OvmfPkg/SEV: don't manage the lifecycle of the SMRAM at the default SMBASE

[mirror_edk2.git] / OvmfPkg / Library / SmmCpuFeaturesLib / SmmCpuFeaturesLib.c

diff --git a/OvmfPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLib.c b/OvmfPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLib.c
index 0bfdeda78d3357d72036318af89358eb78015706..7ef7ed98342e9382585c0ac43d86f26abae29858 100644 (file)
--- a/OvmfPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLib.c
+++ b/OvmfPkg/Library/SmmCpuFeaturesLib/SmmCpuFeaturesLib.c
@@ -6,14 +6,17 @@
   SPDX-License-Identifier: BSD-2-Clause-Patent\r
 **/\r
 \r
+#include <IndustryStandard/Q35MchIch9.h>\r
 #include <Library/BaseLib.h>\r
 #include <Library/BaseMemoryLib.h>\r
 #include <Library/DebugLib.h>\r
 #include <Library/MemEncryptSevLib.h>\r
+#include <Library/PcdLib.h>\r
 #include <Library/SmmCpuFeaturesLib.h>\r
 #include <Library/SmmServicesTableLib.h>\r
 #include <Library/UefiBootServicesTableLib.h>\r
 #include <PiSmm.h>\r
+#include <Register/Intel/SmramSaveStateMap.h>\r
 #include <Register/QemuSmramSaveStateMap.h>\r
 \r
 //\r
@@ -215,8 +218,22 @@ SmmCpuFeaturesSmmRelocationComplete (
 \r
   ZeroMem ((VOID *)MapPagesBase, EFI_PAGES_TO_SIZE (MapPagesCount));\r
 \r
-  Status = gBS->FreePages (MapPagesBase, MapPagesCount);\r
-  ASSERT_EFI_ERROR (Status);\r
+  if (PcdGetBool (PcdQ35SmramAtDefaultSmbase)) {\r
+    //\r
+    // The initial SMRAM Save State Map has been covered as part of a larger\r
+    // reserved memory allocation in PlatformPei's InitializeRamRegions(). That\r
+    // allocation is supposed to survive into OS runtime; we must not release\r
+    // any part of it. Only re-assert the containment here.\r
+    //\r
+    ASSERT (SMM_DEFAULT_SMBASE <= MapPagesBase);\r
+    ASSERT (\r
+      (MapPagesBase + EFI_PAGES_TO_SIZE (MapPagesCount) <=\r
+       SMM_DEFAULT_SMBASE + MCH_DEFAULT_SMBASE_SIZE)\r
+      );\r
+  } else {\r
+    Status = gBS->FreePages (MapPagesBase, MapPagesCount);\r
+    ASSERT_EFI_ERROR (Status);\r
+  }\r
 }\r
 \r
 /**\r