Index: /trunk/src/VBox/Additions/WINNT/Graphics/Video/mp/wddm/VBoxMPMisc.cpp
===================================================================
--- /trunk/src/VBox/Additions/WINNT/Graphics/Video/mp/wddm/VBoxMPMisc.cpp	(revision 41378)
+++ /trunk/src/VBox/Additions/WINNT/Graphics/Video/mp/wddm/VBoxMPMisc.cpp	(revision 41379)
@@ -2341,2 +2341,26 @@
     return STATUS_SUCCESS;
 }
+
+NTSTATUS vboxWddmDrvCfgInit(PUNICODE_STRING pRegStr)
+{
+    HANDLE hKey;
+    OBJECT_ATTRIBUTES ObjAttr;
+
+    InitializeObjectAttributes(&ObjAttr, pRegStr, OBJ_CASE_INSENSITIVE | OBJ_KERNEL_HANDLE, NULL, NULL);
+
+    NTSTATUS Status = ZwOpenKey(&hKey, GENERIC_READ, &ObjAttr);
+    if (!NT_SUCCESS(Status))
+    {
+        WARN(("ZwOpenKey for settings key failed, Status 0x%x", Status));
+        return Status;
+    }
+
+    DWORD dwValue = 0;
+    Status = vboxWddmRegQueryValueDword(hKey, VBOXWDDM_CFG_STR_LOG_UM, &dwValue);
+    if (NT_SUCCESS(Status))
+        g_VBoxLogUm = dwValue;
+
+    ZwClose(hKey);
+
+    return Status;
+}
Index: /trunk/src/VBox/Additions/WINNT/Graphics/Video/mp/wddm/VBoxMPMisc.h
===================================================================
--- /trunk/src/VBox/Additions/WINNT/Graphics/Video/mp/wddm/VBoxMPMisc.h	(revision 41378)
+++ /trunk/src/VBox/Additions/WINNT/Graphics/Video/mp/wddm/VBoxMPMisc.h	(revision 41379)
@@ -198,3 +198,5 @@
 void VBoxWddmVrTerm();
 
+NTSTATUS vboxWddmDrvCfgInit(PUNICODE_STRING pRegStr);
+
 #endif /* #ifndef ___VBoxMPMisc_h__ */
Index: /trunk/src/VBox/Additions/WINNT/Graphics/Video/mp/wddm/VBoxMPWddm.h
===================================================================
--- /trunk/src/VBox/Additions/WINNT/Graphics/Video/mp/wddm/VBoxMPWddm.h	(revision 41378)
+++ /trunk/src/VBox/Additions/WINNT/Graphics/Video/mp/wddm/VBoxMPWddm.h	(revision 41379)
@@ -30,4 +30,9 @@
 
 //#define VBOXWDDM_DEBUG_VIDPN
+
+#define VBOXWDDM_CFG_LOG_UM_BACKDOOR 0x00000001
+#define VBOXWDDM_CFG_LOG_UM_DBGPRINT 0x00000002
+#define VBOXWDDM_CFG_STR_LOG_UM L"VBoxLogUm"
+extern DWORD g_VBoxLogUm;
 
 RT_C_DECLS_BEGIN