Re: [Qemu-devel] Re: [PATCH] Add -no-virtio-balloon command-line option

[Dor Laor <dlaor@redhat.com>]

Anthony Liguori wrote:
> Markus Armbruster wrote:
>> Dor Laor <dlaor@redhat.com> writes:
>>
>>  
>>> Gerd Hoffmann wrote:
>>>    
>>>>> This new option may be used to disable the virtio-balloon device.
>>>>>
>>>>>         
>>>> ACK, looks good.
>>>>
>>>> And I can drop my lazy patch which just comments out virtio-balloon
>>>> in the code ;)
>>>>       
>>> Actually, I rather have the balloon disabled by default. It's like any
>>> other pci device which needs
>>> explicit command line specification. Why consume a pci slot if not
>>> implicitly required?
>>>     
>>
>> I agree.  The command line is plenty magic without implicitly added
>> PCI devices.
>>
>> Besides, negative options -no-virtio-balloon lead to ugly
>> double-negatives like if (!no_virtio_balloon).
>>   
>
> It does no harm to add the device by default so why force the user to 
> explicitly enable it?

It consumes one of the 32 pci devices we have today. It's the same for 
not having -usb as default
or any other type of device. Soon we'll need pci_addr= along with it 
anyway ;)

Dor