Re: [virtio-comment] virtio and endian-ness

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Aug 20, 2013 at 03:25:17PM +0100, Pawel Moll wrote:
> On Tue, 2013-08-20 at 15:11 +0100, Paolo Bonzini wrote:
> > Il 20/08/2013 16:09, Pawel Moll ha scritto:
> > > On Tue, 2013-08-20 at 15:03 +0100, Pawel Moll wrote:
> > >> It must be possible to write a driver that drivers
> > >> both the old and the new specs.
> > > 
> > > Should read: "... that drives devices complaint to both the old and the
> > > new specs".
> > 
> > Both ways should be possible: write a driver for both old and new specs,
> > and write a device for both old and new specs.
> > 
> > In both cases, the differences between old and new specs should be
> > ideally hidden in the virtio layer, or more precisely in the virtio
> > transport layer.  The virtio devices and drivers themselves should be
> > unaffected.
> 
> First of all, I disagree with the assumption that the OASIS spec must
> not bring any changes to the environment. I actually consider it an
> opportunity to fix what was mis-designed, even for a price of changes
> needed in at both sides of the equation.
> 
> Now, as to the "hidden in the transport layer"... By "driver" I meant
> "virtio_mmio.c", which - I believe - is the transport layer you are
> referring to. And this is what I want to change indeed with the
> assumption that virtio_mmio v2 does *not* have to be compatible with
> virtio_mmio v1. And I will be strongly against any attempts of making it
> (*the MMIO device*) more complicated.
> 
> Paweł
> 

Confused.
You want to support old and new devices in the same
driver, don't you? Isn't that making it more complicated?


-- 
MST