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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 14/23] iommu: introduce page response function
Date: Mon, 14 May 2018 14:39:51 +0800	[thread overview]
Message-ID: <5AF92F37.3050404@linux.intel.com> (raw)
In-Reply-To: <1526072055-86990-15-git-send-email-jacob.jun.pan@linux.intel.com>

Hi,

On 05/12/2018 04:54 AM, Jacob Pan wrote:
> IO page faults can be handled outside IOMMU subsystem. For an example,
> when nested translation is turned on and guest owns the
> first level page tables, device page request can be forwared
> to the guest for handling faults. As the page response returns
> by the guest, IOMMU driver on the host need to process the
> response which informs the device and completes the page request
> transaction.
>
> This patch introduces generic API function for page response
> passing from the guest or other in-kernel users. The definitions of
> the generic data is based on PCI ATS specification not limited to
> any vendor.
>
> Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
> Link: https://lkml.org/lkml/2017/12/7/1725
> ---
>  drivers/iommu/iommu.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/iommu.h | 43 +++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 88 insertions(+)
>
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index b3f9daf..02fed3e 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -1533,6 +1533,51 @@ int iommu_sva_invalidate(struct iommu_domain *domain,
>  }
>  EXPORT_SYMBOL_GPL(iommu_sva_invalidate);
>  
> +int iommu_page_response(struct device *dev,
> +			struct page_response_msg *msg)
> +{
> +	struct iommu_param *param = dev->iommu_param;
> +	int ret = -EINVAL;
> +	struct iommu_fault_event *evt;
> +	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
> +
> +	if (!domain || !domain->ops->page_response)
> +		return -ENODEV;
> +
> +	/*
> +	 * Device iommu_param should have been allocated when device is
> +	 * added to its iommu_group.
> +	 */
> +	if (!param || !param->fault_param)
> +		return -EINVAL;
> +
> +	/* Only send response if there is a fault report pending */
> +	mutex_lock(&param->fault_param->lock);
> +	if (list_empty(&param->fault_param->faults)) {
> +		pr_warn("no pending PRQ, drop response\n");
> +		goto done_unlock;
> +	}
> +	/*
> +	 * Check if we have a matching page request pending to respond,
> +	 * otherwise return -EINVAL
> +	 */
> +	list_for_each_entry(evt, &param->fault_param->faults, list) {
> +		if (evt->pasid == msg->pasid &&
> +		    msg->page_req_group_id == evt->page_req_group_id) {
> +			msg->private_data = evt->iommu_private;
> +			ret = domain->ops->page_response(dev, msg);
> +			list_del(&evt->list);
> +			kfree(evt);
> +			break;
> +		}
> +	}

Are above two checks duplicated? We won't find a matching
request if the list is empty. And we need to  printk a message
if we can't find the matching request.

Best regards,
Lu Baolu

> +
> +done_unlock:
> +	mutex_unlock(&param->fault_param->lock);
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(iommu_page_response);
> +
>  static void __iommu_detach_device(struct iommu_domain *domain,
>  				  struct device *dev)
>  {
> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> index b3312ee..722b90f 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -163,6 +163,41 @@ struct iommu_resv_region {
>  #ifdef CONFIG_IOMMU_API
>  
>  /**
> + * enum page_response_code - Return status of fault handlers, telling the IOMMU
> + * driver how to proceed with the fault.
> + *
> + * @IOMMU_PAGE_RESP_SUCCESS: Fault has been handled and the page tables
> + *	populated, retry the access. This is "Success" in PCI PRI.
> + * @IOMMU_PAGE_RESP_FAILURE: General error. Drop all subsequent faults from
> + *	this device if possible. This is "Response Failure" in PCI PRI.
> + * @IOMMU_PAGE_RESP_INVALID: Could not handle this fault, don't retry the
> + *	access. This is "Invalid Request" in PCI PRI.
> + */
> +enum page_response_code {
> +	IOMMU_PAGE_RESP_SUCCESS = 0,
> +	IOMMU_PAGE_RESP_INVALID,
> +	IOMMU_PAGE_RESP_FAILURE,
> +};
> +
> +/**
> + * Generic page response information based on PCI ATS and PASID spec.
> + * @addr: servicing page address
> + * @pasid: contains process address space ID
> + * @resp_code: response code
> + * @page_req_group_id: page request group index
> + * @private_data: uniquely identify device-specific private data for an
> + *                individual page response
> + */
> +struct page_response_msg {
> +	u64 addr;
> +	u32 pasid;
> +	enum page_response_code resp_code;
> +	u32 pasid_present:1;
> +	u32 page_req_group_id;
> +	u64 private_data;
> +};
> +
> +/**
>   * struct iommu_ops - iommu ops and capabilities
>   * @capable: check capability
>   * @domain_alloc: allocate iommu domain
> @@ -195,6 +230,7 @@ struct iommu_resv_region {
>   * @bind_pasid_table: bind pasid table pointer for guest SVM
>   * @unbind_pasid_table: unbind pasid table pointer and restore defaults
>   * @sva_invalidate: invalidate translation caches of shared virtual address
> + * @page_response: handle page request response
>   */
>  struct iommu_ops {
>  	bool (*capable)(enum iommu_cap);
> @@ -250,6 +286,7 @@ struct iommu_ops {
>  				struct device *dev);
>  	int (*sva_invalidate)(struct iommu_domain *domain,
>  		struct device *dev, struct tlb_invalidate_info *inv_info);
> +	int (*page_response)(struct device *dev, struct page_response_msg *msg);
>  
>  	unsigned long pgsize_bitmap;
>  };
> @@ -470,6 +507,7 @@ 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_page_response(struct device *dev, struct page_response_msg *msg);
>  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 *);
> @@ -758,6 +796,11 @@ static inline int iommu_report_device_fault(struct device *dev, struct iommu_fau
>  	return -ENODEV;
>  }
>  
> +static inline int iommu_page_response(struct device *dev, struct page_response_msg *msg)
> +{
> +	return -ENODEV;
> +}
> +
>  static inline int iommu_group_id(struct iommu_group *group)
>  {
>  	return -ENODEV;

  reply	other threads:[~2018-05-14  6:39 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
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 [this message]
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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