diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c
--- a/sys/amd64/amd64/pmap.c
+++ b/sys/amd64/amd64/pmap.c
@@ -9480,6 +9480,37 @@
 	    MAPDEV_FLUSHCACHE));
 }
 
+/*
+ * Version of pmap_qenter intended to map device memory rather than real one.
+ * See pmap_qenter comments.
+ */
+void
+pmap_qmapdev_attr(vm_offset_t sva, vm_pindex_t *pi, int count,
+    vm_memattr_t mode)
+{
+	pt_entry_t *endpte, oldpte, pa, *pte;
+	vm_pindex_t p;
+	int cache_bits;
+
+	oldpte = 0;
+	pte = vtopte(sva);
+	endpte = pte + count;
+	cache_bits = pmap_cache_bits(kernel_pmap, mode, false);
+	while (pte < endpte) {
+		p = *pi++;
+		pa = IDX_TO_OFF(p) | cache_bits;
+		if ((*pte & (PG_FRAME | X86_PG_PTE_CACHE)) != pa) {
+			oldpte |= *pte;
+			pte_store(pte, pa | pg_g | pg_nx | X86_PG_A |
+			    X86_PG_M | X86_PG_RW | X86_PG_V);
+		}
+		pte++;
+	}
+	if (__predict_false((oldpte & X86_PG_V) != 0))
+		pmap_invalidate_range(kernel_pmap, sva, sva + count *
+		    PAGE_SIZE);
+}
+
 void
 pmap_unmapdev(void *p, vm_size_t size)
 {
diff --git a/sys/amd64/include/pmap.h b/sys/amd64/include/pmap.h
--- a/sys/amd64/include/pmap.h
+++ b/sys/amd64/include/pmap.h
@@ -409,6 +409,7 @@
 void	*pmap_mapdev(vm_paddr_t, vm_size_t);
 void	*pmap_mapdev_attr(vm_paddr_t, vm_size_t, int);
 void	*pmap_mapdev_pciecfg(vm_paddr_t pa, vm_size_t size);
+void	pmap_qmapdev_attr(vm_offset_t, vm_pindex_t *, int, vm_memattr_t);
 bool	pmap_not_in_di(void);
 bool	pmap_page_is_mapped(vm_page_t m);
 void	pmap_page_set_memattr(vm_page_t m, vm_memattr_t ma);