RE: [PATCH] vfio: mdev: make mdev_bus_type const

[Kirti Wankhede <kwankhede@nvidia.com>]

> -----Original Message-----
> From: Ricardo B. Marliere <ricardo@marliere.net>
> Sent: Friday, February 9, 2024 1:32 AM
> To: Kirti Wankhede <kwankhede@nvidia.com>; Alex Williamson
> <alex.williamson@redhat.com>
> Cc: kvm@vger.kernel.org; linux-kernel@vger.kernel.org; Greg Kroah-Hartman
> <gregkh@linuxfoundation.org>; Ricardo B. Marliere <ricardo@marliere.net>
> Subject: [PATCH] vfio: mdev: make mdev_bus_type const
> 
> Now that the driver core can properly handle constant struct bus_type,
> move the mdev_bus_type variable to be a constant structure as well,
> placing it into read-only memory which can not be modified at runtime.
> 
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>

Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com> 


> ---
>  drivers/vfio/mdev/mdev_driver.c  | 2 +-
>  drivers/vfio/mdev/mdev_private.h | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/vfio/mdev/mdev_driver.c b/drivers/vfio/mdev/mdev_driver.c
> index 7825d83a55f8..b98322966b3e 100644
> --- a/drivers/vfio/mdev/mdev_driver.c
> +++ b/drivers/vfio/mdev/mdev_driver.c
> @@ -40,7 +40,7 @@ static int mdev_match(struct device *dev, struct
> device_driver *drv)
>  	return 0;
>  }
> 
> -struct bus_type mdev_bus_type = {
> +const struct bus_type mdev_bus_type = {
>  	.name		= "mdev",
>  	.probe		= mdev_probe,
>  	.remove		= mdev_remove,
> diff --git a/drivers/vfio/mdev/mdev_private.h
> b/drivers/vfio/mdev/mdev_private.h
> index af457b27f607..63a1316b08b7 100644
> --- a/drivers/vfio/mdev/mdev_private.h
> +++ b/drivers/vfio/mdev/mdev_private.h
> @@ -13,7 +13,7 @@
>  int  mdev_bus_register(void);
>  void mdev_bus_unregister(void);
> 
> -extern struct bus_type mdev_bus_type;
> +extern const struct bus_type mdev_bus_type;
>  extern const struct attribute_group *mdev_device_groups[];
> 
>  #define to_mdev_type_attr(_attr)	\
> 
> ---
> base-commit: 78f70c02bdbccb5e9b0b0c728185d4aeb7044ace
> change-id: 20240208-bus_cleanup-vfio-75a6180b5efe
> 
> Best regards,
> --
> Ricardo B. Marliere <ricardo@marliere.net>