[Qemu-devel] [RFC 4/8] qdev: link based hotplug

[Igor Mammedov]

Signed-off-by: Igor Mammedov <address@hidden>
---
 hw/core/hotplug.c      |   30 ++++++++++++++++++++++++++++++
 hw/core/qdev.c         |   15 +++++++++++++++
 include/hw/hotplug.h   |    2 ++
 include/hw/qdev-core.h |    6 ++++++
 4 files changed, 53 insertions(+), 0 deletions(-)

diff --git a/hw/core/hotplug.c b/hw/core/hotplug.c
index 5573d9d..1a13ca3 100644
--- a/hw/core/hotplug.c
+++ b/hw/core/hotplug.c
@@ -11,6 +11,36 @@
  */
 #include "hw/hotplug.h"
 #include "qemu/module.h"
+#include <string.h>
+
+HotplugHandler *hotplug_handler_get_from_path(const char *path)
+{
+    Object *obj;
+    const char *sep;
+    bool ambiguous = false;
+    HotplugHandler *hh = NULL;
+    char *current_path = g_strdup(path);
+
+    while ((sep = strrchr(current_path, '/'))) {
+        char *old_path = current_path;
+        if (!sep || sep == current_path) {
+            break;
+        }
+
+        current_path = g_strndup(current_path, sep - current_path);
+        g_free(old_path);
+
+        obj = object_resolve_path(current_path, &ambiguous);
+        g_assert(!ambiguous);
+        hh = (HotplugHandler *)object_dynamic_cast(obj, TYPE_HOTPLUG_HANDLER);
+        if (hh != NULL) {
+            break;
+        }
+    }
+
+    g_free(current_path);
+    return hh;
+}
 
 void hotplug_handler_plug(HotplugHandler *plug_handler,
                           DeviceState *plugged_dev,
diff --git a/hw/core/qdev.c b/hw/core/qdev.c
index 9f0a522..a8d6eea 100644
--- a/hw/core/qdev.c
+++ b/hw/core/qdev.c
@@ -743,6 +743,21 @@ static void device_set_realized(Object *obj, bool value, 
Error **err)
             local_err == NULL) {
             hotplug_handler_plug(dev->parent_bus->hotplug_handler,
                                  dev, &local_err);
+        } else if (dc->hotplug_path != NULL && local_err == NULL) {
+            HotplugHandler *hotplug_ctrl;
+            char *target_name;
+            char *path = dc->hotplug_path(dev);
+
+            hotplug_ctrl = hotplug_handler_get_from_path(path);
+            g_assert(hotplug_ctrl);
+
+            target_name = g_strdup(strrchr(path, '/') + 1);
+            object_property_set_link(OBJECT(hotplug_ctrl), OBJECT(dev),
+                                     target_name, &local_err);
+            g_free(target_name);
+            g_free(path);
+
+            hotplug_handler_plug(hotplug_ctrl, dev, &local_err);
         }
 
         if (qdev_get_vmsd(dev) && local_err == NULL) {
diff --git a/include/hw/hotplug.h b/include/hw/hotplug.h
index a6533cb..7a3815e 100644
--- a/include/hw/hotplug.h
+++ b/include/hw/hotplug.h
@@ -75,4 +75,6 @@ void hotplug_handler_plug(HotplugHandler *plug_handler,
 void hotplug_handler_unplug(HotplugHandler *plug_handler,
                             DeviceState *plugged_dev,
                             Error **errp);
+
+HotplugHandler *hotplug_handler_get_from_path(const char *path);
 #endif
diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
index dbe473c..6cd936d 100644
--- a/include/hw/qdev-core.h
+++ b/include/hw/qdev-core.h
@@ -116,6 +116,12 @@ typedef struct DeviceClass {
     bool cannot_instantiate_with_device_add_yet;
     bool hotpluggable;
 
+    /*
+     * Returns path to link<> that should be set/unset on dev hotplug.
+     * Used for link based bussless devices hotplug.
+     */
+    char* (*hotplug_path)(DeviceState *dev);
+
     /* callbacks */
     void (*reset)(DeviceState *dev);
     DeviceRealize realize;
-- 
1.7.1