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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 8B715C33CB1 for ; Sun, 19 Jan 2020 06:30:53 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 593E620663 for ; Sun, 19 Jan 2020 06:30:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 593E620663 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id 1EE0F8543B; Sun, 19 Jan 2020 06:30:53 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id iTQx7AsiVcKg; Sun, 19 Jan 2020 06:30:48 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by whitealder.osuosl.org (Postfix) with ESMTP id 3DB9A831F5; Sun, 19 Jan 2020 06:30:48 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 2E731C0176; Sun, 19 Jan 2020 06:30:48 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id DC779C0174 for ; Sun, 19 Jan 2020 06:30:46 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id CA3FC8589C for ; Sun, 19 Jan 2020 06:30:46 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id RQjosmqrWF1P for ; Sun, 19 Jan 2020 06:30:46 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by fraxinus.osuosl.org (Postfix) with ESMTPS id EE781851CB for ; Sun, 19 Jan 2020 06:30:45 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 18 Jan 2020 22:30:45 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,337,1574150400"; d="scan'208";a="214929065" Received: from allen-box.sh.intel.com (HELO [10.239.159.138]) ([10.239.159.138]) by orsmga007.jf.intel.com with ESMTP; 18 Jan 2020 22:30:43 -0800 Subject: Re: [RFC PATCH 3/4] iommu: Preallocate iommu group when probing devices To: Joerg Roedel References: <20200101052648.14295-1-baolu.lu@linux.intel.com> <20200101052648.14295-4-baolu.lu@linux.intel.com> <20200117102151.GF15760@8bytes.org> From: Lu Baolu Message-ID: <25e2e7fa-487c-f951-4b2c-27bac5e30815@linux.intel.com> Date: Sun, 19 Jan 2020 14:29:17 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <20200117102151.GF15760@8bytes.org> Content-Language: en-US Cc: kevin.tian@intel.com, ashok.raj@intel.com, Greg Kroah-Hartman , linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, jacob.jun.pan@intel.com, Bjorn Helgaas , Robin Murphy , Christoph Hellwig 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 Joerg, On 1/17/20 6:21 PM, Joerg Roedel wrote: > On Wed, Jan 01, 2020 at 01:26:47PM +0800, Lu Baolu wrote: >> This splits iommu group allocation from adding devices. This makes >> it possible to determine the default domain type for each group as >> all devices belonging to the group have been determined. > > I think its better to keep group allocation as it is and just defer > default domain allocation after each device is in its group. But take I tried defering default domain allocation, but it seems not possible. The call path of adding devices into their groups: iommu_probe_device -> ops->add_device(dev) -> (iommu vendor driver) iommu_group_get_for_dev(dev) After doing this, the vendor driver will get the default domain and apply dma_ops according to the domain type. If we defer the domain allocation, they will get a NULL default domain and cause panic in the vendor driver. Any suggestions? Best regards, baolu > care about the device hotplug path which might add new devices to groups > which already have a default domain, or add new groups that might need a > default domain too. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu