Re: [Qemu-devel] [PATCH] switch balloon initialization to -device.

[Markus Armbruster <armbru@redhat.com>]

Gerd Hoffmann <kraxel@redhat.com> writes:

> On 08/14/09 11:44, Markus Armbruster wrote:
>> Gerd Hoffmann<kraxel@redhat.com>  writes:
>>
>>> With that patch applied "-balloon virtio,args" becomes a shortcut for
>>> "-device virtio-balloon-pci,args".
>>>
>>> Side effects:
>>>   - ballon device gains support for id=<tag>.
>>>   - ballon device is off by default now.
>>>   - initialization order changes, which may in different pci slot
>>>     assignment depending on the VM configuration.
>>>
>>> Signed-off-by: Gerd Hoffmann<kraxel@redhat.com>
>>
>> Looks good on quick inspection (gotta run), just one question: what
>> happens when I (stupidly) do -balloon virtio,driver=e1000 ?  Question
>> might apply to plain -device before this patch as well.
>
> QemuOpts allows overwriting, so who is written last will win.
> Write order is undefined, so don't try that at home ;)
>
> Behavior of the current code:
>
>   -balloon virtio,driver=e1000 will give you a balloon device.
>   -device virtio-blk-pci,driver=e1000 will give you a e1000.

Ugly.  Not sure it's worth fixing.