From: Lu Baolu <baolu.lu@linux.intel.com>
To: Jacob Pan <jacob.jun.pan@linux.intel.com>,
iommu@lists.linux-foundation.org,
LKML <linux-kernel@vger.kernel.org>,
Joerg Roedel <joro@8bytes.org>,
David Woodhouse <dwmw2@infradead.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Alex Williamson <alex.williamson@redhat.com>,
Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Cc: Rafael Wysocki <rafael.j.wysocki@intel.com>,
"Liu, Yi L" <yi.l.liu@intel.com>,
"Tian, Kevin" <kevin.tian@intel.com>,
Raj Ashok <ashok.raj@intel.com>,
Jean Delvare <khali@linux-fr.org>,
Christoph Hellwig <hch@infradead.org>
Subject: Re: [PATCH v5 13/23] iommu: introduce device fault report API
Date: Mon, 14 May 2018 14:01:06 +0800 [thread overview]
Message-ID: <5AF92622.2090902@linux.intel.com> (raw)
In-Reply-To: <1526072055-86990-14-git-send-email-jacob.jun.pan@linux.intel.com>
Hi,
On 05/12/2018 04:54 AM, Jacob Pan wrote:
> 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.
>
> Faults detected by IOMMU is based on the transaction's source ID which
> can be reported at per device basis, regardless of the device type is a
> PCI device or not.
>
> The fault types include recoverable (e.g. page request) and
> unrecoverable faults(e.g. access error). In most cases, faults can be
> handled by IOMMU drivers internally. The primary use cases are as
> follows:
> 1. page request fault originated from an SVM capable device that is
> assigned to guest via vIOMMU. In this case, the first level page tables
> are owned by the guest. Page request must be propagated to the guest to
> let guest OS fault in the pages then send page response. In this
> mechanism, the direct receiver of IOMMU fault notification is VFIO,
> which can relay notification events to QEMU or other user space
> software.
>
> 2. faults need more subtle handling by device drivers. Other than
> simply invoke reset function, there are needs to let device driver
> handle the fault with a smaller impact.
>
> This patchset is intended to create a generic fault report API such
> that it can scale as follows:
> - all IOMMU types
> - PCI and non-PCI devices
> - recoverable and unrecoverable faults
> - VFIO and other other in kernel users
> - DMA & IRQ remapping (TBD)
> The original idea was brought up by David Woodhouse and discussions
> summarized at https://lwn.net/Articles/608914/.
>
> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
> Signed-off-by: Ashok Raj <ashok.raj@intel.com>
> Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
> ---
> drivers/iommu/iommu.c | 149 +++++++++++++++++++++++++++++++++++++++++++++++++-
> include/linux/iommu.h | 35 +++++++++++-
> 2 files changed, 181 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index 3a49b96..b3f9daf 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -609,6 +609,13 @@ 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;
> @@ -639,6 +646,7 @@ 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:
> @@ -685,7 +693,7 @@ 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;
> @@ -820,6 +828,145 @@ 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, call this handler with the fault event
> + * and data as argument. The handler should return 0 on success. If the fault is
> + * recoverable (IOMMU_FAULT_PAGE_REQ), the handler can also complete
> + * the fault by calling iommu_page_response() with one of the following
> + * response code:
> + * - IOMMU_PAGE_RESP_SUCCESS: retry the translation
> + * - IOMMU_PAGE_RESP_INVALID: terminate the fault
> + * - IOMMU_PAGE_RESP_FAILURE: terminate the fault and stop reporting
> + * page faults if possible.
> + *
> + * 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;
> + }
> + mutex_init(¶m->fault_param->lock);
Do we really need this mutex lock? Is param->lock enough?
