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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 17/22] iommu/intel-svm: report device page request
Date: Thu, 22 Mar 2018 20:12:09 -0700	[thread overview]
Message-ID: <1521774734-48433-18-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>

If the source device of a page request has its PASID table pointer
bound to a guest, the first level page tables are owned by the guest.
In this case, we shall let guest OS to manage page fault.

This patch uses the IOMMU fault reporting API to send fault events,
possibly via VFIO, to the guest OS. Once guest pages are fault in, guest
will issue page response which will be passed down via the invalidation
passdown APIs.

Recoverable faults, such as page request reporting is not limitted to
guest use. In kernel driver can also request a chance to receive fault
notifications.

Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
---
 drivers/iommu/intel-svm.c | 71 ++++++++++++++++++++++++++++++++++++++++-------
 include/linux/iommu.h     |  1 +
 2 files changed, 62 insertions(+), 10 deletions(-)

diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
index 99bc9bd..bdc702c 100644
--- a/drivers/iommu/intel-svm.c
+++ b/drivers/iommu/intel-svm.c
@@ -580,6 +580,56 @@ static bool is_canonical_address(u64 addr)
 	return (((saddr << shift) >> shift) == saddr);
 }
 
+static int prq_to_iommu_prot(struct page_req_dsc *req)
+{
+	int prot = 0;
+
+	if (req->rd_req)
+		prot |= IOMMU_FAULT_READ;
+	if (req->wr_req)
+		prot |= IOMMU_FAULT_WRITE;
+	if (req->exe_req)
+		prot |= IOMMU_FAULT_EXEC;
+	if (req->priv_req)
+		prot |= IOMMU_FAULT_PRIV;
+
+	return prot;
+}
+
+static int intel_svm_prq_report(struct page_req_dsc *desc)
+{
+	int ret = 0;
+	struct iommu_fault_event event;
+	struct pci_dev *pdev;
+
+	memset(&event, 0, sizeof(struct iommu_fault_event));
+	pdev = pci_get_bus_and_slot(desc->bus, desc->devfn);
+	if (!pdev) {
+		pr_err("No PCI device found for PRQ [%02x:%02x.%d]\n",
+			desc->bus, PCI_SLOT(desc->devfn),
+			PCI_FUNC(desc->devfn));
+		return -ENODEV;
+	}
+
+	/* Fill in event data for device specific processing */
+	event.type = IOMMU_FAULT_PAGE_REQ;
+	event.addr = (u64)desc->addr << VTD_PAGE_SHIFT;
+	event.pasid = desc->pasid;
+	event.page_req_group_id = desc->prg_index;
+	event.prot = prq_to_iommu_prot(desc);
+	event.last_req = desc->lpig;
+	event.pasid_valid = 1;
+	/* keep track of PRQ so that when the response comes back, we know
+	 * whether we do group response or stream response. SRR[0] and
+	 * private[54:32] bits in the descriptor are stored.
+	 */
+	event.iommu_private = *(u64 *)desc;
+	ret = iommu_report_device_fault(&pdev->dev, &event);
+	pci_dev_put(pdev);
+
+	return ret;
+}
+
 static irqreturn_t prq_event_thread(int irq, void *d)
 {
 	struct intel_iommu *iommu = d;
@@ -628,6 +678,16 @@ static irqreturn_t prq_event_thread(int irq, void *d)
 				goto no_pasid;
 			}
 		}
+		/* If address is not canonical, return invalid response */
+		if (!is_canonical_address(address))
+			goto bad_req;
+
+		/*
+		 * If prq is to be handled outside iommu driver via receiver of
+		 * the fault notifiers, we skip the page response here.
+		 */
+		if (!intel_svm_prq_report(req))
+			goto prq_advance;
 
 		result = QI_RESP_INVALID;
 		/* Since we're using init_mm.pgd directly, we should never take
@@ -638,9 +698,6 @@ static irqreturn_t prq_event_thread(int irq, void *d)
 		if (!mmget_not_zero(svm->mm))
 			goto bad_req;
 
-		/* If address is not canonical, return invalid response */
-		if (!is_canonical_address(address))
-			goto bad_req;
 
 		down_read(&svm->mm->mmap_sem);
 		vma = find_extend_vma(svm->mm, address);
@@ -673,12 +730,6 @@ static irqreturn_t prq_event_thread(int irq, void *d)
 
 		if (WARN_ON(&sdev->list == &svm->devs))
 			sdev = NULL;
-
-		if (sdev && sdev->ops && sdev->ops->fault_cb) {
-			int rwxp = (req->rd_req << 3) | (req->wr_req << 2) |
-				(req->exe_req << 1) | (req->priv_req);
-			sdev->ops->fault_cb(sdev->dev, req->pasid, req->addr, req->private, rwxp, result);
-		}
 		/* We get here in the error case where the PASID lookup failed,
 		   and these can be NULL. Do not use them below this point! */
 		sdev = NULL;
@@ -704,7 +755,7 @@ static irqreturn_t prq_event_thread(int irq, void *d)
 
 			qi_submit_sync(&resp, iommu);
 		}
-
+	prq_advance:
 		head = (head + sizeof(*req)) & PRQ_RING_MASK;
 	}
 
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 94cfda8..dbe2866 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -42,6 +42,7 @@
  * if the IOMMU page table format is equivalent.
  */
 #define IOMMU_PRIV	(1 << 5)
+#define IOMMU_EXEC	(1 << 6)
 
 struct iommu_ops;
 struct iommu_group;
-- 
2.7.4

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

Thread overview: 30+ 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 ` [PATCH v4 13/22] iommu: introduce page response function Jacob Pan
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 ` Jacob Pan [this message]
2018-05-14  6:56   ` [PATCH v4 17/22] iommu/intel-svm: report device page request 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 17/22] iommu/intel-svm: report device page request Jacob Pan

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