Re: [Qemu-devel] [RFC PATCH v6 0/6] Virtio refactoring.

[Michael S. Tsirkin]

On Tue, Dec 18, 2012 at 02:56:58PM +0000, Peter Maydell wrote:
> > True, it is not pure qdev, but it is much simpler and doesn't require
> > convincing grumpy maintainers. :)
> 
> I'm not actually personally all that attached to this design -- it's just
> trying to implement a suggestion by Anthony.
> 
> It does seem frankly bizarre that adding a new transport requires
> knowing about all the backends (notice how s390-virtio-bus.c has
> to register types for each backend).

I agree it's not pretty. The issue is that things like e.g.
PCI class need per-device handling. We could invent our
own class system but that seems like overkill:
it's rare enough to add new devices.

> The kernel gets the transport
> vs backend separation much cleaner and it was much easier to
> add the virtio support there.
> 
> -- PMM

By the way even there the separation does confuse users sometimes.
Things like autoloading are broken
and some tools poking at sysfs get confused.

At this point it's probably not worth changing though.
-- 
MST