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

[Parav Pandit <parav@mellanox.com>]

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@mellanox.com>
---
 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;
+
+	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,
 };
-- 
2.19.2