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=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 CD88DC67790 for ; Fri, 27 Jul 2018 20:02:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7947F20673 for ; Fri, 27 Jul 2018 20:02:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="TFOoUBXQ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7947F20673 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389408AbeG0VZb (ORCPT ); Fri, 27 Jul 2018 17:25:31 -0400 Received: from mail-wm0-f68.google.com ([74.125.82.68]:51190 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389326AbeG0VZb (ORCPT ); Fri, 27 Jul 2018 17:25:31 -0400 Received: by mail-wm0-f68.google.com with SMTP id s12-v6so6444253wmc.0; Fri, 27 Jul 2018 13:02:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=yqkUGJipEj+KbNRGey4YQivwr9wqaIsKHnCwW0FR1KI=; b=TFOoUBXQjKLJ2s74MzWyd6ctAVDxFj1v8bxH8zh7xZtGeLtnWr7zjh2jUQNkKXmhtO U5dfIG2DKB9B0Cu2fckJmtbEVS1PeTPrx2QrnDjxu+i8/R2pMWcSddpyG9+GXLXuQUdv FVWyqItEv/WAIhL4xsQTJUoGOQoBigSDqssYJq9Nso+N36igki/2ajJ5FnXvnIBHlHfX Oh9qI+GJ3t9cfo/M/96k3DXpS3crkwRxIRjyp4saE1uqpSm9YdXlkDpiAVak6LZ+eACs lzvZrQnE3TIBBSjLkglflk1jcPPJSm55EESoOnP+mdnXe7LSmRd4uXsIUonrt87rSxLy I5wg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=yqkUGJipEj+KbNRGey4YQivwr9wqaIsKHnCwW0FR1KI=; b=ssJofaX7RTRoVjl4rRkyU1R858TCjIpbkj7vRicJcD15vDvaUphQ08XP7Y/dhTHm43 sKosrLsbTESW9+kEEU+pSrupXQQc3uB6FdIbXKbncxUF2JHp3yECdaUu09Nzy/NtnJB8 W/Jo/h6iNdnt+/r8AAPCmaMz3E5dPLSDTWot/5LSF034MaIXIGa1yVswQ7roZYM0k9t/ 8yC7LGPIBSPHgOhlLxCyAUbdXcv//GEOPir5z6vhJZvTJHQCza34iIEBMKQf4Vgk8fzj MZJra1v5NWemi/bsdqkat7SXVOiCHyP32AL1Tkhaf4raTCm102fCev+krbUaeFOMII6d R4fg== X-Gm-Message-State: AOUpUlFJiBS1ABAT6PUdQOHYFo4s/0yMoYElIauTkXDVnJdY5R2sQ5g8 d6XiWOrBOJcZix7QeoxBKvA= X-Google-Smtp-Source: AAOMgpcPYNj0dkqP8BKIIcnodQuPLwWjGIEx8+rj57i0CkwDtf+hXIJ/FtdAOBKysD1gzdnPl0xfjA== X-Received: by 2002:a1c:d946:: with SMTP id q67-v6mr5478795wmg.156.1532721723995; Fri, 27 Jul 2018 13:02:03 -0700 (PDT) Received: from dimapc.localnet ([109.252.90.13]) by smtp.gmail.com with ESMTPSA id r16-v6sm8051056wru.59.2018.07.27.13.02.01 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 27 Jul 2018 13:02:03 -0700 (PDT) From: Dmitry Osipenko To: Joerg Roedel , Rob Herring Cc: Will Deacon , Greg Kroah-Hartman , "Rafael J. Wysocki" , Thierry Reding , Jon Hunter , Mikko Perttunen , Frank Rowand , bskeggs@redhat.com, Russell King , Catalin Marinas , kwizart@gmail.com, devicetree@vger.kernel.org, nouveau@lists.freedesktop.org, Linux IOMMU , dri-devel , linux-tegra@vger.kernel.org, "linux-kernel@vger.kernel.org" Subject: Re: [RFC PATCH v1 0/6] Resolve unwanted DMA backing with IOMMU Date: Fri, 27 Jul 2018 23:02:01 +0300 Message-ID: <4850389.K9ByBxYttl@dimapc> In-Reply-To: <20180727183134.GD6738@8bytes.org> References: <20180726231624.21084-1-digetx@gmail.com> <20180727183134.GD6738@8bytes.org> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday, 27 July 2018 21:31:34 MSK Joerg Roedel wrote: > On Fri, Jul 27, 2018 at 11:13:31AM -0600, Rob Herring wrote: > > I don't follow why we need a property rather than being implied by the > > device's (the GPU) compatible string. > > There might be devices where either setup works, with or without IOMMU > translation, and the firmware can set the property depending on whether > the user wants more performance or more security. > > If we have a whitelist in the kernel this gets more complicated, we > probably need additional kernel-parameters to overwrite those whitelist > entries. Having a property in the device-tree seems to be a better way > here, imho. IIUC, device-tree should be considered to be "written in stone" for a consumer device and hence firmware property isn't something that could be easily changed. The kernel-parameter will be much more universal. Anyway the global whitelisting should be a different topic for discussion, right now we need a kind of private whitelisting that is internal to kernel.