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
   8   are licensed and made available under the terms and conditions of the BSD
   9   License which accompanies this distribution.  The full text of the license may
  10   be found at 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
  28   This function clears memory encryption bit for the memory region specified by
  29   BaseAddress and Number of pages from the current page table context.
  30
  31   @param[in]  Cr3BaseAddress          Cr3 Base Address (if zero then use current CR3)
  32   @param[in]  BaseAddress             The physical address that is the start address
  33                                       of a memory region.
  34   @param[in]  NumberOfPages           The number of pages from start memory region.
  35   @param[in]  Flush                   Flush the caches before clearing the bit
  36                                       (mostly TRUE except MMIO addresses)
  37
  38   @retval RETURN_SUCCESS              The attributes were cleared for the memory
  39                                       region.
  40   @retval RETURN_INVALID_PARAMETER    Number of pages is zero.
  41   @retval RETURN_UNSUPPORTED          Clearing the memory encryption attribute is
  42                                       not supported
  43   **/
  44 RETURN_STATUS
  45 EFIAPI
  46 MemEncryptSevClearPageEncMask (
  47   IN PHYSICAL_ADDRESS         Cr3BaseAddress,
  48   IN PHYSICAL_ADDRESS         BaseAddress,
  49   IN UINTN                    NumPages,
  50   IN BOOLEAN                  Flush
  51   )
  52 {
  53   return InternalMemEncryptSevSetMemoryDecrypted (Cr3BaseAddress, BaseAddress, EFI_PAGES_TO_SIZE(NumPages), Flush);
  54 }
  55
  56 /**
  57
  58   This function clears memory encryption bit for the memory region specified by
  59   BaseAddress and Number of pages from the current page table context.
  60
  61   @param[in]  Cr3BaseAddress          Cr3 Base Address (if zero then use current CR3)
  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 cleared for the memory
  69                                       region.
  70   @retval RETURN_INVALID_PARAMETER    Number of pages is zero.
  71   @retval RETURN_UNSUPPORTED          Clearing the memory encryption attribute is
  72                                       not supported
  73   **/
  74 RETURN_STATUS
  75 EFIAPI
  76 MemEncryptSevSetPageEncMask (
  77   IN PHYSICAL_ADDRESS         Cr3BaseAddress,
  78   IN PHYSICAL_ADDRESS         BaseAddress,
  79   IN UINTN                    NumPages,
  80   IN BOOLEAN                  Flush
  81   )
  82 {
  83   return InternalMemEncryptSevSetMemoryEncrypted (Cr3BaseAddress, BaseAddress, EFI_PAGES_TO_SIZE(NumPages), Flush);
  84 }