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2024-01-03 2f7c68cb55ecb7331f2381deb497c27155f32faf 
 kernel/drivers/vfio/vfio.c
....@@ -1,12 +1,9 @@
1
+// SPDX-License-Identifier: GPL-2.0-only
12 /*
23  * VFIO core
34  *
45  * Copyright (C) 2012 Red Hat, Inc.  All rights reserved.
56  *     Author: Alex Williamson <alex.williamson@redhat.com>
6
- *
7
- * This program is free software; you can redistribute it and/or modify
8
- * it under the terms of the GNU General Public License version 2 as
9
- * published by the Free Software Foundation.
107  *
118  * Derived from original vfio:
129  * Copyright 2010 Cisco Systems, Inc.  All rights reserved.
....@@ -49,7 +46,6 @@
4946 	struct mutex			group_lock;
5047 	struct cdev			group_cdev;
5148 	dev_t				group_devt;
52
-	wait_queue_head_t		release_q;
5349 } vfio;
5450 
5551 struct vfio_iommu_driver {
....@@ -88,17 +84,9 @@
8884 	atomic_t			opened;
8985 	wait_queue_head_t		container_q;
9086 	bool				noiommu;
87
+	unsigned int			dev_counter;
9188 	struct kvm			*kvm;
9289 	struct blocking_notifier_head	notifier;
93
-};
94
-
95
-struct vfio_device {
96
-	struct kref			kref;
97
-	struct device			*dev;
98
-	const struct vfio_device_ops	*ops;
99
-	struct vfio_group		*group;
100
-	struct list_head		group_next;
101
-	void				*device_data;
10290 };
10391 
10492 #ifdef CONFIG_VFIO_NOIOMMU
....@@ -534,65 +522,17 @@
534522 /**
535523  * Device objects - create, release, get, put, search
536524  */
537
-static
538
-struct vfio_device *vfio_group_create_device(struct vfio_group *group,
539
-					     struct device *dev,
540
-					     const struct vfio_device_ops *ops,
541
-					     void *device_data)
542
-{
543
-	struct vfio_device *device;
544
-
545
-	device = kzalloc(sizeof(*device), GFP_KERNEL);
546
-	if (!device)
547
-		return ERR_PTR(-ENOMEM);
548
-
549
-	kref_init(&device->kref);
550
-	device->dev = dev;
551
-	device->group = group;
552
-	device->ops = ops;
553
-	device->device_data = device_data;
554
-	dev_set_drvdata(dev, device);
555
-
556
-	/* No need to get group_lock, caller has group reference */
557
-	vfio_group_get(group);
558
-
559
-	mutex_lock(&group->device_lock);
560
-	list_add(&device->group_next, &group->device_list);
561
-	mutex_unlock(&group->device_lock);
562
-
563
-	return device;
564
-}
565
-
566
-static void vfio_device_release(struct kref *kref)
567
-{
568
-	struct vfio_device *device = container_of(kref,
569
-						  struct vfio_device, kref);
570
-	struct vfio_group *group = device->group;
571
-
572
-	list_del(&device->group_next);
573
-	mutex_unlock(&group->device_lock);
574
-
575
-	dev_set_drvdata(device->dev, NULL);
576
-
577
-	kfree(device);
578
-
579
-	/* vfio_del_group_dev may be waiting for this device */
580
-	wake_up(&vfio.release_q);
581
-}
582
-
583525 /* Device reference always implies a group reference */
584526 void vfio_device_put(struct vfio_device *device)
585527 {
586
-	struct vfio_group *group = device->group;
587
-	kref_put_mutex(&device->kref, vfio_device_release, &group->device_lock);
588
-	vfio_group_put(group);
528
+	if (refcount_dec_and_test(&device->refcount))
529
+		complete(&device->comp);
589530 }
590531 EXPORT_SYMBOL_GPL(vfio_device_put);
591532 
592
-static void vfio_device_get(struct vfio_device *device)
533
+static bool vfio_device_try_get(struct vfio_device *device)
593534 {
594
-	vfio_group_get(device->group);
595
-	kref_get(&device->kref);
535
+	return refcount_inc_not_zero(&device->refcount);
596536 }
597537 
598538 static struct vfio_device *vfio_group_get_device(struct vfio_group *group,
....@@ -602,8 +542,7 @@
602542 
603543 	mutex_lock(&group->device_lock);
604544 	list_for_each_entry(device, &group->device_list, group_next) {
605
-		if (device->dev == dev) {
606
-			vfio_device_get(device);
545
+		if (device->dev == dev && vfio_device_try_get(device)) {
607546 			mutex_unlock(&group->device_lock);
608547 			return device;
609548 		}
....@@ -627,9 +566,10 @@
627566  * that error notification via MSI can be affected for platforms that handle
628567  * MSI within the same IOVA space as DMA.
