UefiCpuPkg/Library/VmgExitLibNull/VmgExitLibNull.c

   1 /** @file
   2   VMGEXIT Base Support Library.
   3
   4   Copyright (C) 2020, Advanced Micro Devices, Inc. All rights reserved.<BR>
   5   SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7 **/
   8
   9 #include <Base.h>
  10 #include <Uefi.h>
  11 #include <Library/VmgExitLib.h>
  12
  13 /**
  14   Perform VMGEXIT.
  15
  16   Sets the necessary fields of the GHCB, invokes the VMGEXIT instruction and
  17   then handles the return actions.
  18
  19   The base library function returns an error in the form of a
  20   GHCB_EVENT_INJECTION representing a GP_EXCEPTION.
  21
  22   @param[in, out]  Ghcb       A pointer to the GHCB
  23   @param[in]       ExitCode   VMGEXIT code to be assigned to the SwExitCode
  24                               field of the GHCB.
  25   @param[in]       ExitInfo1  VMGEXIT information to be assigned to the
  26                               SwExitInfo1 field of the GHCB.
  27   @param[in]       ExitInfo2  VMGEXIT information to be assigned to the
  28                               SwExitInfo2 field of the GHCB.
  29
  30   @retval  0                  VMGEXIT succeeded.
  31   @return                     Exception number to be propagated, VMGEXIT
  32                               processing did not succeed.
  33
  34 **/
  35 UINT64
  36 EFIAPI
  37 VmgExit (
  38   IN OUT GHCB                *Ghcb,
  39   IN     UINT64              ExitCode,
  40   IN     UINT64              ExitInfo1,
  41   IN     UINT64              ExitInfo2
  42   )
  43 {
  44   GHCB_EVENT_INJECTION  Event;
  45
  46   Event.Uint64 = 0;
  47   Event.Elements.Vector = GP_EXCEPTION;
  48   Event.Elements.Type   = GHCB_EVENT_INJECTION_TYPE_EXCEPTION;
  49   Event.Elements.Valid  = 1;
  50
  51   return Event.Uint64;
  52 }
  53
  54 /**
  55   Perform pre-VMGEXIT initialization/preparation.
  56
  57   Performs the necessary steps in preparation for invoking VMGEXIT. Must be
  58   called before setting any fields within the GHCB.
  59
  60   The base library function does nothing.
  61
  62   @param[in, out]  Ghcb       A pointer to the GHCB
  63
  64 **/
  65 VOID
  66 EFIAPI
  67 VmgInit (
  68   IN OUT GHCB                *Ghcb
  69   )
  70 {
  71 }
  72
  73 /**
  74   Perform post-VMGEXIT cleanup.
  75
  76   Performs the necessary steps to cleanup after invoking VMGEXIT. Must be
  77   called after obtaining needed fields within the GHCB.
  78
  79   The base library function does nothing.
  80
  81   @param[in, out]  Ghcb       A pointer to the GHCB
  82
  83 **/
  84 VOID
  85 EFIAPI
  86 VmgDone (
  87   IN OUT GHCB                *Ghcb
  88   )
  89 {
  90 }
  91
  92 /**
  93   Handle a #VC exception.
  94
  95   Performs the necessary processing to handle a #VC exception.
  96
  97   The base library function returns an error equal to VC_EXCEPTION,
  98   to be propagated to the standard exception handling stack.
  99
 100   @param[in, out]  ExceptionType  Pointer to an EFI_EXCEPTION_TYPE to be set
 101                                   as value to use on error.
 102   @param[in, out]  SystemContext  Pointer to EFI_SYSTEM_CONTEXT
 103
 104   @retval  EFI_SUCCESS            Exception handled
 105   @retval  EFI_UNSUPPORTED        #VC not supported, (new) exception value to
 106                                   propagate provided
 107   @retval  EFI_PROTOCOL_ERROR     #VC handling failed, (new) exception value to
 108                                   propagate provided
 109
 110 **/
 111 EFI_STATUS
 112 EFIAPI
 113 VmgExitHandleVc (
 114   IN OUT EFI_EXCEPTION_TYPE  *ExceptionType,
 115   IN OUT EFI_SYSTEM_CONTEXT  SystemContext
 116   )
 117 {
 118   *ExceptionType = VC_EXCEPTION;
 119
 120   return EFI_UNSUPPORTED;
 121 }