Index: sys/dev/xen/blkfront/blkfront.c
===================================================================
--- sys/dev/xen/blkfront/blkfront.c
+++ sys/dev/xen/blkfront/blkfront.c
@@ -1439,7 +1439,7 @@
 	if (strcmp(xenbus_get_type(dev), "vbd") != 0)
 		return (ENXIO);
 
-	if (xen_hvm_domain() && xen_disable_pv_disks != 0)
+	if (xen_pv_disks_disabled())
 		return (ENXIO);
 
 	if (xen_hvm_domain()) {
Index: sys/x86/include/xen/xen-os.h
===================================================================
--- sys/x86/include/xen/xen-os.h
+++ sys/x86/include/xen/xen-os.h
@@ -39,6 +39,9 @@
 /* If non-zero, the hypervisor has been configured to use a direct vector */
 extern int xen_vector_callback_enabled;
 
+/* tunable for disabling PV disks */
+extern int xen_disable_pv_disks;
+
 static inline bool
 xen_support_evtchn_rebind(void)
 {
@@ -46,6 +49,13 @@
 	return (!xen_hvm_domain() || xen_vector_callback_enabled);
 }
 
+static inline bool
+xen_pv_disks_disabled(void)
+{
+
+	return (xen_hvm_domain() && xen_disable_pv_disks != 0);
+}
+
 #endif /* !__ASSEMBLY__ */
 
 #endif /* _MACHINE_X86_XEN_XEN_OS_H_ */
Index: sys/xen/xen-os.h
===================================================================
--- sys/xen/xen-os.h
+++ sys/xen/xen-os.h
@@ -101,7 +101,6 @@
 
 extern shared_info_t *HYPERVISOR_shared_info;
 
-extern int xen_disable_pv_disks;
 extern int xen_disable_pv_nics;
 
 extern bool xen_suspend_cancelled;