OvmfPkg/IntelTdx/TdxHelperLib/TdxHelperNull.c

/** @file
  NULL instance of TdxHelperLib

  Copyright (c) 2022 - 2023, Intel Corporation. All rights reserved.<BR>

  SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#include <Base.h>
#include <PiPei.h>

/**
  In Tdx guest, some information need to be passed from host VMM to guest
  firmware. For example, the memory resource, etc. These information are
  prepared by host VMM and put in TdHob which is described in TdxMetadata.
  TDVF processes the TdHob to accept memories.

  @retval   EFI_SUCCESS   Successfully process the TdHob
  @retval   Others        Other error as indicated
**/
EFI_STATUS
EFIAPI
TdxHelperProcessTdHob (
  VOID
  )
{
  return EFI_UNSUPPORTED;
}

/**
  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
  it is consumed, it should be measured and extended.
 *
 * @retval EFI_SUCCESS Successfully measure the TdHob
 * @retval Others      Other error as indicated
 */
EFI_STATUS
EFIAPI
TdxHelperMeasureTdHob (
  VOID
  )
{
  return EFI_UNSUPPORTED;
}

/**
 * In Tdx guest, Configuration FV (CFV) is treated as external input because it
 * may contain the data provided by VMM. From the sucurity perspective Cfv image
 * should be measured before it is consumed.
 *
 * @retval EFI_SUCCESS Successfully measure the CFV image
 * @retval Others      Other error as indicated
 */
EFI_STATUS
EFIAPI
TdxHelperMeasureCfvImage (
  VOID
  )
{
  return EFI_UNSUPPORTED;
}

/**
  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
EFIAPI
TdxHelperBuildGuidHobForTdxMeasurement (
  VOID
  )
{
  return EFI_UNSUPPORTED;
}