Index: /trunk/src/VBox/Additions/WINNT/Graphics/Video/mp/wddm/VBoxMPWddm.cpp
===================================================================
--- /trunk/src/VBox/Additions/WINNT/Graphics/Video/mp/wddm/VBoxMPWddm.cpp	(revision 57847)
+++ /trunk/src/VBox/Additions/WINNT/Graphics/Video/mp/wddm/VBoxMPWddm.cpp	(revision 57848)
@@ -2577,8 +2577,11 @@
                                 Assert(pAllocation->AllocData.SurfDesc.cbSize);
 
-//                                if (!pAllocInfo->fFlags.SharedResource && !pAllocInfo->hostID)
-//                                    pAllocationInfo->Flags.CpuVisible = 1;
-
-                                Assert(!pAllocationInfo->Flags.CpuVisible);
+                                /*
+                                 * Mark the allocation as visible to the CPU so we can
+                                 * lock it in the user mode driver for SYSTEM pool allocations.
+                                 * See @bugref{8040} for further information.
+                                 */
+                                if (!pAllocInfo->fFlags.SharedResource && !pAllocInfo->hostID)
+                                    pAllocationInfo->Flags.CpuVisible = 1;
 
                                 if (pAllocInfo->fFlags.SharedResource)