From patchwork Mon Nov 15 02:05:42 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baolu Lu X-Patchwork-Id: 12618537 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A306DC433F5 for ; Mon, 15 Nov 2021 02:12:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8630860555 for ; Mon, 15 Nov 2021 02:12:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236416AbhKOCOC (ORCPT ); Sun, 14 Nov 2021 21:14:02 -0500 Received: from mga09.intel.com ([134.134.136.24]:44502 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236292AbhKOCNj (ORCPT ); Sun, 14 Nov 2021 21:13:39 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10168"; a="233204636" X-IronPort-AV: E=Sophos;i="5.87,235,1631602800"; d="scan'208,223";a="233204636" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Nov 2021 18:10:31 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.87,235,1631602800"; d="scan'208,223";a="505714533" Received: from allen-box.sh.intel.com ([10.239.159.118]) by orsmga008.jf.intel.com with ESMTP; 14 Nov 2021 18:10:26 -0800 From: Lu Baolu To: Greg Kroah-Hartman , Joerg Roedel , Alex Williamson , Bjorn Helgaas , Jason Gunthorpe , Kevin Tian , Ashok Raj Cc: Will Deacon , rafael@kernel.org, Diana Craciun , Cornelia Huck , Eric Auger , Liu Yi L , Jacob jun Pan , Chaitanya Kulkarni , iommu@lists.linux-foundation.org, linux-pci@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Lu Baolu Subject: [PATCH 01/11] iommu: Add device dma ownership set/release interfaces Date: Mon, 15 Nov 2021 10:05:42 +0800 Message-Id: <20211115020552.2378167-2-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211115020552.2378167-1-baolu.lu@linux.intel.com> References: <20211115020552.2378167-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From the perspective of who is initiating the device to do DMA, device DMA could be divided into the following types: DMA_OWNER_KERNEL: kernel device driver intiates the DMA DMA_OWNER_USER: userspace device driver intiates the DMA DMA_OWNER_KERNEL and DMA_OWNER_USER are exclusive for all devices in same iommu group as an iommu group is the smallest granularity of device isolation and protection that the IOMMU subsystem can guarantee. This extends the iommu core to enforce this exclusion when devices are assigned to userspace. Basically two new interfaces are provided: int iommu_device_set_dma_owner(struct device *dev, enum iommu_dma_owner mode, struct file *user_file); void iommu_device_release_dma_owner(struct device *dev, enum iommu_dma_owner mode); Although above interfaces are per-device, DMA owner is tracked per group under the hood. An iommu group cannot have both DMA_OWNER_KERNEL and DMA_OWNER_USER set at the same time. Violation of this assumption fails iommu_device_set_dma_owner(). Kernel driver which does DMA have DMA_OWNER_KENREL automatically set/released in the driver binding process (see next patch). Kernel driver which doesn't do DMA should not set the owner type (via a new suppress flag in next patch). Device bound to such driver is considered same as a driver-less device which is compatible to all owner types. Userspace driver framework (e.g. vfio) should set DMA_OWNER_USER for a device before the userspace is allowed to access it, plus a fd pointer to mark the user identity so a single group cannot be operated by multiple users simultaneously. Vice versa, the owner type should be released after the user access permission is withdrawn. Signed-off-by: Jason Gunthorpe Signed-off-by: Kevin Tian Signed-off-by: Lu Baolu --- include/linux/iommu.h | 31 ++++++++++++ drivers/iommu/iommu.c | 106 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 137 insertions(+) diff --git a/include/linux/iommu.h b/include/linux/iommu.h index d2f3435e7d17..f77eb9e7788a 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -162,6 +162,18 @@ enum iommu_dev_features { IOMMU_DEV_FEAT_IOPF, }; +/** + * enum iommu_dma_owner - IOMMU DMA ownership + * @DMA_OWNER_NONE: No DMA ownership + * @DMA_OWNER_KERNEL: Device DMAs are initiated by a kernel driver + * @DMA_OWNER_USER: Device DMAs are initiated by a userspace driver + */ +enum iommu_dma_owner { + DMA_OWNER_NONE, + DMA_OWNER_KERNEL, + DMA_OWNER_USER, +}; + #define IOMMU_PASID_INVALID (-1U) #ifdef CONFIG_IOMMU_API @@ -681,6 +693,10 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev, void iommu_sva_unbind_device(struct iommu_sva *handle); u32 iommu_sva_get_pasid(struct iommu_sva *handle); +int iommu_device_set_dma_owner(struct device *dev, enum iommu_dma_owner owner, + struct file *user_file); +void iommu_device_release_dma_owner(struct device *dev, enum iommu_dma_owner owner); + #else /* CONFIG_IOMMU_API */ struct iommu_ops {}; @@ -1081,6 +1097,21 @@ static inline struct iommu_fwspec *dev_iommu_fwspec_get(struct device *dev) { return NULL; } + +static inline int iommu_device_set_dma_owner(struct device *dev, + enum iommu_dma_owner owner, + struct file *user_file) +{ + if (owner != DMA_OWNER_KERNEL) + return -EINVAL; + + return 0; +} + +static inline void iommu_device_release_dma_owner(struct device *dev, + enum iommu_dma_owner owner) +{ +} #endif /* CONFIG_IOMMU_API */ /** diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 8b86406b7162..39493b1b3edf 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -26,6 +26,7 @@ #include #include #include +#include #include static struct kset *iommu_group_kset; @@ -48,6 +49,9 @@ struct iommu_group { struct iommu_domain *default_domain; struct iommu_domain *domain; struct list_head entry; + enum iommu_dma_owner dma_owner; + refcount_t owner_cnt; + struct file *owner_user_file; }; struct group_device { @@ -621,6 +625,7 @@ struct iommu_group *iommu_group_alloc(void) INIT_LIST_HEAD(&group->devices); INIT_LIST_HEAD(&group->entry); BLOCKING_INIT_NOTIFIER_HEAD(&group->notifier); + group->dma_owner = DMA_OWNER_NONE; ret = ida_simple_get(&iommu_group_ida, 0, 0, GFP_KERNEL); if (ret < 0) { @@ -3351,3 +3356,104 @@ static ssize_t iommu_group_store_type(struct iommu_group *group, return ret; } + +static int __iommu_group_set_dma_owner(struct iommu_group *group, + enum iommu_dma_owner owner, + struct file *user_file) +{ + if (group->dma_owner != DMA_OWNER_NONE && group->dma_owner != owner) + return -EBUSY; + + if (owner == DMA_OWNER_USER) { + if (!user_file) + return -EINVAL; + + if (group->owner_user_file && group->owner_user_file != user_file) + return -EPERM; + } + + if (!refcount_inc_not_zero(&group->owner_cnt)) { + group->dma_owner = owner; + refcount_set(&group->owner_cnt, 1); + + if (owner == DMA_OWNER_USER) { + get_file(user_file); + group->owner_user_file = user_file; + } + } + + return 0; +} + +static void __iommu_group_release_dma_owner(struct iommu_group *group, + enum iommu_dma_owner owner) +{ + if (WARN_ON(group->dma_owner != owner)) + return; + + if (refcount_dec_and_test(&group->owner_cnt)) { + group->dma_owner = DMA_OWNER_NONE; + + if (owner == DMA_OWNER_USER) { + fput(group->owner_user_file); + group->owner_user_file = NULL; + } + } +} + +/** + * iommu_device_set_dma_owner() - Set DMA ownership of a device + * @dev: The device. + * @owner: DMA_OWNER_KERNEL or DMA_OWNER_USER. + * @user_file: The device fd when DMA_OWNER_USER is about to set. + * + * Set the DMA ownership of a device. The KERNEL and USER ownership are + * exclusive. For DMA_OWNER_USER, the caller should also specify the fd + * through which the I/O address spaces are managed for the target device. + * This interface guarantees that the USER DMA ownership is only assigned + * to the same fd. + */ +int iommu_device_set_dma_owner(struct device *dev, enum iommu_dma_owner owner, + struct