From patchwork Tue Apr 30 22:49:27 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Parav Pandit X-Patchwork-Id: 10924307 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0FB2D1880 for ; Tue, 30 Apr 2019 22:52:02 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 00C1428D1C for ; Tue, 30 Apr 2019 22:52:02 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E8D3D28ABE; Tue, 30 Apr 2019 22:52:01 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI,UNPARSEABLE_RELAY autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5C22C28D4C for ; Tue, 30 Apr 2019 22:52:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727368AbfD3Wto (ORCPT ); Tue, 30 Apr 2019 18:49:44 -0400 Received: from mail-il-dmz.mellanox.com ([193.47.165.129]:45848 "EHLO mellanox.co.il" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726105AbfD3Wtn (ORCPT ); Tue, 30 Apr 2019 18:49:43 -0400 Received: from Internal Mail-Server by MTLPINE2 (envelope-from parav@mellanox.com) with ESMTPS (AES256-SHA encrypted); 1 May 2019 01:49:40 +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 x3UMncnU009688; Wed, 1 May 2019 01:49:39 +0300 From: Parav Pandit To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, kwankhede@nvidia.com, alex.williamson@redhat.com Cc: cjia@nvidia.com, parav@mellanox.com Subject: [PATCHv2 00/10] vfio/mdev: Improve vfio/mdev core module Date: Tue, 30 Apr 2019 17:49:27 -0500 Message-Id: <20190430224937.57156-1-parav@mellanox.com> X-Mailer: git-send-email 2.19.2 MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP As we would like to use mdev subsystem for wider use case as discussed in [1], [2] apart from an offline discussion. This use case is also discussed with wider forum in [4] in track 'Lightweight NIC HW functions for container offload use cases'. This series is prep-work and improves vfio/mdev module in following ways. Patch-1 Fixes releasing parent dev reference during error unwinding mdev parent registration. Patch-2 Simplifies mdev device for unused kref. Patch-3 Drops redundant extern prefix of exported symbols. Patch-4 Returns right error code from vendor driver. Patch-5 Fixes to use right sysfs remove sequence. Patch-6 Fixes removing all child devices if one of them fails. Patch-7 Remove unnecessary inline Patch-8 Improve the mdev create/remove sequence to match Linux bus, device model Patch-9 Avoid recreating remove file on stale device to eliminate call trace Patch-10 Fix race conditions of create/remove with parent removal This is improved version than using srcu as srcu can take seconds to minutes. This series is tested using (a) mtty with VM using vfio_mdev driver for positive tests and device removal while device in use by VM using vfio_mdev driver (b) mlx5 core driver using RFC patches [3] and internal patches. Internal patches are large and cannot be combined with this prep-work patches. It will posted once prep-work completes. [1] https://www.spinics.net/lists/netdev/msg556978.html [2] https://lkml.org/lkml/2019/3/7/696 [3] https://lkml.org/lkml/2019/3/8/819 [4] https://netdevconf.org/0x13/session.html?workshop-hardware-offload --- Changelog: --- v1->v2: - Addressed comments from Alex - Rebased - Inserted the device checking loop in Patch-6 as original code - Added patch 7 to 10 - Added fixes for race condition in create/remove with parent removal Patch-10 uses simplified refcount and completion, instead of srcu which might take seconds to minutes on busy system. - Added fix for device create/remove sequence to match Linux device, bus model v0->v1: - Dropped device placement on bus sequence patch for this series - Addressed below comments from Alex, Kirti, Maxim. - Added Review-by tag for already reviewed patches. - Dropped incorrect patch of put_device(). - Corrected Fixes commit tag for sysfs remove sequence fix - Split last 8th patch to smaller refactor and fixes patch - Following coding style commenting format - Fixed accidental delete of mutex_lock in mdev_unregister_device - Renamed remove helped to mdev_device_remove_common(). - Rebased for uuid/guid change Parav Pandit (10): vfio/mdev: Avoid release parent reference during error path vfio/mdev: Removed unused kref vfio/mdev: Drop redundant extern for exported symbols vfio/mdev: Avoid masking error code to EBUSY vfio/mdev: Follow correct remove sequence vfio/mdev: Fix aborting mdev child device removal if one fails vfio/mdev: Avoid inline get and put parent helpers vfio/mdev: Improve the create/remove sequence vfio/mdev: Avoid creating sysfs remove file on stale device removal vfio/mdev: Synchronize device create/remove with parent removal drivers/vfio/mdev/mdev_core.c | 162 +++++++++++++------------------ drivers/vfio/mdev/mdev_private.h | 9 +- drivers/vfio/mdev/mdev_sysfs.c | 8 +- include/linux/mdev.h | 21 ++-- 4 files changed, 89 insertions(+), 111 deletions(-)