[edk2-devel] [PATCH V6 05/12] OvmfPkg: Refactor MeasureHobList

Min Xu min.m.xu at intel.com
Fri Feb 3 03:31:40 UTC 2023


From: Min M Xu <min.m.xu at intel.com>

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

MeasureHobList once was implemented in PeilessStartupLib and it does
measurement and logging for TdHob in one go, using TpmMeasureAndLogData().
But it doesn't work in SEC.

This patch splits MeasureHobList into 2 functions and implement them in
SecTdxHelperLib.
 - TdxHelperMeasureTdHob
 - TdxHelperBuildGuidHobForTdxMeasurement

TdxHelperMeasureTdHob measures the TdHob and stores the hash value in
WorkArea. TdxHelperBuildGuidHobForTdxMeasurement builds GuidHob for the
measurement based on the hash value in WorkArea.

After these 2 functions are introduced, PeilessStartupLib should also be
updated:
 - Call these 2 functions instead of the MeasureHobList
 - Delete the duplicated codes in PeilessStartupLib

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>
Acked-by: Gerd Hoffmann <kraxel at redhat.com>
Reviewed-by: Jiewen Yao <jiewen.yao at intel.com>
Signed-off-by: Min Xu <min.m.xu at intel.com>
---
 OvmfPkg/IntelTdx/IntelTdxX64.dsc              |   1 +
 OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelper.c  | 123 ++++++++++++-
 .../IntelTdx/TdxHelperLib/SecTdxHelperLib.inf |   1 +
 .../IntelTdx/TdxHelperLib/TdxMeasurementHob.c | 173 ++++++++++++++++++
 OvmfPkg/Library/PeilessStartupLib/IntelTdx.c  |  71 -------
 .../PeilessStartupLib/PeilessStartup.c        |  12 +-
 .../PeilessStartupInternal.h                  |  15 --
 7 files changed, 308 insertions(+), 88 deletions(-)
 create mode 100644 OvmfPkg/IntelTdx/TdxHelperLib/TdxMeasurementHob.c

diff --git a/OvmfPkg/IntelTdx/IntelTdxX64.dsc b/OvmfPkg/IntelTdx/IntelTdxX64.dsc
index 0f1e970fbbb3..920f1c6080d4 100644
--- a/OvmfPkg/IntelTdx/IntelTdxX64.dsc
+++ b/OvmfPkg/IntelTdx/IntelTdxX64.dsc
@@ -549,6 +549,7 @@
     <LibraryClasses>
       NULL|MdeModulePkg/Library/LzmaCustomDecompressLib/LzmaCustomDecompressLib.inf
       TpmMeasurementLib|SecurityPkg/Library/SecTpmMeasurementLib/SecTpmMeasurementLibTdx.inf
+      NULL|OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelperLib.inf
       BaseCryptLib|CryptoPkg/Library/BaseCryptLib/SecCryptLib.inf
       HashLib|SecurityPkg/Library/HashLibTdx/HashLibTdx.inf
       NULL|SecurityPkg/Library/HashInstanceLibSha384/HashInstanceLibSha384.inf
diff --git a/OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelper.c b/OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelper.c
index ef958b335940..6ca6f01aff57 100644
--- a/OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelper.c
+++ b/OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelper.c
@@ -8,6 +8,31 @@
 **/
 
 #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>
+
+/**
+  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
+InternalBuildGuidHobForTdxMeasurement (
+  VOID
+  );
 
 /**
   In Tdx guest, some information need to be passed from host VMM to guest
@@ -27,6 +52,58 @@ TdxHelperProcessTdHob (
   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
@@ -41,7 +118,47 @@ TdxHelperMeasureTdHob (
   VOID
   )
 {
-  return EFI_UNSUPPORTED;
+  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;
 }
 
 /**
@@ -74,5 +191,9 @@ TdxHelperBuildGuidHobForTdxMeasurement (
   VOID
   )
 {
+ #ifdef TDX_PEI_LESS_BOOT
+  return InternalBuildGuidHobForTdxMeasurement ();
+ #else
   return EFI_UNSUPPORTED;
+ #endif
 }
diff --git a/OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelperLib.inf b/OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelperLib.inf
index 3c6b96f7759a..d17b84c01f20 100644
--- a/OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelperLib.inf
+++ b/OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelperLib.inf
@@ -24,6 +24,7 @@
 
