[edk2-devel] [PATCH V5 2/8] OvmfPkg/PeilessStartupLib: Delete TdxValidateCfv

Min Xu min.m.xu at intel.com
Tue Sep 6 04:35:54 UTC 2022


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

TdxValidateCfv is used to validate the integrity of FlashNvVarStore
(PcdOvmfFlashNvStorageVariableBase) and it is not Tdx specific.
So it will be moved to PlatformInitLib and be renamed to
PlatformValidateNvVarStore in the following patch. And it will be called
before EmuVaribleNvStore is initialized with the content in
FlashNvVarStore.

Cc: Erdem Aktas <erdemaktas at google.com>
Cc: James Bottomley <jejb at linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao at intel.com>
Cc: Tom Lendacky <thomas.lendacky at amd.com>
Cc: Gerd Hoffmann <kraxel at redhat.com>
Acked-by: Gerd Hoffmann <kraxel at redhat.com>
Signed-off-by: Min Xu <min.m.xu at intel.com>
---
 OvmfPkg/Library/PeilessStartupLib/IntelTdx.c  | 153 ------------------
 .../PeilessStartupLib/PeilessStartup.c        |   8 -
 .../PeilessStartupInternal.h                  |  17 --
 3 files changed, 178 deletions(-)

diff --git a/OvmfPkg/Library/PeilessStartupLib/IntelTdx.c b/OvmfPkg/Library/PeilessStartupLib/IntelTdx.c
index 484fd21057c8..216c413caad5 100644
--- a/OvmfPkg/Library/PeilessStartupLib/IntelTdx.c
+++ b/OvmfPkg/Library/PeilessStartupLib/IntelTdx.c
@@ -7,8 +7,6 @@
 #include <Library/BaseLib.h>
 #include <Library/BaseMemoryLib.h>
 #include <Library/DebugLib.h>
-#include <Guid/VariableFormat.h>
-#include <Guid/SystemNvDataGuid.h>
 #include <IndustryStandard/Tpm20.h>
 #include <IndustryStandard/UefiTcgPlatform.h>
 #include <Library/HobLib.h>
@@ -37,157 +35,6 @@ typedef struct {
 
 #pragma pack()
 