629568  */
630
-static const char * const vfio_driver_whitelist[] = { "pci-stub" };
569
+static const char * const vfio_driver_allowed[] = { "pci-stub" };
631570 
632
-static bool vfio_dev_whitelisted(struct device *dev, struct device_driver *drv)
571
+static bool vfio_dev_driver_allowed(struct device *dev,
572
+				    struct device_driver *drv)
633573 {
634574 	if (dev_is_pci(dev)) {
635575 		struct pci_dev *pdev = to_pci_dev(dev);
....@@ -638,8 +578,8 @@
638578 			return true;
639579 	}
640580 
641
-	return match_string(vfio_driver_whitelist,
642
-			    ARRAY_SIZE(vfio_driver_whitelist),
581
+	return match_string(vfio_driver_allowed,
582
+			    ARRAY_SIZE(vfio_driver_allowed),
643583 			    drv->name) >= 0;
644584 }
645585 
....@@ -648,7 +588,7 @@
648588  * one of the following states:
649589  *  - driver-less
650590  *  - bound to a vfio driver
651
- *  - bound to a whitelisted driver
591
+ *  - bound to an otherwise allowed driver
652592  *  - a PCI interconnect device
653593  *
654594  * We use two methods to determine whether a device is bound to a vfio
....@@ -674,7 +614,7 @@
674614 	}
675615 	mutex_unlock(&group->unbound_lock);
676616 
677
-	if (!ret || !drv || vfio_dev_whitelisted(dev, drv))
617
+	if (!ret || !drv || vfio_dev_driver_allowed(dev, drv))
678618 		return 0;
679619 
680620 	device = vfio_group_get_device(group, dev);
....@@ -705,8 +645,8 @@
705645 		return 0;
706646 
707647 	/* TODO Prevent device auto probing */
708
-	WARN(1, "Device %s added to live group %d!\n", dev_name(dev),
709
-	     iommu_group_id(group->iommu_group));
648
+	dev_WARN(dev, "Device added to live group %d!\n",
649
+		 iommu_group_id(group->iommu_group));
710650 
711651 	return 0;
712652 }
....@@ -749,25 +689,22 @@
749689 		 */
750690 		break;
751691 	case IOMMU_GROUP_NOTIFY_BIND_DRIVER:
752
-		pr_debug("%s: Device %s, group %d binding to driver\n",
753
-			 __func__, dev_name(dev),
754
-			 iommu_group_id(group->iommu_group));
692
+		dev_dbg(dev, "%s: group %d binding to driver\n", __func__,
693
+			iommu_group_id(group->iommu_group));
755694 		break;
756695 	case IOMMU_GROUP_NOTIFY_BOUND_DRIVER:
757
-		pr_debug("%s: Device %s, group %d bound to driver %s\n",
758
-			 __func__, dev_name(dev),
759
-			 iommu_group_id(group->iommu_group), dev->driver->name);
696
+		dev_dbg(dev, "%s: group %d bound to driver %s\n", __func__,
697
+			iommu_group_id(group->iommu_group), dev->driver->name);
760698 		BUG_ON(vfio_group_nb_verify(group, dev));
761699 		break;
762700 	case IOMMU_GROUP_NOTIFY_UNBIND_DRIVER:
763
-		pr_debug("%s: Device %s, group %d unbinding from driver %s\n",
764
-			 __func__, dev_name(dev),
765
-			 iommu_group_id(group->iommu_group), dev->driver->name);
701
+		dev_dbg(dev, "%s: group %d unbinding from driver %s\n",
702
+			__func__, iommu_group_id(group->iommu_group),
703
+			dev->driver->name);
766704 		break;
767705 	case IOMMU_GROUP_NOTIFY_UNBOUND_DRIVER:
768
-		pr_debug("%s: Device %s, group %d unbound from driver\n",
769
-			 __func__, dev_name(dev),
770
-			 iommu_group_id(group->iommu_group));
706
+		dev_dbg(dev, "%s: group %d unbound from driver\n", __func__,
707
+			iommu_group_id(group->iommu_group));
771708 		/*
772709 		 * XXX An unbound device in a live group is ok, but we'd
773710 		 * really like to avoid the above BUG_ON by preventing other
....@@ -803,14 +740,23 @@
803740 /**
804741  * VFIO driver API
805742  */
806
-int vfio_add_group_dev(struct device *dev,
807
-		       const struct vfio_device_ops *ops, void *device_data)
743
+void vfio_init_group_dev(struct vfio_device *device, struct device *dev,
744
+			 const struct vfio_device_ops *ops, void *device_data)
808745 {
746
+	init_completion(&device->comp);
747
+	device->dev = dev;
748
+	device->ops = ops;
749
+	device->device_data = device_data;
750
+}
751
+EXPORT_SYMBOL_GPL(vfio_init_group_dev);
752
+
753
+int vfio_register_group_dev(struct vfio_device *device)
754
+{
755
+	struct vfio_device *existing_device;
809756 	struct iommu_group *iommu_group;
810757 	struct vfio_group *group;
811
-	struct vfio_device *device;
812758 
813
-	iommu_group = iommu_group_get(dev);
759
+	iommu_group = iommu_group_get(device->dev);
814760 	if (!iommu_group)
815761 		return -EINVAL;
816762 
....@@ -829,29 +775,50 @@
829775 		iommu_group_put(iommu_group);
830776 	}
831777 
832
-	device = vfio_group_get_device(group, dev);
833
-	if (device) {
834
-		WARN(1, "Device %s already exists on group %d\n",
835
-		     dev_name(dev), iommu_group_id(iommu_group));
836
-		vfio_device_put(device);
778
+	existing_device = vfio_group_get_device(group, device->dev);
779
+	if (existing_device) {
780
+		dev_WARN(device->dev, "Device already exists on group %d\n",
781
+			 iommu_group_id(iommu_group));
782
+		vfio_device_put(existing_device);
837783 		vfio_group_put(group);
838784 		return -EBUSY;
839785 	}
840786 
841
-	device = vfio_group_create_device(group, dev, ops, device_data);
842
-	if (IS_ERR(device)) {
843
-		vfio_group_put(group);
844
-		return PTR_ERR(device);
845
-	}
787
+	/* Our reference on group is moved to the device */
788
+	device->group = group;
846789 
847
-	/*
848
-	 * Drop all but the vfio_device reference.  The vfio_device holds
849
-	 * a reference to the vfio_group, which holds a reference to the
850
-	 * iommu_group.
851
-	 */
852
-	vfio_group_put(group);
790
+	/* Refcounting can't start until the driver calls register */
791
+	refcount_set(&device->refcount, 1);
792
+
793
+	mutex_lock(&group->device_lock);
794
+	list_add(&device->group_next, &group->device_list);
795
+	group->dev_counter++;
796
+	mutex_unlock(&group->device_lock);
853797 
854798 	return 0;
799
+}
800
+EXPORT_SYMBOL_GPL(vfio_register_group_dev);
801
+
802
+int vfio_add_group_dev(struct device *dev, const struct vfio_device_ops *ops,
803
+		       void *device_data)
804
+{
805
+	struct vfio_device *device;
806
+	int ret;
807
+
808
+	device = kzalloc(sizeof(*device), GFP_KERNEL);
809
+	if (!device)
810
+		return -ENOMEM;
811
+
812
+	vfio_init_group_dev(device, dev, ops, device_data);
813
+	ret = vfio_register_group_dev(device);
814
+	if (ret)
815
+		goto err_kfree;
816
+	dev_set_drvdata(dev, device);
817
+	return 0;
818
+
819
+err_kfree:
820
+	kfree(device);
821
+	return ret;
855822 }
856823 EXPORT_SYMBOL_GPL(vfio_add_group_dev);
857824 
....@@ -881,13 +848,24 @@
881848 static struct vfio_device *vfio_device_get_from_name(struct vfio_group *group,
882849 						     char *buf)
883850 {
884
-	struct vfio_device *it, *device = NULL;
851
+	struct vfio_device *it, *device = ERR_PTR(-ENODEV);
885852 
886853 	mutex_lock(&group->device_lock);
887854 	list_for_each_entry(it, &group->device_list, group_next) {
888
-		if (!strcmp(dev_name(it->dev), buf)) {
855
+		int ret;
856
+
857
+		if (it->ops->match) {
858
+			ret = it->ops->match(it->device_data, buf);
859
+			if (ret < 0) {
860
+				device = ERR_PTR(ret);
861
+				break;
862
+			}
863
+		} else {
864
+			ret = !strcmp(dev_name(it->dev), buf);
865
+		}
866
+
867
+		if (ret && vfio_device_try_get(it)) {
889868 			device = it;
890
-			vfio_device_get(device);
891869 			break;
892870 		}
893871 	}
....@@ -908,21 +886,13 @@
908886 /*
909887  * Decrement the device reference count and wait for the device to be
910888  * removed.  Open file descriptors for the device... */
911
-void *vfio_del_group_dev(struct device *dev)
889
+void vfio_unregister_group_dev(struct vfio_device *device)
912890 {
913
-	DEFINE_WAIT_FUNC(wait, woken_wake_function);
914
-	struct vfio_device *device = dev_get_drvdata(dev);
915891 	struct vfio_group *group = device->group;
916
-	void *device_data = device->device_data;
917892 	struct vfio_unbound_dev *unbound;
918893 	unsigned int i = 0;
919894 	bool interrupted = false;
920
-
921
-	/*
922
-	 * The group exists so long as we have a device reference.  Get
923
-	 * a group reference and use it to scan for the device going away.
924
-	 */
925
-	vfio_group_get(group);
895
+	long rc;
926896 
927897 	/*
928898 	 * When the device is removed from the group, the group suddenly
....@@ -935,7 +905,7 @@
935905 	 */
936906 	unbound = kzalloc(sizeof(*unbound), GFP_KERNEL);
937907 	if (unbound) {
938
-		unbound->dev = dev;
908
+		unbound->dev = device->dev;
939909 		mutex_lock(&group->unbound_lock);
940910 		list_add(&unbound->unbound_next, &group->unbound_list);
941911 		mutex_unlock(&group->unbound_lock);
....@@ -943,44 +913,33 @@
943913 	WARN_ON(!unbound);
944914 
945915 	vfio_device_put(device);
946
-
947
-	/*
948
-	 * If the device is still present in the group after the above
949
-	 * 'put', then it is in use and we need to request it from the
950
-	 * bus driver.  The driver may in turn need to request the
951
-	 * device from the user.  We send the request on an arbitrary
952
-	 * interval with counter to allow the driver to take escalating
953
-	 * measures to release the device if it has the ability to do so.
954
-	 */
955
-	add_wait_queue(&vfio.release_q, &wait);
956
-
957
-	do {
958
-		device = vfio_group_get_device(group, dev);
959
-		if (!device)
960
-			break;
961
-
916
+	rc = try_wait_for_completion(&device->comp);
917
+	while (rc <= 0) {
962918 		if (device->ops->request)
963
-			device->ops->request(device_data, i++);
964
-
965
-		vfio_device_put(device);
919
+			device->ops->request(device->device_data, i++);
966920 
967921 		if (interrupted) {
968
-			wait_woken(&wait, TASK_UNINTERRUPTIBLE, HZ * 10);
922
+			rc = wait_for_completion_timeout(&device->comp,
923
+							 HZ * 10);
969924 		} else {
970
-			wait_woken(&wait, TASK_INTERRUPTIBLE, HZ * 10);
971
-			if (signal_pending(current)) {
925
+			rc = wait_for_completion_interruptible_timeout(
926
+				&device->comp, HZ * 10);
927
+			if (rc < 0) {
972928 				interrupted = true;
973
-				dev_warn(dev,
929
+				dev_warn(device->dev,
974930 					 "Device is currently in use, task"
975931 					 " \"%s\" (%d) "
976932 					 "blocked until device is released",
977933 					 current->comm, task_pid_nr(current));
978934 			}
979935 		}
936
+	}
980937 
981
-	} while (1);
938
+	mutex_lock(&group->device_lock);
939
+	list_del(&device->group_next);
940
+	group->dev_counter--;
941
+	mutex_unlock(&group->device_lock);
982942 
983
-	remove_wait_queue(&vfio.release_q, &wait);
984943 	/*
985944 	 * In order to support multiple devices per group, devices can be
986945 	 * plucked from the group while other devices in the group are still
....@@ -998,8 +957,19 @@
998957 	if (list_empty(&group->device_list))
999958 		wait_event(group->container_q, !group->container);
1000959 
960
+	/* Matches the get in vfio_register_group_dev() */
1001961 	vfio_group_put(group);
962
+}
963
