in TdHob which is described in TdxMetadata.
+ TDVF processes the TdHob to accept memories.
+
+ @retval EFI_SUCCESS Successfully process the TdHob
+ @retval Others Other error as indicated
+**/
+EFI_STATUS
+EFIAPI
+TdxHelperProcessTdHob (
+ VOID
+ )
+{
+ return EFI_UNSUPPORTED;
+}
+
+/**
+ In Tdx guest, TdHob is passed from host VMM to guest firmware and it contains
+ the information of the memory resource. From the security perspective before
+ it is consumed, it should be measured and extended.
+ *
+ * @retval EFI_SUCCESS Successfully measure the TdHob
+ * @retval Others Other error as indicated
+ */
+EFI_STATUS
+EFIAPI
+TdxHelperMeasureTdHob (
+ VOID
+ )
+{
+ return EFI_UNSUPPORTED;
+}
+
+/**
+ * In Tdx guest, Configuration FV (CFV) is treated as external input because it
+ * may contain the data provided by VMM. From the sucurity perspective Cfv image
+ * should be measured before it is consumed.
+ *
+ * @retval EFI_SUCCESS Successfully measure the CFV image
+ * @retval Others Other error as indicated
+ */
+EFI_STATUS
+EFIAPI
+TdxHelperMeasureCfvImage (
+ VOID
+ )
+{
+ return EFI_UNSUPPORTED;
+}
+
+/**
+ Build the GuidHob for tdx measurements which were done in SEC phase.
+ The measurement values are stored in WorkArea.
+
+ @retval EFI_SUCCESS The GuidHob is built successfully
+ @retval Others Other errors as indicated
+**/
+EFI_STATUS
+EFIAPI
+TdxHelperBuildGuidHobForTdxMeasurement (
+ VOID
+ )
+{
+ return EFI_UNSUPPORTED;
+}
diff --git a/OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelperLib.inf b/OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelperLib.inf
new file mode 100644
index 000000000000..3c6b96f7759a
--- /dev/null
+++ b/OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelperLib.inf
@@ -0,0 +1,52 @@
+## @file
+# TdxHelperLib SEC instance
+#
+# This module provides Tdx helper functions in SEC phase.
+# Copyright (c) 2021 - 2023, Intel Corporation. All rights reserved.<BR>
+#
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+ INF_VERSION = 0x00010005
+ BASE_NAME = SecTdxHelperLib
+ FILE_GUID = ba69ac6b-0c59-4472-899d-b684590ec1e9
+ MODULE_TYPE = BASE
+ VERSION_STRING = 1.0
+ LIBRARY_CLASS = TdxHelperLib|SEC
+
+#
+# The following information is for reference only and not required by the build tools.
+#
+# VALID_ARCHITECTURES = X64
+#
+
+[Sources]
+ SecTdxHelper.c
+
+[Packages]
+ CryptoPkg/CryptoPkg.dec
+ MdeModulePkg/MdeModulePkg.dec
+ MdePkg/MdePkg.dec
+ OvmfPkg/OvmfPkg.dec
+ SecurityPkg/SecurityPkg.dec
+
+[LibraryClasses]
+ BaseLib
+ BaseCryptLib
+ DebugLib
+ HobLib
+ PcdLib
+ TdxMailboxLib
+ TdxLib
+
+[FixedPcd]
+ gUefiOvmfPkgTokenSpaceGuid.PcdOvmfWorkAreaBase
+ gUefiOvmfPkgTokenSpaceGuid.PcdTdxAcceptPageSize
+ gUefiOvmfPkgTokenSpaceGuid.PcdOvmfSecGhcbBase
+ gUefiOvmfPkgTokenSpaceGuid.PcdOvmfFlashNvStorageVariableBase
+ gUefiOvmfPkgTokenSpaceGuid.PcdCfvRawDataSize
+
+[Guids]
+ gCcEventEntryHobGuid
--
2.29.2.windows.2