Re: [Qemu-trivial] [Qemu-devel] [PATCH v3 2/2] core/qdev: refactor qdev_get_machine() with type assertion

[Markus Armbruster]

Eduardo Habkost <address@hidden> writes:

> On Mon, Apr 15, 2019 at 03:59:45PM +0800, Like Xu wrote:
>> To avoid the misuse of qdev_get_machine() if machine hasn't been created yet,
>> this patch uses qdev_get_machine_uncheck() for obj-common (share with 
>> user-only
>> mode) and adds type assertion to qdev_get_machine() in system-emulation mode.
>> 
>> Suggested-by: Igor Mammedov <address@hidden>
>> Signed-off-by: Like Xu <address@hidden>
>
> Reviewed-by: Eduardo Habkost <address@hidden>
>
> I'm queueing the series on machine-next, thanks!

Hold your horses, please.

I dislike the name qdev_get_machine_uncheck().  I could live with
qdev_get_machine_unchecked().

However, I doubt this is the right approach.

The issue at hand is undisciplined creation of QOM object /machine.

This patch adds an asseertion "undisciplined creation of /machine didn't
create crap", but only in some places.

I think we should never create /machine as (surprising!) side effect of
qdev_get_machine().  Create it explicitly instead, and have
qdev_get_machine() use object_resolve_path("/machine", NULL) to get it.
Look ma, no side effects.