UefiCpuPkg/Include/Library/VmgExitLib.h

   1 /** @file
   2   Public header file for the VMGEXIT Support library class.
   3
   4   This library class defines some routines used when invoking the VMGEXIT
   5   instruction in support of SEV-ES and to handle #VC exceptions.
   6
   7   Copyright (C) 2020, Advanced Micro Devices, Inc. All rights reserved.<BR>
   8   SPDX-License-Identifier: BSD-2-Clause-Patent
   9
  10 **/
  11
  12 #ifndef __VMG_EXIT_LIB_H__
  13 #define __VMG_EXIT_LIB_H__
  14
  15 #include <Protocol/DebugSupport.h>
  16 #include <Register/Amd/Ghcb.h>
  17
  18
  19 /**
  20   Perform VMGEXIT.
  21
  22   Sets the necessary fields of the GHCB, invokes the VMGEXIT instruction and
  23   then handles the return actions.
  24
  25   @param[in, out]  Ghcb       A pointer to the GHCB
  26   @param[in]       ExitCode   VMGEXIT code to be assigned to the SwExitCode
  27                               field of the GHCB.
  28   @param[in]       ExitInfo1  VMGEXIT information to be assigned to the
  29                               SwExitInfo1 field of the GHCB.
  30   @param[in]       ExitInfo2  VMGEXIT information to be assigned to the
  31                               SwExitInfo2 field of the GHCB.
  32
  33   @retval  0                  VMGEXIT succeeded.
  34   @return                     Exception number to be propagated, VMGEXIT
  35                               processing did not succeed.
  36
  37 **/
  38 UINT64
  39 EFIAPI
  40 VmgExit (
  41   IN OUT GHCB                *Ghcb,
  42   IN     UINT64              ExitCode,
  43   IN     UINT64              ExitInfo1,
  44   IN     UINT64              ExitInfo2
  45   );
  46
  47 /**
  48   Perform pre-VMGEXIT initialization/preparation.
  49
  50   Performs the necessary steps in preparation for invoking VMGEXIT. Must be
  51   called before setting any fields within the GHCB.
  52
  53   @param[in, out]  Ghcb       A pointer to the GHCB
  54
  55 **/
  56 VOID
  57 EFIAPI
  58 VmgInit (
  59   IN OUT GHCB                *Ghcb
  60   );
  61
  62 /**
  63   Perform post-VMGEXIT cleanup.
  64
  65   Performs the necessary steps to cleanup after invoking VMGEXIT. Must be
  66   called after obtaining needed fields within the GHCB.
  67
  68   @param[in, out]  Ghcb       A pointer to the GHCB
  69
  70 **/
  71 VOID
  72 EFIAPI
  73 VmgDone (
  74   IN OUT GHCB                *Ghcb
  75   );
  76
  77 /**
  78   Marks a specified offset as valid in the GHCB.
  79
  80   The ValidBitmap area represents the areas of the GHCB that have been marked
  81   valid. Set the bit in ValidBitmap for the input offset.
  82
  83   @param[in, out]  Ghcb       A pointer to the GHCB
  84   @param[in]       Offset     Qword offset in the GHCB to mark valid
  85
  86 **/
  87 VOID
  88 EFIAPI
  89 VmgSetOffsetValid (
  90   IN OUT GHCB                *Ghcb,
  91   IN     GHCB_REGISTER       Offset
  92   );
  93
  94 /**
  95   Checks if a specified offset is valid in the GHCB.
  96
  97   The ValidBitmap area represents the areas of the GHCB that have been marked
  98   valid. Return whether the bit in the ValidBitmap is set for the input offset.
  99
 100   @param[in]  Ghcb            A pointer to the GHCB
 101   @param[in]  Offset          Qword offset in the GHCB to mark valid
 102
 103   @retval TRUE                Offset is marked valid in the GHCB
 104   @retval FALSE               Offset is not marked valid in the GHCB
 105
 106 **/
 107 BOOLEAN
 108 EFIAPI
 109 VmgIsOffsetValid (
 110   IN GHCB                    *Ghcb,
 111   IN GHCB_REGISTER           Offset
 112   );
 113
 114 /**
 115   Handle a #VC exception.
 116
 117   Performs the necessary processing to handle a #VC exception.
 118
 119   The base library function returns an error equal to VC_EXCEPTION,
 120   to be propagated to the standard exception handling stack.
 121
 122   @param[in, out]  ExceptionType  Pointer to an EFI_EXCEPTION_TYPE to be set
 123                                   as value to use on error.
 124   @param[in, out]  SystemContext  Pointer to EFI_SYSTEM_CONTEXT
 125
 126   @retval  EFI_SUCCESS            Exception handled
 127   @retval  EFI_UNSUPPORTED        #VC not supported, (new) exception value to
 128                                   propagate provided
 129   @retval  EFI_PROTOCOL_ERROR     #VC handling failed, (new) exception value to
 130                                   propagate provided
 131
 132 **/
 133 EFI_STATUS
 134 EFIAPI
 135 VmgExitHandleVc (
 136   IN OUT EFI_EXCEPTION_TYPE  *ExceptionType,
 137   IN OUT EFI_SYSTEM_CONTEXT  SystemContext
 138   );
 139
 140 #endif