OvmfPkg/Library/BaseMemEncryptSevLib/Ia32/MemEncryptSevLib.c

   1 /** @file
   2
   3   Secure Encrypted Virtualization (SEV) library helper function
   4
   5   Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
   6
   7   SPDX-License-Identifier: BSD-2-Clause-Patent
   8
   9 **/
  10
  11 #include <Library/BaseLib.h>
  12 #include <Library/DebugLib.h>
  13 #include <Library/MemEncryptSevLib.h>
  14 #include <Register/Amd/Cpuid.h>
  15 #include <Register/Amd/Msr.h>
  16 #include <Register/Cpuid.h>
  17
  18 /**
  19   This function clears memory encryption bit for the memory region specified by
  20   BaseAddress and NumPages from the current page table context.
  21
  22   @param[in]  Cr3BaseAddress          Cr3 Base Address (if zero then use
  23                                       current CR3)
  24   @param[in]  BaseAddress             The physical address that is the start
  25                                       address of a memory region.
  26   @param[in]  NumPages                The number of pages from start memory
  27                                       region.
  28   @param[in]  Flush                   Flush the caches before clearing the bit
  29                                       (mostly TRUE except MMIO addresses)
  30
  31   @retval RETURN_SUCCESS              The attributes were cleared for the
  32                                       memory region.
  33   @retval RETURN_INVALID_PARAMETER    Number of pages is zero.
  34   @retval RETURN_UNSUPPORTED          Clearing the memory encryption attribute
  35                                       is not supported
  36 **/
  37 RETURN_STATUS
  38 EFIAPI
  39 MemEncryptSevClearPageEncMask (
  40   IN PHYSICAL_ADDRESS         Cr3BaseAddress,
  41   IN PHYSICAL_ADDRESS         BaseAddress,
  42   IN UINTN                    NumPages,
  43   IN BOOLEAN                  Flush
  44   )
  45 {
  46   //
  47   // Memory encryption bit is not accessible in 32-bit mode
  48   //
  49   return RETURN_UNSUPPORTED;
  50 }
  51
  52 /**
  53   This function sets memory encryption bit for the memory region specified by
  54   BaseAddress and NumPages from the current page table context.
  55
  56   @param[in]  Cr3BaseAddress          Cr3 Base Address (if zero then use
  57                                       current CR3)
  58   @param[in]  BaseAddress             The physical address that is the start
  59                                       address of a memory region.
  60   @param[in]  NumPages                The number of pages from start memory
  61                                       region.
  62   @param[in]  Flush                   Flush the caches before setting the bit
  63                                       (mostly TRUE except MMIO addresses)
  64
  65   @retval RETURN_SUCCESS              The attributes were set for the memory
  66                                       region.
  67   @retval RETURN_INVALID_PARAMETER    Number of pages is zero.
  68   @retval RETURN_UNSUPPORTED          Setting the memory encryption attribute
  69                                       is not supported
  70 **/
  71 RETURN_STATUS
  72 EFIAPI
  73 MemEncryptSevSetPageEncMask (
  74   IN PHYSICAL_ADDRESS         Cr3BaseAddress,
  75   IN PHYSICAL_ADDRESS         BaseAddress,
  76   IN UINTN                    NumPages,
  77   IN BOOLEAN                  Flush
  78   )
  79 {
  80   //
  81   // Memory encryption bit is not accessible in 32-bit mode
  82   //
  83   return RETURN_UNSUPPORTED;
  84 }