diff --git a/hw/i386/amd_iommu.c b/hw/i386/amd_iommu.c
index c27efa504d..6e78047919 100644
--- a/hw/i386/amd_iommu.c
+++ b/hw/i386/amd_iommu.c
@@ -848,9 +848,10 @@ static inline uint64_t amdvi_get_perms(uint64_t entry)
 static bool amdvi_validate_dte(AMDVIState *s, uint16_t devid,
                                uint64_t *dte)
 {
-    if ((dte[0] & AMDVI_DTE_LOWER_QUAD_RESERVED)
-        || (dte[1] & AMDVI_DTE_MIDDLE_QUAD_RESERVED)
-        || (dte[2] & AMDVI_DTE_UPPER_QUAD_RESERVED) || dte[3]) {
+    if ((dte[0] & AMDVI_DTE_QUAD0_RESERVED) ||
+        (dte[1] & AMDVI_DTE_QUAD1_RESERVED) ||
+        (dte[2] & AMDVI_DTE_QUAD2_RESERVED) ||
+        (dte[3] & AMDVI_DTE_QUAD3_RESERVED)) {
         amdvi_log_illegaldevtab_error(s, devid,
                                       s->devtab +
                                       devid * AMDVI_DEVTAB_ENTRY_SIZE, 0);
diff --git a/hw/i386/amd_iommu.h b/hw/i386/amd_iommu.h
index 3b1d2e9da5..aacb29b617 100644
--- a/hw/i386/amd_iommu.h
+++ b/hw/i386/amd_iommu.h
@@ -25,6 +25,8 @@
 #include "hw/i386/x86-iommu.h"
 #include "qom/object.h"
 
+#define GENMASK64(h, l)  (((~0ULL) >> (63 - (h) + (l))) << (l))
+
 /* Capability registers */
 #define AMDVI_CAPAB_BAR_LOW           0x04
 #define AMDVI_CAPAB_BAR_HIGH          0x08
@@ -162,9 +164,10 @@
 #define AMDVI_FEATURE_PC                  (1ULL << 9) /* Perf counters       */
 
 /* reserved DTE bits */
-#define AMDVI_DTE_LOWER_QUAD_RESERVED  0x80300000000000fc
-#define AMDVI_DTE_MIDDLE_QUAD_RESERVED 0x0000000000000100
-#define AMDVI_DTE_UPPER_QUAD_RESERVED  0x08f0000000000000
+#define AMDVI_DTE_QUAD0_RESERVED        (GENMASK64(6, 2) | GENMASK64(63, 63))
+#define AMDVI_DTE_QUAD1_RESERVED        0
+#define AMDVI_DTE_QUAD2_RESERVED        GENMASK64(53, 52)
+#define AMDVI_DTE_QUAD3_RESERVED        (GENMASK64(14, 0) | GENMASK64(53, 48))
 
 /* AMDVI paging mode */
 #define AMDVI_GATS_MODE                 (2ULL <<  12)