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=-5.2 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 BF62FC433B4 for ; Fri, 21 May 2021 06:39:20 +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 76D01611AB for ; Fri, 21 May 2021 06:39:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 76D01611AB Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=huawei.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 47A9D41858; Fri, 21 May 2021 06:39:20 +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 cLcJ7ex-RnHa; Fri, 21 May 2021 06:39:19 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp4.osuosl.org (Postfix) with ESMTP id 0F9544185B; Fri, 21 May 2021 06:39:19 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id E0A58C000D; Fri, 21 May 2021 06:39:18 +0000 (UTC) Received: from smtp4.osuosl.org (smtp4.osuosl.org [IPv6:2605:bc80:3010::137]) by lists.linuxfoundation.org (Postfix) with ESMTP id CB79BC0001 for ; Fri, 21 May 2021 06:39:17 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id ABB7A4048F for ; Fri, 21 May 2021 06:39:17 +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 gsMpv4a1OrI5 for ; Fri, 21 May 2021 06:39:16 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 Received: from szxga05-in.huawei.com (szxga05-in.huawei.com [45.249.212.191]) by smtp4.osuosl.org (Postfix) with ESMTPS id AE6EA40418 for ; Fri, 21 May 2021 06:39:16 +0000 (UTC) Received: from dggems706-chm.china.huawei.com (unknown [172.30.72.58]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4FmcLQ2VNVzQpjW; Fri, 21 May 2021 14:35:42 +0800 (CST) Received: from dggpemm500022.china.huawei.com (7.185.36.162) by dggems706-chm.china.huawei.com (10.3.19.183) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Fri, 21 May 2021 14:39:14 +0800 Received: from [10.174.187.155] (10.174.187.155) by dggpemm500022.china.huawei.com (7.185.36.162) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Fri, 21 May 2021 14:39:13 +0800 Subject: Re: [RFC PATCH v3 7/8] vfio/type1: Add selective DMA faulting support To: Alex Williamson , Kevin Tian References: <20210409034420.1799-1-lushenming@huawei.com> <20210409034420.1799-8-lushenming@huawei.com> <20210518125813.7b8a78f1.alex.williamson@redhat.com> From: Shenming Lu Message-ID: Date: Fri, 21 May 2021 14:39:12 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.2.2 MIME-Version: 1.0 In-Reply-To: <20210518125813.7b8a78f1.alex.williamson@redhat.com> Content-Language: en-US X-Originating-IP: [10.174.187.155] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpemm500022.china.huawei.com (7.185.36.162) X-CFilter-Loop: Reflected Cc: Jean-Philippe Brucker , kvm@vger.kernel.org, Will Deacon , Cornelia Huck , linux-kernel@vger.kernel.org, Christoph Hellwig , iommu@lists.linux-foundation.org, linux-api@vger.kernel.org, wanghaibin.wang@huawei.com, Robin Murphy , 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-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On 2021/5/19 2:58, Alex Williamson wrote: > On Fri, 9 Apr 2021 11:44:19 +0800 > Shenming Lu wrote: > >> Some devices only allow selective DMA faulting. Similar to the selective >> dirty page tracking, the vendor driver can call vfio_pin_pages() to >> indicate the non-faultable scope, we add a new struct vfio_range to >> record it, then when the IOPF handler receives any page request out >> of the scope, we can directly return with an invalid response. > > Seems like this highlights a deficiency in the design, that the user > can't specify mappings as iopf enabled or disabled. Also, if the > vendor driver has pinned pages within the range, shouldn't that prevent > them from faulting in the first place? Why do we need yet more > tracking structures? Pages pinned by the vendor driver need to count > against the user's locked memory limits regardless of iopf. Thanks, Currently we only have a vfio_pfn struct to track the external pinned pages (single page granularity), so I add a vfio_range struct for efficient lookup. Yeah, by this patch, for the non-pinned scope, we can directly return INVALID, but for the pinned(non-faultable) scope, tracking the pinned range doesn't seem to help more... Thanks, Shenming > > Alex > > . > _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu