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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 BB3A5C07E9C for ; Wed, 14 Jul 2021 10:15:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9EE6D6101B for ; Wed, 14 Jul 2021 10:15:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238887AbhGNKSW (ORCPT ); Wed, 14 Jul 2021 06:18:22 -0400 Received: from 8bytes.org ([81.169.241.247]:37742 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238728AbhGNKSW (ORCPT ); Wed, 14 Jul 2021 06:18:22 -0400 Received: by theia.8bytes.org (Postfix, from userid 1000) id C73C1352; Wed, 14 Jul 2021 12:15:27 +0200 (CEST) Date: Wed, 14 Jul 2021 12:15:20 +0200 From: Joerg Roedel To: Robin Murphy Cc: Doug Anderson , Ulf Hansson , Linux Doc Mailing List , Peter Zijlstra , linux-pci@vger.kernel.org, Konrad Dybcio , Thierry Reding , Joel Fernandes , Rajat Jain , Will Deacon , Rob Clark , Saravana Kannan , Jonathan Corbet , quic_c_gdjako@quicinc.com, Linux ARM , Viresh Kumar , Veerabhadrarao Badiganti , "Paul E. McKenney" , linux-arm-msm , Bjorn Helgaas , Sonny Rao , Vlastimil Babka , Randy Dunlap , Linux MMC List , Adrian Hunter , LKML , "list@263.net:IOMMU DRIVERS" , Andrew Morton , "Maciej W. Rozycki" Subject: Re: [PATCH v2 0/3] iommu: Enable non-strict DMA on QCom SD/MMC Message-ID: References: <20210624171759.4125094-1-dianders@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Hi Robin, On Fri, Jul 09, 2021 at 02:56:47PM +0100, Robin Murphy wrote: > As I mentioned before, conceptually I think this very much belongs in sysfs > as a user decision. We essentially have 4 levels of "strictness": > > 1: DMA domain with bounce pages > 2: DMA domain > 3: DMA domain with flush queue > 4: Identity domain Together with reasonable defaults (influenced by compile-time options) it seems to be a good thing to configure at runtime via sysfs. We already have CONFIG_IOMMU_DEFAULT_PASSTHROUGH, which can probably be extended to be an option list: - CONFIG_IOMMU_DEFAULT_PASSTHROUGH: Trusted devices are identity mapped - CONFIG_IOMMU_DEFAULT_DMA_STRICT: Trusted devices are DMA mapped with strict flush behavior on unmap - CONFIG_IOMMU_DEFAULT_DMA_LAZY: Trusted devices are DMA mapped with flush queues for performance Untrusted devices always get into the DMA domain with bounce pages by default. The defaults can be changed at runtime via sysfs. We already have basic support for runtime switching of the default domain, so that can be re-used. Regards, Joerg 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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 67DACC07E9A for ; Wed, 14 Jul 2021 10:15:39 +0000 (UTC) Received: from smtp1.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 0082D6101D for ; Wed, 14 Jul 2021 10:15:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0082D6101D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=8bytes.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id C0C9F83B78; Wed, 14 Jul 2021 10:15:38 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org 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 YHPPADQpkTRN; Wed, 14 Jul 2021 10:15:36 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp1.osuosl.org (Postfix) with ESMTPS id 919AD83B35; Wed, 14 Jul 2021 10:15:36 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 676FAC001A; Wed, 14 Jul 2021 10:15:36 +0000 (UTC) Received: from smtp1.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id B0B57C000E for ; Wed, 14 Jul 2021 10:15:34 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id 9F37883B35 for ; Wed, 14 Jul 2021 10:15:34 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org 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 VJ_U1hXDqf0e for ; Wed, 14 Jul 2021 10:15:32 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.8.0 Received: from theia.8bytes.org (8bytes.org [81.169.241.247]) by smtp1.osuosl.org (Postfix) with ESMTPS id D4F8083A87 for ; Wed, 14 Jul 2021 10:15:31 +0000 (UTC) Received: by theia.8bytes.org (Postfix, from userid 1000) id C73C1352; Wed, 14 Jul 2021 12:15:27 +0200 (CEST) Date: Wed, 14 Jul 2021 12:15:20 +0200 From: Joerg Roedel To: Robin Murphy Subject: Re: [PATCH v2 0/3] iommu: Enable non-strict DMA on QCom SD/MMC Message-ID: References: <20210624171759.4125094-1-dianders@chromium.