OvmfPkg: add DXE_DRIVER for providing TSEG-as-SMRAM during boot-time DXE

The SMM core depends on EFI_SMM_ACCESS2_PROTOCOL. This small driver (which
is a thin wrapper around "OvmfPkg/SmmAccess/SmramInternal.c" that was
added in the previous patch) provides that protocol.

Notably, EFI_SMM_ACCESS2_PROTOCOL is for boot time only, therefore
our MODULE_TYPE is not DXE_RUNTIME_DRIVER.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Michael Kinney <michael.d.kinney@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19041 6f19259b-4bc3-4df7-8a09-765794883524

OvmfPkg/OvmfPkgIa32.dsc

@@ -642,3 +642,7 @@
 !endif
 
   OvmfPkg/PlatformDxe/Platform.inf
+
+!if $(SMM_REQUIRE) == TRUE
+  OvmfPkg/SmmAccess/SmmAccess2Dxe.inf
+!endif

OvmfPkg/OvmfPkgIa32.fdf

@@ -355,6 +355,10 @@ INF  RuleOverride=CSM OvmfPkg/Csm/Csm16/Csm16.inf
 INF  OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf
 INF  OvmfPkg/PlatformDxe/Platform.inf
 
+!if $(SMM_REQUIRE) == TRUE
+INF  OvmfPkg/SmmAccess/SmmAccess2Dxe.inf
+!endif
+
 ################################################################################
 
 [FV.FVMAIN_COMPACT]

OvmfPkg/OvmfPkgIa32X64.dsc

@@ -649,3 +649,7 @@
 !endif
 
   OvmfPkg/PlatformDxe/Platform.inf
+
+!if $(SMM_REQUIRE) == TRUE
+  OvmfPkg/SmmAccess/SmmAccess2Dxe.inf
+!endif

OvmfPkg/OvmfPkgIa32X64.fdf

@@ -355,6 +355,10 @@ INF  RuleOverride=CSM OvmfPkg/Csm/Csm16/Csm16.inf
 INF  OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf
 INF  OvmfPkg/PlatformDxe/Platform.inf
 
+!if $(SMM_REQUIRE) == TRUE
+INF  OvmfPkg/SmmAccess/SmmAccess2Dxe.inf
+!endif
+
 ################################################################################
 
 [FV.FVMAIN_COMPACT]

OvmfPkg/OvmfPkgX64.dsc

@@ -647,3 +647,7 @@
 !endif
 
   OvmfPkg/PlatformDxe/Platform.inf
+
+!if $(SMM_REQUIRE) == TRUE
+  OvmfPkg/SmmAccess/SmmAccess2Dxe.inf
+!endif

OvmfPkg/OvmfPkgX64.fdf

@@ -355,6 +355,10 @@ INF  RuleOverride=CSM OvmfPkg/Csm/Csm16/Csm16.inf
 INF  OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf
 INF  OvmfPkg/PlatformDxe/Platform.inf
 
+!if $(SMM_REQUIRE) == TRUE
+INF  OvmfPkg/SmmAccess/SmmAccess2Dxe.inf
+!endif
+
 ################################################################################
 
 [FV.FVMAIN_COMPACT]

