qdev: support to get a device firmware path directly

commit 6b1566cb (qdev: Introduce FWPathProvider interface) did a
good job for supproting to get firmware path on some different
architectures.

Moreover further more, we can use the interface to get firmware
path name for a device which isn't attached a specific bus,
such as virtio-bus, scsi-bus etc.

When the device (such as vhost-scsi) realize the TYPE_FW_PATH_PROVIDER
interface, we should introduce a new function to get the correct firmware
path name for it.
Signed-off-by: NGonglei <arei.gonglei@huawei.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

bootdevice.c

@@ -210,7 +210,9 @@ char *get_boot_devices_list(size_t *size, bool ignore_suffixes)
     char *list = NULL;
 
     QTAILQ_FOREACH(i, &fw_boot_order, link) {
-        char *devpath = NULL, *bootpath;
+        char *devpath = NULL,  *suffix = NULL;
+        char *bootpath;
+        char *d;
         size_t len;
 
         if (i->dev) {
@@ -218,21 +220,22 @@ char *get_boot_devices_list(size_t *size, bool ignore_suffixes)
             assert(devpath);
         }
 
-        if (i->suffix && !ignore_suffixes && devpath) {
-            size_t bootpathlen = strlen(devpath) + strlen(i->suffix) + 1;
-
-            bootpath = g_malloc(bootpathlen);
-            snprintf(bootpath, bootpathlen, "%s%s", devpath, i->suffix);
-            g_free(devpath);
-        } else if (devpath) {
-            bootpath = devpath;
-        } else if (!ignore_suffixes) {
-            assert(i->suffix);
-            bootpath = g_strdup(i->suffix);
-        } else {
-            bootpath = g_strdup("");
+        if (!ignore_suffixes) {
+            d = qdev_get_own_fw_dev_path_from_handler(i->dev->parent_bus, i->dev);
+            if (d) {
+                assert(!i->suffix);
+                suffix = d;
+            } else {
+                suffix = g_strdup(i->suffix);
+            }
         }
 
+        bootpath = g_strdup_printf("%s%s",
+                                   devpath ? devpath : "",
+                                   suffix ? suffix : "");
+        g_free(devpath);
+        g_free(suffix);
+
         if (total) {
             list[total-1] = '\n';
         }

hw/core/qdev.c

@@ -818,6 +818,13 @@ static char *qdev_get_fw_dev_path_from_handler(BusState *bus, DeviceState *dev)
     return d;
 }
 
+char *qdev_get_own_fw_dev_path_from_handler(BusState *bus, DeviceState *dev)
+{
+    Object *obj = OBJECT(dev);
+
+    return fw_path_provider_try_get_dev_path(obj, bus, dev);
+}
+
 static int qdev_get_fw_dev_path_helper(DeviceState *dev, char *p, int size)
 {
     int l = 0;

include/hw/qdev-core.h

@@ -342,6 +342,7 @@ void qbus_reset_all_fn(void *opaque);
 BusState *sysbus_get_default(void);
 
 char *qdev_get_fw_dev_path(DeviceState *dev);
+char *qdev_get_own_fw_dev_path_from_handler(BusState *bus, DeviceState *dev);
 
 /**
  * @qdev_machine_init