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
  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
  32                                       current CR3)
  33   @param[in]  BaseAddress             The physical address that is the start
  34                                       address of a memory region.
  35   @param[in]  NumberOfPages           The number of pages from start memory
  36                                       region.
  37   @param[in]  Flush                   Flush the caches before clearing the bit
  38                                       (mostly TRUE except MMIO addresses)
  39
  40   @retval RETURN_SUCCESS              The attributes were cleared for the
  41                                       memory region.
  42   @retval RETURN_INVALID_PARAMETER    Number of pages is zero.
  43   @retval RETURN_UNSUPPORTED          Clearing the memory encryption attribute
  44                                       is not supported
  45   **/
  46 RETURN_STATUS
  47 EFIAPI
  48 MemEncryptSevClearPageEncMask (
  49   IN PHYSICAL_ADDRESS         Cr3BaseAddress,
  50   IN PHYSICAL_ADDRESS         BaseAddress,
  51   IN UINTN                    NumPages,
  52   IN BOOLEAN                  Flush
  53   )
  54 {
  55   return InternalMemEncryptSevSetMemoryDecrypted (
  56            Cr3BaseAddress,
  57            BaseAddress,
  58            EFI_PAGES_TO_SIZE (NumPages),
  59            Flush
  60            );
  61 }
  62
  63 /**
  64
  65   This function clears memory encryption bit for the memory region specified by
  66   BaseAddress and Number of pages from the current page table context.
  67
  68   @param[in]  Cr3BaseAddress          Cr3 Base Address (if zero then use
  69                                       current CR3)
  70   @param[in]  BaseAddress             The physical address that is the start
  71                                       address of a memory region.
  72   @param[in]  NumberOfPages           The number of pages from start memory
  73                                       region.
  74   @param[in]  Flush                   Flush the caches before clearing the bit
  75                                       (mostly TRUE except MMIO addresses)
  76
  77   @retval RETURN_SUCCESS              The attributes were cleared for the
  78                                       memory region.
  79   @retval RETURN_INVALID_PARAMETER    Number of pages is zero.
  80   @retval RETURN_UNSUPPORTED          Clearing the memory encryption attribute
  81                                       is not supported
  82   **/
  83 RETURN_STATUS
  84 EFIAPI
  85 MemEncryptSevSetPageEncMask (
  86   IN PHYSICAL_ADDRESS         Cr3BaseAddress,
  87   IN PHYSICAL_ADDRESS         BaseAddress,
  88   IN UINTN                    NumPages,
  89   IN BOOLEAN                  Flush
  90   )
  91 {
  92   return InternalMemEncryptSevSetMemoryEncrypted (
  93            Cr3BaseAddress,
  94            BaseAddress,
  95            EFI_PAGES_TO_SIZE (NumPages),
  96            Flush
  97            );
  98 }