Re: [Qemu-devel] [RFC 0/9] Virtio-mmio refactoring.

[Evgeny Voevodin <e.voevodin@samsung.com>]

On 04.05.2012 17:19, Anthony Liguori wrote:
> On 05/03/2012 07:14 AM, Peter Maydell wrote:
>> On 25 April 2012 06:54, Evgeny Voevodin<e.voevodin@samsung.com>  wrote:
>>> In this patchset refactoring of virtio-mmio layer is made.
>>> Instead of creating virtio-blk-mmio, virtio-net-mmio, etc on the 
>>> system bus
>>> we create virtio-blk, virtio-net, etc devices on the 
>>> virtio-transport bus.
>>> To create virtio-transport bus virtio-mmio-transport device provided.
>>> Transport device plugs into virtio-mmio bus.
>>> To create virtio-mmio bus virtio-mmio-bridge device provided.
>>
>> This seems to me to have one more layer than it needs. Why not just:
>>   create virtio-blk, virtio-net, etc on the virtio-transport bus
>>   To create virtio-transport bus, we create a virtio-mmio-transport
>>   device, and this device is a sysbus device.
>>
>> ie why do you have separate "virtio-mmio-transport" and
>> "virtio-mmio-bridge" devices, and two different new buses ("virtio-mmio"
>> and "virtio-transport") rather than just "virtio-transport"?
>
> I think using a bus won't work.   You need to create a VirtioDevice 
> that has a link<VirtioTransport>.  I would suggest making 
> VirtioTransport an interface.

Do you mean latest QOM series that qomyfies buses or some issue in pci 
(which I don't see)?
I was planning to refactor virtio-pci, make sure it works and then 
hoping that last QOM series lands in master
convert all the stuff to correspond it.
>
> Then you can have VirtioPCI inherit from PCIDevice and implement 
> VirtioTransport.

-- 
Kind regards,
Evgeny Voevodin,
Leading Software Engineer,
ASWG, Moscow R&D center, Samsung Electronics
e-mail: e.voevodin@samsung.com