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From: Jacob Pan <jacob.jun.pan@linux.intel.com>
To: iommu@lists.linux-foundation.org,
	LKML <linux-kernel@vger.kernel.org>,
	Joerg Roedel <joro@8bytes.org>,
	David Woodhouse <dwmw2@infradead.org>,
	Jean-Philippe Brucker <jean-philippe.brucker@arm.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Rafael Wysocki <rafael.j.wysocki@intel.com>
Cc: "Liu, Yi L" <yi.l.liu@intel.com>,
	Lan Tianyu <tianyu.lan@intel.com>,
	"Tian, Kevin" <kevin.tian@intel.com>,
	Raj Ashok <ashok.raj@intel.com>,
	Alex Williamson <alex.williamson@redhat.com>,
	Jean Delvare <khali@linux-fr.org>,
	"Christoph Hellwig" <hch@infradead.org>,
	Jacob Pan <jacob.jun.pan@linux.intel.com>
Subject: [PATCH v4 13/22] iommu: introduce page response function
Date: Thu, 22 Mar 2018 20:12:05 -0700	[thread overview]
Message-ID: <1521774734-48433-14-git-send-email-jacob.jun.pan@linux.intel.com> (raw)
In-Reply-To: <1521774734-48433-1-git-send-email-jacob.jun.pan@linux.intel.com>

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 | 52 +++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 97 insertions(+)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index cd653ff..42e8f00 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1503,6 +1503,51 @@ 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, *iter;
+	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_safe(evt, iter, &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;
+		}
+	}
+
+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 b89e881..af0e393 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -163,6 +163,55 @@ 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_FAULT_STATUS_SUCCESS: Fault has been handled and the page tables
+ *	populated, retry the access. This is "Success" in PCI PRI.
+ * @IOMMU_FAULT_STATUS_FAILURE: General error. Drop all subsequent faults from
+ *	this device if possible. This is "Response Failure" in PCI PRI.
+ * @IOMMU_FAULT_STATUS_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,
+};
+
+/**
+ * enum page_request_handle_t - Return page request/response handler status
+ *
+ * @IOMMU_FAULT_STATUS_HANDLED: Stop processing the fault, and do not send a
+ *	reply to the device.
+ * @IOMMU_FAULT_STATUS_CONTINUE: Fault was not handled. Call the next handler,
+ *	or terminate.
+ */
+enum page_request_handle_t {
+	IOMMU_PAGE_RESP_HANDLED = 0,
+	IOMMU_PAGE_RESP_CONTINUE,
+};
+
+/**
+ * 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
+ * @type: group or stream/single page response
+ * @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 +244,7 @@ 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 +300,7 @@ 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;
 };
@@ -471,6 +522,7 @@ 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 *);
-- 
2.7.4

  parent reply	other threads:[~2018-03-23  3:12 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-03-23  3:11 [PATCH v4 00/22] IOMMU and VT-d driver support for Shared Virtual Address (SVA) Jacob Pan
2018-03-23  3:11 ` [PATCH v4 01/22] iommu: introduce bind_pasid_table API function Jacob Pan
2018-03-23  3:11 ` [PATCH v4 02/22] iommu/vt-d: move device_domain_info to header Jacob Pan
2018-03-23  3:11 ` [PATCH v4 03/22] iommu/vt-d: add a flag for pasid table bound status Jacob Pan
2018-03-23  3:11 ` [PATCH v4 04/22] iommu/vt-d: add bind_pasid_table function Jacob Pan
2018-03-23  3:11 ` [PATCH v4 05/22] iommu: introduce iommu invalidate API function Jacob Pan
2018-03-23  3:11 ` [PATCH v4 06/22] iommu/vt-d: add definitions for PFSID Jacob Pan
2018-03-23  3:11 ` [PATCH v4 07/22] iommu/vt-d: fix dev iotlb pfsid use Jacob Pan
2018-03-23  3:12 ` [PATCH v4 08/22] iommu/vt-d: support flushing more translation cache types Jacob Pan
2018-03-23  3:12 ` [PATCH v4 09/22] iommu/vt-d: add svm/sva invalidate function Jacob Pan
2018-03-23  3:12 ` [PATCH v4 10/22] iommu: introduce device fault data Jacob Pan
2018-03-23  3:12 ` [PATCH v4 11/22] driver core: add per device iommu param Jacob Pan
2018-03-23  8:12   ` Greg Kroah-Hartman
2018-03-23  3:12 ` [PATCH v4 12/22] iommu: introduce device fault report API Jacob Pan
2018-03-23  3:12 ` Jacob Pan [this message]
2018-03-23  3:12 ` [PATCH v4 14/22] iommu: handle page response timeout Jacob Pan
2018-03-23  3:12 ` [PATCH v4 15/22] iommu/config: add build dependency for dmar Jacob Pan
2018-03-23  3:12 ` [PATCH v4 16/22] iommu/vt-d: report non-recoverable faults to device Jacob Pan
2018-05-14  6:55   ` Liu, Yi L
2018-03-23  3:12 ` [PATCH v4 17/22] iommu/intel-svm: report device page request Jacob Pan
2018-05-14  6:56   ` Liu, Yi L
2018-05-14 18:30     ` Jacob Pan
2018-03-23  3:12 ` [PATCH v4 18/22] iommu/intel-svm: replace dev ops with fault report API Jacob Pan
2018-03-23  3:12 ` [PATCH v4 19/22] iommu/intel-svm: do not flush iotlb for viommu Jacob Pan
2018-03-23  3:12 ` [PATCH v4 20/22] iommu/vt-d: add intel iommu page response function Jacob Pan
2018-03-24 23:19   ` kbuild test robot
2018-03-24 23:19   ` [RFC PATCH] iommu/vt-d: intel_iommu_page_response() can be static kbuild test robot
2018-03-23  3:12 ` [PATCH v4 21/22] trace/iommu: add sva trace events Jacob Pan
2018-03-23  3:12 ` [PATCH v4 22/22] iommu: use sva invalidate and device fault trace event Jacob Pan
2018-04-16 21:48 [PATCH v4 00/22] IOMMU and VT-d driver support for Shared Virtual Address (SVA) Jacob Pan
2018-04-16 21:49 ` [PATCH v4 13/22] iommu: introduce page response function Jacob Pan
2018-04-23 11:47   ` Jean-Philippe Brucker
2018-04-23 12:16     ` Jacob Pan
2018-04-23 15:50       ` Jean-Philippe Brucker

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