set shared bit to MMIO range reported by VMM

TdvfPkg/Library/BaseMemEncryptTdxLib/BaseMemEncryptTdxLib.inf

@@ -15,7 +15,7 @@
   FILE_GUID                      = 9fa36066-4745-47de-b488-7c3b5ba9b261
   MODULE_TYPE                    = BASE
   VERSION_STRING                 = 1.0
-  LIBRARY_CLASS                  = MemEncryptLib|PEIM DXE_DRIVER DXE_RUNTIME_DRIVER DXE_SMM_DRIVER UEFI_DRIVER
+  LIBRARY_CLASS                  = MemEncryptLib|SEC DXE_DRIVER DXE_RUNTIME_DRIVER DXE_SMM_DRIVER UEFI_DRIVER
 
 #
 # The following information is for reference only and not required by the build

TdvfPkg/Library/BaseMemEncryptTdxLib/MemoryEncryption.c

@@ -53,6 +53,15 @@ MemEncryptIsEnabled (
   return TRUE;
 }
 
+VOID
+EFIAPI
+SetMemEncryptionAddressMask (
+  IN UINT64 AddressEncMask
+)
+{
+  mAddressEncMask = AddressEncMask;
+  mAddressEncMaskChecked = TRUE;
+}
 /**
   Get the memory encryption mask
 

TdvfPkg/Override/OvmfPkg/Include/Library/MemEncryptLib.h

@@ -110,4 +110,10 @@ MemEncryptLocateInitialSmramSaveStateMapPages (
   OUT UINTN *BaseAddress,
   OUT UINTN *NumberOfPages
   );
+
+VOID
+EFIAPI
+SetMemEncryptionAddressMask (
+  IN UINT64 AddressEncMask
+);
 #endif // _MEM_ENCRYPT_LIB_H_

TdvfPkg/TdShim/Sec/DxeLoad.c

@@ -21,6 +21,7 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 #include <Library/PrePiLib.h>
 #include "X64/PageTables.h"
 #include <Library/ReportStatusCodeLib.h>
+#include <Library/MemEncryptLib.h>
 
 #include "SecMain.h"
 
@@ -38,6 +39,46 @@ EFI_MEMORY_TYPE_INFORMATION mDefaultMemoryTypeInformation[] = {
 };
 
 
+VOID
+SetMmioShareBit (
+  IN UINTN   PageTables
+  )
+{
+  UINT64                          AddressEncMask;
+  EFI_HOB_CPU *                   CpuHob;
+  VOID                            *HobStart;
+  EFI_PEI_HOB_POINTERS            Hob;
+  EFI_STATUS                      Status;
+
+  if (PcdGetBool(PcdTdxDisableSharedMask) == TRUE) {
+    AddressEncMask = 0;
+  } else {
+    CpuHob = GetFirstHob (EFI_HOB_TYPE_CPU);
+    ASSERT (CpuHob != NULL);
+    AddressEncMask = 1ULL << (CpuHob->SizeOfMemorySpace - 1);
+  }
+
+  SetMemEncryptionAddressMask (AddressEncMask);
+
+  HobStart = GetHobList();
+  Hob.Raw = (UINT8 *) HobStart;
+  while (!END_OF_HOB_LIST (Hob)) {
+    if ((Hob.Header->HobType == EFI_HOB_TYPE_RESOURCE_DESCRIPTOR)
+          && (Hob.ResourceDescriptor->ResourceType == EFI_RESOURCE_MEMORY_MAPPED_IO )) {
+      Status = MemEncryptClearPageEncMask (
+                 PageTables,
+                 Hob.ResourceDescriptor->PhysicalStart,
+                 Hob.ResourceDescriptor->ResourceLength / EFI_PAGE_SIZE,
+                 FALSE
+                 );
+      ASSERT_EFI_ERROR (Status);
+      if (EFI_ERROR (Status)) {
+        CpuDeadLoop ();
+      }
+    }
+    Hob.Raw = GET_NEXT_HOB (Hob);
+  }
+}
 /**
    Transfers control to DxeCore.
 
@@ -95,6 +136,7 @@ HandOffToDxeCore (
   }
 
   if (FeaturePcdGet (PcdDxeIplBuildPageTables)) {
+    SetMmioShareBit (PageTables);
     AsmWriteCr3 (PageTables);
   }
 

TdvfPkg/TdShim/Sec/SecMain.inf

@@ -56,6 +56,7 @@
   CpuExceptionHandlerLib
   SynchronizationLib
   TdxLib
+  MemEncryptLib
 
 [Guids]
   gEfiHobMemoryAllocModuleGuid
@@ -87,6 +88,7 @@
   gUefiTdvfPkgTokenSpaceGuid.PcdBfvSize
   gUefiTdvfPkgTokenSpaceGuid.PcdUseTdxEmulation
   gUefiTdvfPkgTokenSpaceGuid.PcdTdxAcceptPageChunkSize
+  gUefiTdvfPkgTokenSpaceGuid.PcdTdxDisableSharedMask
   gEfiMdeModulePkgTokenSpaceGuid.PcdSetNxForStack               ## CONSUMES