[edk2-devel] [PATCH v2 05/10] OvmfPkg/PlatformInitLib: Create gEfiSmmSmramMemoryGuid

["Wu, Jiaxin" <jiaxin.wu@intel.com>]

Background:
In the PiSmmCpuDxeSmm driver, SMRAM allocation for SMI
handlers and processor Save State areas was traditionally
performed using the Smst->AllocatePages() function during
the DXE phase. The introduction of SmmRelocationLib
changes this process by moving the allocation to the PEI
phase, where Smst->AllocatePages() is not accessible.
Instead, the allocation is now handled by partitioning
the SMRAM based on the information provided by a GUID HOB
(identified by gEfiSmmSMramMemoryGuid).

This patch is to ensure that OVMF produces the
gEfiSmmSMramMemoryGuid HOB, allowing SmmRelocationLib to
reserve the necessary memory for SMBASE relocation.

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>
---
 OvmfPkg/Library/PlatformInitLib/MemDetect.c        | 97 +++++++++++++---------
 .../Library/PlatformInitLib/PlatformInitLib.inf    |  5 +-
 2 files changed, 64 insertions(+), 38 deletions(-)

diff --git a/OvmfPkg/Library/PlatformInitLib/MemDetect.c b/OvmfPkg/Library/PlatformInitLib/MemDetect.c
index 7b6e5102ad..8b98256225 100644
--- a/OvmfPkg/Library/PlatformInitLib/MemDetect.c
+++ b/OvmfPkg/Library/PlatformInitLib/MemDetect.c
@@ -1,9 +1,9 @@
 /**@file
   Memory Detection for Virtual Machines.
 
-  Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2006 - 2024, Intel Corporation. All rights reserved.<BR>
   SPDX-License-Identifier: BSD-2-Clause-Patent
 
 Module Name:
 
   MemDetect.c
@@ -41,10 +41,12 @@ Module Name:
 #include <Library/QemuFwCfgSimpleParserLib.h>
 #include <Library/TdxLib.h>
 
 #include <Library/PlatformInitLib.h>
 
+#include <Guid/SmramMemoryReserve.h>
+
 #define MEGABYTE_SHIFT  20
 
 VOID
 EFIAPI
 PlatformQemuUc32BaseInitialization (
@@ -1027,52 +1029,73 @@ PlatformQemuInitializeRam (
   //
   // Determine total memory size available
   //
   PlatformGetSystemMemorySizeBelow4gb (PlatformInfoHob);
 
