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, 5 insertions, 3 deletions

diff --git a/hw/isa-bus.c b/hw/isa-bus.c
index ebcc081e97..85ba354940 100644
--- a/hw/isa-bus.c
+++ b/hw/isa-bus.c
@@ -104,14 +104,15 @@ void isa_init_irq(ISADevice *dev, qemu_irq *p)
     dev->nirqs++;
 }
 
-static void isa_qdev_init(DeviceState *qdev, DeviceInfo *base)
+static int isa_qdev_init(DeviceState *qdev, DeviceInfo *base)
 {
     ISADevice *dev = DO_UPCAST(ISADevice, qdev, qdev);
     ISADeviceInfo *info = DO_UPCAST(ISADeviceInfo, qdev, base);
 
     dev->isairq[0] = -1;
     dev->isairq[1] = -1;
-    info->init(dev);
+
+    return info->init(dev);
 }
 
 void isa_qdev_register(ISADeviceInfo *info)
@@ -156,9 +157,10 @@ static void isabus_dev_print(Monitor *mon, DeviceState *dev, int indent)
     }
 }
 
-static void isabus_bridge_init(SysBusDevice *dev)
+static int isabus_bridge_init(SysBusDevice *dev)
 {
     /* nothing */
+    return 0;
 }
 
 static SysBusDeviceInfo isabus_bridge_info = {