OvmfPkg/Include/Library/MemEncryptSevLib.h

   1 /** @file
   2
   3   Define Secure Encrypted Virtualization (SEV) base library helper function
   4
   5   Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
   6
   7   This program and the accompanying materials are licensed and made available
   8   under the terms and conditions of the BSD License which accompanies this
   9   distribution.  The full text of the license may be found at
  10   http://opensource.org/licenses/bsd-license.php
  11
  12   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  13   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  14
  15 **/
  16
  17 #ifndef _MEM_ENCRYPT_SEV_LIB_H_
  18 #define _MEM_ENCRYPT_SEV_LIB_H_
  19
  20 #include <Base.h>
  21
  22 /**
  23   Returns a boolean to indicate whether SEV is enabled
  24
  25   @retval TRUE           SEV is active
  26   @retval FALSE          SEV is not enabled
  27   **/
  28 BOOLEAN
  29 EFIAPI
  30 MemEncryptSevIsEnabled (
  31   VOID
  32   );
  33
  34 /**
  35   This function clears memory encryption bit for the memory region specified
  36   by BaseAddress and Number of pages from the current page table context.
  37
  38   @param[in]  BaseAddress           The physical address that is the start address
  39                                     of a memory region.
  40   @param[in]  NumberOfPages         The number of pages from start memory region.
  41   @param[in]  Flush                 Flush the caches before clearing the bit
  42                                     (mostly TRUE except MMIO addresses)
  43
  44   @retval RETURN_SUCCESS            The attributes were cleared for the memory region.
  45   @retval RETURN_INVALID_PARAMETER  Number of pages is zero.
  46   @retval RETURN_UNSUPPORTED        Clearing memory encryption attribute is not
  47                                     supported
  48   **/
  49 RETURN_STATUS
  50 EFIAPI
  51 MemEncryptSevClearPageEncMask (
  52   IN PHYSICAL_ADDRESS         Cr3BaseAddress,
  53   IN PHYSICAL_ADDRESS         BaseAddress,
  54   IN UINTN                    NumberOfPages,
  55   IN BOOLEAN                  CacheFlush
  56   );
  57
  58 /**
  59   This function sets memory encryption bit for the memory region specified by
  60   BaseAddress and Number of pages from the current page table context.
  61
  62   @param[in]  BaseAddress           The physical address that is the start address
  63                                     of a memory region.
  64   @param[in]  NumberOfPages         The number of pages from start memory region.
  65   @param[in]  Flush                 Flush the caches before clearing the bit
  66                                     (mostly TRUE except MMIO addresses)
  67
  68   @retval RETURN_SUCCESS            The attributes were set for the memory region.
  69   @retval RETURN_INVALID_PARAMETER  Number of pages is zero.
  70   @retval RETURN_UNSUPPORTED        Clearing memory encryption attribute is not
  71                                     supported
  72   **/
  73 RETURN_STATUS
  74 EFIAPI
  75 MemEncryptSevSetPageEncMask (
  76   IN PHYSICAL_ADDRESS         Cr3BaseAddress,
  77   IN PHYSICAL_ADDRESS         BaseAddress,
  78   IN UINTN                    NumberOfPages,
  79   IN BOOLEAN                  CacheFlush
  80   );
  81 #endif // _MEM_ENCRYPT_SEV_LIB_H_