MdePkg: Add TdxLib to wrap Tdx operations

RFC: https://bugzilla.tianocore.org/show_bug.cgi?id=3429

TdxLib is created with functions to perform the related Tdx operation.
This includes functions for:
 - TdAcceptPages   : Accept pending private pages and initialize the pages
                     to all-0 using the TD ephemeral private key.
 - TdExtendRtmr    : Extend measurement to one of the RTMR registers.
 - TdSharedPageMask: Get the Td guest shared page mask which indicates it
                     is a Shared or Private page.
 - TdMaxVCpuNum    : Get the maximum number of virtual CPUs.
 - TdVCpuNum       : Get the number of virtual CPUs.

Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Zhiguang Liu <zhiguang.liu@intel.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>

MdePkg/Library/TdxLib/Rtmr.c

@@ -0,0 +1,84 @@
+/** @file
+
+  Extends one of the RTMR measurement registers in TDCS with the provided
+  extension data in memory.
+
+  Copyright (c) 2020 - 2021, Intel Corporation. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Uefi/UefiBaseType.h>
+#include <Library/TdxLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <IndustryStandard/Tpm20.h>
+#include <IndustryStandard/Tdx.h>
+
+#define RTMR_COUNT            4
+#define TD_EXTEND_BUFFER_LEN  (64 + 48)
+
+UINT8  mExtendBuffer[TD_EXTEND_BUFFER_LEN];
+
+/**
+  This function extends one of the RTMR measurement register
+  in TDCS with the provided extension data in memory.
+  RTMR extending supports SHA384 which length is 48 bytes.
+
+  @param[in]  Data      Point to the data to be extended
+  @param[in]  DataLen   Length of the data. Must be 48
+  @param[in]  Index     RTMR index
+
+  @return EFI_SUCCESS
+  @return EFI_INVALID_PARAMETER
+  @return EFI_DEVICE_ERROR
+
+**/
+EFI_STATUS
+EFIAPI
+TdExtendRtmr (
+  IN  UINT32  *Data,
+  IN  UINT32  DataLen,
+  IN  UINT8   Index
+  )
+{
+  EFI_STATUS  Status;
+  UINT64      TdCallStatus;
+  UINT8       *ExtendBuffer;
+
+  Status = EFI_SUCCESS;
+
+  ASSERT (Data != NULL);
+  ASSERT (DataLen == SHA384_DIGEST_SIZE);
+  ASSERT (Index >= 0 && Index < RTMR_COUNT);
+
+  if ((Data == NULL) || (DataLen != SHA384_DIGEST_SIZE) || (Index >= RTMR_COUNT)) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  // TD.RTMR.EXTEND requires 64B-aligned guest physical address of
+  // 48B-extension data. We use ALIGN_POINTER(Pointer, 64) to get
+  // the 64B-aligned guest physical address.
+  ExtendBuffer = ALIGN_POINTER (mExtendBuffer, 64);
+  ASSERT (((UINTN)ExtendBuffer & 0x3f) == 0);
+
+  ZeroMem (ExtendBuffer, SHA384_DIGEST_SIZE);
+  CopyMem (ExtendBuffer, Data, SHA384_DIGEST_SIZE);
+
+  TdCallStatus = TdCall (TDCALL_TDEXTENDRTMR, (UINT64)(UINTN)ExtendBuffer, Index, 0, 0);
+
+  if (TdCallStatus == TDX_EXIT_REASON_SUCCESS) {
+    Status = EFI_SUCCESS;
+  } else if (TdCallStatus == TDX_EXIT_REASON_OPERAND_INVALID) {
+    Status = EFI_INVALID_PARAMETER;
+  } else {
+    Status = EFI_DEVICE_ERROR;
+  }
+
+  if (Status != EFI_SUCCESS) {
+    DEBUG ((DEBUG_ERROR, "Error returned from TdExtendRtmr call - 0x%lx\n", TdCallStatus));
+  }
+
+  return Status;
+}