OvmfPkg/SmmAccess/SmmAccess2Dxe.c

@@ -0,0 +1,156 @@
+/** @file
+
+  A DXE_DRIVER providing SMRAM access by producing EFI_SMM_ACCESS2_PROTOCOL.
+
+  Q35 TSEG is expected to have been verified and set up by the SmmAccessPei
+  driver.
+
+  Copyright (C) 2013, 2015, Red Hat, Inc.<BR>
+  Copyright (c) 2009 - 2010, Intel Corporation. All rights reserved.<BR>
+
+  This program and the accompanying materials are licensed and made available
+  under the terms and conditions of the BSD License which accompanies this
+  distribution. The full text of the license may be found at
+  http://opensource.org/licenses/bsd-license.php
+
+  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
+  WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+#include <Library/DebugLib.h>
+#include <Library/PcdLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Protocol/SmmAccess2.h>
+
+#include "SmramInternal.h"
+
+/**
+  Opens the SMRAM area to be accessible by a boot-service driver.
+
+  This function "opens" SMRAM so that it is visible while not inside of SMM.
+  The function should return EFI_UNSUPPORTED if the hardware does not support
+  hiding of SMRAM. The function should return EFI_DEVICE_ERROR if the SMRAM
+  configuration is locked.
+
+  @param[in] This           The EFI_SMM_ACCESS2_PROTOCOL instance.
+
+  @retval EFI_SUCCESS       The operation was successful.
+  @retval EFI_UNSUPPORTED   The system does not support opening and closing of
+                            SMRAM.
+  @retval EFI_DEVICE_ERROR  SMRAM cannot be opened, perhaps because it is
+                            locked.
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+SmmAccess2DxeOpen (
+  IN EFI_SMM_ACCESS2_PROTOCOL  *This
+  )
+{
+  return SmramAccessOpen (&This->LockState, &This->OpenState);
+}
+
+/**
+  Inhibits access to the SMRAM.
+
+  This function "closes" SMRAM so that it is not visible while outside of SMM.
+  The function should return EFI_UNSUPPORTED if the hardware does not support
+  hiding of SMRAM.
+
+  @param[in] This           The EFI_SMM_ACCESS2_PROTOCOL instance.
+
+  @retval EFI_SUCCESS       The operation was successful.
+  @retval EFI_UNSUPPORTED   The system does not support opening and closing of
+                            SMRAM.
+  @retval EFI_DEVICE_ERROR  SMRAM cannot be closed.
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+SmmAccess2DxeClose (
+  IN EFI_SMM_ACCESS2_PROTOCOL  *This
+  )
+{
+  return SmramAccessClose (&This->LockState, &This->OpenState);
+}
+
+/**
+  Inhibits access to the SMRAM.
+
+  This function prohibits access to the SMRAM region.  This function is usually
+  implemented such that it is a write-once operation.
+
+  @param[in] This          The EFI_SMM_ACCESS2_PROTOCOL instance.
+
+  @retval EFI_SUCCESS      The device was successfully locked.
+  @retval EFI_UNSUPPORTED  The system does not support locking of SMRAM.
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+SmmAccess2DxeLock (
+  IN EFI_SMM_ACCESS2_PROTOCOL  *This
+  )
+{
+  return SmramAccessLock (&This->LockState, &This->OpenState);
+}
+
+/**
+  Queries the memory controller for the possible regions that will support
+  SMRAM.
+
+  @param[in]     This           The EFI_SMM_ACCESS2_PROTOCOL instance.
+  @param[in,out] SmramMapSize   A pointer to the size, in bytes, of the
+                                SmramMemoryMap buffer.
+  @param[in,out] SmramMap       A pointer to the buffer in which firmware
+                                places the current memory map.
+
+  @retval EFI_SUCCESS           The chipset supported the given resource.
+  @retval EFI_BUFFER_TOO_SMALL  The SmramMap parameter was too small.  The
+                                current buffer size needed to hold the memory
+                                map is returned in SmramMapSize.
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+SmmAccess2DxeGetCapabilities (
+  IN CONST EFI_SMM_ACCESS2_PROTOCOL  *This,
+  IN OUT UINTN                       *SmramMapSize,
+  IN OUT EFI_SMRAM_DESCRIPTOR        *SmramMap
+  )
+{
+  return SmramAccessGetCapabilities (This->LockState, This->OpenState,
+           SmramMapSize, SmramMap);
+}
+
+//
+// LockState and OpenState will be filled in by the entry point.
+//
+STATIC EFI_SMM_ACCESS2_PROTOCOL mAccess2 = {
+  &SmmAccess2DxeOpen,
+  &SmmAccess2DxeClose,
+  &SmmAccess2DxeLock,
+  &SmmAccess2DxeGetCapabilities
+};
+
+//
+// Entry point of this driver.
+//
+EFI_STATUS
+EFIAPI
+SmmAccess2DxeEntryPoint (
+  IN EFI_HANDLE       ImageHandle,
+  IN EFI_SYSTEM_TABLE *SystemTable
+  )
+{
+  //
+  // This module should only be included if SMRAM support is required.
+  //
+  ASSERT (FeaturePcdGet (PcdSmmSmramRequire));
+
+  GetStates (&mAccess2.LockState, &mAccess2.OpenState);
+  return gBS->InstallMultipleProtocolInterfaces (&ImageHandle,
+                &gEfiSmmAccess2ProtocolGuid, &mAccess2,
+                NULL);
+}

OvmfPkg/SmmAccess/SmmAccess2Dxe.inf

@@ -0,0 +1,58 @@
+## @file
+# A DXE_DRIVER providing SMRAM access by producing EFI_SMM_ACCESS2_PROTOCOL.
+#
+# Q35 TSEG is expected to have been verified and set up by the SmmAccessPei
+# driver.
+#
+# Copyright (C) 2013, 2015, Red Hat, Inc.
+#
+# This program and the accompanying materials are licensed and made available
+# under the terms and conditions of the BSD License which accompanies this
+# distribution. The full text of the license may be found at
+# http://opensource.org/licenses/bsd-license.php
+#
+# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
+# WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+#
+##
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = SmmAccess2Dxe
+  FILE_GUID                      = AC95AD3D-4366-44BF-9A62-E4B29D7A2206
+  MODULE_TYPE                    = DXE_DRIVER
+  VERSION_STRING                 = 1.0
+  PI_SPECIFICATION_VERSION       = 0x00010400
+  ENTRY_POINT                    = SmmAccess2DxeEntryPoint
+
+#
+# The following information is for reference only and not required by the build tools.
+#
+#  VALID_ARCHITECTURES           = IA32 X64
+#
+
+[Sources]
+  SmmAccess2Dxe.c
+  SmramInternal.c
+  SmramInternal.h
+
+[Packages]
+  MdeModulePkg/MdeModulePkg.dec
+  MdePkg/MdePkg.dec
+  OvmfPkg/OvmfPkg.dec
+
+[LibraryClasses]
+  DebugLib
+  PcdLib
+  PciLib
+  UefiBootServicesTableLib
+  UefiDriverEntryPoint
+
+[Protocols]
+  gEfiSmmAccess2ProtocolGuid   ## PRODUCES
+
+[FeaturePcd]
+  gUefiOvmfPkgTokenSpaceGuid.PcdSmmSmramRequire
+
+[Depex]
+  TRUE