Re: [Qemu-devel] [PATCH V3] hw/virtio-pci: fix virtio behaviour

[Michael S. Tsirkin]

On Thu, Jul 21, 2016 at 11:58:52PM +0200, Gerd Hoffmann wrote:
>   Hi,
> 
> > Actually this can still break existing scripts:
> > stick a device on express bus but add disable-modern=on
> > Gave you a legacy device previously but it no longer does.
> 
> Unlikely to happen in practice because there is little reason to use
> disable-modern=on in 2.6 & older because that is the default ...

Good point, I forgot.

> Still we can default to legacy=yes in case disable-modern=on +
> disable-legacy=auto.

Given the above I'm not sure it's worth it. I'll leave it to Marcel
to decide.

>  And throw and error in case both modern and legacy
> are explicitly disabled (as already suggested elsewhere in this thread).
> 
> cheers,
>   Gerd