[PATCH v1] MinPlatformPkg: Fix SetLargeVariable fail issue

[Xiaoqiang Zhang <xiaoqiang.zhang@intel.com>]

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4454

On Server platform, when the large variable "FspNvsBuffer" is
already in the UEFI variable store and the remaining variable
storage space is less than the large variable size. And also
not in OS runtime then we need to add the size of the current
data that will end up being replaced by the new data to the
remaining space before we decide that there is not enough
space to store the large variable.

Cc: Chasel Chiu <chasel.chiu@intel.com>
Cc: Nate DeSimone <nathaniel.l.desimone@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Eric Dong <eric.dong@intel.com>

Signed-off-by: Xiaoqiang Zhang <xiaoqiang.zhang@intel.com>
---
 Platform/Intel/MinPlatformPkg/Library/BaseLargeVariableLib/LargeVariableWriteLib.c       | 10 +++++++++-
 Platform/Intel/MinPlatformPkg/Library/BaseLargeVariableLib/BaseLargeVariableWriteLib.inf |  1 +
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/Platform/Intel/MinPlatformPkg/Library/BaseLargeVariableLib/LargeVariableWriteLib.c b/Platform/Intel/MinPlatformPkg/Library/BaseLargeVariableLib/LargeVariableWriteLib.c
index de23ae6160..da820f65b9 100644
--- a/Platform/Intel/MinPlatformPkg/Library/BaseLargeVariableLib/LargeVariableWriteLib.c
+++ b/Platform/Intel/MinPlatformPkg/Library/BaseLargeVariableLib/LargeVariableWriteLib.c
@@ -22,7 +22,7 @@
 #include <Library/PrintLib.h>
 #include <Library/VariableReadLib.h>
 #include <Library/VariableWriteLib.h>
-
+#include <Library/LargeVariableReadLib.h>
 #include "LargeVariableCommon.h"
 
 /**
@@ -270,6 +270,7 @@ SetLargeVariable (
   UINT8         *OffsetPtr;
   UINTN         BytesRemaining;
   UINTN         SizeToSave;
+  UINTN         BufferSize = 0;
 
   //
   // Check input parameters.
@@ -365,6 +366,13 @@ SetLargeVariable (
     // Non-Volatile storage to store the data.
     //
     RemainingVariableStorage = GetRemainingVariableStorageSpace ();
+    //
+    // Check if current variable already existed in NV storage variable space
+    //
+    Status = GetLargeVariable (VariableName, VendorGuid, &BufferSize, NULL);
+    if ((Status == EFI_BUFFER_TOO_SMALL) && (BufferSize != 0)) {
+      RemainingVariableStorage = RemainingVariableStorage + BufferSize;
+    }
     if (DataSize > RemainingVariableStorage) {
       DEBUG ((DEBUG_ERROR, "SetLargeVariable: Not enough NV storage space to store the data\n"));
       Status = EFI_OUT_OF_RESOURCES;
diff --git a/Platform/Intel/MinPlatformPkg/Library/BaseLargeVariableLib/BaseLargeVariableWriteLib.inf b/Platform/Intel/MinPlatformPkg/Library/BaseLargeVariableLib/BaseLargeVariableWriteLib.inf
index 2493a94596..cbc2a5d93a 100644
--- a/Platform/Intel/MinPlatformPkg/Library/BaseLargeVariableLib/BaseLargeVariableWriteLib.inf
+++ b/Platform/Intel/MinPlatformPkg/Library/BaseLargeVariableLib/BaseLargeVariableWriteLib.inf
@@ -49,3 +49,4 @@
   PrintLib
   VariableReadLib
   VariableWriteLib
+  LargeVariableReadLib
-- 
2.39.1.windows.1