From f88290964fe528ffeb67ff108e8174fc2ce52741 Mon Sep 17 00:00:00 2001
From: Brijesh Singh <brijesh.singh@amd.com>
Date: Wed, 4 Jul 2018 10:02:16 +0800
Subject: [PATCH] MdeModulePkg/Variable: Check EFI_MEMORY_RUNTIME attribute
 before setting it

Set the EFI_MEMORY_RUNTIME attribute in FtwNotificationEvent() only if
the attribute is not already present. This will ensure that the attributes
set by the platform drivers (e.g Ovmf pflash) is not lost.

Cc: Dong Eric <eric.dong@intel.com>
Cc: Justen Jordan L <jordan.l.justen@intel.com>
Cc: Zeng Star <star.zeng@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Reviewed-by: Star Zeng <star.zeng@intel.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
---
 .../Universal/Variable/RuntimeDxe/VariableDxe.c  | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableDxe.c b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableDxe.c
index 6b04f4f7b3..23186176be 100644
--- a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableDxe.c
+++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableDxe.c
@@ -412,13 +412,15 @@ FtwNotificationEvent (
   if (EFI_ERROR (Status)) {
     DEBUG ((DEBUG_WARN, "Variable driver failed to get flash memory attribute.\n"));
   } else {
-    Status = gDS->SetMemorySpaceAttributes (
-                    BaseAddress,
-                    Length,
-                    GcdDescriptor.Attributes | EFI_MEMORY_RUNTIME
-                    );
-    if (EFI_ERROR (Status)) {
-      DEBUG ((DEBUG_WARN, "Variable driver failed to add EFI_MEMORY_RUNTIME attribute to Flash.\n"));
+    if ((GcdDescriptor.Attributes & EFI_MEMORY_RUNTIME) == 0) {
+      Status = gDS->SetMemorySpaceAttributes (
+                      BaseAddress,
+                      Length,
+                      GcdDescriptor.Attributes | EFI_MEMORY_RUNTIME
+                      );
+      if (EFI_ERROR (Status)) {
+        DEBUG ((DEBUG_WARN, "Variable driver failed to add EFI_MEMORY_RUNTIME attribute to Flash.\n"));
+      }
     }
   }
 
-- 
2.17.1