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   @param[in, out]  InterruptState  A pointer to hold the current interrupt
  55                                    state, used for restoring in VmgDone ()
  56
  57 **/
  58 VOID
  59 EFIAPI
  60 VmgInit (
  61   IN OUT GHCB                *Ghcb,
  62   IN OUT BOOLEAN             *InterruptState
  63   );
  64
  65 /**
  66   Perform post-VMGEXIT cleanup.
  67
  68   Performs the necessary steps to cleanup after invoking VMGEXIT. Must be
  69   called after obtaining needed fields within the GHCB.
  70
  71   @param[in, out]  Ghcb            A pointer to the GHCB
  72   @param[in]       InterruptState  An indicator to conditionally (re)enable
  73                                    interrupts
  74
  75 **/
  76 VOID
  77 EFIAPI
  78 VmgDone (
  79   IN OUT GHCB                *Ghcb,
  80   IN     BOOLEAN             InterruptState
  81   );
  82
  83 /**
  84   Marks a specified offset as valid in the GHCB.
  85
  86   The ValidBitmap area represents the areas of the GHCB that have been marked
  87   valid. Set the bit in ValidBitmap for the input offset.
  88
  89   @param[in, out]  Ghcb       A pointer to the GHCB
  90   @param[in]       Offset     Qword offset in the GHCB to mark valid
  91
  92 **/
  93 VOID
  94 EFIAPI
  95 VmgSetOffsetValid (
  96   IN OUT GHCB                *Ghcb,
  97   IN     GHCB_REGISTER       Offset
  98   );
  99
 100 /**
 101   Checks if a specified offset is valid in the GHCB.
 102
 103   The ValidBitmap area represents the areas of the GHCB that have been marked
 104   valid. Return whether the bit in the ValidBitmap is set for the input offset.
 105
 106   @param[in]  Ghcb            A pointer to the GHCB
 107   @param[in]  Offset          Qword offset in the GHCB to mark valid
 108
 109   @retval TRUE                Offset is marked valid in the GHCB
 110   @retval FALSE               Offset is not marked valid in the GHCB
 111
 112 **/
 113 BOOLEAN
 114 EFIAPI
 115 VmgIsOffsetValid (
 116   IN GHCB                    *Ghcb,
 117   IN GHCB_REGISTER           Offset
 118   );
 119
 120 /**
 121   Handle a #VC exception.
 122
 123   Performs the necessary processing to handle a #VC exception.
 124
 125   The base library function returns an error equal to VC_EXCEPTION,
 126   to be propagated to the standard exception handling stack.
 127
 128   @param[in, out]  ExceptionType  Pointer to an EFI_EXCEPTION_TYPE to be set
 129                                   as value to use on error.
 130   @param[in, out]  SystemContext  Pointer to EFI_SYSTEM_CONTEXT
 131
 132   @retval  EFI_SUCCESS            Exception handled
 133   @retval  EFI_UNSUPPORTED        #VC not supported, (new) exception value to
 134                                   propagate provided
 135   @retval  EFI_PROTOCOL_ERROR     #VC handling failed, (new) exception value to
 136                                   propagate provided
 137
 138 **/
 139 EFI_STATUS
 140 EFIAPI
 141 VmgExitHandleVc (
 142   IN OUT EFI_EXCEPTION_TYPE  *ExceptionType,
 143   IN OUT EFI_SYSTEM_CONTEXT  SystemContext
 144   );
 145
 146 #endif