Re: [Qemu-devel] No more chameleon devices (was: [PATCH] virtio: Provide version-specific variants of virtio PCI devices)

[Gerd Hoffmann]

On Wed, Oct 17, 2018 at 07:57:39AM +0200, Markus Armbruster wrote:
> Laine Stump <address@hidden> writes:
> 
> [...]
> > In the end, having a device that changed PCI ID depending on what kind
> > of slot it was plugged into was an idea "too clever for its own good",
> > should be avoided when new devices are added in the future, and we
> > should at least provide an alternative that doesn't do that for existing
> > devices.
> 
> That means for each chameleon PCI/PCIe device:
> 
> * create a pair of devices that can only go into one kind of slot
> * deprecate the chameleon

I think virtio devices are the only ones which actually change the pci
id and have non-trivial differences.

qemu-xhci can likewise be plugged into both pci and pcie slots.  When
plugged into a pcie slot it'll have pcie endpoint capability.  That is
the only difference though.  Do you consider that a chameleon device?

cheers,
  Gerd