-  if (PlatformInfoHob->BootMode == BOOT_ON_S3_RESUME) {
-    //
-    // Create the following memory HOB as an exception on the S3 boot path.
+  //
+  // CpuMpPei saves the original contents of the borrowed area in permanent
+  // PEI RAM, in a backup buffer allocated with the normal PEI services.
+  // CpuMpPei restores the original contents ("returns" the borrowed area) at
+  // End-of-PEI. End-of-PEI in turn is emitted by S3Resume2Pei before
+  // transferring control to the OS's wakeup vector in the FACS.
+  //
+  // We expect any other PEIMs that "borrow" memory similarly to CpuMpPei to
+  // restore the original contents. Furthermore, we expect all such PEIMs
+  // (CpuMpPei included) to claim the borrowed areas by producing memory
+  // allocation HOBs, and to honor preexistent memory allocation HOBs when
+  // looking for an area to borrow.
+  //
+  QemuInitializeRamBelow1gb (PlatformInfoHob);
+
+  if (PlatformInfoHob->SmmSmramRequire) {
+    UINT32                          TsegSize;
+    UINTN                           BufferSize;
+    UINT8                           SmramRanges;
+    EFI_PEI_HOB_POINTERS            Hob;
+    EFI_SMRAM_HOB_DESCRIPTOR_BLOCK  *SmramHobDescriptorBlock;
+
+    TsegSize = PlatformInfoHob->Q35TsegMbytes * SIZE_1MB;
+    PlatformAddMemoryRangeHob (BASE_1MB, PlatformInfoHob->LowMemory - TsegSize);
+    PlatformAddReservedMemoryBaseSizeHob (
+      PlatformInfoHob->LowMemory - TsegSize,
+      TsegSize,
+      TRUE
+      );
+
+    SmramRanges = 2;
+    BufferSize  = sizeof (EFI_SMRAM_HOB_DESCRIPTOR_BLOCK) + (SmramRanges - 1) * sizeof (EFI_SMRAM_DESCRIPTOR);
+
+    Hob.Raw = BuildGuidHob (
+                &gEfiSmmSmramMemoryGuid,
+                BufferSize
+                );
+    ASSERT (Hob.Raw);
+
+    SmramHobDescriptorBlock                             = (EFI_SMRAM_HOB_DESCRIPTOR_BLOCK *)(Hob.Raw);
+    SmramHobDescriptorBlock->NumberOfSmmReservedRegions = SmramRanges;
+
     //
-    // Normally we'd create memory HOBs only on the normal boot path. However,
-    // CpuMpPei specifically needs such a low-memory HOB on the S3 path as
-    // well, for "borrowing" a subset of it temporarily, for the AP startup
-    // vector.
+    // Create first SMRAM descriptor, which contains data structures used in S3 resume.
+    // One page is enough for the data structure
     //
-    // CpuMpPei saves the original contents of the borrowed area in permanent
-    // PEI RAM, in a backup buffer allocated with the normal PEI services.
-    // CpuMpPei restores the original contents ("returns" the borrowed area) at
-    // End-of-PEI. End-of-PEI in turn is emitted by S3Resume2Pei before
-    // transferring control to the OS's wakeup vector in the FACS.
+    SmramHobDescriptorBlock->Descriptor[0].PhysicalStart = PlatformInfoHob->LowMemory - TsegSize;
+    SmramHobDescriptorBlock->Descriptor[0].CpuStart      = PlatformInfoHob->LowMemory - TsegSize;
+    SmramHobDescriptorBlock->Descriptor[0].PhysicalSize  = EFI_PAGE_SIZE;
+    SmramHobDescriptorBlock->Descriptor[0].RegionState   = EFI_SMRAM_CLOSED | EFI_CACHEABLE | EFI_ALLOCATED;
+
     //
-    // We expect any other PEIMs that "borrow" memory similarly to CpuMpPei to
-    // restore the original contents. Furthermore, we expect all such PEIMs
-    // (CpuMpPei included) to claim the borrowed areas by producing memory
-    // allocation HOBs, and to honor preexistent memory allocation HOBs when
-    // looking for an area to borrow.
+    // Create second SMRAM descriptor, which is free and will be used by SMM foundation.
     //
-    QemuInitializeRamBelow1gb (PlatformInfoHob);
+    SmramHobDescriptorBlock->Descriptor[1].PhysicalStart = SmramHobDescriptorBlock->Descriptor[0].PhysicalStart + EFI_PAGE_SIZE;
+    SmramHobDescriptorBlock->Descriptor[1].CpuStart      = SmramHobDescriptorBlock->Descriptor[0].CpuStart + EFI_PAGE_SIZE;
+    SmramHobDescriptorBlock->Descriptor[1].PhysicalSize  = TsegSize - EFI_PAGE_SIZE;
+    SmramHobDescriptorBlock->Descriptor[1].RegionState   = EFI_SMRAM_CLOSED | EFI_CACHEABLE;
   } else {
-    //
-    // Create memory HOBs
-    //
-    QemuInitializeRamBelow1gb (PlatformInfoHob);
-
-    if (PlatformInfoHob->SmmSmramRequire) {
-      UINT32  TsegSize;
-
-      TsegSize = PlatformInfoHob->Q35TsegMbytes * SIZE_1MB;
-      PlatformAddMemoryRangeHob (BASE_1MB, PlatformInfoHob->LowMemory - TsegSize);
-      PlatformAddReservedMemoryBaseSizeHob (
-        PlatformInfoHob->LowMemory - TsegSize,
-        TsegSize,
-        TRUE
-        );
-    } else {
-      PlatformAddMemoryRangeHob (BASE_1MB, PlatformInfoHob->LowMemory);
-    }
+    PlatformAddMemoryRangeHob (BASE_1MB, PlatformInfoHob->LowMemory);
+  }
 
+  if (PlatformInfoHob->BootMode != BOOT_ON_S3_RESUME) {
     //
     // If QEMU presents an E820 map, then create memory HOBs for the >=4GB RAM
     // entries. Otherwise, create a single memory HOB with the flat >=4GB
     // memory size read from the CMOS.
     //
diff --git a/OvmfPkg/Library/PlatformInitLib/PlatformInitLib.inf b/OvmfPkg/Library/PlatformInitLib/PlatformInitLib.inf
index 5a79d95b68..2bb1c0296f 100644
--- a/OvmfPkg/Library/PlatformInitLib/PlatformInitLib.inf
+++ b/OvmfPkg/Library/PlatformInitLib/PlatformInitLib.inf
@@ -1,10 +1,10 @@
 ## @file
 #  Platform Initialization Lib
 #
 #  This module provides platform specific function to detect boot mode.
-#  Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.<BR>
+#  Copyright (c) 2006 - 2024, Intel Corporation. All rights reserved.<BR>
 #
 #  SPDX-License-Identifier: BSD-2-Clause-Patent
 #
 ##
 
@@ -54,10 +54,13 @@
   PeiHardwareInfoLib
 
 [LibraryClasses.X64]
   TdxLib
 
+[Guids]
+  gEfiSmmSmramMemoryGuid
+
 [Pcd]
   gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress
   gEfiMdeModulePkgTokenSpaceGuid.PcdUse1GPageTable
 
 [FixedPcd]
-- 
2.16.2.windows.1



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