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 36C39C433E0 for ; Thu, 18 Mar 2021 09:13:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F419964F30 for ; Thu, 18 Mar 2021 09:13:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229821AbhCRJND (ORCPT ); Thu, 18 Mar 2021 05:13:03 -0400 Received: from 8bytes.org ([81.169.241.247]:59534 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229564AbhCRJMx (ORCPT ); Thu, 18 Mar 2021 05:12:53 -0400 Received: by theia.8bytes.org (Postfix, from userid 1000) id BF6D82D8; Thu, 18 Mar 2021 10:12:47 +0100 (CET) Date: Thu, 18 Mar 2021 10:12:46 +0100 From: Joerg Roedel To: "Raj, Ashok" Cc: Lu Baolu , Will Deacon , kevin.tian@intel.com, jacob.jun.pan@intel.com, yi.l.liu@intel.com, sanjay.k.kumar@intel.com, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/5] iommu/vt-d: Remove WO permissions on second-level paging entries Message-ID: References: <20210225062654.2864322-1-baolu.lu@linux.intel.com> <20210225062654.2864322-3-baolu.lu@linux.intel.com> <20210304122623.GD26414@8bytes.org> <20210308194746.GA15436@otc-nc-03> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210308194746.GA15436@otc-nc-03> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Mon, Mar 08, 2021 at 11:47:46AM -0800, Raj, Ashok wrote: > That is the primary motivation, given that we have moved to 1st level for > general IOVA, first level doesn't have a WO mapping. I didn't know enough > about the history to determine if a WO without a READ is very useful. I > guess the ZLR was invented to support those cases without a READ in PCIe. I Okay, please update the commit message and re-send. I guess these patches are 5.13 stuff. In that case, Baolu can include them into his pull request later this cycle. Regards, Joerg