On Tue, 17 Sep 2024 09:57:23 +0200
Heiner Kallweit <hkallweit1@xxxxxxxxx> wrote:
> After 7e722083fcc3 ("i2c: Remove I2C_COMPAT config symbol and related code")
> vfio/mdev is that last user of class_compat. This compatibility functionality
> is meant to be used temporarily, and it has been in vfio/mdev since 2016.
> Can it be removed? Or is there any userspace tool which hasn't been updated
> to use the bus interface instead?
> If class_compat can be removed in vfio/mdev, then we may be able to remove
> this functionality completely.
>
Hi Heiner,
I'm afraid we have active userspace tools dependent on
/sys/class/mdev_bus currently, libvirt for one. We link mdev parent
devices here and I believe it's the only way for userspace to find
those parent devices registered for creating mdev devices. If there's a
desire to remove class_compat, we might need to add some mdev
infrastructure to register the class ourselves to maintain the parent
links. Thanks,
Alex
