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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 0B017C12002 for ; Thu, 15 Jul 2021 01:25:35 +0000 (UTC) Received: from smtp4.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (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 94CD2613D0 for ; Thu, 15 Jul 2021 01:25:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 94CD2613D0 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 smtp4.osuosl.org (Postfix) with ESMTP id 532F74053F; Thu, 15 Jul 2021 01:25:34 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id s2EfX8rjIK7f; Thu, 15 Jul 2021 01:25:33 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [IPv6:2605:bc80:3010:104::8cd3:938]) by smtp4.osuosl.org (Postfix) with ESMTPS id D7D784058A; Thu, 15 Jul 2021 01:25:32 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id A1A7AC0010; Thu, 15 Jul 2021 01:25:32 +0000 (UTC) Received: from smtp2.osuosl.org (smtp2.osuosl.org [IPv6:2605:bc80:3010::133]) by lists.linuxfoundation.org (Postfix) with ESMTP id C789AC000E for ; Thu, 15 Jul 2021 01:25:29 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id AE39C40130 for ; Thu, 15 Jul 2021 01:25:29 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id juvnXENLJw4h for ; Thu, 15 Jul 2021 01:25:28 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by smtp2.osuosl.org (Postfix) with ESMTPS id 174E94011D for ; Thu, 15 Jul 2021 01:25:27 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10045"; a="197638816" X-IronPort-AV: E=Sophos;i="5.84,240,1620716400"; d="scan'208";a="197638816" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Jul 2021 18:25:25 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.84,240,1620716400"; d="scan'208";a="466322019" Received: from allen-box.sh.intel.com (HELO [10.239.159.118]) ([10.239.159.118]) by fmsmga008.fm.intel.com with ESMTP; 14 Jul 2021 18:25:23 -0700 Subject: Re: [PATCH v7 00/15] Optimizing iommu_[map/unmap] performance To: Georgi Djakov , Georgi Djakov , will@kernel.org, robin.murphy@arm.com References: <1623850736-389584-1-git-send-email-quic_c_gdjako@quicinc.com> From: Lu Baolu Message-ID: <4d466ea9-2c1a-2e19-af5b-0434441ee7cb@linux.intel.com> Date: Thu, 15 Jul 2021 09:23:22 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US Cc: isaacm@codeaurora.org, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, pratikp@codeaurora.org, linux-arm-kernel@lists.infradead.org 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" On 7/14/21 10:24 PM, Georgi Djakov wrote: > On 16.06.21 16:38, Georgi Djakov wrote: >> When unmapping a buffer from an IOMMU domain, the IOMMU framework unmaps >> the buffer at a granule of the largest page size that is supported by >> the IOMMU hardware and fits within the buffer. For every block that >> is unmapped, the IOMMU framework will call into the IOMMU driver, and >> then the io-pgtable framework to walk the page tables to find the entry >> that corresponds to the IOVA, and then unmaps the entry. >> >> This can be suboptimal in scenarios where a buffer or a piece of a >> buffer can be split into several contiguous page blocks of the same size. >> For example, consider an IOMMU that supports 4 KB page blocks, 2 MB page >> blocks, and 1 GB page blocks, and a buffer that is 4 MB in size is being >> unmapped at IOVA 0. The current call-flow will result in 4 indirect >> calls, >> and 2 page table walks, to unmap 2 entries that are next to each other in >> the page-tables, when both entries could have been unmapped in one shot >> by clearing both page table entries in the same call. >> >> The same optimization is applicable to mapping buffers as well, so >> these patches implement a set of callbacks called unmap_pages and >> map_pages to the io-pgtable code and IOMMU drivers which unmaps or maps >> an IOVA range that consists of a number of pages of the same >> page size that is supported by the IOMMU hardware, and allows for >> manipulating multiple page table entries in the same set of indirect >> calls. The reason for introducing these callbacks is to give other IOMMU >> drivers/io-pgtable formats time to change to using the new callbacks, so >> that the transition to using this approach can be done piecemeal. > > Hi Will, > > Did you get a chance to look at this patchset? Most patches are already > acked/reviewed and all still applies clean on rc1. I also have the ops->[un]map_pages implementation for the Intel IOMMU driver. I will post them once the iommu/core part get applied. Best regards, baolu _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu