qdev: add return value to init() callbacks.

Sorry folks, but it has to be.  One more of these invasive qdev patches.

We have a serious design bug in the qdev interface:  device init
callbacks can't signal failure because the init() callback has no
return value.  This patch fixes it.

We have already one case in-tree where this is needed:
Try -device virtio-blk-pci (without drive= specified) and watch qemu
segfault.  This patch fixes it.

With usb+scsi being converted to qdev we'll get more devices where the
init callback can fail for various reasons.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 6 insertions, 3 deletions

diff --git a/hw/qdev.c b/hw/qdev.c
index c1a7779..1b7d963 100644
--- a/hw/qdev.c
+++ b/hw/qdev.c
@@ -199,16 +199,19 @@ DeviceState *qdev_device_add(QemuOpts *opts)
         qdev_free(qdev);
         return NULL;
     }
-    qdev_init(qdev);
+    if (qdev_init(qdev) != 0) {
+        qdev_free(qdev);
+        return NULL;
+    }
     return qdev;
 }
 
 /* Initialize a device.  Device properties should be set before calling
    this function.  IRQs and MMIO regions should be connected/mapped after
    calling this function.  */
-void qdev_init(DeviceState *dev)
+int qdev_init(DeviceState *dev)
 {
-    dev->info->init(dev, dev->info);
+    return dev->info->init(dev, dev->info);
 }
 
 /* Unlink device from bus and free the structure.  */