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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 DE52BC433ED for ; Thu, 15 Apr 2021 07:13:40 +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 1A0B461103 for ; Thu, 15 Apr 2021 07:13:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1A0B461103 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 smtp4.osuosl.org (Postfix) with ESMTP id BAD2A40F62; Thu, 15 Apr 2021 07:13:39 +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 byFW3U1kDAGo; Thu, 15 Apr 2021 07:13:38 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [IPv6:2605:bc80:3010:104::8cd3:938]) by smtp4.osuosl.org (Postfix) with ESMTP id 23B0C40E9C; Thu, 15 Apr 2021 07:13:38 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 061FFC000C; Thu, 15 Apr 2021 07:13:38 +0000 (UTC) Received: from smtp4.osuosl.org (smtp4.osuosl.org [IPv6:2605:bc80:3010::137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 17DC2C000A for ; Thu, 15 Apr 2021 07:13:36 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id 040E240F62 for ; Thu, 15 Apr 2021 07:13:36 +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 jdWgUHp7S4RU for ; Thu, 15 Apr 2021 07:13:34 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by smtp4.osuosl.org (Postfix) with ESMTPS id A495C40E9C for ; Thu, 15 Apr 2021 07:13:34 +0000 (UTC) IronPort-SDR: Wr2G9hSPdYaFd3FFBT2kqbUI5iUXfAmU2ss//7SqIUvimFEjsU9yYrbecfESRaKQdi6HssU831 EYlDchBOvEJg== X-IronPort-AV: E=McAfee;i="6200,9189,9954"; a="174299038" X-IronPort-AV: E=Sophos;i="5.82,223,1613462400"; d="scan'208";a="174299038" Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Apr 2021 00:13:33 -0700 IronPort-SDR: N7a/losEaCAlfPsp0RkiF5M5/3RUguWGDB4OlvAUxaL1WE0aXMlAc18uuES1cel2X0mOe1zXJ4 U37IARQwIqgw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.82,223,1613462400"; d="scan'208";a="444089450" Received: from allen-box.sh.intel.com (HELO [10.239.159.128]) ([10.239.159.128]) by fmsmga004.fm.intel.com with ESMTP; 15 Apr 2021 00:13:29 -0700 Subject: Re: [PATCH v3 01/12] iommu: Introduce dirty log tracking framework To: Keqian Zhu , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, iommu@lists.linux-foundation.org, Robin Murphy , Will Deacon , Joerg Roedel , Yi Sun , Jean-Philippe Brucker , Jonathan Cameron , Tian Kevin References: <20210413085457.25400-1-zhukeqian1@huawei.com> <20210413085457.25400-2-zhukeqian1@huawei.com> From: Lu Baolu Message-ID: <56b001fa-b4fe-c595-dc5e-f362d2f07a19@linux.intel.com> Date: Thu, 15 Apr 2021 15:03:52 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.1 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US 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-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On 4/15/21 2:18 PM, Keqian Zhu wrote: > Hi Baolu, > > Thanks for the review! > > On 2021/4/14 15:00, Lu Baolu wrote: >> Hi Keqian, >> >> On 4/13/21 4:54 PM, Keqian Zhu wrote: >>> Some types of IOMMU are capable of tracking DMA dirty log, such as >>> ARM SMMU with HTTU or Intel IOMMU with SLADE. This introduces the >>> dirty log tracking framework in the IOMMU base layer. >>> >>> Three new essential interfaces are added, and we maintaince the status >>> of dirty log tracking in iommu_domain. >>> 1. iommu_switch_dirty_log: Perform actions to start|stop dirty log tracking >>> 2. iommu_sync_dirty_log: Sync dirty log from IOMMU into a dirty bitmap >>> 3. iommu_clear_dirty_log: Clear dirty log of IOMMU by a mask bitmap >>> >>> A new dev feature are added to indicate whether a specific type of >>> iommu hardware supports and its driver realizes them. >>> >>> Signed-off-by: Keqian Zhu >>> Signed-off-by: Kunkun Jiang >>> --- >>> drivers/iommu/iommu.c | 150 ++++++++++++++++++++++++++++++++++++++++++ >>> include/linux/iommu.h | 53 +++++++++++++++ >>> 2 files changed, 203 insertions(+) >>> >>> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c >>> index d0b0a15dba84..667b2d6d2fc0 100644 >>> --- a/drivers/iommu/iommu.c >>> +++ b/drivers/iommu/iommu.c >>> @@ -1922,6 +1922,7 @@ static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus, >>> domain->type = type; >>> /* Assume all sizes by default; the driver may override this later */ >>> domain->pgsize_bitmap = bus->iommu_ops->pgsize_bitmap; >>> + mutex_init(&domain->switch_log_lock); >>> return domain; >>> } >>> @@ -2720,6 +2721,155 @@ int iommu_domain_set_attr(struct iommu_domain *domain, >>> } >>> EXPORT_SYMBOL_GPL(iommu_domain_set_attr); >>> +int iommu_switch_dirty_log(struct iommu_domain *domain, bool enable, >>> + unsigned long iova, size_t size, int prot) >>> +{ >>> + const struct iommu_ops *ops = domain->ops; >>> + int ret; >>> + >>> + if (unlikely(!ops || !ops->switch_dirty_log)) >>> + return -ENODEV; >>> + >>> + mutex_lock(&domain->switch_log_lock); >>> + if (enable && domain->dirty_log_tracking) { >>> + ret = -EBUSY; >>> + goto out; >>> + } else if (!enable && !domain->dirty_log_tracking) { >>> + ret = -EINVAL; >>> + goto out; >>> + } >>> + >>> + ret = ops->switch_dirty_log(domain, enable, iova, size, prot); >>> + if (ret) >>> + goto out; >>> + >>> + domain->dirty_log_tracking = enable; >>> +out: >>> + mutex_unlock(&domain->switch_log_lock); >>> + return ret; >>> +} >>> +EXPORT_SYMBOL_GPL(iommu_switch_dirty_log); >> >> Since you also added IOMMU_DEV_FEAT_HWDBM, I am wondering what's the >> difference between >> >> iommu_switch_dirty_log(on) vs. iommu_dev_enable_feature(IOMMU_DEV_FEAT_HWDBM) >> >> iommu_switch_dirty_log(off) vs. iommu_dev_disable_feature(IOMMU_DEV_FEAT_HWDBM) > Indeed. As I can see, IOMMU_DEV_FEAT_AUX is not switchable, so enable/disable > are not applicable for it. IOMMU_DEV_FEAT_SVA is switchable, so we can use these > interfaces for it. > > IOMMU_DEV_FEAT_HWDBM is used to indicate whether hardware supports HWDBM, so we should Previously we had iommu_dev_has_feature() and then was cleaned up due to lack of real users. If you have a real case for it, why not bringing it back? > design it as not switchable. I will modify the commit message of patch#12, thanks! I am not sure that I fully get your point. But I can't see any gaps of using iommu_dev_enable/disable_feature() to switch dirty log on and off. Probably I missed anything. > >> >>> + >>> +int iommu_sync_dirty_log(struct iommu_domain *domain, unsigned long iova, >>> + size_t size, unsigned long *bitmap, >>> + unsigned long base_iova, unsigned long bitmap_pgshift) >>> +{ >>> + const struct iommu_ops *ops = domain->ops; >>> + unsigned int min_pagesz; >>> + size_t pgsize; >>> + int ret = 0; >>> + >>> + if (unlikely(!ops || !ops->sync_dirty_log)) >>> + return -ENODEV; >>> + >>> + min_pagesz = 1 << __ffs(domain->pgsize_bitmap); >>> + if (!IS_ALIGNED(iova | size, min_pagesz)) { >>> + pr_err("unaligned: iova 0x%lx size 0x%zx min_pagesz 0x%x\n", >>> + iova, size, min_pagesz); >>> + return -EINVAL; >>> + } >>> + >>> + mutex_lock(&domain->switch_log_lock); >>> + if (!domain->dirty_log_tracking) { >>> + ret = -EINVAL; >>> + goto out; >>> + } >>> + >>> + while (size) { >>> + pgsize = iommu_pgsize(domain, iova, size); >>> + >>> + ret = ops->sync_dirty_log(domain, iova, pgsize, >>> + bitmap, base_iova, bitmap_pgshift); >> >> Any reason why do you want to do this in a per-4K page manner? This can >> lead to a lot of indirect calls and bad performance. >> >> How about a sync_dirty_pages()? > The function name of iommu_pgsize() is a bit puzzling. Actually it will try to > compute the max size that fit into size, so the pgsize can be a large page size > even if the underlying mapping is 4K. The __iommu_unmap() also has a similar logic. This series has some improvement on the iommu_pgsize() helper. https://lore.kernel.org/linux-iommu/20210405191112.28192-1-isaacm@codeaurora.org/ Best regards, baolu _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu