Hi,
> > .select = VIRTIO_INPUT_CFG_EV_BITS,
> > .subsel = EV_REL,
> > - .size = 1,
> > + .size = 2,
> > .u.bitmap = {
> > - (1 << REL_X) | (1 << REL_Y),
> > + (1 << REL_X) | (1 << REL_Y), (1 << (REL_WHEEL - 8))
>
> Works only when REL_WHEEL is between 8 and 15.
> Add BUILD_BUG_ON?
Not needed IMO, REL_WHEEL value is kernel/userspace abi and will never
change.
>
> > },
> > },
> > { /* end of list */ },
>
> Is it problematic e.g. if you migrate from a host with REL_WHEEL
> to one without? Should we maintain a version without REL_WHEEL
> for old machine types?
Yes, we need a compat property.
Possibly it is easier to fix on the guest side, assuming it is actually
needed (see other reply).
cheers,
Gerd
