Re: [Qemu-devel] Re: [PATCH] Add support for a configuration file

[Anthony Liguori <aliguori@us.ibm.com>]

Fabrice Bellard wrote:
> Avi Kivity wrote:
>> Fabrice Bellard wrote:
>>>
>>> I prefer:
>>>
>>> drive.file=foo.img
>>> drive.if=scsi
>>>
>>
>> That doesn't support multiple drives very well.
>
> Right, I realized it afterwards !
>
> I suggested it because my original plan for the configuration file was 
> based on this syntax with a strong inspiration from the OpenFirmware 
> device tree. The idea was that the object name ("drive" here) had no 
> hardcoded meaning, except for some predefined object names in order to 
> keep a kind of backward compatibility with the current QEMU options. 
> In order to create a new drive for example, you just have to do:
>
> mydrive.class=drive
> mydrive.if=scsi
> mydrive.file=abc.img
>
> the "class" field is used to select the device model. Then all the 
> other parameters are used to initialize the device model. That way it 
> is possible to keep the compatibility with the existing options and 
> add a provision to instanciate arbitrary new device models, such as:

I like this syntax primarily because it provides a means to associate 
arbitrary data with a VM.  It also provides a sane way to keep track of 
which device is which so that the "config" can be updated while the VM 
is running.  I'll update the patch.

Regards,

Anthony Liguori

> mynetworkcard.class="ne2000pci"
> mynetworkcard.bus=1 # pci bus selection
> mynetworkcard.macaddr=00:01:02:03:04:05
> mynetworkcard.vlan=1
>
> I will strongly support configuration file formats having this property.
>
> Regards,
>
> Fabrice.
>