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=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 054E1C4332D for ; Fri, 20 Mar 2020 16:15:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D038720724 for ; Fri, 20 Mar 2020 16:15:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727427AbgCTQPG (ORCPT ); Fri, 20 Mar 2020 12:15:06 -0400 Received: from mga05.intel.com ([192.55.52.43]:34161 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727002AbgCTQPG (ORCPT ); Fri, 20 Mar 2020 12:15:06 -0400 IronPort-SDR: cPJ6GWQUD0izaYg5cvKqraM/ysunOin4y7tqr8rjuwcLuZS+4K9qJ5asAo+krxjKq8ztIQgfhg 6mi7r/tkyb5g== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga105.fm.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 Cc: LKML , iommu@lists.linux-foundation.org, Joerg Roedel , David Woodhouse , Raj Ashok , Yi Liu , jacob.jun.pan@linux.intel.com 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 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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]