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=-5.7 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 1F060C48BE6 for ; Mon, 14 Jun 2021 08:17:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E8AF8608FC for ; Mon, 14 Jun 2021 08:17:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232624AbhFNITY (ORCPT ); Mon, 14 Jun 2021 04:19:24 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]:3229 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232530AbhFNITV (ORCPT ); Mon, 14 Jun 2021 04:19:21 -0400 Received: from fraeml710-chm.china.huawei.com (unknown [172.18.147.207]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4G3P9Y2DN7z6H7X8; Mon, 14 Jun 2021 16:04:17 +0800 (CST) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by fraeml710-chm.china.huawei.com (10.206.15.59) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Mon, 14 Jun 2021 10:17:18 +0200 Received: from [10.47.95.26] (10.47.95.26) by lhreml724-chm.china.huawei.com (10.201.108.75) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Mon, 14 Jun 2021 09:17:17 +0100 Subject: Re: [PATCH v12 2/5] iommu: Enhance IOMMU default DMA mode build options To: Lu Baolu , , , , CC: , , , , References: <1623414043-40745-1-git-send-email-john.garry@huawei.com> <1623414043-40745-3-git-send-email-john.garry@huawei.com> From: John Garry Message-ID: <953e1210-c88f-3e50-fbb9-cc559923829e@huawei.com> Date: Mon, 14 Jun 2021 09:11:14 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.1.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Originating-IP: [10.47.95.26] X-ClientProxiedBy: lhreml725-chm.china.huawei.com (10.201.108.76) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/06/2021 02:21, Lu Baolu wrote: > On 2021/6/11 20:20, John Garry wrote: >> +config IOMMU_DEFAULT_LAZY >> +    bool "lazy" >> +    help >> +      Support lazy mode, where for every IOMMU DMA unmap operation, the >> +      flush operation of IOTLB and the free operation of IOVA are >> deferred. >> +      They are only guaranteed to be done before the related IOVA >> will be >> +      reused. >> + >> +      The isolation provided in this mode is not as secure as STRICT >> mode, >> +      such that a vulnerable time window may be created between the DMA >> +      unmap and the mapping finally being torn down in the IOMMU, >> where the >> +      device can still access the system memory. However this mode may > > " ... and the mappings cached in the IOMMU IOTLB or device TLB finally > being invalidated, where the device probably can still access the memory > which has already been unmapped by the device driver." ok, I can try to incorporate some of this wording. As for this: On 12/06/2021 03:12, Lu Baolu wrote: > On 2021/6/11 20:20, John Garry wrote: >> +choice >> + prompt "IOMMU default DMA mode" > > This is not explicit. > > How about > > "IOMMU DMA default cache invalidation policy" > > ? > OK, but I'd rather use IOTLB, as that better matches the relevant iommu.c API name (iommu_ops.flush_iotlb_all). Thanks, john 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=-5.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,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 8B17EC48BE6 for ; Mon, 14 Jun 2021 08:17:25 +0000 (UTC) Received: from smtp1.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (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 2C160608FC for ; Mon, 14 Jun 2021 08:17:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2C160608FC Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; 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Mon, 14 Jun 2021 09:17:17 +0100 Subject: Re: [PATCH v12 2/5] iommu: Enhance IOMMU default DMA mode build options To: Lu Baolu , , , , References: <1623414043-40745-1-git-send-email-john.garry@huawei.com> <1623414043-40745-3-git-send-email-john.garry@huawei.com> From: John Garry Message-ID: <953e1210-c88f-3e50-fbb9-cc559923829e@huawei.com> Date: Mon, 14 Jun 2021 09:11:14 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.1.2 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-Originating-IP: [10.47.95.26] X-ClientProxiedBy: lhreml725-chm.china.huawei.com (10.201.108.76) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected Cc: iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, linuxarm@huawei.com 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: base64 Content-Type: text/plain; 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