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

[Evgeny Voevodin]

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<address@hidden>  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: address@hidden