From: Lu Baolu <baolu.lu@linux.intel.com>
To: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: 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>,
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: Tue, 15 May 2018 14:52:59 +0800 [thread overview]
Message-ID: <5AFA83CB.2040301@linux.intel.com> (raw)
In-Reply-To: <20180514135548.4b95ab93@jacob-builder>
Hi,
On 05/15/2018 04:55 AM, Jacob Pan wrote:
> On Mon, 14 May 2018 14:01:06 +0800
> Lu Baolu <baolu.lu@linux.intel.com> wrote:
>
>> 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?
>>
> I am trying to provide more fine locking granularity in that
> iommu_param is meant to be expanded as the sole iommu data under struct
> device, so the scope of param->lock may expand.
Okay, got it.
Best regards,
Lu Baolu
>> [...]
>>
>> Best regards,
>> Lu Baolu
> [Jacob Pan]
>
next prev parent reply other threads:[~2018-05-15 6:52 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
2018-05-14 20:55 ` Jacob Pan
2018-05-15 6:52 ` Lu Baolu [this message]
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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