> + param->fault_param->handler = handler;
> + param->fault_param->data = data;
> + INIT_LIST_HEAD(¶m->fault_param->faults);
> +
> +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);
> + /* we cannot unregister handler if there are pending faults */
> + if (!list_empty(¶m->fault_param->faults)) {
> + ret = -EBUSY;
> + 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 model specific drivers when 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)
> +{
> + int ret = 0;
> + struct iommu_fault_event *evt_pending;
> + struct iommu_fault_param *fparam;
> +
> + /* iommu_param is allocated when device is added to group */
> + if (!dev->iommu_param | !evt)
> + return -EINVAL;
> + /* we only report device fault if there is a handler registered */
> + mutex_lock(&dev->iommu_param->lock);
> + if (!dev->iommu_param->fault_param ||
> + !dev->iommu_param->fault_param->handler) {
> + ret = -EINVAL;
> + goto done_unlock;
> + }
> + fparam = dev->iommu_param->fault_param;
> + if (evt->type == IOMMU_FAULT_PAGE_REQ && evt->last_req) {
> + evt_pending = kmemdup(evt, sizeof(struct iommu_fault_event),
> + GFP_KERNEL);
> + if (!evt_pending) {
> + ret = -ENOMEM;
> + goto done_unlock;
> + }
> + mutex_lock(&fparam->lock);
> + list_add_tail(&evt_pending->list, &fparam->faults);
> + mutex_unlock(&fparam->lock);
> + }
> + ret = fparam->handler(evt, fparam->data);
> +done_unlock:
> + mutex_unlock(&dev->iommu_param->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 aeadb4f..b3312ee 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -307,7 +307,8 @@ enum iommu_fault_reason {
> * and PASID spec.
> * - Un-recoverable faults of device interest
> * - DMA remapping and IRQ remapping faults
> -
> + *
> + * @list pending fault event list, used for tracking responses
> * @type contains fault type.
> * @reason fault reasons if relevant outside IOMMU driver, IOMMU driver internal
> * faults are not reported
> @@ -324,6 +325,7 @@ enum iommu_fault_reason {
> * sending the fault response.
> */
> struct iommu_fault_event {
> + struct list_head list;
> enum iommu_fault_type type;
> enum iommu_fault_reason reason;
> u64 addr;
> @@ -340,10 +342,13 @@ 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
> - *
> + * @faults: holds the pending faults which needs response, e.g. page response.
> + * @lock: protect pending PRQ event list
> */
> struct iommu_fault_param {
> iommu_dev_fault_handler_t handler;
> + struct list_head faults;
> + struct mutex lock;
> void *data;
> };
>
> @@ -357,6 +362,7 @@ struct iommu_fault_param {
> * struct iommu_fwspec *iommu_fwspec;
> */
> struct iommu_param {
> + struct mutex lock;
> struct iommu_fault_param *fault_param;
> };
>
> @@ -456,6 +462,14 @@ 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 *);
> @@ -727,6 +741,23 @@ 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;
Best regards,
Lu Baolu
next prev parent reply other threads:[~2018-05-14 6:01 UTC|newest]
Thread overview: 81+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-11 20:53 [PATCH v5 00/23] IOMMU and VT-d driver support for Shared Virtual Address (SVA) Jacob Pan
2018-05-11 20:53 ` [PATCH v5 01/23] iommu: introduce bind_pasid_table API function Jacob Pan
2018-08-23 16:34 ` Auger Eric
2018-08-24 12:47 ` Liu, Yi L
2018-08-24 13:20 ` Auger Eric
2018-08-28 17:04 ` Jacob Pan
2018-08-24 15:00 ` Auger Eric
2018-08-28 5:14 ` Jacob Pan
2018-08-28 8:34 ` Auger Eric
2018-08-28 16:36 ` Jacob Pan
2018-05-11 20:53 ` [PATCH v5 02/23] iommu/vt-d: move device_domain_info to header Jacob Pan
