Re: [Qemu-devel] [PATCH 1/3] block: detach devices from DriveInfo at unrealize time

[Paolo Bonzini]

On 21/03/2016 18:19, Markus Armbruster wrote:
>> >
>> > The other possibility is to make blk_detach_dev do nothing if blk->dev
>> > == NULL, i.e. make it idempotent.  On one hand, who doesn't like
>> > idempotency; on the other hand, removing an assertion is also dirty.
>> >
>> > I chose the easy way here (changing as fewer contracts as possible).
> Why can't we keep the work in the property release() method
> release_drive()?
> 
> The only reason blockdev_mark_auto_del() isn't there is that the device
> decides whether to call it, not the property.

DEVICE_DELETED is currently sent right after setting unrealized to false
(see device_unparent), and you cannnot send it later than that.  In
particular release_drive would mean sending the drive when properties
are removed in instance_finalize; by that time you don't have anymore a
QOM path to include in the event.

Paolo