Re: [PATCH 3/4] mdev: Expose mdev alias in sysfs tree

[Alex Williamson]

On Mon, 26 Aug 2019 15:41:18 -0500
Parav Pandit <parav@xxxxxxxxxxxx> wrote:

> Expose mdev alias as string in a sysfs tree so that such attribute can
> be used to generate netdevice name by systemd/udev or can be used to
> match other kernel objects based on the alias of the mdev.
> 
> Signed-off-by: Parav Pandit <parav@xxxxxxxxxxxx>
> ---
>  drivers/vfio/mdev/mdev_sysfs.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/drivers/vfio/mdev/mdev_sysfs.c b/drivers/vfio/mdev/mdev_sysfs.c
> index 43afe0e80b76..59f4e3cc5233 100644
> --- a/drivers/vfio/mdev/mdev_sysfs.c
> +++ b/drivers/vfio/mdev/mdev_sysfs.c
> @@ -246,7 +246,20 @@ static ssize_t remove_store(struct device *dev, struct device_attribute *attr,
>  
>  static DEVICE_ATTR_WO(remove);
>  
> +static ssize_t alias_show(struct device *device,
> +			  struct device_attribute *attr, char *buf)
> +{
> +	struct mdev_device *dev = mdev_from_dev(device);
> +
> +	if (!dev->alias)
> +		return -EOPNOTSUPP;

Wouldn't it be better to not create the alias at all?  Thanks,

Alex

> +
> +	return sprintf(buf, "%s\n", dev->alias);
> +}
> +static DEVICE_ATTR_RO(alias);
> +
>  static const struct attribute *mdev_device_attrs[] = {
> +	&dev_attr_alias.attr,
>  	&dev_attr_remove.attr,
>  	NULL,
>  };