Changeset 89496 in vbox for trunk/src/VBox/Devices

Timestamp:

Jun 4, 2021 7:38:36 AM (4 years ago)

Author:

vboxsync

Message:

AMD IOMMU: bugref:9654 Assert rather than zero out bits that are already supposed to be zero.

File:

• trunk/src/VBox/Devices/Bus/DevIommuAmd.cpp (modified) (1 diff)

trunk/src/VBox/Devices/Bus/DevIommuAmd.cpp

@@ -810 +810 @@
     RTGCPHYS const GCPhysPrev  = pPageLookupPrev->GCPhysSpa;
     RTGCPHYS const GCPhys      = pPageLookup->GCPhysSpa;
-    uint64_t const offMaskPrev = IOMMU_GET_PAGE_OFF_MASK(pPageLookupPrev->cShift);
-    uint64_t const offMask     = IOMMU_GET_PAGE_OFF_MASK(pPageLookup->cShift);
-
+#ifdef RT_STRICT
     /* Paranoia: Ensure offset bits are 0. */
-    Assert(!(GCPhysPrev & offMaskPrev));
-    Assert(!(GCPhys     & offMask));
-
-    if ((GCPhysPrev & ~offMaskPrev) + cbPrev == (GCPhys & ~offMask))
-        return true;
-    return false;
+    {
+        uint64_t const fOffMaskPrev = IOMMU_GET_PAGE_OFF_MASK(pPageLookupPrev->cShift);
+        uint64_t const fOffMask     = IOMMU_GET_PAGE_OFF_MASK(pPageLookup->cShift);
+        Assert(!(GCPhysPrev & fOffMaskPrev));
+        Assert(!(GCPhys     & fOffMask));
+    }
+#endif
+    return GCPhysPrev + cbPrev == GCPhys;
 }