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   Handle a #VC exception.
  79
  80   Performs the necessary processing to handle a #VC exception.
  81
  82   The base library function returns an error equal to VC_EXCEPTION,
  83   to be propagated to the standard exception handling stack.
  84
  85   @param[in, out]  ExceptionType  Pointer to an EFI_EXCEPTION_TYPE to be set
  86                                   as value to use on error.
  87   @param[in, out]  SystemContext  Pointer to EFI_SYSTEM_CONTEXT
  88
  89   @retval  EFI_SUCCESS            Exception handled
  90   @retval  EFI_UNSUPPORTED        #VC not supported, (new) exception value to
  91                                   propagate provided
  92   @retval  EFI_PROTOCOL_ERROR     #VC handling failed, (new) exception value to
  93                                   propagate provided
  94
  95 **/
  96 EFI_STATUS
  97 EFIAPI
  98 VmgExitHandleVc (
  99   IN OUT EFI_EXCEPTION_TYPE  *ExceptionType,
 100   IN OUT EFI_SYSTEM_CONTEXT  SystemContext
 101   );
 102
 103 #endif