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=-10.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 E1269C433DF for ; Tue, 30 Jun 2020 21:01:13 +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 BB1EF20772 for ; Tue, 30 Jun 2020 21:01:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BB1EF20772 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 92F6F8848A; Tue, 30 Jun 2020 21:01:13 +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 IQ6j8K5+BMmV; Tue, 30 Jun 2020 21:01:11 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by hemlock.osuosl.org (Postfix) with ESMTP id C11D7883DC; Tue, 30 Jun 2020 21:01:11 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id BBE2AC08A7; Tue, 30 Jun 2020 21:01:11 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) by lists.linuxfoundation.org (Postfix) with ESMTP id 3FF8FC016E for ; Tue, 30 Jun 2020 21:01:10 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by silver.osuosl.org (Postfix) with ESMTP id 1F8F820407 for ; Tue, 30 Jun 2020 21:01:10 +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 FPtxMmIcXKTC for ; Tue, 30 Jun 2020 21:01:07 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by silver.osuosl.org (Postfix) with ESMTPS id 45F5722B6D for ; Tue, 30 Jun 2020 21:01:07 +0000 (UTC) IronPort-SDR: XY4k6gQ4nqqRNrjS/tHkz1UpHl+u+pd0XUsmiwn/0LdkY8eUtwmloM9fhRPrcH+qUcj+Ve1HM5 lw1kcYB21f/g== X-IronPort-AV: E=McAfee;i="6000,8403,9668"; a="146382049" X-IronPort-AV: E=Sophos;i="5.75,298,1589266800"; d="scan'208";a="146382049" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Jun 2020 14:01:05 -0700 IronPort-SDR: /wmag5B4Ql9P15sI9srtqyRDa0eh7ubLTsJmfUYXd82SUf6Tho+/plx1WvmKmMlYKGjq3oA2u7 sxgXik/19Wag== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,298,1589266800"; d="scan'208";a="425337243" Received: from jacob-builder.jf.intel.com ([10.7.199.155]) by orsmga004.jf.intel.com with ESMTP; 30 Jun 2020 14:01:05 -0700 From: Jacob Pan To: iommu@lists.linux-foundation.org, LKML , "Lu Baolu" , Joerg Roedel , David Woodhouse Subject: [PATCH v2 7/7] iommu/vt-d: Disable multiple GPASID-dev bind Date: Tue, 30 Jun 2020 14:07:38 -0700 Message-Id: <1593551258-39854-8-git-send-email-jacob.jun.pan@linux.intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1593551258-39854-1-git-send-email-jacob.jun.pan@linux.intel.com> References: <1593551258-39854-1-git-send-email-jacob.jun.pan@linux.intel.com> Cc: "Tian, Kevin" , Raj Ashok 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: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" For the unlikely use case where multiple aux domains from the same pdev are attached to a single guest and then bound to a single process (thus same PASID) within that guest, we cannot easily support this case by refcounting the number of users. As there is only one SL page table per PASID while we have multiple aux domains thus multiple SL page tables for the same PASID. Extra unbinding guest PASID can happen due to race between normal and exception cases. Termination of one aux domain may affect others unless we actively track and switch aux domains to ensure the validity of SL page tables and TLB states in the shared PASID entry. Support for sharing second level PGDs across domains can reduce the complexity but this is not available due to the limitations on VFIO container architecture. We can revisit this decision once sharing PGDs are available. Overall, the complexity and potential glitch do not warrant this unlikely use case thereby removed by this patch. Fixes: 56722a4398a30 ("iommu/vt-d: Add bind guest PASID support") Acked-by: Lu Baolu Cc: Kevin Tian Cc: Lu Baolu Signed-off-by: Liu Yi L Signed-off-by: Jacob Pan --- drivers/iommu/intel/svm.c | 22 +++++++++------------- 1 file changed, 9 insertions(+), 13 deletions(-) diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c index 6c87c807a0ab..d386853121a2 100644 --- a/drivers/iommu/intel/svm.c +++ b/drivers/iommu/intel/svm.c @@ -277,20 +277,16 @@ int intel_svm_bind_gpasid(struct iommu_domain *domain, struct device *dev, goto out; } + /* + * Do not allow multiple bindings of the same device-PASID since + * there is only one SL page tables per PASID. We may revisit + * once sharing PGD across domains are supported. + */ for_each_svm_dev(sdev, svm, dev) { - /* - * For devices with aux domains, we should allow - * multiple bind calls with the same PASID and pdev. - */ - if (iommu_dev_feature_enabled(dev, - IOMMU_DEV_FEAT_AUX)) { - sdev->users++; - } else { - dev_warn_ratelimited(dev, - "Already bound with PASID %u\n", - svm->pasid); - ret = -EBUSY; - } + dev_warn_ratelimited(dev, + "Already bound with PASID %u\n", + svm->pasid); + ret = -EBUSY; goto out; } } else { -- 2.7.4 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu