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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 8BB53C17443 for ; Mon, 11 Nov 2019 03:22:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6174A206A3 for ; Mon, 11 Nov 2019 03:22:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="fOeSPNWU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726885AbfKKDWA (ORCPT ); Sun, 10 Nov 2019 22:22:00 -0500 Received: from mail-io1-f65.google.com ([209.85.166.65]:34465 "EHLO mail-io1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726742AbfKKDV7 (ORCPT ); Sun, 10 Nov 2019 22:21:59 -0500 Received: by mail-io1-f65.google.com with SMTP id q83so13021623iod.1 for ; Sun, 10 Nov 2019 19:21:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=udsQv+N/pb8sImm3oVXMjvN8DC7yoxu7rp8gANjC+ZI=; b=fOeSPNWUQuqmIuXxkOnX4SnvOU9F1lJ2n0a5rpfPfLI4VvySftz2NbnkaajWQOBKTe Ot+czn8T/vy3lXWzebOoOoWAOYNCoJ9zNpNyI+gB1FgicDS9cjtQ0lshhgAhDeslZ8Ki dmKXuCCC7SzdUHLOIo+NDQjG5u9IFaVunyn0g2Eo1AFlqRlXlTd1UPzw/tZ9NBuc45CP rw4negqEtPAJOBxDK/rwOG7BD7gObrQZyeigXG10j+F0tjMTua88kp/Vm4jwRPDeS2K6 hgqbHi6ahDX6Gen/SUKnH7Ia50PPVCiRK8vMF5WeNZIxQ3RtQfx/UQUhM52HctxfZ1cn knFg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=udsQv+N/pb8sImm3oVXMjvN8DC7yoxu7rp8gANjC+ZI=; b=kTQtXlMMbW1dHiJHUkCKrLKkmqpCGK/D62ruKHx0kV213uvyHww2U906jwmNSAACuO SgSwlmDQoTFcqbSZnotU0ctfMPyQAvKVn3k/mBnhHBg9kbhC7eV7bAcHdhgEpPqa4JCM EhML06IRREopCVFXYBvh3hjZej5A0Cd4aIlAQutozIlUtjPWqnj0nFE/ekjoxGnGOojf URGY21E4nPsVGNmDNEqNg7d1aOio34XVZwsoPWsBf3QFlldvfq81H4YVyIMhk65J6oxW XOfsoQmuOHHeCgtbNvl6XMCtoIoiOgJd6QI9lPisSXRL1cN7ZVoNdAUUuNpdEMaabTth noZQ== X-Gm-Message-State: APjAAAUGvv9Db/XHe9vl1flY+kQCZuTvcJ4sUeb20dCDxmHfPDwYhp/4 gjGLbTrOaZYwFwHCYp3Z5xgmgl0/L/MuT8H57boF8A== X-Google-Smtp-Source: APXvYqwqRZFBots0x7hq0WUknPcn7B1YNn618XbuZplmZKM1pbfZk6DfmP7mTrrx/86Q3qmWJpPc5QToVvJPlSSHzwM= X-Received: by 2002:a5e:da45:: with SMTP id o5mr22758469iop.265.1573442517410; Sun, 10 Nov 2019 19:21:57 -0800 (PST) MIME-Version: 1.0 References: <20191110172744.12541-1-deepa.kernel@gmail.com> <9e2e95e2-37ac-c0d6-d438-bd09ba7064bd@linux.intel.com> In-Reply-To: <9e2e95e2-37ac-c0d6-d438-bd09ba7064bd@linux.intel.com> From: Deepa Dinamani Date: Sun, 10 Nov 2019 19:21:45 -0800 Message-ID: Subject: Re: [PATCH v2] iommu/vt-d: Turn off translations at shutdown To: Lu Baolu Cc: Linux Kernel Mailing List , joro@8bytes.org, David Woodhouse , iommu@lists.linux-foundation.org Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Nov 10, 2019 at 5:35 PM Lu Baolu wrote: > > Hi, > > On 11/11/19 1:27 AM, Deepa Dinamani wrote: > > The intel-iommu driver assumes that the iommu state is > > cleaned up at the start of the new kernel. > > But, when we try to kexec boot something other than the > > Linux kernel, the cleanup cannot be relied upon. > > Hence, cleanup before we go down for reboot. > > > > Keeping the cleanup at initialization also, in case BIOS > > leaves the IOMMU enabled. > > Do you mind shining more light on this statement? I can't get your point > here. Currently iommu_shutdown() only happens for reboot, right? In this part, I'm saying that I'm leaving intel_iommu_init() alone. I'm not taking out disabling the iommu from intel_iommu_init(). This will help when BIOS has enabled the IOMMU and for whatever reason, the kernel is booting with IOMMU off. -Deepa