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

[Gerd Hoffmann]

  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 ...

Still we can default to legacy=yes in case disable-modern=on +
disable-legacy=auto.  And throw and error in case both modern and legacy
are explicitly disabled (as already suggested elsewhere in this thread).

cheers,
  Gerd