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, URIBL_BLOCKED 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 3945FC28CBF for ; Sun, 26 May 2019 16:10:38 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (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 1C78D20863 for ; Sun, 26 May 2019 16:10:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1C78D20863 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id E9BB913E8; Sun, 26 May 2019 16:10:37 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id C89D213E7 for ; Sun, 26 May 2019 16:10:36 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 1EBF56C5 for ; Sun, 26 May 2019 16:10:36 +0000 (UTC) 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 74CFF81F2F; Sun, 26 May 2019 16:10:35 +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 A1BA24FA39; Sun, 26 May 2019 16:10:25 +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 Subject: [PATCH v8 03/29] iommu: Introduce device fault report API Date: Sun, 26 May 2019 18:09:38 +0200 Message-Id: <20190526161004.25232-4-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 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 [10.5.110.27]); Sun, 26 May 2019 16:10:35 +0000 (UTC) Cc: marc.zyngier@arm.com, peter.maydell@linaro.org, kevin.tian@intel.com, vincent.stehle@arm.com, ashok.raj@intel.com X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 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 Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org From: Jacob Pan Traditionally, device specific faults are detected and handled within their own device drivers. When IOMMU is enabled, faults such as DMA related transactions are detected by IOMMU. There is no generic reporting mechanism to report faults back to the in-kernel device driver or the guest OS in case of assigned devices. This patch introduces a registration API for device specific fault handlers. This differs from the existing iommu_set_fault_handler/ report_iommu_fault infrastructures in several ways: - it allows to report more sophisticated fault events (both unrecoverable faults and page request faults) due to the nature of the iommu_fault struct - it is device specific and not domain specific. The current iommu_report_device_fault() implementation only handles the "shoot and forget" unrecoverable fault case. Handling of page request faults or stalled faults will come later. Signed-off-by: Jacob Pan Signed-off-by: Ashok Raj Signed-off-by: Jean-Philippe Brucker Signed-off-by: Eric Auger --- drivers/iommu/iommu.c | 127 +++++++++++++++++++++++++++++++++++++++++- include/linux/iommu.h | 33 ++++++++++- 2 files changed, 157 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 67ee6623f9b2..795518445a3a 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -644,6 +644,13 @@ int iommu_group_add_device(struct iommu_group *group, struct device *dev) goto err_free_name; } + dev->iommu_param = kzalloc(sizeof(*dev->iommu_param), GFP_KERNEL); + if (!dev->iommu_param) { + ret = -ENOMEM; + goto err_free_name; + } + mutex_init(&dev->iommu_param->lock); + kobject_get(group->devices_kobj); dev->iommu_group = group; @@ -674,6 +681,7 @@ int iommu_group_add_device(struct iommu_group *group, struct device *dev) mutex_unlock(&group->mutex); dev->iommu_group = NULL; kobject_put(group->devices_kobj); + kfree(dev->iommu_param); err_free_name: kfree(device->name); err_remove_link: @@ -720,7 +728,7 @@ void iommu_group_remove_device(struct device *dev) sysfs_remove_link(&dev->kobj, "iommu_group"); trace_remove_device_from_group(group->id, dev); - + kfree(dev->iommu_param); kfree(device->name); kfree(device); dev->iommu_group = NULL; @@ -854,6 +862,123 @@ int iommu_group_unregister_notifier(struct iommu_group *group, } EXPORT_SYMBOL_GPL(iommu_group_unregister_notifier); +/** + * iommu_register_device_fault_handler() - Register a device fault handler + * @dev: the device + * @handler: the fault handler + * @data: private data passed as argument to the handler + * + * When an IOMMU fault event is received, this handler gets called with the + * fault event and data as argument. + * + * Return 0 if the fault handler was installed successfully, or an error. + */ +int iommu_register_device_fault_handler(struct device *dev, + iommu_dev_fault_handler_t handler, + void *data) +{ + struct iommu_param *param = dev->iommu_param; + int ret = 0; + + /* + * Device iommu_param should have been allocated when device is + * added to its iommu_group. + */ + if (!param) + return -EINVAL; + + mutex_lock(¶m->lock); + /* Only allow one fault handler registered for each device */ + if (param->fault_param) { + ret = -EBUSY; + goto done_unlock; + } + + get_device(dev); + param->fault_param = + kzalloc(sizeof(struct iommu_fault_param), GFP_KERNEL); + if (!param->fault_param) { + put_device(dev); + ret = -ENOMEM; + goto done_unlock; + } + param->fault_param->handler = handler; + param->fault_param->data = data; + +done_unlock: + mutex_unlock(¶m->lock); + + return ret; +} +EXPORT_SYMBOL_GPL(iommu_register_device_fault_handler); + +/** + * iommu_unregister_device_fault_handler() - Unregister the device fault handler + * @dev: the device + * + * Remove the device fault handler installed with + * iommu_register_device_fault_handler(). + * + * Return 0 on success, or an error. + */ +int iommu_unregister_device_fault_handler(struct device *dev) +{ + struct iommu_param *param = dev->iommu_param; + int ret = 0; + + if (!param) + return -EINVAL; + + mutex_lock(¶m->lock); + + if (!param->fault_param) + goto unlock; + + kfree(param->fault_param); + param->fault_param = NULL; + put_device(dev); +unlock: + mutex_unlock(¶m->lock); + + return ret; +} +EXPORT_SYMBOL_GPL(iommu_unregister_device_fault_handler); + + +/** + * iommu_report_device_fault() - Report fault event to device + * @dev: the device + * @evt: fault event data + * + * Called by IOMMU drivers when a fault is detected, typically in a threaded IRQ + * handler. + * + * Return 0 on success, or an error. + */ +int iommu_report_device_fault(struct device *dev, struct iommu_fault_event *evt) +{ + struct iommu_param *param = dev->iommu_param; + struct iommu_fault_param *fparam; + int ret = 0; + + /* iommu_param is allocated when device is added to group */ + if (!param || !evt) + return -EINVAL; + + /* we only report device fault if there is a handler registered */ + mutex_lock(¶m->lock); + fparam = param->fault_param; + if (!fparam || !fparam->handler) { + ret = -EINVAL; + goto done_unlock; + } + ret = fparam->handler(evt, fparam->data); +done_unlock: + mutex_unlock(¶m->lock); + return ret; +} +EXPORT_SYMBOL_GPL(iommu_report_device_fault); + /** * iommu_group_id - Return ID for a group * @group: the group to ID diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 7890a92e496a..b87b74c63cf9 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -322,9 +322,9 @@ struct iommu_fault_event { /** * struct iommu_fault_param - per-device IOMMU fault data - * @dev_fault_handler: Callback function to handle IOMMU faults at device level - * @data: handler private data * + * @handler: Callback function to handle IOMMU faults at device level + * @data: handler private data */ struct iommu_fault_param { iommu_dev_fault_handler_t handler; @@ -341,6 +341,7 @@ struct iommu_fault_param { * struct iommu_fwspec *iommu_fwspec; */ struct iommu_param { + struct mutex lock; struct iommu_fault_param *fault_param; }; @@ -433,6 +434,15 @@ 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); + +extern int iommu_unregister_device_fault_handler(struct device *dev); + +extern int iommu_report_device_fault(struct device *dev, + struct iommu_fault_event *evt); + extern int iommu_group_id(struct iommu_group *group); extern struct iommu_group *iommu_group_get_for_dev(struct device *dev); extern struct iommu_domain *iommu_group_default_domain(struct iommu_group *); @@ -741,6 +751,25 @@ static inline int iommu_group_unregister_notifier(struct iommu_group *group, return 0; } +static inline +int iommu_register_device_fault_handler(struct device *dev, + iommu_dev_fault_handler_t handler, + void *data) +{ + return -ENODEV; +} + +static inline int iommu_unregister_device_fault_handler(struct device *dev) +{ + return 0; +} + +static inline +int iommu_report_device_fault(struct device *dev, struct iommu_fault_event *evt) +{ + return -ENODEV; +} + static inline int iommu_group_id(struct iommu_group *group) { return -ENODEV; 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