+EXPORT_SYMBOL_GPL(vfio_unregister_group_dev);
1002964 
965
+void *vfio_del_group_dev(struct device *dev)
966
+{
967
+	struct vfio_device *device = dev_get_drvdata(dev);
968
+	void *device_data = device->device_data;
969
+
970
+	vfio_unregister_group_dev(device);
971
+	dev_set_drvdata(dev, NULL);
972
+	kfree(device);
1003973 	return device_data;
1004974 }
1005975 EXPORT_SYMBOL_GPL(vfio_del_group_dev);
....@@ -1190,15 +1160,6 @@
11901160 	return ret;
11911161 }
11921162 
1193
-#ifdef CONFIG_COMPAT
1194
-static long vfio_fops_compat_ioctl(struct file *filep,
1195
-				   unsigned int cmd, unsigned long arg)
1196
-{
1197
-	arg = (unsigned long)compat_ptr(arg);
1198
-	return vfio_fops_unl_ioctl(filep, cmd, arg);
1199
-}
1200
-#endif	/* CONFIG_COMPAT */
1201
-
12021163 static int vfio_fops_open(struct inode *inode, struct file *filep)
12031164 {
12041165 	struct vfio_container *container;
....@@ -1281,9 +1242,7 @@
12811242 	.read		= vfio_fops_read,
12821243 	.write		= vfio_fops_write,
12831244 	.unlocked_ioctl	= vfio_fops_unl_ioctl,
1284
-#ifdef CONFIG_COMPAT
1285
-	.compat_ioctl	= vfio_fops_compat_ioctl,
1286
-#endif
1245
+	.compat_ioctl	= compat_ptr_ioctl,
12871246 	.mmap		= vfio_fops_mmap,
12881247 };
12891248 
....@@ -1447,8 +1406,8 @@
14471406 		return -EPERM;
14481407 
14491408 	device = vfio_device_get_from_name(group, buf);
1450
-	if (!device)
1451
-		return -ENODEV;
1409
+	if (IS_ERR(device))
1410
+		return PTR_ERR(device);
14521411 
14531412 	ret = device->ops->open(device->device_data);
14541413 	if (ret) {
....@@ -1562,15 +1521,6 @@
15621521 	return ret;
15631522 }
15641523 
1565
-#ifdef CONFIG_COMPAT
1566
-static long vfio_group_fops_compat_ioctl(struct file *filep,
1567
-					 unsigned int cmd, unsigned long arg)
1568
-{
1569
-	arg = (unsigned long)compat_ptr(arg);
1570
-	return vfio_group_fops_unl_ioctl(filep, cmd, arg);
1571
-}
1572
-#endif	/* CONFIG_COMPAT */
1573
-
15741524 static int vfio_group_fops_open(struct inode *inode, struct file *filep)
15751525 {
15761526 	struct vfio_group *group;
....@@ -1626,9 +1576,7 @@
16261576 static const struct file_operations vfio_group_fops = {
16271577 	.owner		= THIS_MODULE,
16281578 	.unlocked_ioctl	= vfio_group_fops_unl_ioctl,
1629
-#ifdef CONFIG_COMPAT
1630
-	.compat_ioctl	= vfio_group_fops_compat_ioctl,
1631
-#endif
1579
+	.compat_ioctl	= compat_ptr_ioctl,
16321580 	.open		= vfio_group_fops_open,
16331581 	.release	= vfio_group_fops_release,
16341582 };
....@@ -1693,24 +1641,13 @@
16931641 	return device->ops->mmap(device->device_data, vma);
16941642 }
16951643 
1696
-#ifdef CONFIG_COMPAT
1697
-static long vfio_device_fops_compat_ioctl(struct file *filep,
1698
-					  unsigned int cmd, unsigned long arg)
1699
-{
1700
-	arg = (unsigned long)compat_ptr(arg);
1701
-	return vfio_device_fops_unl_ioctl(filep, cmd, arg);
1702
-}
1703
-#endif	/* CONFIG_COMPAT */
1704
-
17051644 static const struct file_operations vfio_device_fops = {
17061645 	.owner		= THIS_MODULE,
17071646 	.release	= vfio_device_fops_release,
17081647 	.read		= vfio_device_fops_read,
17091648 	.write		= vfio_device_fops_write,
17101649 	.unlocked_ioctl	= vfio_device_fops_unl_ioctl,
1711
-#ifdef CONFIG_COMPAT
1712
-	.compat_ioctl	= vfio_device_fops_compat_ioctl,
1713
-#endif
1650
+	.compat_ioctl	= compat_ptr_ioctl,
17141651 	.mmap		= vfio_device_fops_mmap,
17151652 };
17161653 
....@@ -1758,6 +1695,44 @@
17581695 	return group;
17591696 }
17601697 EXPORT_SYMBOL_GPL(vfio_group_get_external_user);
1698
+
1699
+/**
1700
+ * External user API, exported by symbols to be linked dynamically.
