7 files changed, 33 insertions, 17 deletions

diff --git a/exec.c b/exec.c
index 5c9b762..b5d6885 100644
--- a/exec.c
+++ b/exec.c
@@ -2603,8 +2603,8 @@ void qemu_ram_set_idstr(ram_addr_t addr, const char *name, DeviceState *dev)
     assert(new_block);
     assert(!new_block->idstr[0]);
 
-    if (dev && dev->parent_bus && dev->parent_bus->info->get_dev_path) {
-        char *id = dev->parent_bus->info->get_dev_path(dev);
+    if (dev) {
+        char *id = qdev_get_dev_path(dev);
         if (id) {
             snprintf(new_block->idstr, sizeof(new_block->idstr), "%s/", id);
             g_free(id);
diff --git a/hw/qdev.c b/hw/qdev.c
index 7f18590..7b2802d 100644
--- a/hw/qdev.c
+++ b/hw/qdev.c
@@ -494,6 +494,22 @@ char* qdev_get_fw_dev_path(DeviceState *dev)
     return strdup(path);
 }
 
+char *qdev_get_dev_path(DeviceState *dev)
+{
+    BusInfo *businfo;
+
+    if (!dev || !dev->parent_bus) {
+        return NULL;
+    }
+
+    businfo = dev->parent_bus->info;
+    if (businfo->get_dev_path) {
+        return businfo->get_dev_path(dev);
+    }
+
+    return NULL;
+}
+
 /**
  * Legacy property handling
  */
diff --git a/hw/qdev.h b/hw/qdev.h
index 1af5382..013ccf2 100644
--- a/hw/qdev.h
+++ b/hw/qdev.h
@@ -352,4 +352,6 @@ void qdev_set_parent_bus(DeviceState *dev, BusState *bus);
 
 extern int qdev_hotplug;
 
+char *qdev_get_dev_path(DeviceState *dev);
+
 #endif
diff --git a/hw/scsi-bus.c b/hw/scsi-bus.c
index a1d75b9..e79bb54 100644
--- a/hw/scsi-bus.c
+++ b/hw/scsi-bus.c
@@ -1453,12 +1453,10 @@ static char *scsibus_get_dev_path(DeviceState *dev)
 {
     SCSIDevice *d = DO_UPCAST(SCSIDevice, qdev, dev);
     DeviceState *hba = dev->parent_bus->parent;
-    char *id = NULL;
+    char *id;
     char *path;
 
-    if (hba && hba->parent_bus && hba->parent_bus->info->get_dev_path) {
-        id = hba->parent_bus->info->get_dev_path(hba);
-    }
+    id = qdev_get_dev_path(hba);
     if (id) {
         path = g_strdup_printf("%s/%d:%d:%d", id, d->channel, d->id, d->lun);
     } else {
diff --git a/hw/usb/bus.c b/hw/usb/bus.c
index 64887d5..8b08f93 100644
--- a/hw/usb/bus.c
+++ b/hw/usb/bus.c
@@ -467,9 +467,8 @@ static char *usb_get_dev_path(DeviceState *qdev)
     DeviceState *hcd = qdev->parent_bus->parent;
     char *id = NULL;
 
-    if ((dev->flags & (1 << USB_DEV_FLAG_FULL_PATH)) &&
-        hcd && hcd->parent_bus && hcd->parent_bus->info->get_dev_path) {
-        id = hcd->parent_bus->info->get_dev_path(hcd);
+    if (dev->flags & (1 << USB_DEV_FLAG_FULL_PATH)) {
+        id = qdev_get_dev_path(hcd);
     }
     if (id) {
         char *ret = g_strdup_printf("%s/%s", id, dev->port->path);
diff --git a/hw/usb/desc.c b/hw/usb/desc.c
index e8a3c6a..0a9d3c9 100644
--- a/hw/usb/desc.c
+++ b/hw/usb/desc.c
@@ -432,12 +432,13 @@ void usb_desc_create_serial(USBDevice *dev)
     const USBDesc *desc = usb_device_get_usb_desc(dev);
     int index = desc->id.iSerialNumber;
     char serial[64];
+    char *path;
     int dst;
 
     assert(index != 0 && desc->str[index] != NULL);
     dst = snprintf(serial, sizeof(serial), "%s", desc->str[index]);
-    if (hcd && hcd->parent_bus && hcd->parent_bus->info->get_dev_path) {
-        char *path = hcd->parent_bus->info->get_dev_path(hcd);
+    path = qdev_get_dev_path(hcd);
+    if (path) {
         dst += snprintf(serial+dst, sizeof(serial)-dst, "-%s", path);
     }
     dst += snprintf(serial+dst, sizeof(serial)-dst, "-%s", dev->port->path);
diff --git a/savevm.c b/savevm.c
index 2d18bab..818ddfc 100644
--- a/savevm.c
+++ b/savevm.c
@@ -1248,8 +1248,8 @@ int register_savevm_live(DeviceState *dev,
         se->is_ram = 1;
     }
 
-    if (dev && dev->parent_bus && dev->parent_bus->info->get_dev_path) {
-        char *id = dev->parent_bus->info->get_dev_path(dev);
+    if (dev) {
+        char *id = qdev_get_dev_path(dev);
         if (id) {
             pstrcpy(se->idstr, sizeof(se->idstr), id);
             pstrcat(se->idstr, sizeof(se->idstr), "/");
@@ -1292,8 +1292,8 @@ void unregister_savevm(DeviceState *dev, const char *idstr, void *opaque)
     SaveStateEntry *se, *new_se;
     char id[256] = "";
 
-    if (dev && dev->parent_bus && dev->parent_bus->info->get_dev_path) {
-        char *path = dev->parent_bus->info->get_dev_path(dev);
+    if (dev) {
+        char *path = qdev_get_dev_path(dev);
         if (path) {
             pstrcpy(id, sizeof(id), path);
             pstrcat(id, sizeof(id), "/");
@@ -1334,8 +1334,8 @@ int vmstate_register_with_alias_id(DeviceState *dev, int instance_id,
     se->alias_id = alias_id;
     se->no_migrate = vmsd->unmigratable;
 
-    if (dev && dev->parent_bus && dev->parent_bus->info->get_dev_path) {
-        char *id = dev->parent_bus->info->get_dev_path(dev);
+    if (dev) {
+        char *id = qdev_get_dev_path(dev);
         if (id) {
             pstrcpy(se->idstr, sizeof(se->idstr), id);
             pstrcat(se->idstr, sizeof(se->idstr), "/");