diff --git a/qemu/include/exec/memory.h b/qemu/include/exec/memory.h
index 22bbff16..b19c8785 100644
--- a/qemu/include/exec/memory.h
+++ b/qemu/include/exec/memory.h
@@ -577,6 +577,9 @@ static inline bool memory_region_is_romd(MemoryRegion *mr)
  */
 static inline bool memory_region_is_iommu(MemoryRegion *mr)
 {
+    if (mr->alias) {
+        return memory_region_is_iommu(mr->alias);
+    }
     return mr->iommu_ops;
 }