text: /** @file
    Public header file for the VMGEXIT Support library class.
  
    This library class defines some routines used when invoking the VMGEXIT
    instruction in support of SEV-ES and to handle #VC exceptions.
  
    Copyright (C) 2020, Advanced Micro Devices, Inc. All rights reserved.<BR>
    SPDX-License-Identifier: BSD-2-Clause-Patent
  
  **/
  
  #ifndef __VMG_EXIT_LIB_H__
  #define __VMG_EXIT_LIB_H__
  
  #include <Protocol/DebugSupport.h>
  #include <Register/Amd/Ghcb.h>
  
  
  /**
    Perform VMGEXIT.
  
    Sets the necessary fields of the GHCB, invokes the VMGEXIT instruction and
    then handles the return actions.
  
    @param[in, out]  Ghcb       A pointer to the GHCB
    @param[in]       ExitCode   VMGEXIT code to be assigned to the SwExitCode
                                field of the GHCB.
    @param[in]       ExitInfo1  VMGEXIT information to be assigned to the
                                SwExitInfo1 field of the GHCB.
    @param[in]       ExitInfo2  VMGEXIT information to be assigned to the
                                SwExitInfo2 field of the GHCB.
  
    @retval  0                  VMGEXIT succeeded.
    @return                     Exception number to be propagated, VMGEXIT
                                processing did not succeed.
  
  **/
  UINT64
  EFIAPI
  VmgExit (
    IN OUT GHCB                *Ghcb,
    IN     UINT64              ExitCode,
    IN     UINT64              ExitInfo1,
    IN     UINT64              ExitInfo2
    );
  
  /**
    Perform pre-VMGEXIT initialization/preparation.
  
    Performs the necessary steps in preparation for invoking VMGEXIT. Must be
    called before setting any fields within the GHCB.
  
    @param[in, out]  Ghcb            A pointer to the GHCB
    @param[in, out]  InterruptState  A pointer to hold the current interrupt
                                     state, used for restoring in VmgDone ()
  
  **/
  VOID
  EFIAPI
  VmgInit (
    IN OUT GHCB                *Ghcb,
    IN OUT BOOLEAN             *InterruptState
    );
  
  /**
    Perform post-VMGEXIT cleanup.
  
    Performs the necessary steps to cleanup after invoking VMGEXIT. Must be
    called after obtaining needed fields within the GHCB.
  
    @param[in, out]  Ghcb            A pointer to the GHCB
    @param[in]       InterruptState  An indicator to conditionally (re)enable
                                     interrupts
  
  **/
  VOID
  EFIAPI
  VmgDone (
    IN OUT GHCB                *Ghcb,
    IN     BOOLEAN             InterruptState
    );
  
  /**
    Marks a specified offset as valid in the GHCB.
  
    The ValidBitmap area represents the areas of the GHCB that have been marked
    valid. Set the bit in ValidBitmap for the input offset.
  
    @param[in, out]  Ghcb       A pointer to the GHCB
    @param[in]       Offset     Qword offset in the GHCB to mark valid
  
  **/
  VOID
  EFIAPI
  VmgSetOffsetValid (
    IN OUT GHCB                *Ghcb,
    IN     GHCB_REGISTER       Offset
    );
  
  /**
    Checks if a specified offset is valid in the GHCB.
  
    The ValidBitmap area represents the areas of the GHCB that have been marked
    valid. Return whether the bit in the ValidBitmap is set for the input offset.
  
    @param[in]  Ghcb            A pointer to the GHCB
    @param[in]  Offset          Qword offset in the GHCB to mark valid
  
    @retval TRUE                Offset is marked valid in the GHCB
    @retval FALSE               Offset is not marked valid in the GHCB
  
  **/
  BOOLEAN
  EFIAPI
  VmgIsOffsetValid (
    IN GHCB                    *Ghcb,
    IN GHCB_REGISTER           Offset
    );
  
  /**
    Handle a #VC exception.
  
    Performs the necessary processing to handle a #VC exception.
  
    The base library function returns an error equal to VC_EXCEPTION,
    to be propagated to the standard exception handling stack.
  
    @param[in, out]  ExceptionType  Pointer to an EFI_EXCEPTION_TYPE to be set
                                    as value to use on error.
    @param[in, out]  SystemContext  Pointer to EFI_SYSTEM_CONTEXT
  
    @retval  EFI_SUCCESS            Exception handled
    @retval  EFI_UNSUPPORTED        #VC not supported, (new) exception value to
                                    propagate provided
    @retval  EFI_PROTOCOL_ERROR     #VC handling failed, (new) exception value to
                                    propagate provided
  
  **/
  EFI_STATUS
  EFIAPI
  VmgExitHandleVc (
    IN OUT EFI_EXCEPTION_TYPE  *ExceptionType,
    IN OUT EFI_SYSTEM_CONTEXT  SystemContext
    );
  
  #endif
  