Re: [Qemu-discuss] 回复： how use qemu device_add and drive_add

[Kewei Yu]

Hi Liang:

  I don't know how "device_del" handles usb_disk1, But I remembered device_del will auto delete the drive of a device for virtio-blk.

  If my mind is wrong, let me know please.

  Hope the information to be useful. 

--

Regards,

Kewei

2014-07-16 13:04 GMT+08:00 liang <address@hidden>:

thanks for your reply.

in my use, device_del usb_disk11 than  drive_del usb_disk1,

resulted assert too. 

‍

in the end, I Commented out  hw/qdev.c line 439 .

    if (bus->parent) {

        QLIST_INSERT_HEAD(&bus->parent->child_bus, bus, sibling);

        bus->parent->num_child_bus++;

//        object_property_add_child(OBJECT(bus->parent), bus->name, OBJECT(bus), NULL);

    }‍

but I don't know the consequences.

------------------ 原始邮件 ------------------

发件人: "Dale R. Worley";<address@hidden>;

发送时间: 2014年7月3日(星期四) 晚上11:23

收件人: "liang"<address@hidden>;

抄送: "qemu-discuss"<address@hidden>;

主题: Re: [Qemu-discuss] how use qemu device_add and drive_add

> From: "liang" <address@hidden>

> add device use:
> 1  drive_add 0 file=hotplug.raw,if=none,id=usb_disk1
> 2  device_add usb-storage,drive=usb_disk1,id=usb_disk11,removable=on‍
>
> and del device use:
> 3  drive_del  usb_disk1‍
> 4  device_del  usb_disk11‍
>
> but when command 4 the qemu allways "assertion failed: (obj->ref ==
> 0)‍" receive SIGABRT.‍

I expect that you must perform commands 3 and 4 in the reverse order:

  device_del usb_disk11
  drive_del usb_disk1

because the existence of usb_disk11 requires the existence of
usb_disk1.

I expect that if you attempt to delete usb_disk1 while usb_disk11
exists, then either (a) both usb_disk1 and usb_disk11 are deleted, or
(b) the attempt to delete usb_disk1 fails because usb_disk1 is "in
use".

But I am a novice with Qemu.

Dale

.