From patchwork Tue Mar 8 05:44:17 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baolu Lu X-Patchwork-Id: 12772970 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id ACA35C433EF for ; Tue, 8 Mar 2022 05:47:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343634AbiCHFsI (ORCPT ); Tue, 8 Mar 2022 00:48:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40716 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344379AbiCHFry (ORCPT ); Tue, 8 Mar 2022 00:47:54 -0500 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F0DAA3BF85; Mon, 7 Mar 2022 21:46:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1646718416; x=1678254416; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=s2OGRk37vK5B8xKKJOadOBeC3qtF2o4zOEbrM1lxbyk=; b=cEAJok+NllTNjGN/EJ5sXwiLRGGzEAuXx40Wt3RaHj1UnUoO8+txYKjT sdOw6KxxG5xAOb8uSRew11wPAfhuCEjTyIvbxbXGF/MTVGBKGmWAgcUTX HpzCoXfORHe59HTaS72c6Vzc+jwCAueQowRmtDuR4qZe7XxG7BgLsf5V0 MTTwgNBfxcbMiiTU9vdYvWCGbRNLGlKd7q/yXIh6aLbUNb91z5vsFJGS8 XLaxTUhBOi6fcUFy8fRh2FDiz7Cr0CYETkr3RCbtca1E/tNhw2ZENJFEa 28prp29mh+T1+OAbI6YHN3TOYX9iabq9MVkGNC9mVoKz9q/PhFSC98vn7 w==; X-IronPort-AV: E=McAfee;i="6200,9189,10279"; a="235207575" X-IronPort-AV: E=Sophos;i="5.90,163,1643702400"; d="scan'208";a="235207575" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Mar 2022 21:46:55 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.90,163,1643702400"; d="scan'208";a="537430242" Received: from allen-box.sh.intel.com ([10.239.159.48]) by orsmga007.jf.intel.com with ESMTP; 07 Mar 2022 21:46:48 -0800 From: Lu Baolu To: Greg Kroah-Hartman , Joerg Roedel , Alex Williamson , Bjorn Helgaas , Jason Gunthorpe , Christoph Hellwig , Kevin Tian , Ashok Raj Cc: Will Deacon , Robin Murphy , Dan Williams , rafael@kernel.org, Diana Craciun , Cornelia Huck , Eric Auger , Liu Yi L , Jacob jun Pan , Chaitanya Kulkarni , Stuart Yoder , Laurentiu Tudor , Thierry Reding , David Airlie , Daniel Vetter , Jonathan Hunter , Li Yang , Dmitry Osipenko , iommu@lists.linux-foundation.org, linux-pci@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Lu Baolu Subject: [PATCH v8 07/11] vfio: Set DMA ownership for VFIO devices Date: Tue, 8 Mar 2022 13:44:17 +0800 Message-Id: <20220308054421.847385-8-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220308054421.847385-1-baolu.lu@linux.intel.com> References: <20220308054421.847385-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Claim group dma ownership when an IOMMU group is set to a container, and release the dma ownership once the iommu group is unset from the container. This change disallows some unsafe bridge drivers to bind to non-ACS bridges while devices under them are assigned to user space. This is an intentional enhancement and possibly breaks some existing configurations. The recommendation to such an affected user would be that the previously allowed host bridge driver was unsafe for this use case and to continue to enable assignment of devices within that group, the driver should be unbound from the bridge device or replaced with the pci-stub driver. For any bridge driver, we consider it unsafe if it satisfies any of the following conditions: 1) The bridge driver uses DMA. Calling pci_set_master() or calling any kernel DMA API (dma_map_*() and etc.) is an indicate that the driver is doing DMA. 2) If the bridge driver uses MMIO, it should be tolerant to hostile userspace also touching the same MMIO registers via P2P DMA attacks. If the bridge driver turns out to be a safe one, it could be used as before by setting the driver's .driver_managed_dma field, just like what we have done in the pcieport driver. Signed-off-by: Lu Baolu Reviewed-by: Jason Gunthorpe Acked-by: Alex Williamson --- drivers/vfio/fsl-mc/vfio_fsl_mc.c | 1 + drivers/vfio/pci/vfio_pci.c | 1 + drivers/vfio/platform/vfio_amba.c | 1 + drivers/vfio/platform/vfio_platform.c | 1 + drivers/vfio/vfio.c | 10 +++++++++- 5 files changed, 13 insertions(+), 1 deletion(-) diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc.c b/drivers/vfio/fsl-mc/vfio_fsl_mc.c index 6e2e62c6f47a..3feff729f3ce 100644 --- a/drivers/vfio/fsl-mc/vfio_fsl_mc.c +++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c @@ -588,6 +588,7 @@ static struct fsl_mc_driver vfio_fsl_mc_driver = { .name = "vfio-fsl-mc", .owner = THIS_MODULE, }, + .driver_managed_dma = true, }; static int __init vfio_fsl_mc_driver_init(void) diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index a5ce92beb655..941909d3918b 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -193,6 +193,7 @@ static struct pci_driver vfio_pci_driver = { .remove = vfio_pci_remove, .sriov_configure = vfio_pci_sriov_configure, .err_handler = &vfio_pci_core_err_handlers, + .driver_managed_dma = true, }; static void __init vfio_pci_fill_ids(void) diff --git a/drivers/vfio/platform/vfio_amba.c b/drivers/vfio/platform/vfio_amba.c index badfffea14fb..1aaa4f721bd2 100644 --- a/drivers/vfio/platform/vfio_amba.c +++ b/drivers/vfio/platform/vfio_amba.c @@ -95,6 +95,7 @@ static struct amba_driver vfio_amba_driver = { .name = "vfio-amba", .owner = THIS_MODULE, }, + .driver_managed_dma = true, }; module_amba_driver(vfio_amba_driver); diff --git a/drivers/vfio/platform/vfio_platform.c b/drivers/vfio/platform/vfio_platform.c index 68a1c87066d7..04f40c5acfd6 100644 --- a/drivers/vfio/platform/vfio_platform.c +++ b/drivers/vfio/platform/vfio_platform.c @@ -76,6 +76,7 @@ static struct platform_driver vfio_platform_driver = { .driver = { .name = "vfio-platform", }, + .driver_managed_dma = true, }; module_platform_driver(vfio_platform_driver); diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index 735d1d344af9..df9d4b60e5ae 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -1198,6 +1198,8 @@ static void __vfio_group_unset_container(struct vfio_group *group) driver->ops->detach_group(container->iommu_data, group->iommu_group); + iommu_group_release_dma_owner(group->iommu_group); + group->container = NULL; wake_up(&group->container_q); list_del(&group->container_next); @@ -1282,13 +1284,19 @@ static int vfio_group_set_container(struct vfio_group *group, int container_fd) goto unlock_out; } + ret = iommu_group_claim_dma_owner(group->iommu_group, f.file); + if (ret) + goto unlock_out; + driver = container->iommu_driver; if (driver) { ret = driver->ops->attach_group(container->iommu_data, group->iommu_group, group->type); - if (ret) + if (ret) { + iommu_group_release_dma_owner(group->iommu_group); goto unlock_out; + } } group->container = container;