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=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 4CD13C433E3 for ; Wed, 1 Jul 2020 15:27:29 +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 3275520899 for ; Wed, 1 Jul 2020 15:27:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3275520899 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 D533F8AA62; Wed, 1 Jul 2020 15:27:28 +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 WgGmVKiPLAG0; Wed, 1 Jul 2020 15:27:28 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by hemlock.osuosl.org (Postfix) with ESMTP id 4C4838AA17; Wed, 1 Jul 2020 15:27:28 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 46A14C08A5; Wed, 1 Jul 2020 15:27:28 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) by lists.linuxfoundation.org (Postfix) with ESMTP id B5A68C08A2 for ; Wed, 1 Jul 2020 15:27:25 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by silver.osuosl.org (Postfix) with ESMTP id 8421C2E95A for ; Wed, 1 Jul 2020 15:27:25 +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 nz8DtR5lvObM for ; Wed, 1 Jul 2020 15:27:24 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by silver.osuosl.org (Postfix) with ESMTPS id 1A76D267F7 for ; Wed, 1 Jul 2020 15:27:24 +0000 (UTC) IronPort-SDR: 4ySoHomYhkFDXWIC8LTQrMWgd/YL1M7qMRyOA93gaQaPyhWgh7HmB1iRHNEP4/NrMUgwsI2yqb 1lSKuDXcmh2g== X-IronPort-AV: E=McAfee;i="6000,8403,9668"; a="126699726" X-IronPort-AV: E=Sophos;i="5.75,300,1589266800"; d="scan'208";a="126699726" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Jul 2020 08:27:23 -0700 IronPort-SDR: o3kPELFdh3tJaTgju06GQE4B3xyVAEGLqog6K3SnGHeZ0Qz4vdr0fO1PKiAf9yDUcu4NYJJNHY d5+1AbHcsYKQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,300,1589266800"; d="scan'208";a="295591658" Received: from jacob-builder.jf.intel.com ([10.7.199.155]) by orsmga002.jf.intel.com with ESMTP; 01 Jul 2020 08:27:22 -0700 From: Jacob Pan To: iommu@lists.linux-foundation.org, LKML , "Lu Baolu" , Joerg Roedel , David Woodhouse Subject: [PATCH v3 7/7] iommu/vt-d: Disable multiple GPASID-dev bind Date: Wed, 1 Jul 2020 08:33:56 -0700 Message-Id: <1593617636-79385-8-git-send-email-jacob.jun.pan@linux.intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1593617636-79385-1-git-send-email-jacob.jun.pan@linux.intel.com> References: <1593617636-79385-1-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