From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,URIBL_BLOCKED, USER_AGENT_GIT autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CD19CC3A59B for ; Mon, 2 Sep 2019 04:24:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AE5F621881 for ; Mon, 2 Sep 2019 04:24:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729498AbfIBEYu (ORCPT ); Mon, 2 Sep 2019 00:24:50 -0400 Received: from mail-il-dmz.mellanox.com ([193.47.165.129]:35659 "EHLO mellanox.co.il" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729341AbfIBEYt (ORCPT ); Mon, 2 Sep 2019 00:24:49 -0400 Received: from Internal Mail-Server by MTLPINE1 (envelope-from parav@mellanox.com) with ESMTPS (AES256-SHA encrypted); 2 Sep 2019 07:24:42 +0300 Received: from sw-mtx-036.mtx.labs.mlnx (sw-mtx-036.mtx.labs.mlnx [10.12.150.149]) by labmailer.mlnx (8.13.8/8.13.8) with ESMTP id x824OeRK001225; Mon, 2 Sep 2019 07:24:40 +0300 From: Parav Pandit 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 Subject: [PATCH v3 0/5] Introduce variable length mdev alias Date: Sun, 1 Sep 2019 23:24:31 -0500 Message-Id: <20190902042436.23294-1-parav@mellanox.com> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20190826204119.54386-1-parav@mellanox.com> References: <20190826204119.54386-1-parav@mellanox.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org To have consistent naming for the netdevice of a mdev and to have consistent naming of the devlink port [1] of a mdev, which is formed using phys_port_name of the devlink port, current UUID is not usable because UUID is too long. UUID in string format is 36-characters long and in binary 128-bit. Both formats are not able to fit within 15 characters limit of netdev name. It is desired to have mdev device naming consistent using UUID. So that widely used user space framework such as ovs [2] can make use of mdev representor in similar way as PCIe SR-IOV VF and PF representors. Hence, (a) mdev alias is created which is derived using sha1 from the mdev name. (b) Vendor driver describes how long an alias should be for the child mdev created for a given parent. (c) Mdev aliases are unique at system level. (d) alias is created optionally whenever parent requested. This ensures that non networking mdev parents can function without alias creation overhead. This design is discussed at [3]. An example systemd/udev extension will have, 1. netdev name created using mdev alias available in sysfs. mdev UUID=83b8f4f2-509f-382f-3c1e-e6bfe0fa1001 mdev 12 character alias=cd5b146a80a5 netdev name of this mdev = enmcd5b146a80a5 Here en = Ethernet link m = mediated device 2. devlink port phys_port_name created using mdev alias. devlink phys_port_name=pcd5b146a80a5 This patchset enables mdev core to maintain unique alias for a mdev. Patch-1 Introduces mdev alias using sha1. Patch-2 Ensures that mdev alias is unique in a system. Patch-3 Exposes mdev alias in a sysfs hirerchy, update Documentation Patch-4 Introduces mdev_alias() API. Patch-5 Extends mtty driver to optionally provide alias generation. This also enables to test UUID based sha1 collision and trigger error handling for duplicate sha1 results. [1] http://man7.org/linux/man-pages/man8/devlink-port.8.html [2] https://docs.openstack.org/os-vif/latest/user/plugins/ovs.html [3] https://patchwork.kernel.org/cover/11084231/ --- Changelog: v2->v3: - Addressed comment from Yunsheng Lin - Changed strcmp() ==0 to !strcmp() - Addressed comment from Cornelia Hunk - Merged sysfs Documentation patch with syfs patch - Added more description for alias return value v1->v2: - Corrected a typo from 'and' to 'an' - Addressed comments from Alex Williamson - Kept mdev_device naturally aligned - Added error checking for crypt_*() calls - Moved alias NULL check at beginning - Added mdev_alias() API - Updated mtty driver to show example mdev_alias() usage - Changed return type of generate_alias() from int to char* v0->v1: - Addressed comments from Alex Williamson, Cornelia Hunk and Mark Bloch - Moved alias length check outside of the parent lock - Moved alias and digest allocation from kvzalloc to kzalloc - &alias[0] changed to alias - alias_length check is nested under get_alias_length callback check - Changed comments to start with an empty line - Added comment where alias memory ownership is handed over to mdev device - Fixed cleaunup of hash if mdev_bus_register() fails - Updated documentation for new sysfs alias file - Improved commit logs to make description more clear - Fixed inclusiong of alias for NULL check - Added ratelimited debug print for sha1 hash collision error Parav Pandit (5): mdev: Introduce sha1 based mdev alias mdev: Make mdev alias unique among all mdevs mdev: Expose mdev alias in sysfs tree mdev: Introduce an API mdev_alias mtty: Optionally support mtty alias .../driver-api/vfio-mediated-device.rst | 9 ++ drivers/vfio/mdev/mdev_core.c | 142 +++++++++++++++++- drivers/vfio/mdev/mdev_private.h | 5 +- drivers/vfio/mdev/mdev_sysfs.c | 26 +++- include/linux/mdev.h | 5 + samples/vfio-mdev/mtty.c | 13 ++ 6 files changed, 190 insertions(+), 10 deletions(-) -- 2.19.2