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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 41FCCC433E9 for ; Thu, 31 Dec 2020 01:03:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 057B82220B for ; Thu, 31 Dec 2020 01:03:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726575AbgLaBDW (ORCPT ); Wed, 30 Dec 2020 20:03:22 -0500 Received: from mga01.intel.com ([192.55.52.88]:3103 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726485AbgLaBDT (ORCPT ); Wed, 30 Dec 2020 20:03:19 -0500 IronPort-SDR: lrmkp96jvtB2LxO56jBAtlTrYm9X3iYezvV6smLiLA4Wk3Szk50boUhv9nVNWV/99aM6AXVCFo 3Gl4qzQtHukg== X-IronPort-AV: E=McAfee;i="6000,8403,9850"; a="195158333" X-IronPort-AV: E=Sophos;i="5.78,462,1599548400"; d="scan'208";a="195158333" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Dec 2020 17:01:34 -0800 IronPort-SDR: VdyohXsM6+r+Lq5nvwH1B+WPcRdmYY9BkbiYe3k1ia9uo79YSHrJku1qlQwrqrvIGe+aa0J5dc CS7cH9fsZ4Eg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.78,462,1599548400"; d="scan'208";a="460676257" Received: from allen-box.sh.intel.com ([10.239.159.28]) by fmsmga001.fm.intel.com with ESMTP; 30 Dec 2020 17:01:31 -0800 From: Lu Baolu To: Joerg Roedel , Will Deacon Cc: Ashok Raj , Jacob Pan , Guo Kaijie , Liu Yi L , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Lu Baolu Subject: [PATCH 5/5] iommu/vt-d: Fix lockdep splat in sva bind()/unbind() Date: Thu, 31 Dec 2020 08:53:23 +0800 Message-Id: <20201231005323.2178523-5-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20201231005323.2178523-1-baolu.lu@linux.intel.com> References: <20201231005323.2178523-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Lock(&iommu->lock) without disabling irq causes lockdep warnings. ======================================================== WARNING: possible irq lock inversion dependency detected 5.11.0-rc1+ #828 Not tainted -------------------------------------------------------- kworker/0:1H/120 just changed the state of lock: ffffffffad9ea1b8 (device_domain_lock){..-.}-{2:2}, at: iommu_flush_dev_iotlb.part.0+0x32/0x120 but this lock took another, SOFTIRQ-unsafe lock in the past: (&iommu->lock){+.+.}-{2:2} and interrupts could create inverse lock ordering between them. other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&iommu->lock); local_irq_disable(); lock(device_domain_lock); lock(&iommu->lock); lock(device_domain_lock); *** DEADLOCK *** Signed-off-by: Lu Baolu --- drivers/iommu/intel/svm.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c index b16a4791acfb..18a9f05df407 100644 --- a/drivers/iommu/intel/svm.c +++ b/drivers/iommu/intel/svm.c @@ -299,6 +299,7 @@ int intel_svm_bind_gpasid(struct iommu_domain *domain, struct device *dev, struct dmar_domain *dmar_domain; struct device_domain_info *info; struct intel_svm *svm = NULL; + unsigned long iflags; int ret = 0; if (WARN_ON(!iommu) || !data) @@ -400,12 +401,12 @@ int intel_svm_bind_gpasid(struct iommu_domain *domain, struct device *dev, * each bind of a new device even with an existing PASID, we need to * call the nested mode setup function here. */ - spin_lock(&iommu->lock); + spin_lock_irqsave(&iommu->lock, iflags); ret = intel_pasid_setup_nested(iommu, dev, (pgd_t *)(uintptr_t)data->gpgd, data->hpasid, &data->vendor.vtd, dmar_domain, data->addr_width); - spin_unlock(&iommu->lock); + spin_unlock_irqrestore(&iommu->lock, iflags); if (ret) { dev_err_ratelimited(dev, "Failed to set up PASID %llu in nested mode, Err %d\n", data->hpasid, ret); @@ -505,6 +506,7 @@ intel_svm_bind_mm(struct device *dev, unsigned int flags, struct device_domain_info *info; struct intel_svm_dev *sdev; struct intel_svm *svm = NULL; + unsigned long iflags; int pasid_max; int ret; @@ -624,14 +626,14 @@ intel_svm_bind_mm(struct device *dev, unsigned int flags, } } - spin_lock(&iommu->lock); + spin_lock_irqsave(&iommu->lock, iflags); ret = intel_pasid_setup_first_level(iommu, dev, mm ? mm->pgd : init_mm.pgd, svm->pasid, FLPT_DEFAULT_DID, (mm ? 0 : PASID_FLAG_SUPERVISOR_MODE) | (cpu_feature_enabled(X86_FEATURE_LA57) ? PASID_FLAG_FL5LP : 0)); - spin_unlock(&iommu->lock); + spin_unlock_irqrestore(&iommu->lock, iflags); if (ret) { if (mm) mmu_notifier_unregister(&svm->notifier, mm); @@ -651,14 +653,14 @@ intel_svm_bind_mm(struct device *dev, unsigned int flags, * Binding a new device with existing PASID, need to setup * the PASID entry. */ - spin_lock(&iommu->lock); + spin_lock_irqsave(&iommu->lock, iflags); ret = intel_pasid_setup_first_level(iommu, dev, mm ? mm->pgd : init_mm.pgd, svm->pasid, FLPT_DEFAULT_DID, (mm ? 0 : PASID_FLAG_SUPERVISOR_MODE) | (cpu_feature_enabled(X86_FEATURE_LA57) ? PASID_FLAG_FL5LP : 0)); - spin_unlock(&iommu->lock); + spin_unlock_irqrestore(&iommu->lock, iflags); if (ret) { kfree(sdev); goto out; -- 2.25.1