 [Sources]
   SecTdxHelper.c
+  TdxMeasurementHob.c
 
 [Packages]
   CryptoPkg/CryptoPkg.dec
diff --git a/OvmfPkg/IntelTdx/TdxHelperLib/TdxMeasurementHob.c b/OvmfPkg/IntelTdx/TdxHelperLib/TdxMeasurementHob.c
new file mode 100644
index 000000000000..6cbc7600adb6
--- /dev/null
+++ b/OvmfPkg/IntelTdx/TdxHelperLib/TdxMeasurementHob.c
@@ -0,0 +1,173 @@
+/** @file
+  Build GuidHob for tdx measurement.
+
+  Copyright (c) 2022 - 2023, Intel Corporation. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <PiPei.h>
+#include <Library/BaseLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/DebugLib.h>
+#include <IndustryStandard/Tpm20.h>
+#include <IndustryStandard/UefiTcgPlatform.h>
+#include <Library/HobLib.h>
+#include <Library/PrintLib.h>
+#include <WorkArea.h>
+
+#pragma pack(1)
+
+#define HANDOFF_TABLE_DESC  "TdxTable"
+typedef struct {
+  UINT8                      TableDescriptionSize;
+  UINT8                      TableDescription[sizeof (HANDOFF_TABLE_DESC)];
+  UINT64                     NumberOfTables;
+  EFI_CONFIGURATION_TABLE    TableEntry[1];
+} TDX_HANDOFF_TABLE_POINTERS2;
+
+#pragma pack()
+
+/**
+ * Build GuidHob for Tdx measurement.
+ *
+ * Tdx measurement includes the measurement of TdHob and CFV. They're measured
+ * and extended to RTMR registers in SEC phase. Because at that moment the Hob
+ * service are not available. So the values of the measurement are saved in
+ * workarea and will be built into GuidHob after the Hob service is ready.
+ *
+ * @param RtmrIndex     RTMR index
+ * @param EventType     Event type
+ * @param EventData     Event data
+ * @param EventSize     Size of event data
+ * @param HashValue     Hash value
+ * @param HashSize      Size of hash
+ *
+ * @retval EFI_SUCCESS  Successfully build the GuidHobs
+ * @retval Others       Other error as indicated
+ */
+STATIC
+EFI_STATUS
+BuildTdxMeasurementGuidHob (
+  UINT32  RtmrIndex,
+  UINT32  EventType,
+  UINT8   *EventData,
+  UINT32  EventSize,
+  UINT8   *HashValue,
+  UINT32  HashSize
+  )
+{
+  VOID                *EventHobData;
+  UINT8               *Ptr;
+  TPML_DIGEST_VALUES  *TdxDigest;
+
+  if (HashSize != SHA384_DIGEST_SIZE) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  #define TDX_DIGEST_VALUE_LEN  (sizeof (UINT32) + sizeof (TPMI_ALG_HASH) + SHA384_DIGEST_SIZE)
+
+  EventHobData = BuildGuidHob (
+                   &gCcEventEntryHobGuid,
+                   sizeof (TCG_PCRINDEX) + sizeof (TCG_EVENTTYPE) +
+                   TDX_DIGEST_VALUE_LEN +
+                   sizeof (UINT32) + EventSize
+                   );
+
+  if (EventHobData == NULL) {
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  Ptr = (UINT8 *)EventHobData;
+
+  //
+  // There are 2 types of measurement registers in TDX: MRTD and RTMR[0-3].
+  // According to UEFI Spec 2.10 Section 38.4.1, RTMR[0-3] is mapped to MrIndex[1-4].
