xref: /openbmc/linux/drivers/vfio/vfio.h (revision 0cb4228f)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2012 Red Hat, Inc.  All rights reserved.
4  *     Author: Alex Williamson <alex.williamson@redhat.com>
5  */
6 #ifndef __VFIO_VFIO_H__
7 #define __VFIO_VFIO_H__
8 
9 #include <linux/file.h>
10 #include <linux/device.h>
11 #include <linux/cdev.h>
12 #include <linux/module.h>
13 
14 struct iommufd_ctx;
15 struct iommu_group;
16 struct vfio_device;
17 struct vfio_container;
18 
19 void vfio_device_put_registration(struct vfio_device *device);
20 bool vfio_device_try_get_registration(struct vfio_device *device);
21 int vfio_device_open(struct vfio_device *device,
22 		     struct iommufd_ctx *iommufd, struct kvm *kvm);
23 void vfio_device_close(struct vfio_device *device,
24 		       struct iommufd_ctx *iommufd);
25 
26 extern const struct file_operations vfio_device_fops;
27 
28 enum vfio_group_type {
29 	/*
30 	 * Physical device with IOMMU backing.
31 	 */
32 	VFIO_IOMMU,
33 
34 	/*
35 	 * Virtual device without IOMMU backing. The VFIO core fakes up an
36 	 * iommu_group as the iommu_group sysfs interface is part of the
37 	 * userspace ABI.  The user of these devices must not be able to
38 	 * directly trigger unmediated DMA.
39 	 */
40 	VFIO_EMULATED_IOMMU,
41 
42 	/*
43 	 * Physical device without IOMMU backing. The VFIO core fakes up an
44 	 * iommu_group as the iommu_group sysfs interface is part of the
45 	 * userspace ABI.  Users can trigger unmediated DMA by the device,
46 	 * usage is highly dangerous, requires an explicit opt-in and will
47 	 * taint the kernel.
48 	 */
49 	VFIO_NO_IOMMU,
50 };
51 
52 struct vfio_group {
53 	struct device 			dev;
54 	struct cdev			cdev;
55 	/*
56 	 * When drivers is non-zero a driver is attached to the struct device
57 	 * that provided the iommu_group and thus the iommu_group is a valid
58 	 * pointer. When drivers is 0 the driver is being detached. Once users
59 	 * reaches 0 then the iommu_group is invalid.
60 	 */
61 	refcount_t			drivers;
62 	unsigned int			container_users;
63 	struct iommu_group		*iommu_group;
64 	struct vfio_container		*container;
65 	struct list_head		device_list;
66 	struct mutex			device_lock;
67 	struct list_head		vfio_next;
68 #if IS_ENABLED(CONFIG_VFIO_CONTAINER)
69 	struct list_head		container_next;
70 #endif
71 	enum vfio_group_type		type;
72 	struct mutex			group_lock;
73 	struct kvm			*kvm;
74 	struct file			*opened_file;
75 	struct blocking_notifier_head	notifier;
76 	struct iommufd_ctx		*iommufd;
77 };
78 
79 int vfio_device_set_group(struct vfio_device *device,
80 			  enum vfio_group_type type);
81 void vfio_device_remove_group(struct vfio_device *device);
82 void vfio_device_group_register(struct vfio_device *device);
83 void vfio_device_group_unregister(struct vfio_device *device);
84 int vfio_device_group_use_iommu(struct vfio_device *device);
85 void vfio_device_group_unuse_iommu(struct vfio_device *device);
86 void vfio_device_group_close(struct vfio_device *device);
87 bool vfio_device_has_container(struct vfio_device *device);
88 int __init vfio_group_init(void);
89 void vfio_group_cleanup(void);
90 
91 #if IS_ENABLED(CONFIG_VFIO_CONTAINER)
92 /* events for the backend driver notify callback */
93 enum vfio_iommu_notify_type {
94 	VFIO_IOMMU_CONTAINER_CLOSE = 0,
95 };
96 
97 /**
98  * struct vfio_iommu_driver_ops - VFIO IOMMU driver callbacks
99  */
100 struct vfio_iommu_driver_ops {
101 	char		*name;
102 	struct module	*owner;
103 	void		*(*open)(unsigned long arg);
104 	void		(*release)(void *iommu_data);
105 	long		(*ioctl)(void *iommu_data, unsigned int cmd,
106 				 unsigned long arg);
107 	int		(*attach_group)(void *iommu_data,
108 					struct iommu_group *group,
109 					enum vfio_group_type);
110 	void		(*detach_group)(void *iommu_data,
111 					struct iommu_group *group);
112 	int		(*pin_pages)(void *iommu_data,
113 				     struct iommu_group *group,
114 				     dma_addr_t user_iova,
115 				     int npage, int prot,
116 				     struct page **pages);
117 	void		(*unpin_pages)(void *iommu_data,
118 				       dma_addr_t user_iova, int npage);
