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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 34BBAC282E3 for ; Sun, 26 May 2019 16:12:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 16E1F2085A for ; Sun, 26 May 2019 16:12:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728200AbfEZQMA (ORCPT ); Sun, 26 May 2019 12:12:00 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40308 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727950AbfEZQL7 (ORCPT ); Sun, 26 May 2019 12:11:59 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 6D6C33082AED; Sun, 26 May 2019 16:11:59 +0000 (UTC) Received: from laptop.redhat.com (ovpn-116-67.ams2.redhat.com [10.36.116.67]) by smtp.corp.redhat.com (Postfix) with ESMTP id 309244FA39; Sun, 26 May 2019 16:11:51 +0000 (UTC) From: Eric Auger To: eric.auger.pro@gmail.com, eric.auger@redhat.com, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, joro@8bytes.org, alex.williamson@redhat.com, jacob.jun.pan@linux.intel.com, yi.l.liu@intel.com, jean-philippe.brucker@arm.com, will.deacon@arm.com, robin.murphy@arm.com Cc: kevin.tian@intel.com, ashok.raj@intel.com, marc.zyngier@arm.com, peter.maydell@linaro.org, vincent.stehle@arm.com Subject: [PATCH v8 18/29] iommu/smmuv3: Nested mode single MSI doorbell per domain enforcement Date: Sun, 26 May 2019 18:09:53 +0200 Message-Id: <20190526161004.25232-19-eric.auger@redhat.com> In-Reply-To: <20190526161004.25232-1-eric.auger@redhat.com> References: <20190526161004.25232-1-eric.auger@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.45]); Sun, 26 May 2019 16:11:59 +0000 (UTC) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org In nested mode we enforce the rule that all devices belonging to the same iommu_domain share the same msi_domain. Indeed if there were several physical MSI doorbells being used within a single iommu_domain, it becomes really difficult to resolve the nested stage mapping translating into the correct physical doorbell. So let's forbid this situation. Signed-off-by: Eric Auger --- drivers/iommu/arm-smmu-v3.c | 41 +++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index b4813f23f302..31d8028bb997 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -2048,6 +2048,37 @@ static void arm_smmu_detach_dev(struct arm_smmu_master *master) arm_smmu_disable_ats(master); } +static bool arm_smmu_share_msi_domain(struct iommu_domain *domain, + struct device *dev) +{ + struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain); + struct irq_domain *irqd = dev_get_msi_domain(dev); + struct arm_smmu_master *master; + unsigned long flags; + bool share = false; + + if (!irqd) + return true; + + spin_lock_irqsave(&smmu_domain->devices_lock, flags); + list_for_each_entry(master, &smmu_domain->devices, domain_head) { + struct irq_domain *d = dev_get_msi_domain(master->dev); + + if (!d) + continue; + if (irqd != d) { + dev_info(dev, "Nested mode forbids to attach devices " + "using different physical MSI doorbells " + "to the same iommu_domain"); + goto unlock; + } + } + share = true; +unlock: + spin_unlock_irqrestore(&smmu_domain->devices_lock, flags); + return share; +} + static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev) { int ret = 0; @@ -2082,6 +2113,16 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev) ret = -ENXIO; goto out_unlock; } + /* + * In nested mode we must check all devices belonging to the + * domain share the same physical MSI doorbell. Otherwise nested + * stage MSI binding is not supported. + */ + if (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED && + !arm_smmu_share_msi_domain(domain, dev)) { + ret = -EINVAL; + goto out_unlock; + } master->domain = smmu_domain; -- 2.20.1