file *user_file) +{ + struct iommu_group *group = iommu_group_get(dev); + int ret; + + if (!group) { + if (owner == DMA_OWNER_KERNEL) + return 0; + else + return -ENODEV; + } + + mutex_lock(&group->mutex); + ret = __iommu_group_set_dma_owner(group, owner, user_file); + mutex_unlock(&group->mutex); + iommu_group_put(group); + + return ret; +} +EXPORT_SYMBOL_GPL(iommu_device_set_dma_owner); + +/** + * iommu_device_release_dma_owner() - Release DMA ownership of a device + * @dev: The device. + * @owner: DMA_OWNER_KERNEL or DMA_OWNER_USER. + * + * Release the DMA ownership claimed by iommu_device_set_dma_owner(). + */ +void iommu_device_release_dma_owner(struct device *dev, enum iommu_dma_owner owner) +{ + struct iommu_group *group = iommu_group_get(dev); + + if (!group) { + WARN_ON(owner != DMA_OWNER_KERNEL); + return; + } + + mutex_lock(&group->mutex); + __iommu_group_release_dma_owner(group, owner); + mutex_unlock(&group->mutex); + iommu_group_put(group); +} +EXPORT_SYMBOL_GPL(iommu_device_release_dma_owner); From patchwork Mon Nov 15 02:05:43 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baolu Lu X-Patchwork-Id: 12618533 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8E96DC433FE for ; Mon, 15 Nov 2021 02:10:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7BB1360F46 for ; Mon, 15 Nov 2021 02:10:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236271AbhKOCNm (ORCPT ); Sun, 14 Nov 2021 21:13:42 -0500 Received: from mga06.intel.com ([134.134.136.31]:51230 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236259AbhKOCNf (ORCPT ); Sun, 14 Nov 2021 21:13:35 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10168"; a="294186331" X-IronPort-AV: E=Sophos;i="5.87,235,1631602800"; d="scan'208";a="294186331" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Nov 2021 18:10:36 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.87,235,1631602800"; d="scan'208";a="505714551" Received: from allen-box.sh.intel.com ([10.239.159.118]) by orsmga008.jf.intel.com with ESMTP; 14 Nov 2021 18:10:31 -0800 From: Lu Baolu To: Greg Kroah-Hartman , Joerg Roedel , Alex Williamson , Bjorn Helgaas , Jason Gunthorpe , Kevin Tian , Ashok Raj Cc: Will Deacon , rafael@kernel.org, Diana Craciun , Cornelia Huck , Eric Auger , Liu Yi L , Jacob jun Pan , Chaitanya Kulkarni , iommu@lists.linux-foundation.org, linux-pci@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Lu Baolu Subject: [PATCH 02/11] driver core: Set DMA ownership during driver bind/unbind Date: Mon, 15 Nov 2021 10:05:43 +0800 Message-Id: <20211115020552.2378167-3-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211115020552.2378167-1-baolu.lu@linux.intel.com> References: <20211115020552.2378167-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org This extends really_probe() to allow checking for dma ownership conflict during the driver binding process. By default, the DMA_OWNER_KERNEL is claimed for the bound driver before calling its .probe() callback. If this operation fails (e.g. the iommu group of the target device already has the DMA_OWNER_USER set), the binding process is aborted to avoid breaking the security contract for devices in the iommu group. Without this change, the vfio driver has to listen to a bus BOUND_DRIVER event and then BUG_ON() in case of dma ownership conflict. This leads to bad user experience since careless driver binding operation may crash the system if the admin overlooks the group restriction. Aside from bad design, this leads to a security problem as a root user, even with lockdown=integrity, can force the kernel to BUG. Driver may set a new flag (suppress_auto_claim_dma_owner) to disable auto claim in the binding process. Examples include kernel drivers (pci_stub, PCI bridge drivers, etc.) which don't trigger DMA at all thus can be safely exempted in DMA ownership check and userspace framework drivers (vfio/vdpa etc.) which need to manually claim DMA_OWNER_USER when assigning a device to userspace. Suggested-by: Jason Gunthorpe Link: https://lore.kernel.org/linux-iommu/20210922123931.GI327412@nvidia.com/ Link: https://lore.kernel.org/linux-iommu/20210928115751.GK964074@nvidia.com/ Signed-off-by: Lu Baolu --- include/linux/device/driver.h | 7 ++++++- drivers/base/dd.c | 12 ++++++++++++ 2 files changed, 18 insertions(+), 1 deletion(-) diff --git a/include/linux/device/driver.h b/include/linux/device/driver.h index a498ebcf4993..25d39c64c4d9 100644 --- a/include/linux/device/driver.h +++ b/include/linux/device/driver.h @@ -54,6 +54,10 @@ enum probe_type { * @owner: The module owner. * @mod_name: Used for built-in modules. * @suppress_bind_attrs: Disables bind/unbind via sysfs. + * @suppress_auto_claim_dma_owner: Disable auto claiming of kernel DMA owner. + * Drivers which don't require DMA or want to manually claim the + * owner type (e.g. userspace driver frameworks) could set this + * flag. * @probe_type: Type of the probe (synchronous or asynchronous) to use. * @of_match_table: The open firmware table. * @acpi_match_table: The ACPI match table. @@ -99,7 +103,8 @@ struct device_driver { struct module *owner; const char *mod_name; /* used for built-in modules */ - bool suppress_bind_attrs; /* disables bind/unbind via sysfs */ + bool suppress_bind_attrs:1; /* disables bind/unbind via sysfs */ + bool suppress_auto_claim_dma_owner:1; enum probe_type probe_type; const struct of_device_id *of_match_table; diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 68ea1f949daa..ab3333351f19 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -28,6 +28,7 @@ #include #include #include +#include #include "base.h" #include "power/power.h" @@ -566,6 +567,12 @@ static int really_probe(struct device *dev, struct device_driver *drv) goto done; } + if (!drv->suppress_auto_claim_dma_owner) { + ret = iommu_device_set_dma_owner(dev, DMA_OWNER_KERNEL, NULL); + if (ret) + return ret; + } + re_probe: dev->driver = drv; @@ -673,6 +680,8 @@ static int really_probe(struct device *dev, struct device_driver *drv) dev->pm_domain->dismiss(dev); pm_runtime_reinit(dev); dev_pm_set_driver_flags(dev, 0); + if (!drv->suppress_auto_claim_dma_owner) + iommu_device_release_dma_owner(dev, DMA_OWNER_KERNEL); done: return ret; } @@ -1215,6 +1224,9 @@ static void __device_release_driver(struct device *dev, struct device *parent) pm_runtime_reinit(dev); dev_pm_set_driver_flags(dev, 0); + if (!drv->suppress_auto_claim_dma_owner) + iommu_device_release_dma_owner(dev, DMA_OWNER_KERNEL); + klist_remove(&dev->p->knode_driver); device_pm_check_callbacks(dev); if (dev->bus) From patchwork Mon Nov 15 02:05:44 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baolu Lu X-Patchwork-Id: 12618535 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 15D23C4332F for ; Mon, 15 Nov 2021 02:11:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F3FCB61156 for ; Mon, 15 Nov 2021 02:11:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236264AbhKOCNp (ORCPT ); Sun, 14 Nov 2021 21:13:45 -0500 Received: from mga04.intel.com ([192.55.52.120]:50553 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236208AbhKOCNi (ORCPT ); Sun, 14 Nov 2021 21:13:38 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10168"; a="232086636" X-IronPort-AV: E=Sophos;i="5.87,235,1631602800"; d="scan'208";a="232086636" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Nov 2021 18:10:42 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.87,235,1631602800"; d="scan'208";a="505714566" Received: from allen-box.sh.intel.com ([10.239.159.118]) by orsmga008.jf.intel.com with ESMTP; 14 Nov 2021 18:10:37 -0800 From: Lu Baolu To: Greg Kroah-Hartman , Joerg Roedel , Alex Williamson , Bjorn Helgaas , Jason Gunthorpe , Kevin Tian , Ashok Raj Cc: Will Deacon , rafael@kernel.org, Diana Craciun , Cornelia Huck , Eric Auger , Liu Yi L , Jacob jun Pan , Chaitanya Kulkarni , iommu@lists.linux-foundation.org, linux-pci@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Lu Baolu Subject: [PATCH 03/11] PCI: pci_stub: Suppress kernel DMA ownership auto-claiming Date: Mon, 15 Nov 2021 10:05:44 +0800 Message-Id: <20211115020552.2378167-4-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211115020552.2378167-1-baolu.lu@linux.intel.com> References: <20211115020552.2378167-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org pci_stub allows the admin to block driver binding on a device and make it permanently shared with userspace. Since pci_stub does not do DMA, it is safe. However the admin must understand that using pci_stub allows userspace to attack whatever device it was bound to. Signed-off-by: Lu Baolu --- drivers/pci/pci-stub.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/pci/pci-stub.c b/drivers/pci/pci-stub.c index e408099fea52..6324c68602b4 100644 --- a/drivers/pci/pci-stub.c +++ b/drivers/pci/pci-stub.c @@ -36,6 +36,9 @@ static struct pci_driver stub_driver = { .name = "pci-stub", .id_table = NULL, /* only dynamic id's */ .probe = pci_stub_probe, + .driver = { + .suppress_auto_claim_dma_owner = true, + }, }; static int __init pci_stub_init(void) From patchwork Mon Nov 15 02:05:45 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baolu Lu X-Patchwork-Id: 12618539 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 33132C433EF for ; Mon, 15 Nov 2021 02:13:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0BDD360FD8 for ; Mon, 15 Nov 2021 02:13:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236455AbhKOCPH (ORCPT ); Sun, 14 Nov 2021 21:15:07 -0500 Received: from mga04.intel.com ([192.55.52.120]:50553 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236253AbhKOCNm (ORCPT ); Sun, 14 Nov 2021 21:13:42 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10168"; a="232086645" X-IronPort-AV: E=Sophos;i="5.87,235,1631602800"; d="scan'208";a="232086645" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Nov 2021 18:10:47 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.87,235,1631602800"; d="scan'208";a="505714581" Received: from allen-box.sh.intel.com ([10.239.159.118]) by orsmga008.jf.intel.com with ESMTP; 14 Nov 2021 18:10:42 -0800 From: Lu Baolu To: Greg Kroah-Hartman , Joerg Roedel , Alex Williamson , Bjorn Helgaas , Jason Gunthorpe , Kevin Tian , Ashok Raj Cc: Will Deacon , rafael@kernel.org, Diana Craciun , Cornelia Huck , Eric Auger , Liu Yi L , Jacob jun Pan , Chaitanya Kulkarni , iommu@lists.linux-foundation.org, linux-pci@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Lu Baolu Subject: [PATCH 04/11] PCI: portdrv: Suppress kernel DMA ownership auto-claiming Date: Mon, 15 Nov 2021 10:05:45 +0800 Message-Id: <20211115020552.2378167-5-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211115020552.2378167-1-baolu.lu@linux.intel.com> References: <20211115020552.2378167-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org IOMMU grouping on PCI necessitates that if we lack isolation on a bridge then all of the downstream devices will be part of the same IOMMU group as the bridge. As long as the bridge kernel driver doesn't map and access any PCI mmio bar, it's safe to bind it to the device in a USER- owned group. Hence, safe to suppress the kernel DMA ownership auto- claiming. The commit 5f096b14d421b ("vfio: Whitelist PCI bridges") permitted a class of kernel drivers. This is not always safe. For example, the SHPC system design requires that it must be integrated into a PCI-to-PCI bridge or a host bridge. The shpchp_core driver relies on the PCI mmio bar access for the controller functionality. Binding it to the device belonging to a USER-owned group will allow the user to change the controller via p2p transactions which is unknown to the hot-plug driver and could lead to some unpredictable consequences. Now that we have driver self-declaration of safety we should rely on that. This change may cause regression on some platforms, since all bridges were exempted before, but now they have to be manually audited before doing so. This is actually the desired outcome anyway. Suggested-by: Jason Gunthorpe Suggested-by: Kevin Tian Signed-off-by: Lu Baolu --- drivers/pci/pcie/portdrv_pci.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c index 35eca6277a96..1285862a9aa8 100644 --- a/drivers/pci/pcie/portdrv_pci.c +++ b/drivers/pci/pcie/portdrv_pci.c @@ -203,6 +203,8 @@ static struct pci_driver pcie_portdriver = { .err_handler = &pcie_portdrv_err_handler, .driver.pm = PCIE_PORTDRV_PM_OPS, + + .driver.suppress_auto_claim_dma_owner = true, }; static int __init dmi_pcie_pme_disable_msi(const struct dmi_system_id *d) From patchwork Mon Nov 15 02:05:46 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baolu Lu X-Patchwork-Id: 12618563 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4F2B0C433FE for ; Mon, 15 Nov 2021 02:14:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2BDC660FD8 for ; Mon, 15 Nov 2021 02:14:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236413AbhKOCRp (ORCPT ); Sun, 14 Nov 2021 21:17:45 -0500 Received: from mga17.intel.com ([192.55.52.151]:40570 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236341AbhKOCNw (ORCPT ); Sun, 14 Nov 2021 21:13:52 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10168"; a="214088760" X-IronPort-AV: E=Sophos;i="5.87,235,1631602800"; d="scan'208";a="214088760" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Nov 2021 18:10:52 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.87,235,1631602800"; d="scan'208";a="505714599" Received: from allen-box.sh.intel.com ([10.239.159.118]) by orsmga008.jf.intel.com with ESMTP; 14 Nov 2021 18:10:47 -0800 From: Lu Baolu To: Greg Kroah-Hartman , Joerg Roedel , Alex Williamson , Bjorn Helgaas , Jason Gunthorpe , Kevin Tian , Ashok Raj Cc: Will Deacon , rafael@kernel.org, Diana Craciun , Cornelia Huck , Eric Auger , Liu Yi L , Jacob jun Pan , Chaitanya Kulkarni , iommu@lists.linux-foundation.org, linux-pci@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Lu Baolu Subject: [PATCH 05/11] iommu: Add security context management for assigned devices Date: Mon, 15 Nov 2021 10:05:46 +0800 Message-Id: <20211115020552.2378167-6-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211115020552.2378167-1-baolu.lu@linux.intel.com> References: <20211115020552.2378167-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org When an iommu group has DMA_OWNER_USER set for the first time, it is a contract that the group could be assigned to userspace from now on. It 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 I/O address space. Vice versa, the default domain should be re-attached to the group after the last DMA_OWNER_USER is released. Signed-off-by: Lu Baolu --- drivers/iommu/iommu.c | 36 +++++++++++++++++++++++++++++++++--- 1 file changed, 33 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 39493b1b3edf..916a4d448150 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -293,7 +293,11 @@ 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_USER) { ret = __iommu_attach_device(group->default_domain, dev); if (ret) { mutex_unlock(&group->mutex); @@ -2325,7 +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, @@ -2362,7 +2366,11 @@ 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_USER) { __iommu_group_for_each_dev(group, domain, iommu_group_do_detach_device); group->domain = NULL; @@ -3377,6 +3385,21 @@ static int __iommu_group_set_dma_owner(struct iommu_group *group, refcount_set(&group->owner_cnt, 1); if (owner == DMA_OWNER_USER) { + /* + * The UNMANAGED domain shouldn't be attached before + * claiming the USER ownership for the first time. + */ + if (group->domain) { + if (group->domain != group->default_domain) { + group->dma_owner = DMA_OWNER_NONE; + refcount_set(&group->owner_cnt, 0); + + return -EBUSY; + } + + __iommu_detach_group(group->domain, group); + } + get_file(user_file); group->owner_user_file = user_file; } @@ -3397,6 +3420,13 @@ static void __iommu_group_release_dma_owner(struct iommu_group *group, if (owner == DMA_OWNER_USER) { fput(group->owner_user_file); group->owner_user_file = NULL; + + /* + * The UNMANAGED domain should be detached before all USER + * owners have been released. + */ + if (!WARN_ON(group->domain) && group->default_domain) + __iommu_attach_group(group->default_domain, group); } } } From patchwork Mon Nov 15 02:05:47 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baolu Lu X-Patchwork-Id: 12618561 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B8B68C433F5 for ; Mon, 15 Nov 2021 02:14:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9D9DF611C1 for ; Mon, 15 Nov 2021 02:14:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236550AbhKOCRk (ORCPT ); Sun, 14 Nov 2021 21:17:40 -0500 Received: from mga03.intel.com ([134.134.136.65]:15446 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236378AbhKOCNw (ORCPT ); Sun, 14 Nov 2021 21:13:52 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10168"; a="233307253" X-IronPort-AV: E=Sophos;i="5.87,235,1631602800"; d="scan'208";a="233307253" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Nov 2021 18:10:57 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.87,235,1631602800"; d="scan'208";a="505714623" Received: from allen-box.sh.intel.com ([10.239.159.118]) by orsmga008.jf.intel.com with ESMTP; 14 Nov 2021 18:10:52 -0800 From: Lu Baolu To: Greg Kroah-Hartman , Joerg Roedel , Alex Williamson , Bjorn Helgaas , Jason Gunthorpe , Kevin Tian , Ashok Raj Cc: Will Deacon , rafael@kernel.org, Diana Craciun , Cornelia Huck , Eric Auger , Liu Yi L , Jacob jun Pan , Chaitanya Kulkarni , iommu@lists.linux-foundation.org, linux-pci@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Lu Baolu Subject: [PATCH 06/11] iommu: Expose group variants of dma ownership interfaces Date: Mon, 15 Nov 2021 10:05:47 +0800 Message-Id: <20211115020552.2378167-7-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211115020552.2378167-1-baolu.lu@linux.intel.com> References: <20211115020552.2378167-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org The vfio needs to set DMA_OWNER_USER for the entire group when attaching it to a vfio container. So expose group variants of setting/releasing dma ownership for this purpose. This also exposes the helper iommu_group_dma_owner_unclaimed() for vfio report to userspace if the group is viable to user assignment, for compatibility with VFIO_GROUP_FLAGS_VIABLE. Signed-off-by: Lu Baolu --- include/linux/iommu.h | 21 ++++++++++++++++ drivers/iommu/iommu.c | 57 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 78 insertions(+) diff --git a/include/linux/iommu.h b/include/linux/iommu.h index f77eb9e7788a..3d2dfd220d3c 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -696,6 +696,10 @@ u32 iommu_sva_get_pasid(struct iommu_sva *handle); int iommu_device_set_dma_owner(struct device *dev, enum iommu_dma_owner owner, struct file *user_file); void iommu_device_release_dma_owner(struct device *dev, enum iommu_dma_owner owner); +int iommu_group_set_dma_owner(struct iommu_group *group, enum iommu_dma_owner owner, + struct file *user_file); +void iommu_group_release_dma_owner(struct iommu_group *group, enum iommu_dma_owner owner); +bool iommu_group_dma_owner_unclaimed(struct iommu_group *group); #else /* CONFIG_IOMMU_API */ @@ -1112,6 +1116,23 @@ static inline void iommu_device_release_dma_owner(struct device *dev, enum iommu_dma_owner owner) { } + +static inline int iommu_group_set_dma_owner(struct iommu_group *group, + enum iommu_dma_owner owner, + struct file *user_file) +{ + return -EINVAL; +} + +static inline void iommu_group_release_dma_owner(struct iommu_group *group, + enum iommu_dma_owner owner) +{ +} + +static inline bool iommu_group_dma_owner_unclaimed(struct iommu_group *group) +{ + return false; +} #endif /* CONFIG_IOMMU_API */ /** diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 916a4d448150..3dcd3fc4290a 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -3431,6 +3431,63 @@ static void __iommu_group_release_dma_owner(struct iommu_group *group, } } +/** + * iommu_group_set_dma_owner() - Set DMA ownership of a group + * @group: The group. + * @owner: DMA_OWNER_KERNEL or DMA_OWNER_USER. + * @user_file: The device fd when set USER ownership. + * + * This is to support backward compatibility for legacy vfio which manages + * dma ownership in group level. New invocations on this interface should be + * prohibited. Instead, please turn to iommu_device_set_dma_owner(). + */ +int iommu_group_set_dma_owner(struct iommu_group *group, enum iommu_dma_owner owner, + struct file *user_file) +{ + int ret; + + mutex_lock(&group->mutex); + ret = __iommu_group_set_dma_owner(group, owner, user_file); + mutex_unlock(&group->mutex); + + return ret; +} +EXPORT_SYMBOL_GPL(iommu_group_set_dma_owner); + +/** + * iommu_group_release_dma_owner() - Release DMA ownership of a group + * @group: The group. + * @owner: DMA_OWNER_KERNEL or DMA_OWNER_USER. + * + * Release the DMA ownership claimed by iommu_group_set_dma_owner(). + */ +void iommu_group_release_dma_owner(struct iommu_group *group, enum iommu_dma_owner owner) +{ + mutex_lock(&group->mutex); + __iommu_group_release_dma_owner(group, owner); + mutex_unlock(&group->mutex); +} +EXPORT_SYMBOL_GPL(iommu_group_release_dma_owner); + +/** + * iommu_group_dma_owner_unclaimed() - Is group dma ownership claimed + * @group: The group. + * + * This provides status check on a given group. It is racey and only for + * non-binding status reporting. + */ +bool iommu_group_dma_owner_unclaimed(struct iommu_group *group) +{ + enum iommu_dma_owner owner; + + mutex_lock(&group->mutex); + owner = group->dma_owner; + mutex_unlock(&group->mutex); + + return owner == DMA_OWNER_NONE; +} +EXPORT_SYMBOL_GPL(iommu_group_dma_owner_unclaimed); + /** * iommu_device_set_dma_owner() - Set DMA ownership of a device * @dev: The device. From patchwork Mon Nov 15 02:05:48 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baolu Lu X-Patchwork-Id: 12618541 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 53CEFC433EF for ; Mon, 15 Nov 2021 02:13:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3DC5260FD8 for ; Mon, 15 Nov 2021 02:13:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236344AbhKOCQV (ORCPT ); Sun, 14 Nov 2021 21:16:21 -0500 Received: from mga05.intel.com ([192.55.52.43]:53953 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236329AbhKOCOR (ORCPT ); Sun, 14 Nov 2021 21:14:17 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10168"; a="319573952" X-IronPort-AV: E=Sophos;i="5.87,235,1631602800"; d="scan'208";a="319573952" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Nov 2021 18:11:03 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.87,235,1631602800"; d="scan'208";a="505714658" Received: from allen-box.sh.intel.com ([10.239.159.118]) by orsmga008.jf.intel.com with