Re: Use of virtio device IDs

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

Rusty Russell wrote:
> On Wednesday 07 November 2007 16:40:13 Avi Kivity wrote:
>   
>> Gregory Haskins wrote:
>>     
>>>  but FWIW: This is a major motivation for the reason that the
>>> IOQ stuff I posted a while back used strings for device identification
>>> instead of a fixed length, centrally managed namespace like PCI
>>> vendor/dev-id.  Then you can just name your device something reasonably
>>> unique (e.g. "qumranet::veth", or "ibm-pvirt-clock").
>>>       
>> I dislike strings.  They make it look as if you have a nice extensible
>> interface, where in reality you have a poorly documented interface which
>> leads to poor interoperability.
>>     
>
> Yes, you end up with exactly names like "qumranet::veth" 
> and "ibm-pvirt-clock".  I would recommend looking very hard at /proc, Open 
> Firmware on a modern system, or the Xen store, to see what a lack of 
> limitation can do to you :)
>   

FWIW, I've switched to using the PCI subsystem vendor/device IDs for 
virtio which Rusty suggested.  I think this makes even more sense than 
using the main vendor/device ID since I do think that we only should use 
a single vendor/device ID for all virtio PCI devices and then 
differentiate based on the subsystem IDs.

Regards,

Anthony Liguori

>> We will support non-pci for s390, but in order to support Windows and
>> older Linux PCI is necessary.
>>     
>
> The aim is that PCI support is clean, but that we're not really tied to PCI.  
> I think we're getting closer with the recent config changes.
>
> Cheers,
> Rusty.
>