From patchwork Thu Nov 7 16:08:24 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Parav Pandit X-Patchwork-Id: 11233361 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CFC9C1390 for ; Thu, 7 Nov 2019 16:10:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B8BEA218AE for ; Thu, 7 Nov 2019 16:10:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389485AbfKGQKK (ORCPT ); Thu, 7 Nov 2019 11:10:10 -0500 Received: from mail-il-dmz.mellanox.com ([193.47.165.129]:53543 "EHLO mellanox.co.il" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2389491AbfKGQJN (ORCPT ); Thu, 7 Nov 2019 11:09:13 -0500 Received: from Internal Mail-Server by MTLPINE1 (envelope-from parav@mellanox.com) with ESMTPS (AES256-SHA encrypted); 7 Nov 2019 18:09:11 +0200 Received: from sw-mtx-036.mtx.labs.mlnx (sw-mtx-036.mtx.labs.mlnx [10.9.150.149]) by labmailer.mlnx (8.13.8/8.13.8) with ESMTP id xA7G8d4J007213; Thu, 7 Nov 2019 18:09:09 +0200 From: Parav Pandit To: alex.williamson@redhat.com, davem@davemloft.net, kvm@vger.kernel.org, netdev@vger.kernel.org Cc: saeedm@mellanox.com, kwankhede@nvidia.com, leon@kernel.org, cohuck@redhat.com, jiri@mellanox.com, linux-rdma@vger.kernel.org, Parav Pandit Subject: [PATCH net-next 09/19] vfio/mdev: Expose mdev alias in sysfs tree Date: Thu, 7 Nov 2019 10:08:24 -0600 Message-Id: <20191107160834.21087-9-parav@mellanox.com> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20191107160834.21087-1-parav@mellanox.com> References: <20191107160448.20962-1-parav@mellanox.com> <20191107160834.21087-1-parav@mellanox.com> MIME-Version: 1.0 Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org 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. Reviewed-by: Saeed Mahameed Signed-off-by: Parav Pandit --- Documentation/driver-api/vfio-mediated-device.rst | 9 +++++++++ drivers/vfio/mdev/mdev_sysfs.c | 13 +++++++++++++ 2 files changed, 22 insertions(+) diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentation/driver-api/vfio-mediated-device.rst index 25eb7d5b834b..7d6d87102f64 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 that +parent is assigned a unique alias by the mdev core. +This file shows the alias of the mdev device. + +Reading this file either returns a valid alias when assigned or returns the +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, };