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 5A445C433B4 for ; Fri, 14 May 2021 02:30:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1DBBD61421 for ; Fri, 14 May 2021 02:30:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231241AbhENCbh (ORCPT ); Thu, 13 May 2021 22:31:37 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:3750 "EHLO szxga04-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229952AbhENCbf (ORCPT ); Thu, 13 May 2021 22:31:35 -0400 Received: from DGGEMS404-HUB.china.huawei.com (unknown [172.30.72.59]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4FhC8g5hHQzqTlk; Fri, 14 May 2021 10:26:59 +0800 (CST) Received: from [10.174.187.224] (10.174.187.224) by DGGEMS404-HUB.china.huawei.com (10.3.19.204) with Microsoft SMTP Server id 14.3.498.0; Fri, 14 May 2021 10:30:17 +0800 Subject: Re: [RFC PATCH v4 01/13] iommu: Introduce dirty log tracking framework To: Lu Baolu , , , , Robin Murphy , Will Deacon , "Joerg Roedel" , Jean-Philippe Brucker , Yi Sun , Tian Kevin References: <20210507102211.8836-1-zhukeqian1@huawei.com> <20210507102211.8836-2-zhukeqian1@huawei.com> <18ac787a-179e-71f7-728b-c43feda80a16@huawei.com> <55fda826-9ab6-a3a0-b17e-a4d4879f00bc@linux.intel.com> <60182a35-e151-7150-3708-4e58dd8e78da@huawei.com> <36cc7267-6aa3-db54-b08c-c2dfc0bbacb6@linux.intel.com> <7fb678c7-509b-dbb5-d533-32c5ce2a0476@linux.intel.com> CC: Alex Williamson , Kirti Wankhede , Cornelia Huck , Jonathan Cameron , , , , From: Keqian Zhu Message-ID: <81d0731d-3331-a5f4-1867-5cc1f3f97a29@huawei.com> Date: Fri, 14 May 2021 10:30:17 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.187.224] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021/5/13 20:02, Lu Baolu wrote: > On 5/13/21 6:58 PM, Keqian Zhu wrote: >> >> >> On 2021/5/12 19:36, Lu Baolu wrote: >>> Hi keqian, >>> >>> On 5/12/21 4:44 PM, Keqian Zhu wrote: >>>> >>>> >>>> On 2021/5/12 11:20, Lu Baolu wrote: >>>>> On 5/11/21 3:40 PM, Keqian Zhu wrote: >>>>>>> For upper layers, before starting page tracking, they check the >>>>>>> dirty_page_trackable attribution of the domain and start it only it's >>>>>>> capable. Once the page tracking is switched on the vendor iommu driver >>>>>>> (or iommu core) should block further device attach/detach operations >>>>>>> until page tracking is stopped. >>>>>> But when a domain becomes capable after detaching a device, the upper layer >>>>>> still needs to query it and enable dirty log for it... >>>>>> >>>>>> To make things coordinated, maybe the upper layer can register a notifier, >>>>>> when the domain's capability change, the upper layer do not need to query, instead >>>>>> they just need to realize a callback, and do their specific policy in the callback. >>>>>> What do you think? >>>>>> >>>>> >>>>> That might be an option. But why not checking domain's attribution every >>>>> time a new tracking period is about to start? >>>> Hi Baolu, >>>> >>>> I'll add an attribution in iommu_domain, and the vendor iommu driver will update >>>> the attribution when attach/detach devices. >>>> >>>> The attribute should be protected by a lock, so the upper layer shouldn't access >>>> the attribute directly. Then the iommu_domain_support_dirty_log() still should be >>>> retained. Does this design looks good to you? >>> >>> Yes, that's what I was thinking of. But I am not sure whether it worth >>> of a lock here. It seems not to be a valid behavior for upper layer to >>> attach or detach any device while doing the dirty page tracking. >> Hi Baolu, >> >> Right, if the "detach|attach" interfaces and "dirty tracking" interfaces can be called concurrently, >> a lock in iommu_domain_support_dirty_log() is still not enough. I will add another note for the dirty >> tracking interfaces. >> >> Do you have other suggestions? I will accelerate the progress, so I plan to send out v5 next week. > > No further comments expect below nit: > > "iommu_switch_dirty_log: Perform actions to start|stop dirty log tracking" > > How about splitting it into > - iommu_start_dirty_log() > - iommu_stop_dirty_log() Yeah, actually this is my original version, and the "switch" style is suggested by Yi Sun. Anyway, I think both is OK, and the "switch" style can reduce some code. Thanks, Keqian > > Not a strong opinion anyway. > > 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,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 B72DDC433B4 for ; Fri, 14 May 2021 02:30:34 +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 322506143C for ; Fri, 14 May 2021 02:30:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 322506143C 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 EA6244037D; Fri, 14 May 2021 02:30:33 +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 u7XFK6u5WFQj; Fri, 14 May 2021 02:30:33 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp4.osuosl.org (Postfix) with ESMTP id 9DE094036C; Fri, 14 May 2021 02:30:32 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 7C9AFC000D; Fri, 14 May 2021 02:30:32 +0000 (UTC) Received: from smtp4.osuosl.org (smtp4.osuosl.org [IPv6:2605:bc80:3010::137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 43112C0001 for ; Fri, 14 May 2021 02:30:30 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id 1EA8240379 for ; Fri, 14 May 2021 02:30:30 +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 xg1KjDhQrkxK for ; Fri, 14 May 2021 02:30:28 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 Received: from szxga04-in.huawei.com (szxga04-in.huawei.com [45.249.212.190]) by smtp4.osuosl.org (Postfix) with ESMTPS id CBD8B4036C for ; Fri, 14 May 2021 02:30:27 +0000 (UTC) Received: from DGGEMS404-HUB.china.huawei.com (unknown [172.30.72.59]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4FhC8g5hHQzqTlk; Fri, 14 May 2021 10:26:59 +0800 (CST) Received: from [10.174.187.224] (10.174.187.224) by DGGEMS404-HUB.china.huawei.com (10.3.19.204) with Microsoft SMTP Server id 14.3.498.0; Fri, 14 May 2021 10:30:17 +0800 Subject: Re: [RFC PATCH v4 01/13] iommu: Introduce dirty log tracking framework To: Lu Baolu , , , , Robin Murphy , Will Deacon , "Joerg Roedel" , Jean-Philippe Brucker , Yi Sun , Tian Kevin References: <20210507102211.8836-1-zhukeqian1@huawei.com> <20210507102211.8836-2-zhukeqian1@huawei.com> <18ac787a-179e-71f7-728b-c43feda80a16@huawei.com> <55fda826-9ab6-a3a0-b17e-a4d4879f00bc@linux.intel.com> <60182a35-e151-7150-3708-4e58dd8e78da@huawei.com> <36cc7267-6aa3-db54-b08c-c2dfc0bbacb6@linux.intel.com> <7fb678c7-509b-dbb5-d533-32c5ce2a0476@linux.intel.com> From: Keqian Zhu Message-ID: <81d0731d-3331-a5f4-1867-5cc1f3f97a29@huawei.com> Date: Fri, 14 May 2021 10:30:17 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1 MIME-Version: 1.0 In-Reply-To: X-Originating-IP: [10.174.187.224] X-CFilter-Loop: Reflected Cc: jiangkunkun@huawei.com, Cornelia Huck , Kirti Wankhede , lushenming@huawei.com, Alex Williamson , wanghaibin.wang@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-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On 2021/5/13 20:02, Lu Baolu wrote: > On 5/13/21 6:58 PM, Keqian Zhu wrote: >> >> >> On 2021/5/12 19:36, Lu Baolu wrote: >>> Hi keqian, >>> >>> On 5/12/21 4:44 PM, Keqian Zhu wrote: >>>> >>>> >>>> On 2021/5/12 11:20, Lu Baolu wrote: >>>>> On 5/11/21 3:40 PM, Keqian Zhu wrote: >>>>>>> For upper layers, before starting page tracking, they check the >>>>>>> dirty_page_trackable attribution of the domain and start it only it's >>>>>>> capable. Once the page tracking is switched on the vendor iommu driver >>>>>>> (or iommu core) should block further device attach/detach operations >>>>>>> until page tracking is stopped. >>>>>> But when a domain becomes capable after detaching a device, the upper layer >>>>>> still needs to query it and enable dirty log for it... >>>>>> >>>>>> To make things coordinated, maybe the upper layer can register a notifier, >>>>>> when the domain's capability change, the upper layer do not need to query, instead >>>>>> they just need to realize a callback, and do their specific policy in the callback. >>>>>> What do you think? >>>>>> >>>>> >>>>> That might be an option. But why not checking domain's attribution every >>>>> time a new tracking period is about to start? >>>> Hi Baolu, >>>> >>>> I'll add an attribution in iommu_domain, and the vendor iommu driver will update >>>> the attribution when attach/detach devices. >>>> >>>> The attribute should be protected by a lock, so the upper layer shouldn't access >>>> the attribute directly. Then the iommu_domain_support_dirty_log() still should be >>>> retained. Does this design looks good to you? >>> >>> Yes, that's what I was thinking of. But I am not sure whether it worth >>> of a lock here. It seems not to be a valid behavior for upper layer to >>> attach or detach any device while doing the dirty page tracking. >> Hi Baolu, >> >> Right, if the "detach|attach" interfaces and "dirty tracking" interfaces can be called concurrently, >> a lock in iommu_domain_support_dirty_log() is still not enough. I will add another note for the dirty >> tracking interfaces. >> >> Do you have other suggestions? I will accelerate the progress, so I plan to send out v5 next week. > > No further comments expect below nit: > > "iommu_switch_dirty_log: Perform actions to start|stop dirty log tracking" > > How about splitting it into > - iommu_start_dirty_log() > - iommu_stop_dirty_log() Yeah, actually this is my original version, and the "switch" style is suggested by Yi Sun. Anyway, I think both is OK, and the "switch" style can reduce some code. Thanks, Keqian > > Not a strong opinion anyway. > > Best regards, > baolu > . > _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu 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=-6.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,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 5625FC433B4 for ; Fri, 14 May 2021 02:32:53 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 D331861278 for ; 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Received: from szxga04-in.huawei.com ([45.249.212.190]) by bombadil.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lhNb1-00BfYz-97 for linux-arm-kernel@lists.infradead.org; Fri, 14 May 2021 02:30:37 +0000 Received: from DGGEMS404-HUB.china.huawei.com (unknown [172.30.72.59]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4FhC8g5hHQzqTlk; Fri, 14 May 2021 10:26:59 +0800 (CST) Received: from [10.174.187.224] (10.174.187.224) by DGGEMS404-HUB.china.huawei.com (10.3.19.204) with Microsoft SMTP Server id 14.3.498.0; Fri, 14 May 2021 10:30:17 +0800 Subject: Re: [RFC PATCH v4 01/13] iommu: Introduce dirty log tracking framework To: Lu Baolu , , , , Robin Murphy , Will Deacon , "Joerg Roedel" , Jean-Philippe Brucker , Yi Sun , Tian Kevin References: <20210507102211.8836-1-zhukeqian1@huawei.com> <20210507102211.8836-2-zhukeqian1@huawei.com> <18ac787a-179e-71f7-728b-c43feda80a16@huawei.com> <55fda826-9ab6-a3a0-b17e-a4d4879f00bc@linux.intel.com> <60182a35-e151-7150-3708-4e58dd8e78da@huawei.com> <36cc7267-6aa3-db54-b08c-c2dfc0bbacb6@linux.intel.com> <7fb678c7-509b-dbb5-d533-32c5ce2a0476@linux.intel.com> CC: Alex Williamson , Kirti Wankhede , Cornelia Huck , Jonathan Cameron , , , , From: Keqian Zhu Message-ID: <81d0731d-3331-a5f4-1867-5cc1f3f97a29@huawei.com> Date: Fri, 14 May 2021 10:30:17 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1 MIME-Version: 1.0 In-Reply-To: X-Originating-IP: [10.174.187.224] X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210513_193035_680211_9587301F X-CRM114-Status: GOOD ( 19.97 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 2021/5/13 20:02, Lu Baolu wrote: > On 5/13/21 6:58 PM, Keqian Zhu wrote: >> >> >> On 2021/5/12 19:36, Lu Baolu wrote: >>> Hi keqian, >>> >>> On 5/12/21 4:44 PM, Keqian Zhu wrote: >>>> >>>> >>>> On 2021/5/12 11:20, Lu Baolu wrote: >>>>> On 5/11/21 3:40 PM, Keqian Zhu wrote: >>>>>>> For upper layers, before starting page tracking, they check the >>>>>>> dirty_page_trackable attribution of the domain and start it only it's >>>>>>> capable. Once the page tracking is switched on the vendor iommu driver >>>>>>> (or iommu core) should block further device attach/detach operations >>>>>>> until page tracking is stopped. >>>>>> But when a domain becomes capable after detaching a device, the upper layer >>>>>> still needs to query it and enable dirty log for it... >>>>>> >>>>>> To make things coordinated, maybe the upper layer can register a notifier, >>>>>> when the domain's capability change, the upper layer do not need to query, instead >>>>>> they just need to realize a callback, and do their specific policy in the callback. >>>>>> What do you think? >>>>>> >>>>> >>>>> That might be an option. But why not checking domain's attribution every >>>>> time a new tracking period is about to start? >>>> Hi Baolu, >>>> >>>> I'll add an attribution in iommu_domain, and the vendor iommu driver will update >>>> the attribution when attach/detach devices. >>>> >>>> The attribute should be protected by a lock, so the upper layer shouldn't access >>>> the attribute directly. Then the iommu_domain_support_dirty_log() still should be >>>> retained. Does this design looks good to you? >>> >>> Yes, that's what I was thinking of. But I am not sure whether it worth >>> of a lock here. It seems not to be a valid behavior for upper layer to >>> attach or detach any device while doing the dirty page tracking. >> Hi Baolu, >> >> Right, if the "detach|attach" interfaces and "dirty tracking" interfaces can be called concurrently, >> a lock in iommu_domain_support_dirty_log() is still not enough. I will add another note for the dirty >> tracking interfaces. >> >> Do you have other suggestions? I will accelerate the progress, so I plan to send out v5 next week. > > No further comments expect below nit: > > "iommu_switch_dirty_log: Perform actions to start|stop dirty log tracking" > > How about splitting it into > - iommu_start_dirty_log() > - iommu_stop_dirty_log() Yeah, actually this is my original version, and the "switch" style is suggested by Yi Sun. Anyway, I think both is OK, and the "switch" style can reduce some code. Thanks, Keqian > > Not a strong opinion anyway. > > Best regards, > baolu > . > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel