Index: sys/dev/iommu/iommu.h
===================================================================
--- sys/dev/iommu/iommu.h
+++ sys/dev/iommu/iommu.h
@@ -35,6 +35,7 @@
 #define _SYS_IOMMU_H_
 
 #include <sys/queue.h>
+#include <sys/sysctl.h>
 #include <sys/taskqueue.h>
 #include <sys/tree.h>
 #include <sys/types.h>
@@ -210,4 +211,6 @@
 int iommu_gas_reserve_region(struct iommu_domain *domain, iommu_gaddr_t start,
     iommu_gaddr_t end);
 
+SYSCTL_DECL(_hw_iommu);
+
 #endif /* !_SYS_IOMMU_H_ */
Index: sys/dev/iommu/iommu_gas.c
===================================================================
--- sys/dev/iommu/iommu_gas.c
+++ sys/dev/iommu/iommu_gas.c
@@ -732,9 +732,9 @@
 	return (error);
 }
 
+SYSCTL_NODE(_hw, OID_AUTO, iommu, CTLFLAG_RW | CTLFLAG_MPSAFE, NULL, "");
+
 #ifdef INVARIANTS
-static SYSCTL_NODE(_hw, OID_AUTO, iommu, CTLFLAG_RD | CTLFLAG_MPSAFE, NULL,
-    "");
 SYSCTL_INT(_hw_iommu, OID_AUTO, check_free, CTLFLAG_RWTUN,
     &iommu_check_free, 0,
     "Check the GPA RBtree for free_down and free_after validity");
Index: sys/x86/iommu/intel_utils.c
===================================================================
--- sys/x86/iommu/intel_utils.c
+++ sys/x86/iommu/intel_utils.c
@@ -641,6 +641,7 @@
 	    dmar_hw_timeout.tv_nsec);
 }
 
+#ifdef INVARIANTS
 static int
 dmar_timeout_sysctl(SYSCTL_HANDLER_ARGS)
 {
@@ -655,15 +656,16 @@
 	return (error);
 }
 
-static SYSCTL_NODE(_hw, OID_AUTO, dmar, CTLFLAG_RD | CTLFLAG_MPSAFE, NULL,
-    "");
-SYSCTL_INT(_hw_dmar, OID_AUTO, tbl_pagecnt, CTLFLAG_RD,
+static SYSCTL_NODE(_hw_iommu, OID_AUTO, dmar, CTLFLAG_RD | CTLFLAG_MPSAFE,
+    NULL, "");
+SYSCTL_INT(_hw_iommu_dmar, OID_AUTO, tbl_pagecnt, CTLFLAG_RD,
     &dmar_tbl_pagecnt, 0,
     "Count of pages used for DMAR pagetables");
-SYSCTL_INT(_hw_dmar, OID_AUTO, batch_coalesce, CTLFLAG_RWTUN,
+SYSCTL_INT(_hw_iommu_dmar, OID_AUTO, batch_coalesce, CTLFLAG_RWTUN,
     &dmar_batch_coalesce, 0,
     "Number of qi batches between interrupt");
-SYSCTL_PROC(_hw_dmar, OID_AUTO, timeout,
+SYSCTL_PROC(_hw_iommu_dmar, OID_AUTO, timeout,
     CTLTYPE_U64 | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 0,
     dmar_timeout_sysctl, "QU",
     "Timeout for command wait, in nanoseconds");
+#endif