QemuQ35Pkg/SmmAccess: Drop S3 and Lock Box support

Main change is to compensate for the single MMRAM range used now that the S3 resume area is removed from MMRAM. A single range is now used to cover all of TSEG. Signed-off-by: Michael Kubacki <Michael.kubacki@microsoft.com>
microsoft · Sep 24, 2024 · 2fad849 · 2fad849
1 parent b22b4e7
commit 2fad849
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Showing 4 changed files with 12 additions and 59 deletions.
diff --git a/Platforms/QemuQ35Pkg/SmmAccess/SmmAccessPei.c b/Platforms/QemuQ35Pkg/SmmAccess/SmmAccessPei.c
@@ -2,10 +2,8 @@
 
   A PEIM with the following responsibilities:
 
-  - verify & configure the Q35 TSEG in the entry point,
-  - provide SMRAM access by producing PEI_SMM_ACCESS_PPI,
-  - set aside the SMM_S3_RESUME_STATE object at the bottom of TSEG, and expose
-    it via the gEfiAcpiVariableGuid GUID HOB.
+  - verify & configure the Q35 TSEG in the entry point
+  - provide SMRAM access by producing PEI_SMM_ACCESS_PPI
 
   This PEIM runs from RAM, so we can write to variables with static storage
   duration.
@@ -17,7 +15,6 @@
 
 **/
 
-#include <Guid/AcpiS3Context.h>
 #include <Guid/MmramMemoryReserve.h> // MU_CHANGE: Added support for Standalone MM mode
 #include <Library/BaseLib.h>
 #include <Library/BaseMemoryLib.h>
@@ -248,7 +245,6 @@ SmmAccessPeiEntryPoint (
   EFI_STATUS            Status;
   UINTN                 SmramMapSize;
   EFI_SMRAM_DESCRIPTOR  SmramMap[DescIdxCount];
-  VOID                  *GuidHob;
 
   //
   // This module should only be included if SMRAM support is required.
@@ -403,31 +399,12 @@ SmmAccessPeiEntryPoint (
   }
   DEBUG_CODE_END ();
 
-  GuidHob = BuildGuidHob (
-              &gEfiAcpiVariableGuid,
-              sizeof SmramMap[DescIdxSmmS3ResumeState]
-              );
-  if (GuidHob == NULL) {
-    return EFI_OUT_OF_RESOURCES;
-  }
-
-  CopyMem (
-    GuidHob,
-    &SmramMap[DescIdxSmmS3ResumeState],
-    sizeof SmramMap[DescIdxSmmS3ResumeState]
-    );
-
   //
   // SmramAccessLock() depends on "mQ35SmramAtDefaultSmbase"; init the latter
   // just before exposing the former via PEI_SMM_ACCESS_PPI.Lock().
   //
   InitQ35SmramAtDefaultSmbase ();
 
-  //
-  // We're done. The next step should succeed, but even if it fails, we can't
-  // roll back the above BuildGuidHob() allocation, because PEI doesn't support
-  // releasing memory.
-  //
   return PeiServicesInstallPpi (mPpiList);
 
 WrongConfig:

diff --git a/Platforms/QemuQ35Pkg/SmmAccess/SmmAccessPei.inf b/Platforms/QemuQ35Pkg/SmmAccess/SmmAccessPei.inf
@@ -1,10 +1,8 @@
 ## @file
 # A PEIM with the following responsibilities:
 #
-# - provide SMRAM access by producing PEI_SMM_ACCESS_PPI,
-# - verify & configure the Q35 TSEG in the entry point,
-# - set aside the SMM_S3_RESUME_STATE object at the bottom of TSEG, and expose
-#   it via the gEfiAcpiVariableGuid GUIDed HOB.
+# - provide SMRAM access by producing PEI_SMM_ACCESS_PPI
+# - verify & configure the Q35 TSEG in the entry point
 #
 # Copyright (C) 2013, 2015, Red Hat, Inc.
 #

diff --git a/Platforms/QemuQ35Pkg/SmmAccess/SmramInternal.c b/Platforms/QemuQ35Pkg/SmmAccess/SmramInternal.c
@@ -8,7 +8,6 @@
 
 **/
 
-#include <Guid/AcpiS3Context.h>
 #include <IndustryStandard/Q35MchIch9.h>
 #include <Library/DebugLib.h>
 #include <Library/PcdLib.h>
@@ -196,18 +195,6 @@ SmramAccessGetCapabilities (
                       (LockState ? EFI_SMRAM_LOCKED : 0) |
                       EFI_CACHEABLE;
 
-  //
-  // 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;
-
   //
   // Get the TSEG size bits from the ESMRAMC register.
   //
@@ -217,16 +204,13 @@ SmramAccessGetCapabilities (
   //
   // The second region is the main one, following the first.
   //
-  SmramMap[DescIdxMain].PhysicalStart =
-    SmramMap[DescIdxSmmS3ResumeState].PhysicalStart +
-    SmramMap[DescIdxSmmS3ResumeState].PhysicalSize;
-  SmramMap[DescIdxMain].CpuStart     = SmramMap[DescIdxMain].PhysicalStart;
-  SmramMap[DescIdxMain].PhysicalSize =
+  SmramMap[DescIdxMain].PhysicalStart = TsegMemoryBase;
+  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;
+     mQ35TsegMbytes * SIZE_1MB);
   SmramMap[DescIdxMain].RegionState = CommonRegionState;
 
   return EFI_SUCCESS;

diff --git a/Platforms/QemuQ35Pkg/SmmAccess/SmramInternal.h b/Platforms/QemuQ35Pkg/SmmAccess/SmramInternal.h
@@ -3,6 +3,7 @@
   Functions and types shared by the SMM accessor PEI and DXE modules.
 
   Copyright (C) 2015, Red Hat, Inc.
+  Copyright (c) Microsoft Corporation
 
   SPDX-License-Identifier: BSD-2-Clause-Patent
 
@@ -14,18 +15,11 @@
 #include <Pi/PiMultiPhase.h>
 
 //
-// We'll have two SMRAM ranges.
-//
-// The first is a tiny one that hosts an SMM_S3_RESUME_STATE object, to be
-// filled in by the CPU SMM driver during normal boot, for the PEI instance of
-// the LockBox library (which will rely on the object during S3 resume).
-//
-// The other SMRAM range is the main one, for the SMM core and the SMM drivers.
+// A single MMRAM range is used for both the MM core and MM drivers.
 //
 typedef enum {
-  DescIdxSmmS3ResumeState = 0,
-  DescIdxMain             = 1,
-  DescIdxCount            = 2
+  DescIdxMain  = 0,
+  DescIdxCount = 1
 } DESCRIPTOR_INDEX;
 
 //