| Message ID | 20190902042436.23294-4-parav@mellanox.com |
|---|---|
| State | Not Applicable |
| Delegated to: | David Miller |
| Headers | show |
| Series | Introduce variable length mdev alias | expand |
On Sun, 1 Sep 2019 23:24:34 -0500 Parav Pandit <parav@mellanox.com> wrote: > 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. > > Updated documentation for optional read only sysfs attribute. > > Signed-off-by: Parav Pandit <parav@mellanox.com> > > --- > Changelog: > v2->v3: > - Merged sysfs documentation patch with sysfs addition > - Added more description for alias return value > v0->v1: > - Addressed comments from Cornelia Huck > - Updated commit description > --- > Documentation/driver-api/vfio-mediated-device.rst | 9 +++++++++ > drivers/vfio/mdev/mdev_sysfs.c | 13 +++++++++++++ > 2 files changed, 22 insertions(+) > (...) > @@ -281,6 +282,14 @@ Example:: > > # echo 1 > /sys/bus/mdev/devices/$mdev_UUID/remove > > +* alias (read only, optional) > +Whenever a parent requested to generate an alias, each mdev device of such s/such/that/ > +parent is assigned unique alias by the mdev core. s/unique alias/a unique alias/ > +This file shows the alias of the mdev device. > + > +Reading file either returns valid alias when assigned or returns error code s/file/this file/ s/valid alias/a valid alias/ s/error code/the error code/ > +-EOPNOTSUPP when unsupported. > + > Mediated device Hot plug > ------------------------ With the nits above fixed, Reviewed-by: Cornelia Huck <cohuck@redhat.com>
diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentation/driver-api/vfio-mediated-device.rst index 25eb7d5b834b..0b7d2bf843b6 100644 --- a/Documentation/driver-api/vfio-mediated-device.rst +++ b/Documentation/driver-api/vfio-mediated-device.rst @@ -270,6 +270,7 @@ Directories and Files Under the sysfs for Each mdev Device |--- remove |--- mdev_type {link to its type} |--- vendor-specific-attributes [optional] + |--- alias * remove (write only) @@ -281,6 +282,14 @@ Example:: # echo 1 > /sys/bus/mdev/devices/$mdev_UUID/remove +* alias (read only, optional) +Whenever a parent requested to generate an alias, each mdev device of such +parent is assigned unique alias by the mdev core. +This file shows the alias of the mdev device. + +Reading file either returns valid alias when assigned or returns error code +-EOPNOTSUPP when unsupported. + Mediated device Hot plug ------------------------ 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, };
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. Updated documentation for optional read only sysfs attribute. Signed-off-by: Parav Pandit <parav@mellanox.com> --- Changelog: v2->v3: - Merged sysfs documentation patch with sysfs addition - Added more description for alias return value v0->v1: - Addressed comments from Cornelia Huck - Updated commit description --- Documentation/driver-api/vfio-mediated-device.rst | 9 +++++++++ drivers/vfio/mdev/mdev_sysfs.c | 13 +++++++++++++ 2 files changed, 22 insertions(+)