ESMTP; 14 Nov 2021 18:10:58 -0800 From: Lu Baolu To: Greg Kroah-Hartman , Joerg Roedel , Alex Williamson , Bjorn Helgaas , Jason Gunthorpe , Kevin Tian , Ashok Raj Cc: Will Deacon , rafael@kernel.org, Diana Craciun , Cornelia Huck , Eric Auger , Liu Yi L , Jacob jun Pan , Chaitanya Kulkarni , iommu@lists.linux-foundation.org, linux-pci@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Lu Baolu Subject: [PATCH 07/11] vfio: Use DMA_OWNER_USER to declaim passthrough devices Date: Mon, 15 Nov 2021 10:05:48 +0800 Message-Id: <20211115020552.2378167-8-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211115020552.2378167-1-baolu.lu@linux.intel.com> References: <20211115020552.2378167-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Set DMA_OWNER_USER when an iommu group is set to a container, and release DMA_OWNER_USER once the iommu group is unset from a container. Signed-off-by: Lu Baolu --- drivers/vfio/fsl-mc/vfio_fsl_mc.c | 1 + drivers/vfio/pci/vfio_pci.c | 3 +++ drivers/vfio/platform/vfio_amba.c | 1 + drivers/vfio/platform/vfio_platform.c | 1 + drivers/vfio/vfio.c | 12 +++++++++++- 5 files changed, 17 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..b749d092a185 100644 --- a/drivers/vfio/fsl-mc/vfio_fsl_mc.c +++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c @@ -587,6 +587,7 @@ static struct fsl_mc_driver vfio_fsl_mc_driver = { .driver = { .name = "vfio-fsl-mc", .owner = THIS_MODULE, + .suppress_auto_claim_dma_owner = true, }, }; diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index a5ce92beb655..8961bfaf0eb5 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -193,6 +193,9 @@ 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 = { + .suppress_auto_claim_dma_owner = 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..2146ee52901a 100644 --- a/drivers/vfio/platform/vfio_amba.c +++ b/drivers/vfio/platform/vfio_amba.c @@ -94,6 +94,7 @@ static struct amba_driver vfio_amba_driver = { .drv = { .name = "vfio-amba", .owner = THIS_MODULE, + .suppress_auto_claim_dma_owner = true, }, }; diff --git a/drivers/vfio/platform/vfio_platform.c b/drivers/vfio/platform/vfio_platform.c index 68a1c87066d7..5ef06e668192 100644 --- a/drivers/vfio/platform/vfio_platform.c +++ b/drivers/vfio/platform/vfio_platform.c @@ -75,6 +75,7 @@ static struct platform_driver vfio_platform_driver = { .remove = vfio_platform_remove, .driver = { .name = "vfio-platform", + .suppress_auto_claim_dma_owner = true, }, }; diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index 82fb75464f92..4e21b37e0ea8 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, DMA_OWNER_USER); + group->container = NULL; wake_up(&group->container_q); list_del(&group->container_next); @@ -1282,13 +1284,21 @@ static int vfio_group_set_container(struct vfio_group *group, int container_fd) goto unlock_out; } + ret = iommu_group_set_dma_owner(group->iommu_group, + DMA_OWNER_USER, 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, + DMA_OWNER_USER); goto unlock_out; + } } group->container = container; From patchwork Mon Nov 15 02:05:49 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baolu Lu X-Patchwork-Id: 12618557 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 00A6FC433F5 for ; Mon, 15 Nov 2021 02:13:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D882B610A6 for ; Mon, 15 Nov 2021 02:13:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236429AbhKOCQ2 (ORCPT ); Sun, 14 Nov 2021 21:16:28 -0500 Received: from mga05.intel.com ([192.55.52.43]:53956 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236317AbhKOCOR (ORCPT ); Sun, 14 Nov 2021 21:14:17 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10168"; a="319573956" X-IronPort-AV: E=Sophos;i="5.87,235,1631602800"; d="scan'208";a="319573956" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Nov 2021 18:11:08 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.87,235,1631602800"; d="scan'208";a="505714687" Received: from allen-box.sh.intel.com ([10.239.159.118]) by orsmga008.jf.intel.com with ESMTP; 14 Nov 2021 18:11:03 -0800 From: Lu Baolu To: Greg Kroah-Hartman , Joerg Roedel , Alex Williamson , Bjorn Helgaas , Jason Gunthorpe , Kevin Tian , Ashok Raj Cc: Will Deacon , rafael@kernel.org, Diana Craciun , Cornelia Huck , Eric Auger , Liu Yi L , Jacob jun Pan , Chaitanya Kulkarni , iommu@lists.linux-foundation.org, linux-pci@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Lu Baolu Subject: [PATCH 08/11] vfio: Remove use of vfio_group_viable() Date: Mon, 15 Nov 2021 10:05:49 +0800 Message-Id: <20211115020552.2378167-9-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211115020552.2378167-1-baolu.lu@linux.intel.com> References: <20211115020552.2378167-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org As DMA_OWNER_USER is claimed for the iommu group when a vfio group is added to a vfio container, the vfio group viability is guaranteed as long as group->container_users > 0. Remove those unnecessary group viability checks which are only hit when group->container_users is not zero. The only remaining reference is in GROUP_GET_STATUS, which could be called at any time when group fd is valid. Here we just replace the vfio_group_viable() by directly calling iommu core to get viability status. Signed-off-by: Lu Baolu --- drivers/vfio/vfio.c | 18 ++++++------------ 1 file changed, 6 insertions(+), 12 deletions(-) diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index 4e21b37e0ea8..6847117fac6a 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -1315,12 +1315,6 @@ static int vfio_group_set_container(struct vfio_group *group, int container_fd) return ret; } -static bool vfio_group_viable(struct vfio_group *group) -{ - return (iommu_group_for_each_dev(group->iommu_group, - group, vfio_dev_viable) == 0); -} - static int vfio_group_add_container_user(struct vfio_group *group) { if (!atomic_inc_not_zero(&group->container_users)) @@ -1330,7 +1324,7 @@ static int vfio_group_add_container_user(struct vfio_group *group) atomic_dec(&group->container_users); return -EPERM; } - if (!group->container->iommu_driver || !vfio_group_viable(group)) { + if (!group->container->iommu_driver) { atomic_dec(&group->container_users); return -EINVAL; } @@ -1348,7 +1342,7 @@ static int vfio_group_get_device_fd(struct vfio_group *group, char *buf) int ret = 0; if (0 == atomic_read(&group->container_users) || - !group->container->iommu_driver || !vfio_group_viable(group)) + !group->container->iommu_driver) return -EINVAL; if (group->type == VFIO_NO_IOMMU && !capable(CAP_SYS_RAWIO)) @@ -1440,11 +1434,11 @@ static long vfio_group_fops_unl_ioctl(struct file *filep, status.flags = 0; - if (vfio_group_viable(group)) - status.flags |= VFIO_GROUP_FLAGS_VIABLE; - if (group->container) - status.flags |= VFIO_GROUP_FLAGS_CONTAINER_SET; + status.flags |= VFIO_GROUP_FLAGS_CONTAINER_SET | + VFIO_GROUP_FLAGS_VIABLE; + else if (iommu_group_dma_owner_unclaimed(group->iommu_group)) + status.flags |= VFIO_GROUP_FLAGS_VIABLE; if (copy_to_user((void __user *)arg, &status, minsz)) return -EFAULT; From patchwork Mon Nov 15 02:05:50 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baolu Lu X-Patchwork-Id: 12618567 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 49E4DC433EF for ; Mon, 15 Nov 2021 02:15:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3072860FD8 for ; Mon, 15 Nov 2021 02:15:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236493AbhKOCRw (ORCPT ); Sun, 14 Nov 2021 21:17:52 -0500 Received: from mga06.intel.com ([134.134.136.31]:51252 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236486AbhKOCPS (ORCPT ); Sun, 14 Nov 2021 21:15:18 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10168"; a="294186394" X-IronPort-AV: E=Sophos;i="5.87,235,1631602800"; d="scan'208";a="294186394" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Nov 2021 18:11:13 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.87,235,1631602800"; d="scan'208";a="505714710" Received: from allen-box.sh.intel.com ([10.239.159.118]) by orsmga008.jf.intel.com with ESMTP; 14 Nov 2021 18:11:08 -0800 From: Lu Baolu To: Greg Kroah-Hartman , Joerg Roedel , Alex Williamson , Bjorn Helgaas , Jason Gunthorpe , Kevin Tian , Ashok Raj Cc: Will Deacon , rafael@kernel.org, Diana Craciun , Cornelia Huck , Eric Auger , Liu Yi L , Jacob jun Pan , Chaitanya Kulkarni , iommu@lists.linux-foundation.org, linux-pci@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Lu Baolu Subject: [PATCH 09/11] vfio: Delete the unbound_list Date: Mon, 15 Nov 2021 10:05:50 +0800 Message-Id: <20211115020552.2378167-10-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211115020552.2378167-1-baolu.lu@linux.intel.com> References: <20211115020552.2378167-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Jason Gunthorpe commit 60720a0fc646 ("vfio: Add device tracking during unbind") added the unbound list to plug a problem with KVM where KVM_DEV_VFIO_GROUP_DEL relied on vfio_group_get_external_user() succeeding to return the vfio_group from a group file descriptor. The unbound list allowed vfio_group_get_external_user() to continue to succeed in edge cases. However commit 5d6dee80a1e9 ("vfio: New external user group/file match") deleted the call to vfio_group_get_external_user() during KVM_DEV_VFIO_GROUP_DEL. Instead vfio_external_group_match_file() is used to directly match the file descriptor to the group pointer. This in turn avoids the call down to vfio_dev_viable() during KVM_DEV_VFIO_GROUP_DEL and also avoids the trouble the first commit was trying to fix. There are no other users of vfio_dev_viable() that care about the time after vfio_unregister_group_dev() returns, so simply delete the unbound_list entirely. Reviewed-by: Chaitanya Kulkarni Signed-off-by: Jason Gunthorpe Signed-off-by: Lu Baolu --- drivers/vfio/vfio.c | 74 ++------------------------------------------- 1 file changed, 2 insertions(+), 72 deletions(-) diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index 6847117fac6a..8c317d1a0f3c 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -62,11 +62,6 @@ struct vfio_container { bool noiommu; }; -struct vfio_unbound_dev { - struct device *dev; - struct list_head unbound_next; -}; - struct vfio_group { struct device dev; struct cdev cdev; @@ -79,8 +74,6 @@ struct vfio_group { struct notifier_block nb; struct list_head vfio_next; struct list_head container_next; - struct list_head unbound_list; - struct mutex unbound_lock; atomic_t opened; wait_queue_head_t container_q; enum vfio_group_type type; @@ -340,16 +333,8 @@ vfio_group_get_from_iommu(struct iommu_group *iommu_group) static void vfio_group_release(struct device *dev) { struct vfio_group *group = container_of(dev, struct vfio_group, dev); - struct vfio_unbound_dev *unbound, *tmp; - - list_for_each_entry_safe(unbound, tmp, - &group->unbound_list, unbound_next) { - list_del(&unbound->unbound_next); - kfree(unbound); - } mutex_destroy(&group->device_lock); - mutex_destroy(&group->unbound_lock); iommu_group_put(group->iommu_group); ida_free(&vfio.group_ida, MINOR(group->dev.devt)); kfree(group); @@ -381,8 +366,6 @@ static struct vfio_group *vfio_group_alloc(struct iommu_group *iommu_group, refcount_set(&group->users, 1); INIT_LIST_HEAD(&group->device_list); mutex_init(&group->device_lock); - INIT_LIST_HEAD(&group->unbound_list); - mutex_init(&group->unbound_lock); init_waitqueue_head(&group->container_q); group->iommu_group = iommu_group; /* put in vfio_group_release() */ @@ -571,19 +554,8 @@ static int vfio_dev_viable(struct device *dev, void *data) struct vfio_group *group = data; struct vfio_device *device; struct device_driver *drv = READ_ONCE(dev->driver); - struct vfio_unbound_dev *unbound; - int ret = -EINVAL; - mutex_lock(&group->unbound_lock); - list_for_each_entry(unbound, &group->unbound_list, unbound_next) { - if (dev == unbound->dev) { - ret = 0; - break; - } - } - mutex_unlock(&group->unbound_lock); - - if (!ret || !drv || vfio_dev_driver_allowed(dev, drv)) + if (!drv || vfio_dev_driver_allowed(dev, drv)) return 0; device = vfio_group_get_device(group, dev); @@ -592,7 +564,7 @@ static int vfio_dev_viable(struct device *dev, void *data) return 0; } - return ret; + return -EINVAL; } /** @@ -634,7 +606,6 @@ static int vfio_iommu_group_notifier(struct notifier_block *nb, { struct vfio_group *group = container_of(nb, struct vfio_group, nb); struct device *dev = data; - struct vfio_unbound_dev *unbound; switch (action) { case IOMMU_GROUP_NOTIFY_ADD_DEVICE: @@ -663,28 +634,6 @@ static int vfio_iommu_group_notifier(struct notifier_block *nb, __func__, iommu_group_id(group->iommu_group), dev->driver->name); break; - case IOMMU_GROUP_NOTIFY_UNBOUND_DRIVER: - dev_dbg(dev, "%s: group %d unbound from driver\n", __func__, - iommu_group_id(group->iommu_group)); - /* - * XXX An unbound device in a live group is ok, but we'd - * really like to avoid the above BUG_ON by preventing other - * drivers from binding to it. Once that occurs, we have to - * stop the system to maintain isolation. At a minimum, we'd - * want a toggle to disable driver auto probe for this device. - */ - - mutex_lock(&group->unbound_lock); - list_for_each_entry(unbound, - &group->unbound_list, unbound_next) { - if (dev == unbound->dev) { - list_del(&unbound->unbound_next); - kfree(unbound); - break; - } - } - mutex_unlock(&group->unbound_lock); - break; } return NOTIFY_OK; } @@ -889,29 +838,10 @@ static struct vfio_device *vfio_device_get_from_name(struct vfio_group *group, void vfio_unregister_group_dev(struct vfio_device *device) { struct vfio_group *group = device->group; - struct vfio_unbound_dev *unbound; unsigned int i = 0; bool interrupted = false; long rc; - /* - * When the device is removed from the group, the group suddenly - * becomes non-viable; the device has a driver (until the unbind - * completes), but it's not present in the group. This is bad news - * for any external users that need to re-acquire a group reference - * in order to match and release their existing reference. To - * solve this, we track such devices on the unbound_list to bridge - * the gap until they're fully unbound. - */ - unbound = kzalloc(sizeof(*unbound), GFP_KERNEL); - if (unbound) { - unbound->dev = device->dev; - mutex_lock(&group->unbound_lock); - list_add(&unbound->unbound_next, &group->unbound_list); - mutex_unlock(&group->unbound_lock); - } - WARN_ON(!unbound); - vfio_device_put(device); rc = try_wait_for_completion(&device->comp); while (rc <= 0) { From patchwork Mon Nov 15 02:05:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baolu Lu X-Patchwork-Id: 12618565 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7C5DFC433F5 for ; Mon, 15 Nov 2021 02:14:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5BA186112E for ; Mon, 15 Nov 2021 02:14:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235690AbhKOCRq (ORCPT ); Sun, 14 Nov 2021 21:17:46 -0500 Received: from mga01.intel.com ([192.55.52.88]:29668 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236497AbhKOCP1 (ORCPT ); Sun, 14 Nov 2021 21:15:27 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10168"; a="257099781" X-IronPort-AV: E=Sophos;i="5.87,235,1631602800"; d="scan'208";a="257099781" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Nov 2021 18:11:19 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.87,235,1631602800"; d="scan'208";a="505714733" Received: from allen-box.sh.intel.com ([10.239.159.118]) by orsmga008.jf.intel.com with ESMTP; 14 Nov 2021 18:11:13 -0800 From: Lu Baolu To: Greg Kroah-Hartman , Joerg Roedel , Alex Williamson , Bjorn Helgaas , Jason Gunthorpe , Kevin Tian , Ashok Raj Cc: Will Deacon , rafael@kernel.org, Diana Craciun , Cornelia Huck , Eric Auger , Liu Yi L , Jacob jun Pan , Chaitanya Kulkarni , iommu@lists.linux-foundation.org, linux-pci@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Lu Baolu Subject: [PATCH 10/11] vfio: Remove iommu group notifier Date: Mon, 15 Nov 2021 10:05:51 +0800 Message-Id: <20211115020552.2378167-11-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211115020552.2378167-1-baolu.lu@linux.intel.com> References: <20211115020552.2378167-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org The iommu core and driver core have been enhanced to avoid unsafe driver binding to a live group after iommu_group_set_dma_owner(DMA_MODE_USER) has been called. There's no need to register iommu group notifier. This removes the iommu group notifer which contains BUG_ON() and WARN(). Signed-off-by: Lu Baolu --- drivers/vfio/vfio.c | 147 -------------------------------------------- 1 file changed, 147 deletions(-) diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c index 8c317d1a0f3c..c74e10044af4 100644 --- a/drivers/vfio/vfio.c +++ b/drivers/vfio/vfio.c @@ -71,7 +71,6 @@ struct vfio_group { struct vfio_container *container; struct list_head device_list; struct mutex device_lock; - struct notifier_block nb; struct list_head vfio_next; struct list_head container_next; atomic_t opened; @@ -274,8 +273,6 @@ void vfio_unregister_iommu_driver(const struct vfio_iommu_driver_ops *ops) } EXPORT_SYMBOL_GPL(vfio_unregister_iommu_driver); -static int vfio_iommu_group_notifier(struct notifier_block *nb, - unsigned long action, void *data); static void vfio_group_get(struct vfio_group *group); /** @@ -395,13 +392,6 @@ static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group, goto err_put; } - group->nb.notifier_call = vfio_iommu_group_notifier; - err = iommu_group_register_notifier(iommu_group, &group->nb); - if (err) { - ret = ERR_PTR(err); - goto err_put; - } - mutex_lock(&vfio.group_lock); /* Did we race creating this group? */ @@ -422,7 +412,6 @@ static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group, err_unlock: mutex_unlock(&vfio.group_lock); - iommu_group_unregister_notifier(group->iommu_group, &group->nb); err_put: put_device(&group->dev); return ret; @@ -447,7 +436,6 @@ static void vfio_group_put(struct vfio_group *group) cdev_device_del(&group->cdev, &group->dev); mutex_unlock(&vfio.group_lock); - iommu_group_unregister_notifier(group->iommu_group, &group->nb); put_device(&group->dev); } @@ -503,141 +491,6 @@ static struct vfio_device *vfio_group_get_device(struct vfio_group *group, return NULL; } -/* - * Some drivers, like pci-stub, are only used to prevent other drivers from - * claiming a device and are therefore perfectly legitimate for a user owned - * group. The pci-stub driver has no dependencies on DMA or the IOVA mapping - * of the device, but it does prevent the user from having direct access to - * the device, which is useful in some circumstances. - * - * We also assume that we can include PCI interconnect devices, ie. bridges. - * IOMMU grouping on PCI necessitates that if we lack isolation on a bridge - * then all of the downstream devices will be part of the same IOMMU group as - * the bridge. Thus, if placing the bridge into the user owned IOVA space - * breaks anything, it only does so for user owned devices downstream. Note - * that error notification via MSI can be affected for platforms that handle - * MSI within the same IOVA space as DMA. - */ -static const char * const vfio_driver_allowed[] = { "pci-stub" }; - -static bool vfio_dev_driver_allowed(struct device *dev, - struct device_driver *drv) -{ - if (dev_is_pci(dev)) { - struct pci_dev *pdev = to_pci_dev(dev); - - if (pdev->hdr_type != PCI_HEADER_TYPE_NORMAL) - return true; - } - - return match_string(vfio_driver_allowed, - ARRAY_SIZE(vfio_driver_allowed), - drv->name) >= 0; -} - -/* - * A vfio group is viable for use by userspace if all devices are in - * one of the following states: - * - driver-less - * - bound to a vfio driver - * - bound to an otherwise allowed driver - * - a PCI interconnect device - * - * We use two methods to determine whether a device is bound to a vfio - * driver. The first is to test whether the device exists in the vfio - * group. The second is to test if the device exists on the group - * unbound_list, indicating it's in the middle of transitioning from - * a vfio driver to driver-less. - */ -static int vfio_dev_viable(struct device *dev, void *data) -{ - struct vfio_group *group = data; - struct vfio_device *device; - struct device_driver *drv = READ_ONCE(dev->driver); - - if (!drv || vfio_dev_driver_allowed(dev, drv)) - return 0; - - device = vfio_group_get_device(group, dev); - if (device) { - vfio_device_put(device); - return 0; - } - - return -EINVAL; -} - -/** - * Async device support - */ -static int vfio_group_nb_add_dev(struct vfio_group *group, struct device *dev) -{ - struct vfio_device *device; - - /* Do we already know about it? We shouldn't */ - device = vfio_group_get_device(group, dev); - if (WARN_ON_ONCE(device)) { - vfio_device_put(device); - return 0; - } - - /* Nothing to do for idle groups */ - if (!atomic_read(&group->container_users)) - return 0; - - /* TODO Prevent device auto probing */ - dev_WARN(dev, "Device added to live group %d!\n", - iommu_group_id(group->iommu_group)); - - return 0; -} - -static int vfio_group_nb_verify(struct vfio_group *group, struct device *dev) -{ - /* We don't care what happens when the group isn't in use */ - if (!atomic_read(&group->container_users)) - return 0; - - return vfio_dev_viable(dev, group); -} - -static int vfio_iommu_group_notifier(struct notifier_block *nb, - unsigned long action, void *data) -{ - struct vfio_group *group = container_of(nb, struct vfio_group, nb); - struct device *dev = data; - - switch (action) { - case IOMMU_GROUP_NOTIFY_ADD_DEVICE: - vfio_group_nb_add_dev(group, dev); - break; - case IOMMU_GROUP_NOTIFY_DEL_DEVICE: - /* - * Nothing to do here. If the device is in use, then the - * vfio sub-driver should block the remove callback until - * it is unused. If the device is unused or attached to a - * stub driver, then it should be released and we don't - * care that it will be going away. - */ - break; - case IOMMU_GROUP_NOTIFY_BIND_DRIVER: - dev_dbg(dev, "%s: group %d binding to driver\n", __func__, - iommu_group_id(group->iommu_group)); - break; - case IOMMU_GROUP_NOTIFY_BOUND_DRIVER: - dev_dbg(dev, "%s: group %d bound to driver %s\n", __func__, - iommu_group_id(group->iommu_group), dev->driver->name); - BUG_ON(vfio_group_nb_verify(group, dev)); - break; - case IOMMU_GROUP_NOTIFY_UNBIND_DRIVER: - dev_dbg(dev, "%s: group %d unbinding from driver %s\n", - __func__, iommu_group_id(group->iommu_group), - dev->driver->name); - break; - } - return NOTIFY_OK; -} - /** * VFIO driver API */ From patchwork Mon Nov 15 02:05:52 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baolu Lu X-Patchwork-Id: 12618559 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5B1BAC433F5 for ; Mon, 15 Nov 2021 02:13:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 40B5F60FD8 