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: Cc: Ulf Hansson , Linux Doc Mailing List , Peter Zijlstra , linux-pci@vger.kernel.org, Konrad Dybcio , Adrian Hunter , Thierry Reding , Joel Fernandes , Rajat Jain , Will Deacon , Rob Clark , Saravana Kannan , Jonathan Corbet , quic_c_gdjako@quicinc.com, Linux ARM , Viresh Kumar , Veerabhadrarao Badiganti , "Paul E. McKenney" , linux-arm-msm , Bjorn Helgaas , Sonny Rao , Vlastimil Babka , Randy Dunlap , Linux MMC List , Doug Anderson , LKML , "list@263.net:IOMMU DRIVERS" , Andrew Morton , "Maciej W. Rozycki" 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-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" Hi Robin, On Fri, Jul 09, 2021 at 02:56:47PM +0100, Robin Murphy wrote: > As I mentioned before, conceptually I think this very much belongs in sysfs > as a user decision. We essentially have 4 levels of "strictness": > > 1: DMA domain with bounce pages > 2: DMA domain > 3: DMA domain with flush queue > 4: Identity domain Together with reasonable defaults (influenced by compile-time options) it seems to be a good thing to configure at runtime via sysfs. We already have CONFIG_IOMMU_DEFAULT_PASSTHROUGH, which can probably be extended to be an option list: - CONFIG_IOMMU_DEFAULT_PASSTHROUGH: Trusted devices are identity mapped - CONFIG_IOMMU_DEFAULT_DMA_STRICT: Trusted devices are DMA mapped with strict flush behavior on unmap - CONFIG_IOMMU_DEFAULT_DMA_LAZY: Trusted devices are DMA mapped with flush queues for performance Untrusted devices always get into the DMA domain with bounce pages by default. The defaults can be changed at runtime via sysfs. We already have basic support for runtime switching of the default domain, so that can be re-used. Regards, Joerg _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu 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=-4.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 DBB92C07E9A for ; Wed, 14 Jul 2021 10:17:22 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 9E5B46101D for ; Wed, 14 Jul 2021 10:17:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9E5B46101D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=8bytes.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=rbWpuVgPEAxiIviwCrSqd9B/0fQmX85thPio1x0LZXg=; b=oHnd6377cd+B56 siWNjsH0UbH3q0Qv9X50LK+r2wFmPZrKcZOCW/0ssDdrFPg4hJGMiiPtX5uNeFiz+AjKxlXeD5BCU BY6Avzx/d8e6hztuKGdH5DDsa/z9PeOgQjCqhpRqMliH/eBYLl5DWdvkGOg6mWrdDuk+YVWAruNLl qVQvSCmNvnLVqPZ8xBVRUth6B4sEKKRT1IBAwVoTSoN412a0AhVT0wvbGaZkzUUZDEbWKVJ78xyeS AGuBovkITDp2s+kD+A7gFudflm1b/zv6xB2cm9AMpicwkg5cSl2fjIq1qZyBVM2DJFFYeKWdgtDOw uRKTJdU0pfTDepI6jlog==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1m3bvZ-00D4qA-2O; Wed, 14 Jul 2021 10:15:41 +0000 Received: from 8bytes.org ([2a01:238:4383:600:38bc:a715:4b6d:a889] helo=theia.8bytes.org) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1m3bvS-00D4l1-9r for linux-arm-kernel@lists.infradead.org; Wed, 14 Jul 2021 10:15:35 +0000 Received: by theia.8bytes.org (Postfix, from userid 1000) id C73C1352; Wed, 14 Jul 2021 12:15:27 +0200 (CEST) Date: Wed, 14 Jul 2021 12:15:20 +0200 From: Joerg Roedel To: Robin Murphy Cc: Doug Anderson , Ulf Hansson , Linux Doc Mailing List , Peter Zijlstra , linux-pci@vger.kernel.org, Konrad Dybcio , Thierry Reding , Joel Fernandes , Rajat Jain , Will Deacon , Rob Clark , Saravana Kannan , Jonathan Corbet , quic_c_gdjako@quicinc.com, Linux ARM , Viresh Kumar , Veerabhadrarao Badiganti , "Paul E. McKenney" , linux-arm-msm , Bjorn Helgaas , Sonny Rao , Vlastimil Babka , Randy Dunlap , Linux MMC List , Adrian Hunter , LKML , "list@263.net:IOMMU DRIVERS" , Andrew Morton , "Maciej W. Rozycki" Subject: Re: [PATCH v2 0/3] iommu: Enable non-strict DMA on QCom SD/MMC Message-ID: References: <20210624171759.4125094-1-dianders@chromium.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210714_031534_581001_ACFC81A8 X-CRM114-Status: GOOD ( 14.17 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Robin, On Fri, Jul 09, 2021 at 02:56:47PM +0100, Robin Murphy wrote: > As I mentioned before, conceptually I think this very much belongs in sysfs > as a user decision. We essentially have 4 levels of "strictness": > > 1: DMA domain with bounce pages > 2: DMA domain > 3: DMA domain with flush queue > 4: Identity domain Together with reasonable defaults (influenced by compile-time options) it seems to be a good thing to configure at runtime via sysfs. We already have CONFIG_IOMMU_DEFAULT_PASSTHROUGH, which can probably be extended to be an option list: - CONFIG_IOMMU_DEFAULT_PASSTHROUGH: Trusted devices are identity mapped - CONFIG_IOMMU_DEFAULT_DMA_STRICT: Trusted devices are DMA mapped with strict flush behavior on unmap - CONFIG_IOMMU_DEFAULT_DMA_LAZY: Trusted devices are DMA mapped with flush queues for performance Untrusted devices always get into the DMA domain with bounce pages by default. The defaults can be changed at runtime via sysfs. We already have basic support for runtime switching of the default domain, so that can be re-used. Regards, Joerg _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel