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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 E65ADC4742C for ; Wed, 4 Nov 2020 01:08:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AC61C223C7 for ; Wed, 4 Nov 2020 01:08:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730263AbgKDBIQ (ORCPT ); Tue, 3 Nov 2020 20:08:16 -0500 Received: from mga02.intel.com ([134.134.136.20]:23720 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730224AbgKDBIQ (ORCPT ); Tue, 3 Nov 2020 20:08:16 -0500 IronPort-SDR: hmZyPRz1wrZ4Y2z8UBVk3cl+zjS0tb0gKi/un7n8KPyDKa4si1/UErAGG4XZx8GO58xHgzcszJ HMG4UXIUUKYg== X-IronPort-AV: E=McAfee;i="6000,8403,9794"; a="156138385" X-IronPort-AV: E=Sophos;i="5.77,449,1596524400"; d="scan'208";a="156138385" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Nov 2020 17:08:15 -0800 IronPort-SDR: 6BDOhAxZNbTJaLs1zswBH9VvB33E9mCxyRQnmqn8lJanXDeBq9qh2Xzq/St4ALkLm6+iLLBUHE /gffL0gGUCwg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.77,449,1596524400"; d="scan'208";a="426518233" Received: from allen-box.sh.intel.com (HELO [10.239.159.139]) ([10.239.159.139]) by fmsmga001.fm.intel.com with ESMTP; 03 Nov 2020 17:08:14 -0800 Cc: baolu.lu@linux.intel.com, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH 1/1] iommu: Fix deferred domain attachment in iommu_probe_device() To: Joerg Roedel References: <20201026063008.24849-1-baolu.lu@linux.intel.com> <20201103132358.GG22888@8bytes.org> From: Lu Baolu Message-ID: <399fbf3e-e940-d2a3-e0e7-20f4da988184@linux.intel.com> Date: Wed, 4 Nov 2020 09:01:22 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20201103132358.GG22888@8bytes.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Joerg, On 11/3/20 9:23 PM, Joerg Roedel wrote: > Hi Baolu, > > On Mon, Oct 26, 2020 at 02:30:08PM +0800, Lu Baolu wrote: >> @@ -264,7 +266,8 @@ int iommu_probe_device(struct device *dev) >> */ >> iommu_alloc_default_domain(group, dev); >> >> - if (group->default_domain) >> + if (group->default_domain && >> + !iommu_is_attach_deferred(group->default_domain, dev)) >> ret = __iommu_attach_device(group->default_domain, dev); > > This is the hotplug path, not used for boot-initialization. Have you > seen failures from the missing check here? I haven't seen any failure. Just wondered why deferred attaching was not checked here. It's fine to me if it's only for hotplug path. Please ignore this change. Best regards, baolu