OvmfPkg: Refine SmmAccess implementation

This patch refines the SmmAccess implementation:
1. SmramMap will be retrieved from the
gEfiSmmSmramMemoryGuid instead of original from
the TSEG Memory Base register.
2. Remove the gEfiAcpiVariableGuid creation, thus
the DESCRIPTOR_INDEX definition can be also cleaned.
3. The gEfiAcpiVariableGuid HOB is moved to the
OvmfPkg/Library/PlatformInitLib/PlatformInitLib.inf.

Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Ray Ni <ray.ni@intel.com>
Signed-off-by: Jiaxin Wu <jiaxin.wu@intel.com>
Tested-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Jiewen Yao <Jiewen.yao@intel.com>

1 files changed, 23 insertions, 49 deletions

diff --git a/OvmfPkg/SmmAccess/SmramInternal.c b/OvmfPkg/SmmAccess/SmramInternal.c
index d391ddc..ff67d30 100644
--- a/OvmfPkg/SmmAccess/SmramInternal.c
+++ b/OvmfPkg/SmmAccess/SmramInternal.c
@@ -3,12 +3,11 @@
   Functions and types shared by the SMM accessor PEI and DXE modules.

 

   Copyright (C) 2015, Red Hat, Inc.

+  Copyright (c) 2024 Intel Corporation.

 

   SPDX-License-Identifier: BSD-2-Clause-Patent

 

 **/

-

-#include <Guid/AcpiS3Context.h>

 #include <IndustryStandard/Q35MchIch9.h>

 #include <Library/DebugLib.h>

 #include <Library/PcdLib.h>

@@ -166,68 +165,43 @@ SmramAccessLock (
 

 EFI_STATUS

 SmramAccessGetCapabilities (

-  IN BOOLEAN                   LockState,

-  IN BOOLEAN                   OpenState,

   IN OUT UINTN                 *SmramMapSize,

   IN OUT EFI_SMRAM_DESCRIPTOR  *SmramMap

   )

 {

-  UINTN   OriginalSize;

-  UINT32  TsegMemoryBaseMb, TsegMemoryBase;

-  UINT64  CommonRegionState;

-  UINT8   TsegSizeBits;

-

-  OriginalSize  = *SmramMapSize;

-  *SmramMapSize = DescIdxCount * sizeof *SmramMap;

-  if (OriginalSize < *SmramMapSize) {

-    return EFI_BUFFER_TOO_SMALL;

-  }

+  UINTN                           BufferSize;

+  EFI_HOB_GUID_TYPE               *GuidHob;

+  EFI_SMRAM_HOB_DESCRIPTOR_BLOCK  *DescriptorBlock;

+  UINTN                           Index;

 

   //

-  // Read the TSEG Memory Base register.

+  // Get Hob list

   //

-  TsegMemoryBaseMb = PciRead32 (DRAMC_REGISTER_Q35 (MCH_TSEGMB));

-  TsegMemoryBase   = (TsegMemoryBaseMb >> MCH_TSEGMB_MB_SHIFT) << 20;

+  GuidHob         = GetFirstGuidHob (&gEfiSmmSmramMemoryGuid);

+  DescriptorBlock = GET_GUID_HOB_DATA (GuidHob);

+  ASSERT (DescriptorBlock);

 

-  //

-  // Precompute the region state bits that will be set for all regions.

-  //

-  CommonRegionState = (OpenState ? EFI_SMRAM_OPEN : EFI_SMRAM_CLOSED) |

-                      (LockState ? EFI_SMRAM_LOCKED : 0) |

-                      EFI_CACHEABLE;

+  BufferSize = DescriptorBlock->NumberOfSmmReservedRegions * sizeof (EFI_SMRAM_DESCRIPTOR);

 

-  //

-  // The first region hosts an SMM_S3_RESUME_STATE object. It is located at the

-  // start of TSEG. We round up the size to whole pages, and we report it as

-  // EFI_ALLOCATED, so that the SMM_CORE stays away from it.

-  //

-  SmramMap[DescIdxSmmS3ResumeState].PhysicalStart = TsegMemoryBase;

-  SmramMap[DescIdxSmmS3ResumeState].CpuStart      = TsegMemoryBase;

-  SmramMap[DescIdxSmmS3ResumeState].PhysicalSize  =

-    EFI_PAGES_TO_SIZE (EFI_SIZE_TO_PAGES (sizeof (SMM_S3_RESUME_STATE)));

-  SmramMap[DescIdxSmmS3ResumeState].RegionState =

-    CommonRegionState | EFI_ALLOCATED;

+  if (*SmramMapSize < BufferSize) {

+    *SmramMapSize = BufferSize;

+    return EFI_BUFFER_TOO_SMALL;

+  }

 

   //

-  // Get the TSEG size bits from the ESMRAMC register.

+  // Update SmramMapSize to real return SMRAM map size

   //

-  TsegSizeBits = PciRead8 (DRAMC_REGISTER_Q35 (MCH_ESMRAMC)) &

-                 MCH_ESMRAMC_TSEG_MASK;

+  *SmramMapSize = BufferSize;

 

   //

-  // The second region is the main one, following the first.

+  // Use the hob to publish SMRAM capabilities

   //

-  SmramMap[DescIdxMain].PhysicalStart =

-    SmramMap[DescIdxSmmS3ResumeState].PhysicalStart +

-    SmramMap[DescIdxSmmS3ResumeState].PhysicalSize;

-  SmramMap[DescIdxMain].CpuStart     = SmramMap[DescIdxMain].PhysicalStart;

-  SmramMap[DescIdxMain].PhysicalSize =

-    (TsegSizeBits == MCH_ESMRAMC_TSEG_8MB ? SIZE_8MB :

-     TsegSizeBits == MCH_ESMRAMC_TSEG_2MB ? SIZE_2MB :

-     TsegSizeBits == MCH_ESMRAMC_TSEG_1MB ? SIZE_1MB :

-     mQ35TsegMbytes * SIZE_1MB) -

-    SmramMap[DescIdxSmmS3ResumeState].PhysicalSize;

-  SmramMap[DescIdxMain].RegionState = CommonRegionState;

+  for (Index = 0; Index < DescriptorBlock->NumberOfSmmReservedRegions; Index++) {

+    SmramMap[Index].PhysicalStart = DescriptorBlock->Descriptor[Index].PhysicalStart;

+    SmramMap[Index].CpuStart      = DescriptorBlock->Descriptor[Index].CpuStart;

+    SmramMap[Index].PhysicalSize  = DescriptorBlock->Descriptor[Index].PhysicalSize;

+    SmramMap[Index].RegionState   = DescriptorBlock->Descriptor[Index].RegionState;

+  }

 

   return EFI_SUCCESS;

 }