+  // So RtmrIndex must be increased by 1 before the event log is created.
+  //
+  RtmrIndex++;
+  CopyMem (Ptr, &RtmrIndex, sizeof (UINT32));
+  Ptr += sizeof (UINT32);
+
+  CopyMem (Ptr, &EventType, sizeof (TCG_EVENTTYPE));
+  Ptr += sizeof (TCG_EVENTTYPE);
+
+  TdxDigest                     = (TPML_DIGEST_VALUES *)Ptr;
+  TdxDigest->count              = 1;
+  TdxDigest->digests[0].hashAlg = TPM_ALG_SHA384;
+  CopyMem (
+    TdxDigest->digests[0].digest.sha384,
+    HashValue,
+    SHA384_DIGEST_SIZE
+    );
+  Ptr += TDX_DIGEST_VALUE_LEN;
+
+  CopyMem (Ptr, &EventSize, sizeof (UINT32));
+  Ptr += sizeof (UINT32);
+
+  CopyMem (Ptr, (VOID *)EventData, EventSize);
+  Ptr += EventSize;
+
+  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
+InternalBuildGuidHobForTdxMeasurement (
+  VOID
+  )
+{
+  EFI_STATUS                   Status;
+  OVMF_WORK_AREA               *WorkArea;
+  VOID                         *TdHobList;
+  TDX_HANDOFF_TABLE_POINTERS2  HandoffTables;
+  UINT8                        *HashValue;
+
+  if (!TdIsEnabled ()) {
+    ASSERT (FALSE);
+    return EFI_UNSUPPORTED;
+  }
+
+  WorkArea = (OVMF_WORK_AREA *)FixedPcdGet32 (PcdOvmfWorkAreaBase);
+  if (WorkArea == NULL) {
+    return EFI_ABORTED;
+  }
+
+  Status = EFI_SUCCESS;
+
+  //
+  // Build the GuidHob for TdHob measurement
+  //
+  TdHobList = (VOID *)(UINTN)FixedPcdGet32 (PcdOvmfSecGhcbBase);
+  if (WorkArea->TdxWorkArea.SecTdxWorkArea.TdxMeasurementsData.MeasurementsBitmap & TDX_MEASUREMENT_TDHOB_BITMASK) {
+    HashValue                          = WorkArea->TdxWorkArea.SecTdxWorkArea.TdxMeasurementsData.TdHobHashValue;
+    HandoffTables.TableDescriptionSize = sizeof (HandoffTables.TableDescription);
+    CopyMem (HandoffTables.TableDescription, HANDOFF_TABLE_DESC, sizeof (HandoffTables.TableDescription));
+    HandoffTables.NumberOfTables = 1;
+    CopyGuid (&(HandoffTables.TableEntry[0].VendorGuid), &gUefiOvmfPkgTokenSpaceGuid);
+    HandoffTables.TableEntry[0].VendorTable = TdHobList;
+
+    Status = BuildTdxMeasurementGuidHob (
+               0,                               // RtmrIndex
+               EV_EFI_HANDOFF_TABLES2,          // EventType
+               (UINT8 *)(UINTN)&HandoffTables,  // EventData
+               sizeof (HandoffTables),          // EventSize
+               HashValue,                       // HashValue
+               SHA384_DIGEST_SIZE               // HashSize
+               );
+  }
+
+  if (EFI_ERROR (Status)) {
+    ASSERT (FALSE);
+    return Status;
+  }
+
+  return EFI_SUCCESS;
+}
diff --git a/OvmfPkg/Library/PeilessStartupLib/IntelTdx.c b/OvmfPkg/Library/PeilessStartupLib/IntelTdx.c
index 4e8dca3d7712..ae0ffcc95da5 100644
--- a/OvmfPkg/Library/PeilessStartupLib/IntelTdx.c
+++ b/OvmfPkg/Library/PeilessStartupLib/IntelTdx.c
@@ -16,80 +16,9 @@
 