1701
+ * The external user passes in a device pointer
1702
+ * to verify that:
1703
+ *	- A VFIO group is assiciated with the device;
1704
+ *	- IOMMU is set for the group.
1705
+ * If both checks passed, vfio_group_get_external_user_from_dev()
1706
+ * increments the container user counter to prevent the VFIO group
1707
+ * from disposal before external user exits and returns the pointer
1708
+ * to the VFIO group.
1709
+ *
1710
+ * When the external user finishes using the VFIO group, it calls
1711
+ * vfio_group_put_external_user() to release the VFIO group and
1712
+ * decrement the container user counter.
1713
+ *
1714
+ * @dev [in]	: device
1715
+ * Return error PTR or pointer to VFIO group.
1716
+ */
1717
+
1718
+struct vfio_group *vfio_group_get_external_user_from_dev(struct device *dev)
1719
+{
1720
+	struct vfio_group *group;
1721
+	int ret;
1722
+
1723
+	group = vfio_group_get_from_dev(dev);
1724
+	if (!group)
1725
+		return ERR_PTR(-ENODEV);
1726
+
1727
+	ret = vfio_group_add_container_user(group);
1728
+	if (ret) {
1729
+		vfio_group_put(group);
1730
+		return ERR_PTR(ret);
1731
+	}
1732
+
1733
+	return group;
1734
+}
1735
+EXPORT_SYMBOL_GPL(vfio_group_get_external_user_from_dev);
17611736 
17621737 void vfio_group_put_external_user(struct vfio_group *group)
17631738 {
....@@ -1808,6 +1783,7 @@
18081783 	buf = krealloc(caps->buf, caps->size + size, GFP_KERNEL);
18091784 	if (!buf) {
18101785 		kfree(caps->buf);
1786
+		caps->buf = NULL;
18111787 		caps->size = 0;
18121788 		return ERR_PTR(-ENOMEM);
18131789 	}
....@@ -1934,6 +1910,11 @@
19341910 	if (!group)
19351911 		return -ENODEV;
19361912 
1913
+	if (group->dev_counter > 1) {
1914
+		ret = -EINVAL;
1915
+		goto err_pin_pages;
1916
+	}
1917
+
19371918 	ret = vfio_group_add_container_user(group);
19381919 	if (ret)
19391920 		goto err_pin_pages;
....@@ -1941,7 +1922,8 @@
19411922 	container = group->container;
19421923 	driver = container->iommu_driver;
19431924 	if (likely(driver && driver->ops->pin_pages))
1944
-		ret = driver->ops->pin_pages(container->iommu_data, user_pfn,
1925
+		ret = driver->ops->pin_pages(container->iommu_data,
1926
+					     group->iommu_group, user_pfn,
19451927 					     npage, prot, phys_pfn);
19461928 	else
19471929 		ret = -ENOTTY;
....@@ -1999,6 +1981,149 @@
19991981 	return ret;
20001982 }
20011983 EXPORT_SYMBOL(vfio_unpin_pages);
1984
+
1985
+/*
1986
+ * Pin a set of guest IOVA PFNs and return their associated host PFNs for a
1987
+ * VFIO group.
