Index: head/sys/dev/iommu/iommu_gas.c
===================================================================
--- head/sys/dev/iommu/iommu_gas.c
+++ head/sys/dev/iommu/iommu_gas.c
@@ -258,7 +258,8 @@
 	entry = RB_MIN(iommu_gas_entries_tree, &domain->rb_root);
 	KASSERT(entry->start == 0, ("start entry start %p", domain));
 	KASSERT(entry->end == IOMMU_PAGE_SIZE, ("start entry end %p", domain));
-	KASSERT(entry->flags == IOMMU_MAP_ENTRY_PLACE,
+	KASSERT(entry->flags ==
+	    (IOMMU_MAP_ENTRY_PLACE | IOMMU_MAP_ENTRY_UNMAPPED),
 	    ("start entry flags %p", domain));
 	RB_REMOVE(iommu_gas_entries_tree, &domain->rb_root, entry);
 	iommu_gas_free_entry(domain, entry);
@@ -266,7 +267,8 @@
 	entry = RB_MAX(iommu_gas_entries_tree, &domain->rb_root);
 	KASSERT(entry->start == domain->end, ("end entry start %p", domain));
 	KASSERT(entry->end == domain->end, ("end entry end %p", domain));
-	KASSERT(entry->flags == IOMMU_MAP_ENTRY_PLACE,
+	KASSERT(entry->flags ==
+	    (IOMMU_MAP_ENTRY_PLACE | IOMMU_MAP_ENTRY_UNMAPPED),
 	    ("end entry flags %p", domain));
 	RB_REMOVE(iommu_gas_entries_tree, &domain->rb_root, entry);
 	iommu_gas_free_entry(domain, entry);