 #include "PeilessStartupInternal.h"
 
-#pragma pack(1)
-
-#define HANDOFF_TABLE_DESC  "TdxTable"
-typedef struct {
-  UINT8                      TableDescriptionSize;
-  UINT8                      TableDescription[sizeof (HANDOFF_TABLE_DESC)];
-  UINT64                     NumberOfTables;
-  EFI_CONFIGURATION_TABLE    TableEntry[1];
-} TDX_HANDOFF_TABLE_POINTERS2;
-
-#pragma pack()
-
 #define FV_HANDOFF_TABLE_DESC  "Fv(XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX)"
 typedef PLATFORM_FIRMWARE_BLOB2_STRUCT CFV_HANDOFF_TABLE_POINTERS2;
 
-/**
-  Measure the Hoblist passed from the VMM.
-
-  @param[in] VmmHobList    The Hoblist pass the firmware
-
-  @retval EFI_SUCCESS           Fv image is measured successfully
-                                or it has been already measured.
-  @retval Others                Other errors as indicated
-**/
-EFI_STATUS
-EFIAPI
-MeasureHobList (
-  IN CONST VOID  *VmmHobList
-  )
-{
-  EFI_PEI_HOB_POINTERS         Hob;
-  TDX_HANDOFF_TABLE_POINTERS2  HandoffTables;
-  EFI_STATUS                   Status;
-
-  if (!TdIsEnabled ()) {
-    ASSERT (FALSE);
-    return EFI_UNSUPPORTED;
-  }
-
-  Hob.Raw = (UINT8 *)VmmHobList;
-
-  //
-  // Parse the HOB list until end of list.
-  //
-  while (!END_OF_HOB_LIST (Hob)) {
-    Hob.Raw = GET_NEXT_HOB (Hob);
-  }
-
-  //
-  // Init the log event for HOB measurement
-  //
-
-  HandoffTables.TableDescriptionSize = sizeof (HandoffTables.TableDescription);
-  CopyMem (HandoffTables.TableDescription, HANDOFF_TABLE_DESC, sizeof (HandoffTables.TableDescription));
-  HandoffTables.NumberOfTables = 1;
-  CopyGuid (&(HandoffTables.TableEntry[0].VendorGuid), &gUefiOvmfPkgTokenSpaceGuid);
-  HandoffTables.TableEntry[0].VendorTable = (VOID *)VmmHobList;
-
-  Status = TpmMeasureAndLogData (
-             1,                                              // PCRIndex
-             EV_EFI_HANDOFF_TABLES2,                         // EventType
-             (VOID *)&HandoffTables,                         // EventData
-             sizeof (HandoffTables),                         // EventSize
-             (UINT8 *)(UINTN)VmmHobList,                     // HashData
-             (UINTN)((UINT8 *)Hob.Raw - (UINT8 *)VmmHobList) // HashDataLen
-             );
-
-  if (EFI_ERROR (Status)) {
-    ASSERT (FALSE);
-  }
-
-  return Status;
-}
-
 /**
   Get the FvName from the FV header.
 
diff --git a/OvmfPkg/Library/PeilessStartupLib/PeilessStartup.c b/OvmfPkg/Library/PeilessStartupLib/PeilessStartup.c
index 928120d183ba..4efbc14d5921 100644
--- a/OvmfPkg/Library/PeilessStartupLib/PeilessStartup.c
+++ b/OvmfPkg/Library/PeilessStartupLib/PeilessStartup.c
@@ -17,6 +17,7 @@
 #include <Library/PrePiLib.h>
 #include <Library/PeilessStartupLib.h>
 #include <Library/PlatformInitLib.h>
+#include <Library/TdxHelperLib.h>
 #include <ConfidentialComputingGuestAttr.h>
 #include <Guid/MemoryTypeInformation.h>
 #include <OvmfPlatforms.h>
@@ -179,7 +180,16 @@ PeilessStartup (
     //
     // Measure HobList
     //
-    Status = MeasureHobList (VmmHobList);
+    Status = TdxHelperMeasureTdHob ();
+    if (EFI_ERROR (Status)) {
+      ASSERT (FALSE);
+      CpuDeadLoop ();
+    }
+
+    //
+    // Build GuidHob for tdx measurement
+    //
+    Status = TdxHelperBuildGuidHobForTdxMeasurement ();
     if (EFI_ERROR (Status)) {
       ASSERT (FALSE);
       CpuDeadLoop ();
diff --git a/OvmfPkg/Library/PeilessStartupLib/PeilessStartupInternal.h b/OvmfPkg/Library/PeilessStartupLib/PeilessStartupInternal.h
index f56bc3578e5e..a2d2c1c9145b 100644
--- a/OvmfPkg/Library/PeilessStartupLib/PeilessStartupInternal.h
+++ b/OvmfPkg/Library/PeilessStartupLib/PeilessStartupInternal.h
@@ -58,21 +58,6 @@ EFIAPI
 ConstructSecHobList (
   );
 
-/**
-  Measure the Hoblist passed from the VMM.
-
-  @param[in] VmmHobList    The Hoblist pass the firmware
-
-  @retval EFI_SUCCESS           Fv image is measured successfully
-                                or it has been already measured.
-  @retval Others                Other errors as indicated
-**/
-EFI_STATUS
-EFIAPI
-MeasureHobList (
-  IN CONST VOID  *VmmHobList
-  );
-
 /**
   Measure FV image.
 
-- 
2.29.2.windows.2



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