[edk2-devel] [PATCH V4 03/12] OvmfPkg/IntelTdx: Add SecTdxHelperLib
Min Xu
min.m.xu at intel.com
Fri Jan 27 00:10:57 UTC 2023
From: Min M Xu <min.m.xu at intel.com>
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 TdxHelperMeasureTdHob and TdxHelperMeasureCfvImage.
TdxHelperProcessTdHob and TdxHelperBuildGuidHobForTdxMeasurement will be
implemented in the following patches. Because these 2 functions are to be
moved from other files, such as PlatformInitLib/IntelTdx.c.
Cc: Erdem Aktas <erdemaktas at google.com>
Cc: James Bottomley <jejb at linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao at intel.com>
Cc: Gerd Hoffmann <kraxel at redhat.com>
Cc: Tom Lendacky <thomas.lendacky at amd.com>
Cc: Michael Roth <michael.roth at amd.com>
Signed-off-by: Min Xu <min.m.xu at intel.com>
---
OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelper.c | 212 ++++++++++++++++++
.../IntelTdx/TdxHelperLib/SecTdxHelperLib.inf | 52 +++++
2 files changed, 264 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..f64071827658
--- /dev/null
+++ b/OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelper.c
@@ -0,0 +1,212 @@
+/** @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 <Base.h>
+#include <PiPei.h>
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/HobLib.h>
+#include <Library/BaseCryptLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <IndustryStandard/Tdx.h>
+#include <IndustryStandard/IntelTdx.h>
+#include <IndustryStandard/Tpm20.h>
+#include <Library/TdxLib.h>
+#include <Pi/PrePiHob.h>
+#include <WorkArea.h>
+#include <ConfidentialComputingGuestAttr.h>
+#include <Library/TdxHelperLib.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;
+}
+
+/**
+ * Calculate the sha384 of input Data and extend it to RTMR register.
+ *
+ * @param RtmrIndex Index of the RTMR register
+ * @param DataToHash Data to be hashed
+ * @param DataToHashLen Length of the data
+ * @param Digest Hash value of the input data
+ * @param DigestLen Length of the hash value
+ *
+ * @retval EFI_SUCCESS Successfully hash and extend to RTMR
+ * @retval Others Other errors as indicated
+ */
+STATIC
+EFI_STATUS
+HashAndExtendToRtmr (
+ IN UINT32 RtmrIndex,
+ IN VOID *DataToHash,
+ IN UINTN DataToHashLen,
+ OUT UINT8 *Digest,
+ IN UINTN DigestLen
+ )
+{
+ EFI_STATUS Status;
+
+ if ((DataToHash == NULL) || (DataToHashLen == 0)) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ if ((Digest == NULL) || (DigestLen != SHA384_DIGEST_SIZE)) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ //
+ // Calculate the sha384 of the data
+ //
+ if (!Sha384HashAll (DataToHash, DataToHashLen, Digest)) {
+ return EFI_ABORTED;
+ }
+
+ //
+ // Extend to RTMR
+ //
+ Status = TdExtendRtmr (
+ (UINT32 *)Digest,
+ SHA384_DIGEST_SIZE,
+ (UINT8)RtmrIndex
+ );
+
+ ASSERT (!EFI_ERROR (Status));
+ return Status;
+}
+
+/**
+ 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
+ )
+{
+ EFI_PEI_HOB_POINTERS Hob;
+ EFI_STATUS Status;
+ UINT8 Digest[SHA384_DIGEST_SIZE];
+ OVMF_WORK_AREA *WorkArea;
+ VOID *TdHob;
+
+ TdHob = (VOID *)(UINTN)FixedPcdGet32 (PcdOvmfSecGhcbBase);
+ Hob.Raw = (UINT8 *)TdHob;
+
+ //
+ // Walk thru the TdHob list until end of list.
+ //
+ while (!END_OF_HOB_LIST (Hob)) {
+ Hob.Raw = GET_NEXT_HOB (Hob);
+ }
+
+ Status = HashAndExtendToRtmr (
+ 0,
+ (UINT8 *)TdHob,
+ (UINTN)((UINT8 *)Hob.Raw - (UINT8 *)TdHob),
+ Digest,
+ SHA384_DIGEST_SIZE
+ );
+
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ //
+ // This function is called in SEC phase and at that moment the Hob service
+ // is not available. So the TdHob measurement value is stored in workarea.
+ //
+ WorkArea = (OVMF_WORK_AREA *)FixedPcdGet32 (PcdOvmfWorkAreaBase);
+ if (WorkArea == NULL) {
+ return EFI_DEVICE_ERROR;
+ }
+
+ WorkArea->TdxWorkArea.SecTdxWorkArea.TdxMeasurementsData.MeasurementsBitmap |= TDX_MEASUREMENT_TDHOB_BITMASK;
+ CopyMem (WorkArea->TdxWorkArea.SecTdxWorkArea.TdxMeasurementsData.TdHobHashValue, Digest, SHA384_DIGEST_SIZE);
+
+ return EFI_SUCCESS;
+}
+
+/**
+ * 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
+ )
+{
+ EFI_STATUS Status;
+ UINT8 Digest[SHA384_DIGEST_SIZE];
+ OVMF_WORK_AREA *WorkArea;
+
+ Status = HashAndExtendToRtmr (
+ 0,
+ (UINT8 *)(UINTN)PcdGet32 (PcdOvmfFlashNvStorageVariableBase),
+ (UINT64)PcdGet32 (PcdCfvRawDataSize),
+ Digest,
+ SHA384_DIGEST_SIZE
+ );
+
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ //
+ // This function is called in SEC phase and at that moment the Hob service
+ // is not available. So CfvImage measurement value is stored in workarea.
+ //
+ WorkArea = (OVMF_WORK_AREA *)FixedPcdGet32 (PcdOvmfWorkAreaBase);
+ if (WorkArea == NULL) {
+ return EFI_DEVICE_ERROR;
+ }
+
+ WorkArea->TdxWorkArea.SecTdxWorkArea.TdxMeasurementsData.MeasurementsBitmap |= TDX_MEASUREMENT_CFVIMG_BITMASK;
+ CopyMem (WorkArea->TdxWorkArea.SecTdxWorkArea.TdxMeasurementsData.CfvImgHashValue, Digest, SHA384_DIGEST_SIZE);
+
+ return EFI_SUCCESS;
+}
+
+/**
+ 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
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