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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 4DC4DC432C0 for ; Wed, 4 Dec 2019 00:28:19 +0000 (UTC) Received: from fraxinus.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 18A9E206E4 for ; Wed, 4 Dec 2019 00:28:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 18A9E206E4 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 fraxinus.osuosl.org (Postfix) with ESMTP id D1CF586A53; Wed, 4 Dec 2019 00:28:18 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 1JdfV-tyUml0; Wed, 4 Dec 2019 00:28:18 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by fraxinus.osuosl.org (Postfix) with ESMTP id 43BF886407; Wed, 4 Dec 2019 00:28:18 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 3B685C18DC; Wed, 4 Dec 2019 00:28:18 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 7C926C1798 for ; Wed, 4 Dec 2019 00:28:17 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id B19E2881BB for ; Wed, 4 Dec 2019 00:27:49 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id R-DCassjTXx4 for ; Wed, 4 Dec 2019 00:27:49 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by hemlock.osuosl.org (Postfix) with ESMTPS id 206CC87F5D for ; Wed, 4 Dec 2019 00:27:49 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Dec 2019 16:27:48 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,275,1571727600"; d="scan'208";a="223028262" Received: from allen-box.sh.intel.com (HELO [10.239.159.136]) ([10.239.159.136]) by orsmga002.jf.intel.com with ESMTP; 03 Dec 2019 16:27:46 -0800 Subject: Re: [PATCH 0/5] iommu/vt-d: Consolidate various cache flush ops To: David Woodhouse , Joerg Roedel References: <20191122030449.28892-1-baolu.lu@linux.intel.com> <22759c43f440eecee60b2d318b6f8e8fe2587bcb.camel@infradead.org> From: Lu Baolu Message-ID: <4100ad7a-0818-7fc1-aaf5-bf0ef44f3f54@linux.intel.com> Date: Wed, 4 Dec 2019 08:27:10 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.1 MIME-Version: 1.0 In-Reply-To: <22759c43f440eecee60b2d318b6f8e8fe2587bcb.camel@infradead.org> Content-Language: en-US Cc: kevin.tian@intel.com, ashok.raj@intel.com, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.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" Hi David, On 12/3/19 4:49 PM, David Woodhouse wrote: > On Fri, 2019-11-22 at 11:04 +0800, Lu Baolu wrote: >> Intel VT-d 3.0 introduces more caches and interfaces for software to >> flush when it runs in the scalable mode. Currently various cache flush >> helpers are scattered around. This consolidates them by putting them in >> the existing iommu_flush structure. >> >> /* struct iommu_flush - Intel IOMMU cache invalidation ops >> * >> * @cc_inv: invalidate context cache >> * @iotlb_inv: Invalidate IOTLB and paging structure caches when software >> * has changed second-level tables. >> * @p_iotlb_inv: Invalidate IOTLB and paging structure caches when software >> * has changed first-level tables. >> * @pc_inv: invalidate pasid cache >> * @dev_tlb_inv: invalidate cached mappings used by requests-without-PASID >> * from the Device-TLB on a endpoint device. >> * @p_dev_tlb_inv: invalidate cached mappings used by requests-with-PASID >> * from the Device-TLB on an endpoint device >> */ >> struct iommu_flush { >> void (*cc_inv)(struct intel_iommu *iommu, u16 did, >> u16 sid, u8 fm, u64 type); >> void (*iotlb_inv)(struct intel_iommu *iommu, u16 did, u64 addr, >> unsigned int size_order, u64 type); >> void (*p_iotlb_inv)(struct intel_iommu *iommu, u16 did, u32 pasid, >> u64 addr, unsigned long npages, bool ih); >> void (*pc_inv)(struct intel_iommu *iommu, u16 did, u32 pasid, >> u64 granu); >> void (*dev_tlb_inv)(struct intel_iommu *iommu, u16 sid, u16 pfsid, >> u16 qdep, u64 addr, unsigned int mask); >> void (*p_dev_tlb_inv)(struct intel_iommu *iommu, u16 sid, u16 pfsid, >> u32 pasid, u16 qdep, u64 addr, >> unsigned long npages); >> }; >> >> The name of each cache flush ops is defined according to the spec section 6.5 >> so that people are easy to look up them in the spec. > > Hm, indirect function calls are quite expensive these days. Good consideration. Thanks! > > I would have preferred to go in the opposite direction, since surely > aren't going to have *many* of these implementations. Currently there's > only one for register-based and one for queued invalidation, right? > Even if VT-d 3.0 throws an extra version in, I think I'd prefer to take > out the indirection completely and have an if/then helper. > > Would love to see a microbenchmark of unmap operations before and after > this patch series with retpoline enabled, to see the effect. Yes. Need some micro-bench tests to address the concern. Best regards, baolu _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu