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 CA45CC48BE6 for ; Sat, 12 Jun 2021 01:22:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A6A3E61246 for ; Sat, 12 Jun 2021 01:22:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230331AbhFLBYE (ORCPT ); Fri, 11 Jun 2021 21:24:04 -0400 Received: from mga14.intel.com ([192.55.52.115]:27949 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229942AbhFLBYE (ORCPT ); Fri, 11 Jun 2021 21:24:04 -0400 IronPort-SDR: SHfz12V4XM5GN/V3nwuTVG1Wmh7khPlWkwM6xa0ally7u2cMlRA9cuyPXkAnOf0uhr+WdOuanJ zffATOqw/iEg== X-IronPort-AV: E=McAfee;i="6200,9189,10012"; a="205453110" X-IronPort-AV: E=Sophos;i="5.83,268,1616482800"; d="scan'208";a="205453110" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jun 2021 18:22:05 -0700 IronPort-SDR: HGSyKzehp43FjYp0rgwHlcVfxC/9mqaKeNAcAIonOHPHnDnfDerhV26RKa823oHg4ZqVAypTei ihffYAKT/tTA== X-IronPort-AV: E=Sophos;i="5.83,268,1616482800"; d="scan'208";a="483464843" Received: from blu2-mobl3.ccr.corp.intel.com (HELO [10.238.4.20]) ([10.238.4.20]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jun 2021 18:22:02 -0700 Cc: baolu.lu@linux.intel.com, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, linuxarm@huawei.com, thunder.leizhen@huawei.com, chenxiang66@hisilicon.com To: John Garry , joro@8bytes.org, will@kernel.org, dwmw2@infradead.org, robin.murphy@arm.com References: <1623414043-40745-1-git-send-email-john.garry@huawei.com> <1623414043-40745-3-git-send-email-john.garry@huawei.com> From: Lu Baolu Subject: Re: [PATCH v12 2/5] iommu: Enhance IOMMU default DMA mode build options Message-ID: Date: Sat, 12 Jun 2021 09:21:59 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <1623414043-40745-3-git-send-email-john.garry@huawei.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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." Best regards, baolu 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,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 C0B22C48BE5 for ; Sat, 12 Jun 2021 01:22:10 +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 4501D613AA for ; Sat, 12 Jun 2021 01:22:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4501D613AA 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 smtp1.osuosl.org (Postfix) with ESMTP id E01ED83DE1; Sat, 12 Jun 2021 01:22:09 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id GC6wn7iQaKf6; Sat, 12 Jun 2021 01:22:09 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp1.osuosl.org (Postfix) with ESMTPS id DA4E783DBB; Sat, 12 Jun 2021 01:22:08 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id B0CC6C000E; Sat, 12 Jun 2021 01:22:08 +0000 (UTC) Received: from smtp1.osuosl.org (smtp1.osuosl.org [IPv6:2605:bc80:3010::138]) by lists.linuxfoundation.org (Postfix) with ESMTP id 81727C000B for ; Sat, 12 Jun 2021 01:22:07 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id 74A8683DBB for ; Sat, 12 Jun 2021 01:22:07 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id sSE1i3hrCNK9 for ; Sat, 12 Jun 2021 01:22:06 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by smtp1.osuosl.org (Postfix) with ESMTPS id 0D6D583DE1 for ; Sat, 12 Jun 2021 01:22:05 +0000 (UTC) IronPort-SDR: PV5JWMLp3DtVmq4JDseWDbEKAauGpUnfWy+ZNzvQymaLdstJnKY5VduFWrM1wdUOpQKqwJCvJY kcfMlFiqxBfg== X-IronPort-AV: E=McAfee;i="6200,9189,10012"; a="203805064" X-IronPort-AV: E=Sophos;i="5.83,268,1616482800"; d="scan'208";a="203805064" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jun 2021 18:22:05 -0700 IronPort-SDR: HGSyKzehp43FjYp0rgwHlcVfxC/9mqaKeNAcAIonOHPHnDnfDerhV26RKa823oHg4ZqVAypTei ihffYAKT/tTA== X-IronPort-AV: E=Sophos;i="5.83,268,1616482800"; d="scan'208";a="483464843" Received: from blu2-mobl3.ccr.corp.intel.com (HELO [10.238.4.20]) ([10.238.4.20]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jun 2021 18:22:02 -0700 To: John Garry , joro@8bytes.org, will@kernel.org, dwmw2@infradead.org, robin.murphy@arm.com References: <1623414043-40745-1-git-send-email-john.garry@huawei.com> <1623414043-40745-3-git-send-email-john.garry@huawei.com> From: Lu Baolu Subject: Re: [PATCH v12 2/5] iommu: Enhance IOMMU default DMA mode build options Message-ID: Date: Sat, 12 Jun 2021 09:21:59 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <1623414043-40745-3-git-send-email-john.garry@huawei.com> Content-Language: en-US Cc: linuxarm@huawei.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" 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." Best regards, baolu _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu