[PATCH V4 06/12] OvmfPkg/PeilessStartupLib: Build GuidHob for Tdx measurement


Min Xu
 

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

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

2 new functions are added in PeilessStartupLib/IntelTdx.c.
- BuildTdxMeasurementGuidHob
- InternalBuildGuidHobForTdxMeasurement

These 2 functions build GuidHob for Tdx measurement. These 2 functions
are to be moved to TdxHelperLib in the following patch. That is to make
the code more reviewable.

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/Library/PeilessStartupLib/IntelTdx.c | 180 ++++++++++++++++++
.../PeilessStartupLib/PeilessStartupLib.inf | 2 +
2 files changed, 182 insertions(+)

diff --git a/OvmfPkg/Library/PeilessStartupLib/IntelTdx.c b/OvmfPkg/Library/PeilessStartupLib/IntelTdx.c
index 4e8dca3d7712..8c2a031ee9c7 100644
--- a/OvmfPkg/Library/PeilessStartupLib/IntelTdx.c
+++ b/OvmfPkg/Library/PeilessStartupLib/IntelTdx.c
@@ -13,6 +13,7 @@
#include <Library/PrintLib.h>
#include <Library/TcgEventLogRecordLib.h>
#include <Library/TpmMeasurementLib.h>
+#include <WorkArea.h>

#include "PeilessStartupInternal.h"

@@ -90,6 +91,89 @@ MeasureHobList (
return Status;
}

+/**
+ * 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;
+}
+
/**
Get the FvName from the FV header.

@@ -136,6 +220,102 @@ GetFvName (
return &FvExtHeader->FvName;
}

+/**
+ 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;
+ VOID *FvName;
+ CFV_HANDOFF_TABLE_POINTERS2 FvBlob2;
+ EFI_PHYSICAL_ADDRESS FvBase;
+ UINT64 FvLength;
+ 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;
+ }
+
+ //
+ // Build the GuidHob for Cfv measurement
+ //
+ if (WorkArea->TdxWorkArea.SecTdxWorkArea.TdxMeasurementsData.MeasurementsBitmap & TDX_MEASUREMENT_CFVIMG_BITMASK) {
+ HashValue = WorkArea->TdxWorkArea.SecTdxWorkArea.TdxMeasurementsData.CfvImgHashValue;
+ FvBase = (UINT64)PcdGet32 (PcdOvmfFlashNvStorageVariableBase);
+ FvLength = (UINT64)PcdGet32 (PcdCfvRawDataSize);
+ FvBlob2.BlobDescriptionSize = sizeof (FvBlob2.BlobDescription);
+ CopyMem (FvBlob2.BlobDescription, FV_HANDOFF_TABLE_DESC, sizeof (FvBlob2.BlobDescription));
+ FvName = GetFvName (FvBase, FvLength);
+ if (FvName != NULL) {
+ AsciiSPrint ((CHAR8 *)FvBlob2.BlobDescription, sizeof (FvBlob2.BlobDescription), "Fv(%g)", FvName);
+ }
+
+ FvBlob2.BlobBase = FvBase;
+ FvBlob2.BlobLength = FvLength;
+
+ Status = BuildTdxMeasurementGuidHob (
+ 0, // RtmrIndex
+ EV_EFI_PLATFORM_FIRMWARE_BLOB2, // EventType
+ (VOID *)&FvBlob2, // EventData
+ sizeof (FvBlob2), // EventSize
+ HashValue, // HashValue
+ SHA384_DIGEST_SIZE // HashSize
+ );
+ }
+
+ if (EFI_ERROR (Status)) {
+ ASSERT (FALSE);
+ return Status;
+ }
+
+ return EFI_SUCCESS;
+}
+
/**
Measure FV image.

diff --git a/OvmfPkg/Library/PeilessStartupLib/PeilessStartupLib.inf b/OvmfPkg/Library/PeilessStartupLib/PeilessStartupLib.inf
index 5c6eb1597bea..f9012ccd68d0 100644
--- a/OvmfPkg/Library/PeilessStartupLib/PeilessStartupLib.inf
+++ b/OvmfPkg/Library/PeilessStartupLib/PeilessStartupLib.inf
@@ -89,3 +89,5 @@
gEfiMdeModulePkgTokenSpaceGuid.PcdNullPointerDetectionPropertyMask ## CONSUMES
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfDxeMemFvBase
gUefiOvmfPkgTokenSpaceGuid.PcdOvmfDxeMemFvSize
+ gUefiOvmfPkgTokenSpaceGuid.PcdOvmfFlashNvStorageVariableBase
+ gUefiOvmfPkgTokenSpaceGuid.PcdOvmfWorkAreaBase
--
2.29.2.windows.2

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