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 Received: from smtp3.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B0035C433EF for ; Sun, 28 Nov 2021 02:52:09 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id 6ED1A607DF; Sun, 28 Nov 2021 02:52:09 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id TJ3BdqlVeUdR; Sun, 28 Nov 2021 02:52:08 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp3.osuosl.org (Postfix) with ESMTPS id 50112607D2; Sun, 28 Nov 2021 02:52:08 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 26E51C001C; Sun, 28 Nov 2021 02:52:08 +0000 (UTC) Received: from smtp4.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id A112AC000A for ; Sun, 28 Nov 2021 02:52:07 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id 82E8440572 for ; Sun, 28 Nov 2021 02:52:07 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id qddr3P7CeAxw for ; Sun, 28 Nov 2021 02:52:07 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by smtp4.osuosl.org (Postfix) with ESMTPS id DED7F40562 for ; Sun, 28 Nov 2021 02:52:06 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10181"; a="236040263" X-IronPort-AV: E=Sophos;i="5.87,270,1631602800"; d="scan'208";a="236040263" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Nov 2021 18:52:06 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.87,270,1631602800"; d="scan'208";a="652489062" Received: from allen-box.sh.intel.com ([10.239.159.118]) by fmsmga001.fm.intel.com with ESMTP; 27 Nov 2021 18:51:59 -0800 From: Lu Baolu To: Greg Kroah-Hartman , Joerg Roedel , Alex Williamson , Bjorn Helgaas , Jason Gunthorpe , Christoph Hellwig , Kevin Tian , Ashok Raj Subject: [PATCH v2 09/17] iommu: Add security context management for assigned devices Date: Sun, 28 Nov 2021 10:50:43 +0800 Message-Id: <20211128025051.355578-10-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211128025051.355578-1-baolu.lu@linux.intel.com> References: <20211128025051.355578-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Cc: kvm@vger.kernel.org, rafael@kernel.org, David Airlie , linux-pci@vger.kernel.org, Thierry Reding , Diana Craciun , Will Deacon , Stuart Yoder , Jonathan Hunter , Chaitanya Kulkarni , Dan Williams , Cornelia Huck , linux-kernel@vger.kernel.org, Li Yang , iommu@lists.linux-foundation.org, Jacob jun Pan , Daniel Vetter , Robin Murphy 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" When an iommu group has DMA_OWNER_PRIVATE_DOMAIN_USER set for the first time, it is a contract that the group could be assigned to userspace from now on. The group must be detached from the default iommu domain and all devices in this group are blocked from doing DMA until it is attached to a user controlled iommu_domain. Correspondingly, the default domain should be reattached after the last DMA_OWNER_USER is released. Signed-off-by: Lu Baolu --- drivers/iommu/iommu.c | 42 +++++++++++++++++++++++++++++++++++++++--- 1 file changed, 39 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 1de520a07518..0cba04a8ea3b 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -292,7 +292,12 @@ int iommu_probe_device(struct device *dev) mutex_lock(&group->mutex); iommu_alloc_default_domain(group, dev); - if (group->default_domain) { + /* + * If any device in the group has been initialized for user dma, + * avoid attaching the default domain. + */ + if (group->default_domain && + group->dma_owner != DMA_OWNER_PRIVATE_DOMAIN_USER) { ret = __iommu_attach_device(group->default_domain, dev); if (ret) { mutex_unlock(&group->mutex); @@ -2324,7 +2329,7 @@ static int __iommu_attach_group(struct iommu_domain *domain, { int ret; - if (group->default_domain && group->domain != group->default_domain) + if (group->domain && group->domain != group->default_domain) return -EBUSY; ret = __iommu_group_for_each_dev(group, domain, @@ -2361,7 +2366,12 @@ static void __iommu_detach_group(struct iommu_domain *domain, { int ret; - if (!group->default_domain) { + /* + * If any device in the group has been initialized for user dma, + * avoid re-attaching the default domain. + */ + if (!group->default_domain || + group->dma_owner == DMA_OWNER_PRIVATE_DOMAIN_USER) { __iommu_group_for_each_dev(group, domain, iommu_group_do_detach_device); group->domain = NULL; @@ -3371,6 +3381,23 @@ static int __iommu_group_set_dma_owner(struct iommu_group *group, } group->dma_owner = owner; + + /* + * We must ensure that any device DMAs issued after this call + * are discarded. DMAs can only reach real memory once someone + * has attached a real domain. + */ + if (owner == DMA_OWNER_PRIVATE_DOMAIN_USER) { + if (group->domain) { + if (group->domain != group->default_domain) { + group->dma_owner = DMA_OWNER_NONE; + return -EBUSY; + } + + __iommu_detach_group(group->domain, group); + } + } + group->owner_cookie = owner_cookie; refcount_set(&group->owner_cnt, 1); @@ -3387,6 +3414,15 @@ static void __iommu_group_release_dma_owner(struct iommu_group *group, return; group->dma_owner = DMA_OWNER_NONE; + + /* + * The UNMANAGED domain should be detached before all USER + * owners have been released. + */ + if (owner == DMA_OWNER_PRIVATE_DOMAIN_USER) { + if (!WARN_ON(group->domain) && group->default_domain) + __iommu_attach_group(group->default_domain, group); + } } /** -- 2.25.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu