[PATCH] UefiCpuPkg/PiSmmCpu: Check XdSupport before set NX.

[Jiewen Yao <jiewen.yao@intel.com>]

When XD is not supported, the BIT63 is reserved.
We should not set BIT63 in the page table.

Test OVMF IA32/IA32X64 with XD enabled/disabled.

Analyzed-by: Laszlo Ersek <lersek@redhat.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Jeff Fan <jeff.fan@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jiewen Yao <jiewen.yao@intel.com>
---
 UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c b/UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c
index b4f8861..c85e025 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c
@@ -209,10 +209,12 @@ ConvertPageEntryAttribute (
     }
   }
   if ((Attributes & EFI_MEMORY_XP) != 0) {
-    if (IsSet) {
-      NewPageEntry |= IA32_PG_NX;
-    } else {
-      NewPageEntry &= ~IA32_PG_NX;
+    if (mXdSupported) {
+      if (IsSet) {
+        NewPageEntry |= IA32_PG_NX;
+      } else {
+        NewPageEntry &= ~IA32_PG_NX;
+      }
     }
   }
   *PageEntry = NewPageEntry;
-- 
2.7.4.windows.1