qdev: provide an interface to return canonical path from root (v2)

The canonical path is the path in the composition tree from the root to the
device.  This is effectively the name of the device.

This is an incredibly unefficient implementation that will be optimized in
a future patch.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

diff --git a/hw/qdev.c b/hw/qdev.c
index bb0b9f7d6a8d56fdf7bded154facebc953da189a..79849c9bfd1da4571b5a4f0372ae545a098af55c 100644 (file)
--- a/hw/qdev.c
+++ b/hw/qdev.c
@@ -1173,3 +1173,51 @@ DeviceState *qdev_get_root(void)
 
     return qdev_root;
 }
+
+static gchar *qdev_get_path_in(DeviceState *parent, DeviceState *dev)
+{
+    DeviceProperty *prop;
+
+    if (parent == dev) {
+        return g_strdup("");
+    }
+
+    QTAILQ_FOREACH(prop, &parent->properties, node) {
+        gchar *subpath;
+
+        if (!strstart(prop->type, "child<", NULL)) {
+            continue;
+        }
+
+        /* Check to see if the device is one of parent's children */
+        if (prop->opaque == dev) {
+            return g_strdup(prop->name);
+        }
+
+        /* Check to see if the device is a child of our child */
+        subpath = qdev_get_path_in(prop->opaque, dev);
+        if (subpath) {
+            gchar *path;
+
+            path = g_strdup_printf("%s/%s", prop->name, subpath);
+            g_free(subpath);
+
+            return path;
+        }
+    }
+
+    return NULL;
+}
+
+gchar *qdev_get_canonical_path(DeviceState *dev)
+{
+    gchar *path, *newpath;
+
+    path = qdev_get_path_in(qdev_get_root(), dev);
+    g_assert(path != NULL);
+
+    newpath = g_strdup_printf("/%s", path);
+    g_free(path);
+
+    return newpath;
+}

diff --git a/hw/qdev.h b/hw/qdev.h
index 52aadd2f1f612aaeb2405a8f8fe47f5c4409a240..0f004971a2cf9e5603fe6fdb976040e669a7db1c 100644 (file)
--- a/hw/qdev.h
+++ b/hw/qdev.h
@@ -490,4 +490,13 @@ void qdev_property_add_legacy(DeviceState *dev, Property *prop, Error **errp);
  */
 DeviceState *qdev_get_root(void);
 
+/**
+ * @qdev_get_canonical_path - returns the canonical path for a device.  This
+ * is the path within the composition tree starting from the root.
+ *
+ * Returns:
+ *   The canonical path in the composition tree.
+ */
+gchar *qdev_get_canonical_path(DeviceState *dev);
+
 #endif