Re: [Qemu-devel] [PATCH RFC v6 19/20] virtio-blk: revision specific feature bits

[Cornelia Huck]

On Sun, 28 Dec 2014 12:24:46 +0200
"Michael S. Tsirkin" <address@hidden> wrote:

> On Thu, Dec 11, 2014 at 02:25:21PM +0100, Cornelia Huck wrote:
> > Wire up virtio-blk to provide different feature bit sets depending
> > on whether legacy or v1.0 has been requested.
> > 
> > Note that VERSION_1 is still disabled due to missing ANY_LAYOUT support.
> > 
> > Signed-off-by: Cornelia Huck <address@hidden>
> 
> So we need some way for devices to tell transports
> not to negotiate rev 1.
> Does clearing VERSION_1 have this effect?
> 
I just noticed that my patch is running in circles here.

What we need is probably the transport-dependent maximum revision
checker (which at least for ccw is acting on a device) pass in the
requested revision and check if the feature bits for the revision
include VERSION_1. Does that make sense?