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
  64   This function clears memory encryption bit for the memory region specified by
  65   BaseAddress and Number of pages from the current page table context.
  66
  67   @param[in]  Cr3BaseAddress          Cr3 Base Address (if zero then use
  68                                       current CR3)
  69   @param[in]  BaseAddress             The physical address that is the start
  70                                       address of a memory region.
  71   @param[in]  NumberOfPages           The number of pages from start memory
  72                                       region.
  73   @param[in]  Flush                   Flush the caches before clearing the bit
  74                                       (mostly TRUE except MMIO addresses)
  75
  76   @retval RETURN_SUCCESS              The attributes were cleared for the
  77                                       memory region.
  78   @retval RETURN_INVALID_PARAMETER    Number of pages is zero.
  79   @retval RETURN_UNSUPPORTED          Clearing the memory encryption attribute
  80                                       is not supported
  81   **/
  82 RETURN_STATUS
  83 EFIAPI
  84 MemEncryptSevSetPageEncMask (
  85   IN PHYSICAL_ADDRESS         Cr3BaseAddress,
  86   IN PHYSICAL_ADDRESS         BaseAddress,
  87   IN UINTN                    NumPages,
  88   IN BOOLEAN                  Flush
  89   )
  90 {
  91   return InternalMemEncryptSevSetMemoryEncrypted (
  92            Cr3BaseAddress,
  93            BaseAddress,
  94            EFI_PAGES_TO_SIZE (NumPages),
  95            Flush
  96            );
  97 }