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 Received: from smtp3.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 7842FC43219 for ; Tue, 12 Apr 2022 11:56:26 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id 209776100D; Tue, 12 Apr 2022 11:56:26 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id BQHxrZhLtl1G; Tue, 12 Apr 2022 11:56:25 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [IPv6:2605:bc80:3010:104::8cd3:938]) by smtp3.osuosl.org (Postfix) with ESMTPS id 1156D60E61; Tue, 12 Apr 2022 11:56:24 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id DD6C6C002F; Tue, 12 Apr 2022 11:56:24 +0000 (UTC) Received: from smtp1.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id BB2B1C002C for ; Tue, 12 Apr 2022 11:56:23 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id 9A1938308A for ; Tue, 12 Apr 2022 11:56:23 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Authentication-Results: smtp1.osuosl.org (amavisd-new); dkim=pass (2048-bit key) header.d=intel.com Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id BmNlbuqsWO4v for ; Tue, 12 Apr 2022 11:56:22 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by smtp1.osuosl.org (Postfix) with ESMTPS id 74D9883089 for ; Tue, 12 Apr 2022 11:56:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1649764582; x=1681300582; h=message-id:date:mime-version:cc:subject:to:references: from:in-reply-to:content-transfer-encoding; bh=L0qUnMQOFRRb2Pk8gqURd8V55DtzojRRl0dzjoOnUPY=; b=A6mL7VXFmmLC4J9SdW0jPo68F0khU0bWfNwSqS6fPzDaqpSzLfcBBPtO pWFbKhW7c5CRdvcZJqa1eiLhwSGJ3bwdNHDR03jgpOgW3y27lbnpN7tUW /rmMbmMKmBugqqrRdJ5gpIrUbI7qqSm3/3CYPIEUfTsUsAWzjBkxOq/jU fMI9TMmI09R6U6W3xBkGrXpw1m40Ud3Hwhdz2ELCVT05tEb6jucqRwSIR iv2K+SudwhxjIAiQaCThqWtHwaZipoWnKG4Z6WSQfV4/mzeUNqwVWFmYW Fo2uNV3qqEPcPOBpXEClQlZOgxuYIWMCIiuuD+ZCiJK/eiRBTe2duIljW A==; X-IronPort-AV: E=McAfee;i="6400,9594,10314"; a="259953459" X-IronPort-AV: E=Sophos;i="5.90,253,1643702400"; d="scan'208";a="259953459" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Apr 2022 04:56:20 -0700 X-IronPort-AV: E=Sophos;i="5.90,253,1643702400"; d="scan'208";a="572730132" Received: from blu2-mobl3.ccr.corp.intel.com (HELO [10.254.210.174]) ([10.254.210.174]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Apr 2022 04:56:16 -0700 Message-ID: <317c1d39-13df-2559-dff7-2a5c82630739@linux.intel.com> Date: Tue, 12 Apr 2022 19:56:14 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.8.0 Subject: Re: [PATCH RFC v3 02/12] iommu: Add a flag to indicate immutable singleton group Content-Language: en-US To: Yi Liu , "Tian, Kevin" , Joerg Roedel , Jason Gunthorpe , Christoph Hellwig , "Raj, Ashok" , Will Deacon , Robin Murphy , Jean-Philippe Brucker References: <20220410102443.294128-1-baolu.lu@linux.intel.com> <20220410102443.294128-3-baolu.lu@linux.intel.com> <7c70a136-6871-b48c-8e46-852bb1b62958@linux.intel.com> From: Lu Baolu In-Reply-To: Cc: "iommu@lists.linux-foundation.org" , "Pan, Jacob jun" , "linux-kernel@vger.kernel.org" X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" Hi Yi, On 2022/4/12 14:34, Yi Liu wrote: >>> >>>> >>>> This adds a flag in the iommu_group struct to indicate an immutable >>>> singleton group, and uses standard PCI bus topology, isolation >>>> features, >>>> and DMA alias quirks to set the flag. If the device came from DT, >>>> assume >>>> it is static and then the singleton attribute can know from the device >>>> count in the group. >>> >>> where does the assumption come from? >> >> Hotplug is the only factor that can dynamically affect the >> characteristics of IOMMU group singleton as far as I can see. If a >> device node was created from the DT, it could be treated as static, >> hence we can judge the singleton in iommu probe phase during boot. > > not sure if hotplug is the only factor. Is it possible that admin modifies > the ACS configuration on the bridge? Not likely. This will completely change the existing iommu_group settings. Best regards, baolu _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu