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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham 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 83ACDC34022 for ; Wed, 19 Feb 2020 03:15:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6343F24655 for ; Wed, 19 Feb 2020 03:15:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728297AbgBSDPm (ORCPT ); Tue, 18 Feb 2020 22:15:42 -0500 Received: from mga11.intel.com ([192.55.52.93]:7614 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728203AbgBSDPl (ORCPT ); Tue, 18 Feb 2020 22:15:41 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 18 Feb 2020 19:15:41 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,459,1574150400"; d="scan'208";a="253956967" Received: from blu2-mobl3.ccr.corp.intel.com (HELO [10.254.213.252]) ([10.254.213.252]) by orsmga002.jf.intel.com with ESMTP; 18 Feb 2020 19:15:38 -0800 Subject: Re: [PATCH] iommu/vt-d: Fix a bug in intel_iommu_iova_to_phys() for huge page To: Yonghyun Hwang , David Woodhouse , Joerg Roedel Cc: iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Havard Skinnemoen , Deepa Dinamani , Moritz Fischer References: <20200218222324.231915-1-yonghyun@google.com> From: Lu Baolu Message-ID: <8efc6ea2-d51e-624c-5cc2-4049bb224122@linux.intel.com> Date: Wed, 19 Feb 2020 11:15:36 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <20200218222324.231915-1-yonghyun@google.com> 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 Yonghyun, Thanks for the patch. On 2020/2/19 6:23, Yonghyun Hwang wrote: > intel_iommu_iova_to_phys() has a bug when it translates an IOVA for a huge > page onto its corresponding physical address. This commit fixes the bug by > accomodating the level of page entry for the IOVA and adds IOVA's lower > address to the physical address. > > Signed-off-by: Yonghyun Hwang > --- > drivers/iommu/intel-iommu.c | 11 +++++++++-- > 1 file changed, 9 insertions(+), 2 deletions(-) > > diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c > index 0c8d81f56a30..ed6e69adb578 100644 > --- a/drivers/iommu/intel-iommu.c > +++ b/drivers/iommu/intel-iommu.c > @@ -5555,13 +5555,20 @@ static phys_addr_t intel_iommu_iova_to_phys(struct iommu_domain *domain, > struct dma_pte *pte; > int level = 0; > u64 phys = 0; > + const unsigned long pfn = iova >> VTD_PAGE_SHIFT; Why do you need a "const unsigned long" here? > > if (dmar_domain->flags & DOMAIN_FLAG_LOSE_CHILDREN) > return 0; > > - pte = pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT, &level); > - if (pte) > + pte = pfn_to_dma_pte(dmar_domain, pfn, &level); > + if (pte) { > phys = dma_pte_addr(pte); > + if (level > 1) > + phys += (pfn & > + ((1UL << level_to_offset_bits(level)) - 1)) > + << VTD_PAGE_SHIFT; > + phys += iova & (VTD_PAGE_SIZE - 1); How about diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 9dc37672bf89..bd17c2510bb2 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -5693,8 +5693,14 @@ static phys_addr_t intel_iommu_iova_to_phys(struct iommu_domain *domain, u64 phys = 0; pte = pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT, &level); - if (pte) + if (pte) { + unsigned long offset_mask; + + offset_mask = BIT_MASK(level_to_offset_bits(level) + + VTD_PAGE_SHIFT) - 1; phys = dma_pte_addr(pte); + phys += iova & (bitmask - 1); + } return phys; } Best regards, baolu