2018-05-11 20:53 ` [PATCH v5 03/23] iommu/vt-d: add a flag for pasid table bound status Jacob Pan
2018-05-13 7:33 ` Lu Baolu
2018-05-14 18:51 ` Jacob Pan
2018-05-13 8:01 ` Lu Baolu
2018-05-14 18:52 ` Jacob Pan
2018-05-11 20:53 ` [PATCH v5 04/23] iommu/vt-d: add bind_pasid_table function Jacob Pan
2018-05-13 9:29 ` Lu Baolu
2018-05-14 20:22 ` Jacob Pan
2018-05-11 20:53 ` [PATCH v5 05/23] iommu: introduce iommu invalidate API function Jacob Pan
2018-05-11 20:53 ` [PATCH v5 06/23] iommu/vt-d: add definitions for PFSID Jacob Pan
2018-05-14 1:36 ` Lu Baolu
2018-05-14 20:30 ` Jacob Pan
2018-05-11 20:53 ` [PATCH v5 07/23] iommu/vt-d: fix dev iotlb pfsid use Jacob Pan
2018-05-14 1:52 ` Lu Baolu
2018-05-14 20:38 ` Jacob Pan
2018-05-11 20:54 ` [PATCH v5 08/23] iommu/vt-d: support flushing more translation cache types Jacob Pan
2018-05-14 2:18 ` Lu Baolu
2018-05-14 20:46 ` Jacob Pan
2018-05-17 8:44 ` kbuild test robot
2018-05-11 20:54 ` [PATCH v5 09/23] iommu/vt-d: add svm/sva invalidate function Jacob Pan
2018-05-14 3:35 ` Lu Baolu
2018-05-14 20:49 ` Jacob Pan
2018-05-11 20:54 ` [PATCH v5 10/23] iommu: introduce device fault data Jacob Pan
2018-09-21 10:07 ` Auger Eric
2018-09-21 17:05 ` Jacob Pan
2018-09-26 10:20 ` Auger Eric
2018-05-11 20:54 ` [PATCH v5 11/23] driver core: add per device iommu param Jacob Pan
2018-05-14 5:27 ` Lu Baolu
2018-05-14 20:52 ` Jacob Pan
2018-05-11 20:54 ` [PATCH v5 12/23] iommu: add a timeout parameter for prq response Jacob Pan
2018-05-11 20:54 ` [PATCH v5 13/23] iommu: introduce device fault report API Jacob Pan
2018-05-14 6:01 ` Lu Baolu [this message]
2018-05-14 20:55 ` Jacob Pan
2018-05-15 6:52 ` Lu Baolu
2018-05-17 11:41 ` Liu, Yi L
2018-05-17 15:59 ` Jacob Pan
2018-05-17 23:22 ` Liu, Yi L
2018-05-21 23:03 ` Jacob Pan
2018-09-06 9:25 ` Auger Eric
2018-09-06 12:42 ` Jean-Philippe Brucker
2018-09-06 13:14 ` Auger Eric
2018-09-06 17:06 ` Jean-Philippe Brucker
2018-09-07 7:11 ` Auger Eric
2018-09-07 11:23 ` Jean-Philippe Brucker
2018-09-14 13:24 ` Auger Eric
2018-09-17 16:57 ` Jacob Pan
2018-09-25 14:58 ` Jean-Philippe Brucker
2018-09-25 22:17 ` Jacob Pan
2018-09-26 10:14 ` Jean-Philippe Brucker
2018-05-11 20:54 ` [PATCH v5 14/23] iommu: introduce page response function Jacob Pan
2018-05-14 6:39 ` Lu Baolu
2018-05-29 16:13 ` Jacob Pan
2018-09-10 14:52 ` Auger Eric
2018-09-10 17:50 ` Jacob Pan
2018-09-10 19:06 ` Auger Eric
2018-05-11 20:54 ` [PATCH v5 15/23] iommu: handle page response timeout Jacob Pan
2018-05-14 7:43 ` Lu Baolu
2018-05-29 16:20 ` Jacob Pan
2018-05-30 7:46 ` Lu Baolu
2018-05-11 20:54 ` [PATCH v5 16/23] iommu/config: add build dependency for dmar Jacob Pan
2018-05-11 20:54 ` [PATCH v5 17/23] iommu/vt-d: report non-recoverable faults to device Jacob Pan
2018-05-14 8:17 ` Lu Baolu
2018-05-29 17:33 ` Jacob Pan
2018-05-11 20:54 ` [PATCH v5 18/23] iommu/intel-svm: report device page request Jacob Pan
2018-05-11 20:54 ` [PATCH v5 19/23] iommu/intel-svm: replace dev ops with fault report API Jacob Pan
2018-05-11 20:54 ` [PATCH v5 20/23] iommu/intel-svm: do not flush iotlb for viommu Jacob Pan
2018-05-11 20:54 ` [PATCH v5 21/23] iommu/vt-d: add intel iommu page response function Jacob Pan
2018-05-11 20:54 ` [PATCH v5 22/23] trace/iommu: add sva trace events Jacob Pan
2018-05-11 20:54 ` [PATCH v5 23/23] iommu: use sva invalidate and device fault trace event Jacob Pan
2018-05-29 15:54 ` [PATCH v5 00/23] IOMMU and VT-d driver support for Shared Virtual Address (SVA) Jacob Pan
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