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=-11.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,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 E0428C433E2 for ; Mon, 31 Aug 2020 01:21:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C77BD2076D for ; Mon, 31 Aug 2020 01:21:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727051AbgHaBVq (ORCPT ); Sun, 30 Aug 2020 21:21:46 -0400 Received: from mga02.intel.com ([134.134.136.20]:18375 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727021AbgHaBVl (ORCPT ); Sun, 30 Aug 2020 21:21:41 -0400 IronPort-SDR: /gjYJnUWtj7VAIUwFNQDDiewG7VRfx9bMJqEJUMOoRSvUI2d8tUy52tfxc8j9RD5H4B17ZPHAg zj6uaVBu45yw== X-IronPort-AV: E=McAfee;i="6000,8403,9729"; a="144639119" X-IronPort-AV: E=Sophos;i="5.76,373,1592895600"; d="scan'208";a="144639119" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Aug 2020 18:21:41 -0700 IronPort-SDR: qjEmzA0Hzk/Z7aJAVcRPHrQ+lVeFSGOwvrJe/040UfCFmiT+3vNbiK3/3n2WxVtP2xhLZ9QTWS WO2OalPcCPSA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.76,373,1592895600"; d="scan'208";a="324742092" Received: from allen-box.sh.intel.com (HELO [10.239.159.139]) ([10.239.159.139]) by fmsmga004.fm.intel.com with ESMTP; 30 Aug 2020 18:21:38 -0700 Cc: baolu.lu@linux.intel.com, "iommu@lists.linux-foundation.org" , "linux-kernel@vger.kernel.org" , Jacob Pan , "Raj, Ashok" , Jean-Philippe Brucker Subject: Re: [PATCH 1/1] iommu/vt-d: Use device numa domain if RHSA is missing To: "Tian, Kevin" , Joerg Roedel References: <20200827055640.31408-1-baolu.lu@linux.intel.com> From: Lu Baolu Message-ID: <757c4e10-519a-6736-8f22-7ae7308434b4@linux.intel.com> Date: Mon, 31 Aug 2020 09:16:03 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Kevin, Thanks a lot for looking at my patch. On 8/28/20 10:13 AM, Tian, Kevin wrote: >> From: Lu Baolu >> Sent: Thursday, August 27, 2020 1:57 PM >> >> If there are multiple NUMA domains but the RHSA is missing in ACPI/DMAR >> table, we could default to the device NUMA domain as fall back. This also >> benefits the vIOMMU use case where only a single vIOMMU is exposed, >> hence >> no RHSA will be present but device numa domain can be correct. > > this benefits vIOMMU but not necessarily only applied to single-vIOMMU > case. The logic still holds in multiple vIOMMU cases as long as RHSA is > not provided. Yes. Will refine the description. > >> >> Cc: Jacob Pan >> Cc: Kevin Tian >> Cc: Ashok Raj >> Signed-off-by: Lu Baolu >> --- >> drivers/iommu/intel/iommu.c | 31 +++++++++++++++++++++++++++++-- >> 1 file changed, 29 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c >> index e0516d64d7a3..bce158468abf 100644 >> --- a/drivers/iommu/intel/iommu.c >> +++ b/drivers/iommu/intel/iommu.c >> @@ -700,12 +700,41 @@ static int >> domain_update_iommu_superpage(struct dmar_domain *domain, >> return fls(mask); >> } >> >> +static int domain_update_device_node(struct dmar_domain *domain) >> +{ >> + struct device_domain_info *info; >> + int nid = NUMA_NO_NODE; >> + >> + assert_spin_locked(&device_domain_lock); >> + >> + if (list_empty(&domain->devices)) >> + return NUMA_NO_NODE; >> + >> + list_for_each_entry(info, &domain->devices, link) { >> + if (!info->dev) >> + continue; >> + >> + nid = dev_to_node(info->dev); >> + if (nid != NUMA_NO_NODE) >> + break; >> + } > > There could be multiple device numa nodes as devices within the > same domain may sit behind different IOMMUs. Of course there > is no perfect answer in such situation, and this patch is still an > obvious improvement on current always-on-node0 policy. But > some comment about such implication is welcomed. I will add some comments here. Without more knowledge, currently we choose to use the first hit. > >> + >> + return nid; >> +} >> + >> /* Some capabilities may be different across iommus */ >> static void domain_update_iommu_cap(struct dmar_domain *domain) >> { >> domain_update_iommu_coherency(domain); >> domain->iommu_snooping = >> domain_update_iommu_snooping(NULL); >> domain->iommu_superpage = >> domain_update_iommu_superpage(domain, NULL); >> + >> + /* >> + * If RHSA is missing, we should default to the device numa domain >> + * as fall back. >> + */ >> + if (domain->nid == NUMA_NO_NODE) >> + domain->nid = domain_update_device_node(domain); >> } >> >> struct context_entry *iommu_context_addr(struct intel_iommu *iommu, u8 >> bus, >> @@ -5086,8 +5115,6 @@ static struct iommu_domain >> *intel_iommu_domain_alloc(unsigned type) >> if (type == IOMMU_DOMAIN_DMA) >> intel_init_iova_domain(dmar_domain); >> >> - domain_update_iommu_cap(dmar_domain); >> - > > Is it intended or by mistake? If the former, looks it is a separate fix... It's a cleanup. When a domain is newly created, this function is actually a no-op. > >> domain = &dmar_domain->domain; >> domain->geometry.aperture_start = 0; >> domain->geometry.aperture_end = >> -- >> 2.17.1 > Best regards, baolu