[PATCH v2 3/6] mdev: Expose mdev alias in sysfs tree

From: Parav Pandit
Date: Thu Aug 29 2019 - 07:20:06 EST


Expose the optional alias for an mdev device as a sysfs attribute.
This way, userspace tools such as udev may make use of the alias, for
example to create a netdevice name for the mdev.

Signed-off-by: Parav Pandit <parav@xxxxxxxxxxxx>

---
Changelog:
v0->v1:
- Addressed comments from Cornelia Huck
- Updated commit description
---
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