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From:   Parav Pandit <parav@mellanox.com>
To:     alex.williamson@redhat.com, jiri@mellanox.com,
        kwankhede@nvidia.com, cohuck@redhat.com, davem@davemloft.net
Cc:     kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
        netdev@vger.kernel.org, Parav Pandit <parav@mellanox.com>
Subject: [PATCH v2 3/6] mdev: Expose mdev alias in sysfs tree
Date:   Thu, 29 Aug 2019 06:19:01 -0500
Message-Id: <20190829111904.16042-4-parav@mellanox.com>
In-Reply-To: <20190829111904.16042-1-parav@mellanox.com>
References: <20190826204119.54386-1-parav@mellanox.com>
 <20190829111904.16042-1-parav@mellanox.com>
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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@mellanox.com>

---
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