1988
+ *
1989
+ * The caller needs to call vfio_group_get_external_user() or
1990
+ * vfio_group_get_external_user_from_dev() prior to calling this interface,
1991
+ * so as to prevent the VFIO group from disposal in the middle of the call.
1992
+ * But it can keep the reference to the VFIO group for several calls into
1993
+ * this interface.
1994
+ * After finishing using of the VFIO group, the caller needs to release the
1995
+ * VFIO group by calling vfio_group_put_external_user().
1996
+ *
1997
+ * @group [in]		: VFIO group
1998
+ * @user_iova_pfn [in]	: array of user/guest IOVA PFNs to be pinned.
1999
+ * @npage [in]		: count of elements in user_iova_pfn array.
2000
+ *			  This count should not be greater
2001
+ *			  VFIO_PIN_PAGES_MAX_ENTRIES.
2002
+ * @prot [in]		: protection flags
2003
+ * @phys_pfn [out]	: array of host PFNs
2004
+ * Return error or number of pages pinned.
2005
+ */
2006
+int vfio_group_pin_pages(struct vfio_group *group,
2007
+			 unsigned long *user_iova_pfn, int npage,
2008
+			 int prot, unsigned long *phys_pfn)
2009
+{
2010
+	struct vfio_container *container;
2011
+	struct vfio_iommu_driver *driver;
2012
+	int ret;
2013
+
2014
+	if (!group || !user_iova_pfn || !phys_pfn || !npage)
2015
+		return -EINVAL;
2016
+
2017
+	if (group->dev_counter > 1)
2018
+		return -EINVAL;
2019
+
2020
+	if (npage > VFIO_PIN_PAGES_MAX_ENTRIES)
2021
+		return -E2BIG;
2022
+
2023
+	container = group->container;
2024
+	driver = container->iommu_driver;
2025
+	if (likely(driver && driver->ops->pin_pages))
2026
+		ret = driver->ops->pin_pages(container->iommu_data,
2027
+					     group->iommu_group, user_iova_pfn,
2028
+					     npage, prot, phys_pfn);
2029
+	else
2030
+		ret = -ENOTTY;
2031
+
2032
+	return ret;
2033
+}
2034
+EXPORT_SYMBOL(vfio_group_pin_pages);
2035
+
2036
+/*
2037
+ * Unpin a set of guest IOVA PFNs for a VFIO group.
2038
+ *
2039
+ * The caller needs to call vfio_group_get_external_user() or
2040
+ * vfio_group_get_external_user_from_dev() prior to calling this interface,
2041
+ * so as to prevent the VFIO group from disposal in the middle of the call.
2042
+ * But it can keep the reference to the VFIO group for several calls into
2043
+ * this interface.
2044
+ * After finishing using of the VFIO group, the caller needs to release the
2045
+ * VFIO group by calling vfio_group_put_external_user().
2046
+ *
2047
+ * @group [in]		: vfio group
2048
+ * @user_iova_pfn [in]	: array of user/guest IOVA PFNs to be unpinned.
2049
+ * @npage [in]		: count of elements in user_iova_pfn array.
2050
+ *			  This count should not be greater than
2051
+ *			  VFIO_PIN_PAGES_MAX_ENTRIES.
2052
+ * Return error or number of pages unpinned.
2053
+ */
2054
+int vfio_group_unpin_pages(struct vfio_group *group,
2055
+			   unsigned long *user_iova_pfn, int npage)
2056
+{
2057
+	struct vfio_container *container;
2058
+	struct vfio_iommu_driver *driver;
2059
+	int ret;
2060
+
2061
+	if (!group || !user_iova_pfn || !npage)
2062
+		return -EINVAL;
2063
+
2064
+	if (npage > VFIO_PIN_PAGES_MAX_ENTRIES)
2065
+		return -E2BIG;
2066
+
2067
+	container = group->container;
2068
+	driver = container->iommu_driver;
2069
+	if (likely(driver && driver->ops->unpin_pages))
2070
+		ret = driver->ops->unpin_pages(container->iommu_data,
2071
+					       user_iova_pfn, npage);
2072
+	else
2073
+		ret = -ENOTTY;
2074
+
2075
+	return ret;
2076
+}
2077
+EXPORT_SYMBOL(vfio_group_unpin_pages);
2078
+
2079
+
2080
+/*
2081
+ * This interface allows the CPUs to perform some sort of virtual DMA on
2082
+ * behalf of the device.
