From patchwork Wed Feb 19 06:07:23 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiang Liu X-Patchwork-Id: 3678561 Return-Path: X-Original-To: patchwork-dmaengine@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id F3D22BF40C for ; Wed, 19 Feb 2014 06:13:28 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 0DA732011E for ; Wed, 19 Feb 2014 06:13:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 275AA20117 for ; Wed, 19 Feb 2014 06:13:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750777AbaBSGNC (ORCPT ); Wed, 19 Feb 2014 01:13:02 -0500 Received: from mga09.intel.com ([134.134.136.24]:18482 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752108AbaBSGHK (ORCPT ); Wed, 19 Feb 2014 01:07:10 -0500 Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga102.jf.intel.com with ESMTP; 18 Feb 2014 22:02:50 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,504,1389772800"; d="scan'208";a="485626446" Received: from gerry-dev.bj.intel.com ([10.238.158.74]) by orsmga002.jf.intel.com with ESMTP; 18 Feb 2014 22:07:06 -0800 From: Jiang Liu To: Joerg Roedel , David Woodhouse , Yinghai Lu , Bjorn Helgaas , Dan Williams , Vinod Koul , "Rafael J . Wysocki" Cc: Jiang Liu , Ashok Raj , Yijing Wang , Tony Luck , iommu@lists.linux-foundation.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org Subject: [Patch Part2 V2 03/17] iommu/vt-d: avoid caching stale domain_device_info when hot-removing PCI device Date: Wed, 19 Feb 2014 14:07:23 +0800 Message-Id: <1392790057-32434-4-git-send-email-jiang.liu@linux.intel.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1392790057-32434-1-git-send-email-jiang.liu@linux.intel.com> References: <1392790057-32434-1-git-send-email-jiang.liu@linux.intel.com> Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org X-Spam-Status: No, score=-4.6 required=5.0 tests=BAYES_00,KHOP_BIG_TO_CC, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Function device_notifier() in intel-iommu.c only remove domain_device_info data structure associated with a PCI device when handling PCI device driver unbinding events. If a PCI device has never been bound to a PCI device driver, there won't be BUS_NOTIFY_UNBOUND_DRIVER event when hot-removing the PCI device. So associated domain_device_info data structure may get lost. On the other hand, if iommu_pass_through is enabled, function iommu_prepare_static_indentify_mapping() will create domain_device_info data structure for each PCIe to PCIe bridge and PCIe endpoint, no matter whether there are drivers associated with those PCIe devices or not. So those domain_device_info data structures will get lost when hot-removing the assocated PCIe devices if they have never bound to any PCI device driver. To be even worse, it's not only an memory leak issue, but also an caching of stale information bug because the memory are kept in device_domain_list and domain->devices lists. Fix the bug by trying to remove domain_device_info data structure when handling BUS_NOTIFY_DEL_DEVICE event. Signed-off-by: Jiang Liu --- drivers/iommu/intel-iommu.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index f75d3ae..5a411e8 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -3603,18 +3603,19 @@ static int device_notifier(struct notifier_block *nb, if (iommu_dummy(pdev)) return 0; + if (action != BUS_NOTIFY_UNBOUND_DRIVER && + action != BUS_NOTIFY_DEL_DEVICE) + return 0; + domain = find_domain(pdev); if (!domain) return 0; - if (action == BUS_NOTIFY_UNBOUND_DRIVER) { - domain_remove_one_dev_info(domain, pdev); - - if (!(domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE) && - !(domain->flags & DOMAIN_FLAG_STATIC_IDENTITY) && - list_empty(&domain->devices)) - domain_exit(domain); - } + domain_remove_one_dev_info(domain, pdev); + if (!(domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE) && + !(domain->flags & DOMAIN_FLAG_STATIC_IDENTITY) && + list_empty(&domain->devices)) + domain_exit(domain); return 0; }