for ; Mon, 15 Nov 2021 02:13:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236205AbhKOCQe (ORCPT ); Sun, 14 Nov 2021 21:16:34 -0500 Received: from mga12.intel.com ([192.55.52.136]:64444 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236431AbhKOCOT (ORCPT ); Sun, 14 Nov 2021 21:14:19 -0500 X-IronPort-AV: E=McAfee;i="6200,9189,10168"; a="213398885" X-IronPort-AV: E=Sophos;i="5.87,235,1631602800"; d="scan'208";a="213398885" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Nov 2021 18:11:24 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.87,235,1631602800"; d="scan'208";a="505714747" Received: from allen-box.sh.intel.com ([10.239.159.118]) by orsmga008.jf.intel.com with ESMTP; 14 Nov 2021 18:11:19 -0800 From: Lu Baolu To: Greg Kroah-Hartman , Joerg Roedel , Alex Williamson , Bjorn Helgaas , Jason Gunthorpe , Kevin Tian , Ashok Raj Cc: Will Deacon , rafael@kernel.org, Diana Craciun , Cornelia Huck , Eric Auger , Liu Yi L , Jacob jun Pan , Chaitanya Kulkarni , iommu@lists.linux-foundation.org, linux-pci@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Lu Baolu , Christoph Hellwig Subject: [PATCH 11/11] iommu: Remove iommu group changes notifier Date: Mon, 15 Nov 2021 10:05:52 +0800 Message-Id: <20211115020552.2378167-12-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20211115020552.2378167-1-baolu.lu@linux.intel.com> References: <20211115020552.2378167-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org The iommu group changes notifer is not referenced in the tree. Remove it to avoid dead code. Suggested-by: Christoph Hellwig Signed-off-by: Lu Baolu --- include/linux/iommu.h | 23 ------------- drivers/iommu/iommu.c | 75 ------------------------------------------- 2 files changed, 98 deletions(-) diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 3d2dfd220d3c..d8946f22edd5 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -414,13 +414,6 @@ static inline void iommu_iotlb_gather_init(struct iommu_iotlb_gather *gather) }; } -#define IOMMU_GROUP_NOTIFY_ADD_DEVICE 1 /* Device added */ -#define IOMMU_GROUP_NOTIFY_DEL_DEVICE 2 /* Pre Device removed */ -#define IOMMU_GROUP_NOTIFY_BIND_DRIVER 3 /* Pre Driver bind */ -#define IOMMU_GROUP_NOTIFY_BOUND_DRIVER 4 /* Post Driver bind */ -#define IOMMU_GROUP_NOTIFY_UNBIND_DRIVER 5 /* Pre Driver unbind */ -#define IOMMU_GROUP_NOTIFY_UNBOUND_DRIVER 6 /* Post Driver unbind */ - extern int bus_set_iommu(struct bus_type *bus, const struct iommu_ops *ops); extern int bus_iommu_probe(struct bus_type *bus); extern bool iommu_present(struct bus_type *bus); @@ -493,10 +486,6 @@ extern int iommu_group_for_each_dev(struct iommu_group *group, void *data, extern struct iommu_group *iommu_group_get(struct device *dev); extern struct iommu_group *iommu_group_ref_get(struct iommu_group *group); extern void iommu_group_put(struct iommu_group *group); -extern int iommu_group_register_notifier(struct iommu_group *group, - struct notifier_block *nb); -extern int iommu_group_unregister_notifier(struct iommu_group *group, - struct notifier_block *nb); extern int iommu_register_device_fault_handler(struct device *dev, iommu_dev_fault_handler_t handler, void *data); @@ -897,18 +886,6 @@ static inline void iommu_group_put(struct iommu_group *group) { } -static inline int iommu_group_register_notifier(struct iommu_group *group, - struct notifier_block *nb) -{ - return -ENODEV; -} - -static inline int iommu_group_unregister_notifier(struct iommu_group *group, - struct notifier_block *nb) -{ - return 0; -} - static inline int iommu_register_device_fault_handler(struct device *dev, iommu_dev_fault_handler_t handler, diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 3dcd3fc4290a..064d0679906a 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -18,7 +18,6 @@ #include #include #include -#include #include #include #include @@ -41,7 +40,6 @@ struct iommu_group { struct kobject *devices_kobj; struct list_head devices; struct mutex mutex; - struct blocking_notifier_head notifier; void *iommu_data; void (*iommu_data_release)(void *iommu_data); char *name; @@ -628,7 +626,6 @@ struct iommu_group *iommu_group_alloc(void) mutex_init(&group->mutex); INIT_LIST_HEAD(&group->devices); INIT_LIST_HEAD(&group->entry); - BLOCKING_INIT_NOTIFIER_HEAD(&group->notifier); group->dma_owner = DMA_OWNER_NONE; ret = ida_simple_get(&iommu_group_ida, 0, 0, GFP_KERNEL); @@ -904,10 +901,6 @@ int iommu_group_add_device(struct iommu_group *group, struct device *dev) if (ret) goto err_put_group; - /* Notify any listeners about change to group. */ - blocking_notifier_call_chain(&group->notifier, - IOMMU_GROUP_NOTIFY_ADD_DEVICE, dev); - trace_add_device_to_group(group->id, dev); dev_info(dev, "Adding to iommu group %d\n", group->id); @@ -949,10 +942,6 @@ void iommu_group_remove_device(struct device *dev) dev_info(dev, "Removing from iommu group %d\n", group->id); - /* Pre-notify listeners that a device is being removed. */ - blocking_notifier_call_chain(&group->notifier, - IOMMU_GROUP_NOTIFY_DEL_DEVICE, dev); - mutex_lock(&group->mutex); list_for_each_entry(tmp_device, &group->devices, list) { if (tmp_device->dev == dev) { @@ -1075,36 +1064,6 @@ void iommu_group_put(struct iommu_group *group) } EXPORT_SYMBOL_GPL(iommu_group_put); -/** - * iommu_group_register_notifier - Register a notifier for group changes - * @group: the group to watch - * @nb: notifier block to signal - * - * This function allows iommu group users to track changes in a group. - * See include/linux/iommu.h for actions sent via this notifier. Caller - * should hold a reference to the group throughout notifier registration. - */ -int iommu_group_register_notifier(struct iommu_group *group, - struct notifier_block *nb) -{ - return blocking_notifier_chain_register(&group->notifier, nb); -} -EXPORT_SYMBOL_GPL(iommu_group_register_notifier); - -/** - * iommu_group_unregister_notifier - Unregister a notifier - * @group: the group to watch - * @nb: notifier block to signal - * - * Unregister a previously registered group notifier block. - */ -int iommu_group_unregister_notifier(struct iommu_group *group, - struct notifier_block *nb) -{ - return blocking_notifier_chain_unregister(&group->notifier, nb); -} -EXPORT_SYMBOL_GPL(iommu_group_unregister_notifier); - /** * iommu_register_device_fault_handler() - Register a device fault handler * @dev: the device @@ -1653,14 +1612,8 @@ static int remove_iommu_group(struct device *dev, void *data) static int iommu_bus_notifier(struct notifier_block *nb, unsigned long action, void *data) { - unsigned long group_action = 0; struct device *dev = data; - struct iommu_group *group; - /* - * ADD/DEL call into iommu driver ops if provided, which may - * result in ADD/DEL notifiers to group->notifier - */ if (action == BUS_NOTIFY_ADD_DEVICE) { int ret; @@ -1671,34 +1624,6 @@ static int iommu_bus_notifier(struct notifier_block *nb, return NOTIFY_OK; } - /* - * Remaining BUS_NOTIFYs get filtered and republished to the - * group, if anyone is listening - */ - group = iommu_group_get(dev); - if (!group) - return 0; - - switch (action) { - case BUS_NOTIFY_BIND_DRIVER: - group_action = IOMMU_GROUP_NOTIFY_BIND_DRIVER; - break; - case BUS_NOTIFY_BOUND_DRIVER: - group_action = IOMMU_GROUP_NOTIFY_BOUND_DRIVER; - break; - case BUS_NOTIFY_UNBIND_DRIVER: - group_action = IOMMU_GROUP_NOTIFY_UNBIND_DRIVER; - break; - case BUS_NOTIFY_UNBOUND_DRIVER: - group_action = IOMMU_GROUP_NOTIFY_UNBOUND_DRIVER; - break; - } - - if (group_action) - blocking_notifier_call_chain(&group->notifier, - group_action, dev); - - iommu_group_put(group); return 0; }