2083
+ *
2084
+ * CPUs read/write from/into a range of IOVAs pointing to user space memory
2085
+ * into/from a kernel buffer.
2086
+ *
2087
+ * As the read/write of user space memory is conducted via the CPUs and is
2088
+ * not a real device DMA, it is not necessary to pin the user space memory.
2089
+ *
2090
+ * The caller needs to call vfio_group_get_external_user() or
2091
+ * vfio_group_get_external_user_from_dev() prior to calling this interface,
2092
+ * so as to prevent the VFIO group from disposal in the middle of the call.
2093
+ * But it can keep the reference to the VFIO group for several calls into
2094
+ * this interface.
2095
+ * After finishing using of the VFIO group, the caller needs to release the
2096
+ * VFIO group by calling vfio_group_put_external_user().
2097
+ *
2098
+ * @group [in]		: VFIO group
2099
+ * @user_iova [in]	: base IOVA of a user space buffer
2100
+ * @data [in]		: pointer to kernel buffer
2101
+ * @len [in]		: kernel buffer length
2102
+ * @write		: indicate read or write
2103
+ * Return error code on failure or 0 on success.
2104
+ */
2105
+int vfio_dma_rw(struct vfio_group *group, dma_addr_t user_iova,
2106
+		void *data, size_t len, bool write)
2107
+{
2108
+	struct vfio_container *container;
2109
+	struct vfio_iommu_driver *driver;
2110
+	int ret = 0;
2111
+
2112
+	if (!group || !data || len <= 0)
2113
+		return -EINVAL;
2114
+
2115
+	container = group->container;
2116
+	driver = container->iommu_driver;
2117
+
2118
+	if (likely(driver && driver->ops->dma_rw))
2119
+		ret = driver->ops->dma_rw(container->iommu_data,
2120
+					  user_iova, data, len, write);
2121
+	else
2122
+		ret = -ENOTTY;
2123
+
2124
+	return ret;
2125
+}
2126
+EXPORT_SYMBOL(vfio_dma_rw);
20022127 
20032128 static int vfio_register_iommu_notifier(struct vfio_group *group,
20042129 					unsigned long *events,
....@@ -2192,7 +2317,6 @@
21922317 	mutex_init(&vfio.iommu_drivers_lock);
21932318 	INIT_LIST_HEAD(&vfio.group_list);
21942319 	INIT_LIST_HEAD(&vfio.iommu_drivers_list);
2195
-	init_waitqueue_head(&vfio.release_q);
21962320 
21972321 	ret = misc_register(&vfio_dev);
21982322 	if (ret) {
....@@ -2209,12 +2333,12 @@
22092333 
22102334 	vfio.class->devnode = vfio_devnode;
22112335 
2212
-	ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK, "vfio");
2336
+	ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1, "vfio");
22132337 	if (ret)
22142338 		goto err_alloc_chrdev;
22152339 
22162340 	cdev_init(&vfio.group_cdev, &vfio_group_fops);
2217
-	ret = cdev_add(&vfio.group_cdev, vfio.group_devt, MINORMASK);
2341
+	ret = cdev_add(&vfio.group_cdev, vfio.group_devt, MINORMASK + 1);
22182342 	if (ret)
22192343 		goto err_cdev_add;
22202344 
....@@ -2226,7 +2350,7 @@
22262350 	return 0;
22272351 
22282352 err_cdev_add:
2229
-	unregister_chrdev_region(vfio.group_devt, MINORMASK);
2353
+	unregister_chrdev_region(vfio.group_devt, MINORMASK + 1);
22302354 err_alloc_chrdev:
22312355 	class_destroy(vfio.class);
22322356 	vfio.class = NULL;
....@@ -2244,7 +2368,7 @@
22442368 #endif
22452369 	idr_destroy(&vfio.group_idr);
22462370 	cdev_del(&vfio.group_cdev);
2247
-	unregister_chrdev_region(vfio.group_devt, MINORMASK);
2371
+	unregister_chrdev_region(vfio.group_devt, MINORMASK + 1);
22482372 	class_destroy(vfio.class);
22492373 	vfio.class = NULL;
22502374 	misc_deregister(&vfio_dev);