-/**
-  Check padding data all bit should be 1.
-
-  @param[in] Buffer     - A pointer to buffer header
-  @param[in] BufferSize - Buffer size
-
-  @retval  TRUE   - The padding data is valid.
-  @retval  TRUE  - The padding data is invalid.
-
-**/
-BOOLEAN
-CheckPaddingData (
-  IN UINT8   *Buffer,
-  IN UINT32  BufferSize
-  )
-{
-  UINT32  index;
-
-  for (index = 0; index < BufferSize; index++) {
-    if (Buffer[index] != 0xFF) {
-      return FALSE;
-    }
-  }
-
-  return TRUE;
-}
-
-/**
-  Check the integrity of CFV data.
-
-  @param[in] TdxCfvBase - A pointer to CFV header
-  @param[in] TdxCfvSize - CFV data size
-
-  @retval  TRUE   - The CFV data is valid.
-  @retval  FALSE  - The CFV data is invalid.
-
-**/
-BOOLEAN
-EFIAPI
-TdxValidateCfv (
-  IN UINT8   *TdxCfvBase,
-  IN UINT32  TdxCfvSize
-  )
-{
-  UINT16                         Checksum;
-  UINTN                          VariableBase;
-  UINT32                         VariableOffset;
-  UINT32                         VariableOffsetBeforeAlign;
-  EFI_FIRMWARE_VOLUME_HEADER     *CfvFvHeader;
-  VARIABLE_STORE_HEADER          *CfvVariableStoreHeader;
-  AUTHENTICATED_VARIABLE_HEADER  *VariableHeader;
-
-  static EFI_GUID  FvHdrGUID       = EFI_SYSTEM_NV_DATA_FV_GUID;
-  static EFI_GUID  VarStoreHdrGUID = EFI_AUTHENTICATED_VARIABLE_GUID;
-
-  VariableOffset = 0;
-
-  if (TdxCfvBase == NULL) {
-    DEBUG ((DEBUG_ERROR, "TDX CFV: CFV pointer is NULL\n"));
-    return FALSE;
-  }
-
-  //
-  // Verify the header zerovetor, filesystemguid,
-  // revision, signature, attributes, fvlength, checksum
-  // HeaderLength cannot be an odd number
-  //
-  CfvFvHeader = (EFI_FIRMWARE_VOLUME_HEADER *)TdxCfvBase;
-
-  if ((!IsZeroBuffer (CfvFvHeader->ZeroVector, 16)) ||
-      (!CompareGuid (&FvHdrGUID, &CfvFvHeader->FileSystemGuid)) ||
-      (CfvFvHeader->Signature != EFI_FVH_SIGNATURE) ||
-      (CfvFvHeader->Attributes != 0x4feff) ||
-      (CfvFvHeader->Revision != EFI_FVH_REVISION) ||
-      (CfvFvHeader->FvLength != TdxCfvSize)
-      )
-  {
-    DEBUG ((DEBUG_ERROR, "TDX CFV: Basic FV headers were invalid\n"));
-    return FALSE;
-  }
-
-  //
-  // Verify the header checksum
-  //
-  Checksum = CalculateSum16 ((VOID *)CfvFvHeader, CfvFvHeader->HeaderLength);
-
-  if (Checksum != 0) {
-    DEBUG ((DEBUG_ERROR, "TDX CFV: FV checksum was invalid\n"));
-    return FALSE;
-  }
-
-  //
-  // Verify the header signature, size, format, state
-  //
-  CfvVariableStoreHeader = (VARIABLE_STORE_HEADER *)(TdxCfvBase + CfvFvHeader->HeaderLength);
-  if ((!CompareGuid (&VarStoreHdrGUID, &CfvVariableStoreHeader->Signature)) ||
-      (CfvVariableStoreHeader->Format != VARIABLE_STORE_FORMATTED) ||
-      (CfvVariableStoreHeader->State != VARIABLE_STORE_HEALTHY) ||
-      (CfvVariableStoreHeader->Size > (CfvFvHeader->FvLength - CfvFvHeader->HeaderLength)) ||
-      (CfvVariableStoreHeader->Size < sizeof (VARIABLE_STORE_HEADER))
-      )
-  {
-    DEBUG ((DEBUG_ERROR, "TDX CFV: Variable Store header was invalid\n"));
-    return FALSE;
-  }
-
-  //
-  // Verify the header startId, state
-  // Verify data to the end
-  //
-  VariableBase = (UINTN)TdxCfvBase + CfvFvHeader->HeaderLength + sizeof (VARIABLE_STORE_HEADER);
-  while (VariableOffset  < (CfvVariableStoreHeader->Size - sizeof (VARIABLE_STORE_HEADER))) {
-    VariableHeader = (AUTHENTICATED_VARIABLE_HEADER *)(VariableBase + VariableOffset);
-    if (VariableHeader->StartId != VARIABLE_DATA) {
-      if (!CheckPaddingData ((UINT8 *)VariableHeader, CfvVariableStoreHeader->Size - sizeof (VARIABLE_STORE_HEADER) - VariableOffset)) {
-        DEBUG ((DEBUG_ERROR, "TDX CFV: Variable header was invalid\n"));
-        return FALSE;
-      }
-
-      VariableOffset = CfvVariableStoreHeader->Size - sizeof (VARIABLE_STORE_HEADER);
-    } else {
-      if (!((VariableHeader->State == VAR_IN_DELETED_TRANSITION) ||
-            (VariableHeader->State == VAR_DELETED) ||
-            (VariableHeader->State == VAR_HEADER_VALID_ONLY) ||
-            (VariableHeader->State == VAR_ADDED)))
-      {
-        DEBUG ((DEBUG_ERROR, "TDX CFV: Variable header was invalid\n"));
-        return FALSE;
-      }
-
-      VariableOffset += sizeof (AUTHENTICATED_VARIABLE_HEADER) + VariableHeader->NameSize + VariableHeader->DataSize;
-      // Verify VariableOffset should be less than or equal CfvVariableStoreHeader->Size - sizeof(VARIABLE_STORE_HEADER)
-      if (VariableOffset > (CfvVariableStoreHeader->Size - sizeof (VARIABLE_STORE_HEADER))) {
-        DEBUG ((DEBUG_ERROR, "TDX CFV: Variable header was invalid\n"));
-        return FALSE;
-      }
-
-      VariableOffsetBeforeAlign = VariableOffset;
-      // 4 byte align
-      VariableOffset = (VariableOffset  + 3) & (UINTN)(~3);
-
-      if (!CheckPaddingData ((UINT8 *)(VariableBase + VariableOffsetBeforeAlign), VariableOffset - VariableOffsetBeforeAlign)) {
-        DEBUG ((DEBUG_ERROR, "TDX CFV: Variable header was invalid\n"));
-        return FALSE;
-      }
-    }
-  }
-
-  return TRUE;
-}
-
 /**
   Measure the Hoblist passed from the VMM.
 
diff --git a/OvmfPkg/Library/PeilessStartupLib/PeilessStartup.c b/OvmfPkg/Library/PeilessStartupLib/PeilessStartup.c
index fdfefd00d732..7502ec44669e 100644
--- a/OvmfPkg/Library/PeilessStartupLib/PeilessStartup.c
+++ b/OvmfPkg/Library/PeilessStartupLib/PeilessStartup.c
@@ -179,14 +179,6 @@ PeilessStartup (
       CpuDeadLoop ();
     }
 
-    //
-    // Validate Tdx CFV
-    //
-    if (!TdxValidateCfv (CfvBase, FixedPcdGet32 (PcdCfvRawDataSize))) {
-      ASSERT (FALSE);
-      CpuDeadLoop ();
-    }
-
     //
     // Measure Tdx CFV
     //
diff --git a/OvmfPkg/Library/PeilessStartupLib/PeilessStartupInternal.h b/OvmfPkg/Library/PeilessStartupLib/PeilessStartupInternal.h
index 74b5f46552c2..09cac3e26c67 100644
--- a/OvmfPkg/Library/PeilessStartupLib/PeilessStartupInternal.h
+++ b/OvmfPkg/Library/PeilessStartupLib/PeilessStartupInternal.h
@@ -52,23 +52,6 @@ EFIAPI
 ConstructSecHobList (
   );
 
-/**
-  Check the integrity of CFV data.
-
-  @param[in] TdxCfvBase - A pointer to CFV header
-  @param[in] TdxCfvSize - CFV data size
-
-  @retval  TRUE   - The CFV data is valid.
-  @retval  FALSE  - The CFV data is invalid.
-
-**/
-BOOLEAN
-EFIAPI
-TdxValidateCfv (
-  IN UINT8   *TdxCfvBase,
-  IN UINT32  TdxCfvSize
-  );
-
 /**
   Measure the Hoblist passed from the VMM.
 
-- 
2.29.2.windows.2



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