UefiCpuPkg: Implement library support for VMGEXIT

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198

To support handling #VC exceptions and issuing VMGEXIT instructions,
create a library with functions that can be used to perform these
#VC/VMGEXIT related operations. This includes functions for:
  - Handling #VC exceptions
  - Preparing for and issuing a VMGEXIT
  - Performing MMIO-related write operations to support flash emulation
  - Performing AP related boot opeations

The base functions in this driver will not do anything and will return
an error if a return value is required. It is expected that other packages
(like OvmfPkg) will create a version of the library to fully support an
SEV-ES guest.

Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
This commit is contained in:
Tom Lendacky 2020-08-12 15:21:36 -05:00 committed by mergify[bot]
parent f8422f1e0b
commit 8714978781
6 changed files with 271 additions and 0 deletions

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/** @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
**/
VOID
EFIAPI
VmgInit (
IN OUT GHCB *Ghcb
);
/**
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
**/
VOID
EFIAPI
VmgDone (
IN OUT GHCB *Ghcb
);
/**
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

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/** @file
VMGEXIT Base Support Library.
Copyright (C) 2020, Advanced Micro Devices, Inc. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <Base.h>
#include <Uefi.h>
#include <Library/VmgExitLib.h>
/**
Perform VMGEXIT.
Sets the necessary fields of the GHCB, invokes the VMGEXIT instruction and
then handles the return actions.
The base library function returns an error in the form of a
GHCB_EVENT_INJECTION representing a GP_EXCEPTION.
@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
)
{
GHCB_EVENT_INJECTION Event;
Event.Uint64 = 0;
Event.Elements.Vector = GP_EXCEPTION;
Event.Elements.Type = GHCB_EVENT_INJECTION_TYPE_EXCEPTION;
Event.Elements.Valid = 1;
return Event.Uint64;
}
/**
Perform pre-VMGEXIT initialization/preparation.
Performs the necessary steps in preparation for invoking VMGEXIT. Must be
called before setting any fields within the GHCB.
The base library function does nothing.
@param[in, out] Ghcb A pointer to the GHCB
**/
VOID
EFIAPI
VmgInit (
IN OUT GHCB *Ghcb
)
{
}
/**
Perform post-VMGEXIT cleanup.
Performs the necessary steps to cleanup after invoking VMGEXIT. Must be
called after obtaining needed fields within the GHCB.
The base library function does nothing.
@param[in, out] Ghcb A pointer to the GHCB
**/
VOID
EFIAPI
VmgDone (
IN OUT GHCB *Ghcb
)
{
}
/**
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
)
{
*ExceptionType = VC_EXCEPTION;
return EFI_UNSUPPORTED;
}

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## @file
# VMGEXIT Support Library.
#
# Copyright (C) 2020, Advanced Micro Devices, Inc. All rights reserved.<BR>
# SPDX-License-Identifier: BSD-2-Clause-Patent
#
##
[Defines]
INF_VERSION = 0x00010005
BASE_NAME = VmgExitLibNull
MODULE_UNI_FILE = VmgExitLibNull.uni
FILE_GUID = 3cd7368f-ef9b-4a9b-9571-2ed93813677e
MODULE_TYPE = BASE
VERSION_STRING = 1.0
LIBRARY_CLASS = VmgExitLib
[Sources.common]
VmgExitLibNull.c
[Packages]
MdePkg/MdePkg.dec
UefiCpuPkg/UefiCpuPkg.dec
[LibraryClasses]
BaseLib

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// /** @file
// VMGEXIT support library instance.
//
// VMGEXIT support library instance.
//
// Copyright (C) 2020, Advanced Micro Devices, Inc. All rights reserved.<BR>
// SPDX-License-Identifier: BSD-2-Clause-Patent
//
// **/
#string STR_MODULE_ABSTRACT #language en-US "VMGEXIT support NULL library instance"
#string STR_MODULE_DESCRIPTION #language en-US "VMGEXIT support NULL library instance."

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@ -53,6 +53,9 @@
##
MpInitLib|Include/Library/MpInitLib.h
## @libraryclass Provides function to support VMGEXIT processing.
VmgExitLib|Include/Library/VmgExitLib.h
[Guids]
gUefiCpuPkgTokenSpaceGuid = { 0xac05bf33, 0x995a, 0x4ed4, { 0xaa, 0xb8, 0xef, 0x7a, 0xe8, 0xf, 0x5c, 0xb0 }}
gMsegSmramGuid = { 0x5802bce4, 0xeeee, 0x4e33, { 0xa1, 0x30, 0xeb, 0xad, 0x27, 0xf0, 0xe4, 0x39 }}

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@ -56,6 +56,7 @@
PeCoffGetEntryPointLib|MdePkg/Library/BasePeCoffGetEntryPointLib/BasePeCoffGetEntryPointLib.inf
PeCoffExtraActionLib|MdePkg/Library/BasePeCoffExtraActionLibNull/BasePeCoffExtraActionLibNull.inf
TpmMeasurementLib|MdeModulePkg/Library/TpmMeasurementLibNull/TpmMeasurementLibNull.inf
VmgExitLib|UefiCpuPkg/Library/VmgExitLibNull/VmgExitLibNull.inf
[LibraryClasses.common.SEC]
PlatformSecLib|UefiCpuPkg/Library/PlatformSecLibNull/PlatformSecLibNull.inf
@ -143,6 +144,7 @@
UefiCpuPkg/Library/SmmCpuPlatformHookLibNull/SmmCpuPlatformHookLibNull.inf
UefiCpuPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLib.inf
UefiCpuPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLibStm.inf
UefiCpuPkg/Library/VmgExitLibNull/VmgExitLibNull.inf
UefiCpuPkg/PiSmmCommunication/PiSmmCommunicationPei.inf
UefiCpuPkg/PiSmmCommunication/PiSmmCommunicationSmm.inf
UefiCpuPkg/SecCore/SecCore.inf