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=-9.7 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 A8105C433EA for ; Tue, 7 Jul 2020 00:06:28 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (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 857A32065D for ; Tue, 7 Jul 2020 00:06:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 857A32065D 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 fraxinus.osuosl.org (Postfix) with ESMTP id 0DD9D87231; Tue, 7 Jul 2020 00:06:28 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id mo74Rp3a6KIs; Tue, 7 Jul 2020 00:06:27 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by fraxinus.osuosl.org (Postfix) with ESMTP id 48B8087A3B; Tue, 7 Jul 2020 00:06:27 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 33B11C0891; Tue, 7 Jul 2020 00:06:27 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 83B47C016F for ; Tue, 7 Jul 2020 00:06:24 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 72AF1879D7 for ; Tue, 7 Jul 2020 00:06:24 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id NeJujaH0uiYD for ; Tue, 7 Jul 2020 00:06:23 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by fraxinus.osuosl.org (Postfix) with ESMTPS id 2555D87231 for ; Tue, 7 Jul 2020 00:06:22 +0000 (UTC) IronPort-SDR: RBdiz882DfwuHWolXx4usHmfSOAWKgIEaa3iF0UxfoWC1k/6VRNJ6oG3+PXyMGJawfIuBv4bex cIwMkFS1ufdQ== X-IronPort-AV: E=McAfee;i="6000,8403,9674"; a="232379354" X-IronPort-AV: E=Sophos;i="5.75,321,1589266800"; d="scan'208";a="232379354" 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; 06 Jul 2020 17:06:19 -0700 IronPort-SDR: zIKUYel984wcBdO+TLjmSOReSJwSakFRRGa9gt4eyUT3zw+W/tvb3jMJlmnjGzGml0C6FqTgnX xPgt4TuSi+Fw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,321,1589266800"; d="scan'208";a="456913831" Received: from jacob-builder.jf.intel.com ([10.7.199.155]) by orsmga005.jf.intel.com with ESMTP; 06 Jul 2020 17:06:17 -0700 From: Jacob Pan To: iommu@lists.linux-foundation.org, LKML , "Lu Baolu" , Joerg Roedel , David Woodhouse Subject: [PATCH v4 7/7] iommu/vt-d: Disable multiple GPASID-dev bind Date: Mon, 6 Jul 2020 17:12:54 -0700 Message-Id: <1594080774-33413-8-git-send-email-jacob.jun.pan@linux.intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1594080774-33413-1-git-send-email-jacob.jun.pan@linux.intel.com> References: <1594080774-33413-1-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 Reviewed-by: Eric Auger 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