OvmfPkg: Refactor MeaureFvImage

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

MeasureFvImage once was implemented in PeilessStartupLib and it does
measurement and logging for Configuration FV (Cfv) image in one go,
using TpmMeasureAndLogData(). But it doesn't work in SEC.

This patch splits MeasureFvImage into 2 functions and implement them in
SecTdxHelperLib.
 - TdxHelperMeasureCfvImage
 - TdxHelperBuildGuidHobForTdxMeasurement

TdxHelperMeasureCfvImage measures the Cfv image 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 MeasureFvImage
 - Delete the duplicated codes in PeilessStartupLib

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

2 files changed, 115 insertions, 1 deletions

diff --git a/OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelper.c b/OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelper.c
index 6ca6f01aff..1929093f91 100644
--- a/OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelper.c
+++ b/OvmfPkg/IntelTdx/TdxHelperLib/SecTdxHelper.c
@@ -175,7 +175,35 @@ TdxHelperMeasureCfvImage (
   VOID

   )

 {

-  return EFI_UNSUPPORTED;

+  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;

 }

 

 /**

diff --git a/OvmfPkg/IntelTdx/TdxHelperLib/TdxMeasurementHob.c b/OvmfPkg/IntelTdx/TdxHelperLib/TdxMeasurementHob.c
index 6cbc7600ad..a4c7095cff 100644
--- a/OvmfPkg/IntelTdx/TdxHelperLib/TdxMeasurementHob.c
+++ b/OvmfPkg/IntelTdx/TdxHelperLib/TdxMeasurementHob.c
@@ -15,6 +15,7 @@
 #include <IndustryStandard/UefiTcgPlatform.h>

 #include <Library/HobLib.h>

 #include <Library/PrintLib.h>

+#include <Library/TcgEventLogRecordLib.h>

 #include <WorkArea.h>

 

 #pragma pack(1)

@@ -29,6 +30,9 @@ typedef struct {
 

 #pragma pack()

 

+#define FV_HANDOFF_TABLE_DESC  "Fv(XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX)"

+typedef PLATFORM_FIRMWARE_BLOB2_STRUCT CFV_HANDOFF_TABLE_POINTERS2;

+

 /**

  * Build GuidHob for Tdx measurement.

  *

@@ -113,6 +117,52 @@ BuildTdxMeasurementGuidHob (
 }

 

 /**

+  Get the FvName from the FV header.

+

+  Causion: The FV is untrusted input.

+

+  @param[in]  FvBase            Base address of FV image.

+  @param[in]  FvLength          Length of FV image.

+

+  @return FvName pointer

+  @retval NULL   FvName is NOT found

+**/

+VOID *

+GetFvName (

+  IN EFI_PHYSICAL_ADDRESS  FvBase,

+  IN UINT64                FvLength

+  )

+{

+  EFI_FIRMWARE_VOLUME_HEADER      *FvHeader;

+  EFI_FIRMWARE_VOLUME_EXT_HEADER  *FvExtHeader;

+

+  if (FvBase >= MAX_ADDRESS) {

+    return NULL;

+  }

+

+  if (FvLength >= MAX_ADDRESS - FvBase) {

+    return NULL;

+  }

+

+  if (FvLength < sizeof (EFI_FIRMWARE_VOLUME_HEADER)) {

+    return NULL;

+  }

+

+  FvHeader = (EFI_FIRMWARE_VOLUME_HEADER *)(UINTN)FvBase;

+  if (FvHeader->ExtHeaderOffset < sizeof (EFI_FIRMWARE_VOLUME_HEADER)) {

+    return NULL;

+  }

+

+  if (FvHeader->ExtHeaderOffset + sizeof (EFI_FIRMWARE_VOLUME_EXT_HEADER) > FvLength) {

+    return NULL;

+  }

+

+  FvExtHeader = (EFI_FIRMWARE_VOLUME_EXT_HEADER *)(UINTN)(FvBase + FvHeader->ExtHeaderOffset);

+

+  return &FvExtHeader->FvName;

+}

+

+/**

   Build the GuidHob for tdx measurements which were done in SEC phase.

   The measurement values are stored in WorkArea.

 

@@ -128,6 +178,10 @@ InternalBuildGuidHobForTdxMeasurement (
   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 ()) {

@@ -169,5 +223,37 @@ InternalBuildGuidHobForTdxMeasurement (
     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;

 }