Re: [PATCH] vfio/pci: Require vfio_device_ops.name

["Danilo Krummrich" <dakr@kernel.org>]

On Tue Mar 31, 2026 at 10:24 PM CEST, Alex Williamson wrote:
> vfio-pci-core code makes use of the vfio_device_ops.name field in order
> to set a default driver_override for VFs created on a user-owned PF.
> This avoids default driver matching, which might otherwise bind those
> VFs to native drivers.
>
> The mechanism for this currently uses kasprintf(), which will set
> driver_override to the literal "(null)" if name is NULL.  This is
> effective in sequestering the device, but presents a challenging debug
> situation to differentiate driver_override being set to "(null)" versus
> being NULL and interpreted as "(null)" via the sysfs show attribute.
>
> There's also a tree-wide effort to convert to generic driver_override
> support, where passing NULL will generate an error, resulting in a
> WARN_ON without setting any driver_override.
>
> All drivers making use of vfio-pci-core already set a driver name,
> therefore by requiring this behavior, all of these corner cases are
> rendered moot.  This is expected to have no impact on current
> in-kernel drivers.
>
> Suggested-by: Danilo Krummrich <dakr@kernel.org>
> Signed-off-by: Alex Williamson <alex.williamson@nvidia.com>

Reviewed-by: Danilo Krummrich <dakr@kernel.org>