OvmfPkg/Library/BaseMemEncryptSevLib/X64/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   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 #include <Library/BaseLib.h>
  18 #include <Library/DebugLib.h>
  19 #include <Register/Cpuid.h>
  20 #include <Register/Amd/Cpuid.h>
  21 #include <Register/Amd/Msr.h>
  22 #include <Library/MemEncryptSevLib.h>
  23
  24 #include "VirtualMemory.h"
  25
  26 /**
  27   This function clears memory encryption bit for the memory region specified by
  28   BaseAddress and NumPages from the current page table context.
  29
  30   @param[in]  Cr3BaseAddress          Cr3 Base Address (if zero then use
  31                                       current CR3)
  32   @param[in]  BaseAddress             The physical address that is the start
  33                                       address of a memory region.
  34   @param[in]  NumPages                The number of pages from start memory
  35                                       region.
  36   @param[in]  Flush                   Flush the caches before clearing the bit
  37                                       (mostly TRUE except MMIO addresses)
  38
  39   @retval RETURN_SUCCESS              The attributes were cleared for the
  40                                       memory region.
  41   @retval RETURN_INVALID_PARAMETER    Number of pages is zero.
  42   @retval RETURN_UNSUPPORTED          Clearing the memory encryption attribute
  43                                       is not supported
  44 **/
  45 RETURN_STATUS
  46 EFIAPI
  47 MemEncryptSevClearPageEncMask (
  48   IN PHYSICAL_ADDRESS         Cr3BaseAddress,
  49   IN PHYSICAL_ADDRESS         BaseAddress,
  50   IN UINTN                    NumPages,
  51   IN BOOLEAN                  Flush
  52   )
  53 {
  54   return InternalMemEncryptSevSetMemoryDecrypted (
  55            Cr3BaseAddress,
  56            BaseAddress,
  57            EFI_PAGES_TO_SIZE (NumPages),
  58            Flush
  59            );
  60 }
  61
  62 /**
  63   This function sets memory encryption bit for the memory region specified by
  64   BaseAddress and NumPages from the current page table context.
  65
  66   @param[in]  Cr3BaseAddress          Cr3 Base Address (if zero then use
  67                                       current CR3)
  68   @param[in]  BaseAddress             The physical address that is the start
  69                                       address of a memory region.
  70   @param[in]  NumPages                The number of pages from start memory
  71                                       region.
  72   @param[in]  Flush                   Flush the caches before setting the bit
  73                                       (mostly TRUE except MMIO addresses)
  74
  75   @retval RETURN_SUCCESS              The attributes were set for the memory
  76                                       region.
  77   @retval RETURN_INVALID_PARAMETER    Number of pages is zero.
  78   @retval RETURN_UNSUPPORTED          Setting the memory encryption attribute
  79                                       is not supported
  80 **/
  81 RETURN_STATUS
  82 EFIAPI
  83 MemEncryptSevSetPageEncMask (
  84   IN PHYSICAL_ADDRESS         Cr3BaseAddress,
  85   IN PHYSICAL_ADDRESS         BaseAddress,
  86   IN UINTN                    NumPages,
  87   IN BOOLEAN                  Flush
  88   )
  89 {
  90   return InternalMemEncryptSevSetMemoryEncrypted (
  91            Cr3BaseAddress,
  92            BaseAddress,
  93            EFI_PAGES_TO_SIZE (NumPages),
  94            Flush
  95            );
  96 }