119 	void		(*register_device)(void *iommu_data,
120 					   struct vfio_device *vdev);
121 	void		(*unregister_device)(void *iommu_data,
122 					     struct vfio_device *vdev);
123 	int		(*dma_rw)(void *iommu_data, dma_addr_t user_iova,
124 				  void *data, size_t count, bool write);
125 	struct iommu_domain *(*group_iommu_domain)(void *iommu_data,
126 						   struct iommu_group *group);
127 	void		(*notify)(void *iommu_data,
128 				  enum vfio_iommu_notify_type event);
129 };
130 
131 struct vfio_iommu_driver {
132 	const struct vfio_iommu_driver_ops	*ops;
133 	struct list_head			vfio_next;
134 };
135 
136 int vfio_register_iommu_driver(const struct vfio_iommu_driver_ops *ops);
137 void vfio_unregister_iommu_driver(const struct vfio_iommu_driver_ops *ops);
138 
139 struct vfio_container *vfio_container_from_file(struct file *filep);
140 int vfio_group_use_container(struct vfio_group *group);
141 void vfio_group_unuse_container(struct vfio_group *group);
142 int vfio_container_attach_group(struct vfio_container *container,
143 				struct vfio_group *group);
144 void vfio_group_detach_container(struct vfio_group *group);
145 void vfio_device_container_register(struct vfio_device *device);
146 void vfio_device_container_unregister(struct vfio_device *device);
147 int vfio_device_container_pin_pages(struct vfio_device *device,
148 				    dma_addr_t iova, int npage,
149 				    int prot, struct page **pages);
150 void vfio_device_container_unpin_pages(struct vfio_device *device,
151 				       dma_addr_t iova, int npage);
152 int vfio_device_container_dma_rw(struct vfio_device *device,
153 				 dma_addr_t iova, void *data,
154 				 size_t len, bool write);
155 
156 int __init vfio_container_init(void);
157 void vfio_container_cleanup(void);
158 #else
159 static inline struct vfio_container *
160 vfio_container_from_file(struct file *filep)
161 {
162 	return NULL;
163 }
164 
165 static inline int vfio_group_use_container(struct vfio_group *group)
166 {
167 	return -EOPNOTSUPP;
168 }
169 
170 static inline void vfio_group_unuse_container(struct vfio_group *group)
171 {
172 }
173 
174 static inline int vfio_container_attach_group(struct vfio_container *container,
175 					      struct vfio_group *group)
176 {
177 	return -EOPNOTSUPP;
178 }
179 
180 static inline void vfio_group_detach_container(struct vfio_group *group)
181 {
182 }
183 
184 static inline void vfio_device_container_register(struct vfio_device *device)
185 {
186 }
187 
188 static inline void vfio_device_container_unregister(struct vfio_device *device)
189 {
190 }
191 
192 static inline int vfio_device_container_pin_pages(struct vfio_device *device,
193 						  dma_addr_t iova, int npage,
194 						  int prot, struct page **pages)
195 {
196 	return -EOPNOTSUPP;
197 }
198 
199 static inline void vfio_device_container_unpin_pages(struct vfio_device *device,
200 						     dma_addr_t iova, int npage)
201 {
202 }
203 
204 static inline int vfio_device_container_dma_rw(struct vfio_device *device,
205 					       dma_addr_t iova, void *data,
206 					       size_t len, bool write)
207 {
208 	return -EOPNOTSUPP;
209 }
210 
211 static inline int vfio_container_init(void)
212 {
213 	return 0;
214 }
215 static inline void vfio_container_cleanup(void)
216 {
217 }
218 #endif
219 
220 #if IS_ENABLED(CONFIG_IOMMUFD)
221 int vfio_iommufd_bind(struct vfio_device *device, struct iommufd_ctx *ictx);
222 void vfio_iommufd_unbind(struct vfio_device *device);
223 #else
224 static inline int vfio_iommufd_bind(struct vfio_device *device,
225 				    struct iommufd_ctx *ictx)
226 {
227 	return -EOPNOTSUPP;
228 }
229 
230 static inline void vfio_iommufd_unbind(struct vfio_device *device)
231 {
232 }
233 #endif
234 
235 #if IS_ENABLED(CONFIG_VFIO_VIRQFD)
236 int __init vfio_virqfd_init(void);
237 void vfio_virqfd_exit(void);
238 #else
239 static inline int __init vfio_virqfd_init(void)
240 {
241 	return 0;
242 }
243 static inline void vfio_virqfd_exit(void)
244 {
245 }
246 #endif
247 
248 #ifdef CONFIG_VFIO_NOIOMMU
249 extern bool vfio_noiommu __read_mostly;
250 #else
251 enum { vfio_noiommu = false };
252 #endif
253 
254 #endif
255