From cc3620f304acc8dce4af8149348919c4fdc22544 Mon Sep 17 00:00:00 2001
From: Min Xu <min.m.xu@intel.com>
Date: Thu, 21 Oct 2021 16:49:12 +0800
Subject: [PATCH] UefiCpuPkg: Update AddressEncMask in CpuPageTable

RFC: https://bugzilla.tianocore.org/show_bug.cgi?id=3429

MMIO region in Tdx guest is set with PcdTdxSharedBitMask in TdxDxe's
entry point. In SEV guest the page table entries is set with
PcdPteMemoryEncryptionAddressOrMask when creating 1:1 identity table.

So the AddressEncMask in GetPageTableEntry (@CpuPageTable.c) is either
PcdPteMemoryEncryptionAddressOrMask (in SEV guest), or
PcdTdxSharedBitMask (in TDX guest), or all-0 (in Legacy guest).

Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>
---
 UefiCpuPkg/CpuDxe/CpuDxe.inf     | 1 +
 UefiCpuPkg/CpuDxe/CpuPageTable.c | 3 +++
 2 files changed, 4 insertions(+)

diff --git a/UefiCpuPkg/CpuDxe/CpuDxe.inf b/UefiCpuPkg/CpuDxe/CpuDxe.inf
index d87fe503d1..2352418992 100644
--- a/UefiCpuPkg/CpuDxe/CpuDxe.inf
+++ b/UefiCpuPkg/CpuDxe/CpuDxe.inf
@@ -80,6 +80,7 @@
   gEfiMdeModulePkgTokenSpaceGuid.PcdNullPointerDetectionPropertyMask    ## CONSUMES
   gUefiCpuPkgTokenSpaceGuid.PcdCpuStackSwitchExceptionList              ## CONSUMES
   gUefiCpuPkgTokenSpaceGuid.PcdCpuKnownGoodStackSize                    ## CONSUMES
+  gEfiMdeModulePkgTokenSpaceGuid.PcdTdxSharedBitMask                    ## CONSUMES
 
 [Depex]
   TRUE
diff --git a/UefiCpuPkg/CpuDxe/CpuPageTable.c b/UefiCpuPkg/CpuDxe/CpuPageTable.c
index d9e65ab4b2..f7a4d92e92 100644
--- a/UefiCpuPkg/CpuDxe/CpuPageTable.c
+++ b/UefiCpuPkg/CpuDxe/CpuPageTable.c
@@ -307,6 +307,9 @@ GetPageTableEntry (
   // Make sure AddressEncMask is contained to smallest supported address field.
   //
   AddressEncMask = PcdGet64 (PcdPteMemoryEncryptionAddressOrMask) & PAGING_1G_ADDRESS_MASK_64;
+  if (AddressEncMask == 0) {
+    AddressEncMask = PcdGet64 (PcdTdxSharedBitMask) & PAGING_1G_ADDRESS_MASK_64;
+  }
 
   if (PagingContext->MachineType == IMAGE_FILE_MACHINE_X64) {
     if ((PagingContext->ContextData.X64.Attributes & PAGE_TABLE_LIB_PAGING_CONTEXT_IA32_X64_ATTRIBUTES_5_LEVEL) != 0) {