diff --git a/usr.sbin/bhyve/config.h b/usr.sbin/bhyve/config.h
--- a/usr.sbin/bhyve/config.h
+++ b/usr.sbin/bhyve/config.h
@@ -45,6 +45,16 @@
  * OIDs.
  */
 
+/*
+ * Recursively walk the nodes under a parent nvlist. For each node that
+ * itself references a nvlist, the name of the node is appended to the
+ * prefix for the recursive call. For nodes representing a configuration
+ * variable, call the given callback function passing the current prefix,
+ * name and value of the variable, and the given argument.
+ */
+void walk_config_nodes(const char *prefix, const nvlist_t *parent, void *arg,
+    void (*cb)(const char *p, const char *n, const char *v, void *a));
+
 /*
  * Fetches the value of a configuration variable.  If the "raw" value
  * contains references to other configuration variables, this function
diff --git a/usr.sbin/bhyve/config.c b/usr.sbin/bhyve/config.c
--- a/usr.sbin/bhyve/config.c
+++ b/usr.sbin/bhyve/config.c
@@ -434,31 +434,38 @@
 	set_config_value_node(parent, name, value ? "true" : "false");
 }
 
-static void
-dump_tree(const char *prefix, const nvlist_t *nvl)
+void
+walk_config_nodes(const char *prefix, const nvlist_t *parent, void *arg,
+    void (*cb)(const char *p, const char *n, const char *v, void *a))
 {
+	void *cookie = NULL;
 	const char *name;
-	void *cookie;
 	int type;
 
-	cookie = NULL;
-	while ((name = nvlist_next(nvl, &type, &cookie)) != NULL) {
+	while ((name = nvlist_next(parent, &type, &cookie)) != NULL) {
 		if (type == NV_TYPE_NVLIST) {
 			char *new_prefix;
 
 			asprintf(&new_prefix, "%s%s.", prefix, name);
-			dump_tree(new_prefix, nvlist_get_nvlist(nvl, name));
+			walk_config_nodes(new_prefix,
+			    nvlist_get_nvlist(parent, name), arg, cb);
 			free(new_prefix);
 		} else {
 			assert(type == NV_TYPE_STRING);
-			printf("%s%s=%s\n", prefix, name,
-			    nvlist_get_string(nvl, name));
+			cb(prefix, name, nvlist_get_string(parent, name), arg);
 		}
 	}
 }
 
+static void
+dump_node_cb(const char *prefix, const char *name, const char *value,
+    void *arg __unused)
+{
+	printf("%s%s=%s\n", prefix, name, value);
+}
+
 void
 dump_config(void)
 {
-	dump_tree("", config_root);
+	walk_config_nodes("", config_root, NULL, dump_node_cb);
 }