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_2 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 E2A52C4332D for ; Fri, 20 Mar 2020 16:15:11 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (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 B420820724 for ; Fri, 20 Mar 2020 16:15:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B420820724 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 hemlock.osuosl.org (Postfix) with ESMTP id 9C14F88B83; Fri, 20 Mar 2020 16:15:11 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id qqBRwZ9rMPGQ; Fri, 20 Mar 2020 16:15:09 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by hemlock.osuosl.org (Postfix) with ESMTP id 0794688AEE; Fri, 20 Mar 2020 16:15:09 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id E0428C1D88; Fri, 20 Mar 2020 16:15:08 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) by lists.linuxfoundation.org (Postfix) with ESMTP id 9EA2CC1830 for ; Fri, 20 Mar 2020 16:15:07 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by silver.osuosl.org (Postfix) with ESMTP id 9B267204FF for ; Fri, 20 Mar 2020 16:15:07 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from silver.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id upLjC1sQtucx for ; Fri, 20 Mar 2020 16:15:06 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by silver.osuosl.org (Postfix) with ESMTPS id C03BB22622 for ; Fri, 20 Mar 2020 16:15:06 +0000 (UTC) IronPort-SDR: VcoJzZw19FG1pMtmDB4lt9I0qwZA5l9FDGXMjaXQsItCALXmYeT4EMglNbPN0O+q8rU8iMrsE9 crLUU78hx08w== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Mar 2020 09:15:06 -0700 IronPort-SDR: nfbF9FQqKHkQ9x3+7AJIAWSbRldf4humNn2N1DChKht7YMxC+rThaYhyh30bvSaeO6vZ5Pi7Qi tg2lPKnv9Zew== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,285,1580803200"; d="scan'208";a="418762631" Received: from jacob-builder.jf.intel.com (HELO jacob-builder) ([10.7.199.155]) by orsmga005.jf.intel.com with ESMTP; 20 Mar 2020 09:15:06 -0700 Date: Fri, 20 Mar 2020 09:20:47 -0700 From: Jacob Pan To: Lu Baolu Subject: Re: [PATCH 1/3] iommu/vt-d: Remove redundant IOTLB flush Message-ID: <20200320092047.4a4cf551@jacob-builder> In-Reply-To: <26ab1917-f087-aafa-e861-6a2478000a6f@linux.intel.com> References: <1584678751-43169-1-git-send-email-jacob.jun.pan@linux.intel.com> <1584678751-43169-2-git-send-email-jacob.jun.pan@linux.intel.com> <26ab1917-f087-aafa-e861-6a2478000a6f@linux.intel.com> Organization: OTC X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 Cc: Raj Ashok , LKML , iommu@lists.linux-foundation.org, David Woodhouse 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 Fri, 20 Mar 2020 21:45:26 +0800 Lu Baolu wrote: > On 2020/3/20 12:32, Jacob Pan wrote: > > IOTLB flush already included in the PASID tear down process. There > > is no need to flush again. > > It seems that intel_pasid_tear_down_entry() doesn't flush the pasid > based device TLB? > I saw this code in intel_pasid_tear_down_entry(). Isn't the last line flush the devtlb? Not in guest of course since the passdown tlb flush is inclusive. pasid_cache_invalidation_with_pasid(iommu, did, pasid); iotlb_invalidation_with_pasid(iommu, did, pasid); /* Device IOTLB doesn't need to be flushed in caching mode. */ if (!cap_caching_mode(iommu->cap)) devtlb_invalidation_with_pasid(iommu, dev, pasid); > Best regards, > baolu > > > > > Cc: Lu Baolu > > Signed-off-by: Jacob Pan > > --- > > drivers/iommu/intel-svm.c | 6 ++---- > > 1 file changed, 2 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c > > index 8f42d717d8d7..1483f1845762 100644 > > --- a/drivers/iommu/intel-svm.c > > +++ b/drivers/iommu/intel-svm.c > > @@ -268,10 +268,9 @@ static void intel_mm_release(struct > > mmu_notifier *mn, struct mm_struct *mm) > > * *has* to handle gracefully without affecting other > > processes. */ > > rcu_read_lock(); > > - list_for_each_entry_rcu(sdev, &svm->devs, list) { > > + list_for_each_entry_rcu(sdev, &svm->devs, list) > > intel_pasid_tear_down_entry(svm->iommu, > > sdev->dev, svm->pasid); > > - intel_flush_svm_range_dev(svm, sdev, 0, -1, 0); > > - } > > + > > rcu_read_unlock(); > > > > } > > @@ -731,7 +730,6 @@ int intel_svm_unbind_mm(struct device *dev, int > > pasid) > > * large and has to be physically > > contiguous. So it's > > * hard to be as defensive as we might > > like. */ intel_pasid_tear_down_entry(iommu, dev, svm->pasid); > > - intel_flush_svm_range_dev(svm, sdev, 0, > > -1, 0); kfree_rcu(sdev, rcu); > > > > if (list_empty(&svm->devs)) { > > [Jacob Pan] _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu