xref: /openbmc/linux/drivers/vfio/vfio.h (revision 9e6bfd42b14b45737cae8bc84c759f1874949b8b)
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 #include <linux/vfio.h>
14 
15 struct iommufd_ctx;
16 struct iommu_group;
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 static inline bool vfio_device_is_noiommu(struct vfio_device *vdev)
92 {
93 	return IS_ENABLED(CONFIG_VFIO_NOIOMMU) &&
94 	       vdev->group->type == VFIO_NO_IOMMU;
95 }
96 
97 #if IS_ENABLED(CONFIG_VFIO_CONTAINER)
98 /* events for the backend driver notify callback */
99 enum vfio_iommu_notify_type {
100 	VFIO_IOMMU_CONTAINER_CLOSE = 0,
101 };
102 
103 /**
104  * struct vfio_iommu_driver_ops - VFIO IOMMU driver callbacks
105  */
106 struct vfio_iommu_driver_ops {
107 	char		*name;
108 	struct module	*owner;
109 	void		*(*open)(unsigned long arg);
110 	void		(*release)(void *iommu_data);
111 	long		(*ioctl)(void *iommu_data, unsigned int cmd,
112 				 unsigned long arg);
113 	int		(*attach_group)(void *iommu_data,
114 					struct iommu_group *group,
115 					enum vfio_group_type);
116 	void		(*detach_group)(void *iommu_data,
117 					struct iommu_group *group);
118 	int		(*pin_pages)(void *iommu_data,
119 				     struct iommu_group *group,
120 				     dma_addr_t user_iova,
121 				     int npage, int prot,
122 				     struct page **pages);
123 	void		(*unpin_pages)(void *iommu_data,
124 				       dma_addr_t user_iova, int npage);
125 	void		(*register_device)(void *iommu_data,
126 					   struct vfio_device *vdev);
127 	void		(*unregister_device)(void *iommu_data,
128 					     struct vfio_device *vdev);
129 	int		(*dma_rw)(void *iommu_data, dma_addr_t user_iova,
130 				  void *data, size_t count, bool write);
131 	struct iommu_domain *(*group_iommu_domain)(void *iommu_data,
132 						   struct iommu_group *group);
133 	void		(*notify)(void *iommu_data,
134 				  enum vfio_iommu_notify_type event);
135 };
136 
137 struct vfio_iommu_driver {
138 	const struct vfio_iommu_driver_ops	*ops;
139 	struct list_head			vfio_next;
140 };
141 
142 int vfio_register_iommu_driver(const struct vfio_iommu_driver_ops *ops);
143 void vfio_unregister_iommu_driver(const struct vfio_iommu_driver_ops *ops);
144 
145 struct vfio_container *vfio_container_from_file(struct file *filep);
146 int vfio_group_use_container(struct vfio_group *group);
147 void vfio_group_unuse_container(struct vfio_group *group);
148 int vfio_container_attach_group(struct vfio_container *container,
149 				struct vfio_group *group);
150 void vfio_group_detach_container(struct vfio_group *group);
151 void vfio_device_container_register(struct vfio_device *device);
152 void vfio_device_container_unregister(struct vfio_device *device);
153 int vfio_device_container_pin_pages(struct vfio_device *device,
154 				    dma_addr_t iova, int npage,
155 				    int prot, struct page **pages);
156 void vfio_device_container_unpin_pages(struct vfio_device *device,
157 				       dma_addr_t iova, int npage);
158 int vfio_device_container_dma_rw(struct vfio_device *device,
159 				 dma_addr_t iova, void *data,
160 				 size_t len, bool write);
161 
162 int __init vfio_container_init(void);
163 void vfio_container_cleanup(void);
164 #else
165 static inline struct vfio_container *
166 vfio_container_from_file(struct file *filep)
167 {
168 	return NULL;
169 }
170 
171 static inline int vfio_group_use_container(struct vfio_group *group)
172 {
173 	return -EOPNOTSUPP;
174 }
175 
176 static inline void vfio_group_unuse_container(struct vfio_group *group)
177 {
178 }
179 
180 static inline int vfio_container_attach_group(struct vfio_container *container,
181 					      struct vfio_group *group)
182 {
183 	return -EOPNOTSUPP;
184 }
185 
186 static inline void vfio_group_detach_container(struct vfio_group *group)
187 {
188 }
189 
190 static inline void vfio_device_container_register(struct vfio_device *device)
191 {
192 }
193 
194 static inline void vfio_device_container_unregister(struct vfio_device *device)
195 {
196 }
197 
198 static inline int vfio_device_container_pin_pages(struct vfio_device *device,
199 						  dma_addr_t iova, int npage,
200 						  int prot, struct page **pages)
201 {
202 	return -EOPNOTSUPP;
203 }
204 
205 static inline void vfio_device_container_unpin_pages(struct vfio_device *device,
206 						     dma_addr_t iova, int npage)
207 {
208 }
209 
210 static inline int vfio_device_container_dma_rw(struct vfio_device *device,
211 					       dma_addr_t iova, void *data,
212 					       size_t len, bool write)
213 {
214 	return -EOPNOTSUPP;
215 }
216 
217 static inline int vfio_container_init(void)
218 {
219 	return 0;
220 }
221 static inline void vfio_container_cleanup(void)
222 {
223 }
224 #endif
225 
226 #if IS_ENABLED(CONFIG_IOMMUFD)
227 int vfio_iommufd_bind(struct vfio_device *device, struct iommufd_ctx *ictx);
228 void vfio_iommufd_unbind(struct vfio_device *device);
229 #else
230 static inline int vfio_iommufd_bind(struct vfio_device *device,
231 				    struct iommufd_ctx *ictx)
232 {
233 	return -EOPNOTSUPP;
234 }
235 
236 static inline void vfio_iommufd_unbind(struct vfio_device *device)
237 {
238 }
239 #endif
240 
241 #if IS_ENABLED(CONFIG_VFIO_VIRQFD)
242 int __init vfio_virqfd_init(void);
243 void vfio_virqfd_exit(void);
244 #else
245 static inline int __init vfio_virqfd_init(void)
246 {
247 	return 0;
248 }
249 static inline void vfio_virqfd_exit(void)
250 {
251 }
252 #endif
253 
254 #ifdef CONFIG_VFIO_NOIOMMU
255 extern bool vfio_noiommu __read_mostly;
256 #else
257 enum { vfio_noiommu = false };
258 #endif
259 
260 #endif
261