xref: /openbmc/linux/drivers/vfio/vfio.h (revision 0545810f)
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, struct iommufd_ctx *iommufd);
22 void vfio_device_close(struct vfio_device *device,
23 		       struct iommufd_ctx *iommufd);
24 
25 extern const struct file_operations vfio_device_fops;
26 
27 enum vfio_group_type {
28 	/*
29 	 * Physical device with IOMMU backing.
30 	 */
31 	VFIO_IOMMU,
32 
33 	/*
34 	 * Virtual device without IOMMU backing. The VFIO core fakes up an
35 	 * iommu_group as the iommu_group sysfs interface is part of the
36 	 * userspace ABI.  The user of these devices must not be able to
37 	 * directly trigger unmediated DMA.
38 	 */
39 	VFIO_EMULATED_IOMMU,
40 
41 	/*
42 	 * Physical device without IOMMU backing. The VFIO core fakes up an
43 	 * iommu_group as the iommu_group sysfs interface is part of the
44 	 * userspace ABI.  Users can trigger unmediated DMA by the device,
45 	 * usage is highly dangerous, requires an explicit opt-in and will
46 	 * taint the kernel.
47 	 */
48 	VFIO_NO_IOMMU,
49 };
50 
51 struct vfio_group {
52 	struct device 			dev;
53 	struct cdev			cdev;
54 	/*
55 	 * When drivers is non-zero a driver is attached to the struct device
56 	 * that provided the iommu_group and thus the iommu_group is a valid
57 	 * pointer. When drivers is 0 the driver is being detached. Once users
58 	 * reaches 0 then the iommu_group is invalid.
59 	 */
60 	refcount_t			drivers;
61 	unsigned int			container_users;
62 	struct iommu_group		*iommu_group;
63 	struct vfio_container		*container;
64 	struct list_head		device_list;
65 	struct mutex			device_lock;
66 	struct list_head		vfio_next;
67 #if IS_ENABLED(CONFIG_VFIO_CONTAINER)
68 	struct list_head		container_next;
69 #endif
70 	enum vfio_group_type		type;
71 	struct mutex			group_lock;
72 	struct kvm			*kvm;
73 	struct file			*opened_file;
74 	struct blocking_notifier_head	notifier;
75 	struct iommufd_ctx		*iommufd;
76 	spinlock_t			kvm_ref_lock;
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 /**
99  * struct vfio_iommu_driver_ops - VFIO IOMMU driver callbacks
100  */
101 struct vfio_iommu_driver_ops {
102 	char		*name;
103 	struct module	*owner;
104 	void		*(*open)(unsigned long arg);
105 	void		(*release)(void *iommu_data);
106 	long		(*ioctl)(void *iommu_data, unsigned int cmd,
107 				 unsigned long arg);
108 	int		(*attach_group)(void *iommu_data,
109 					struct iommu_group *group,
110 					enum vfio_group_type);
111 	void		(*detach_group)(void *iommu_data,
112 					struct iommu_group *group);
113 	int		(*pin_pages)(void *iommu_data,
114 				     struct iommu_group *group,
115 				     dma_addr_t user_iova,
116 				     int npage, int prot,
117 				     struct page **pages);
118 	void		(*unpin_pages)(void *iommu_data,
119 				       dma_addr_t user_iova, int npage);
120 	void		(*register_device)(void *iommu_data,
121 					   struct vfio_device *vdev);
122 	void		(*unregister_device)(void *iommu_data,
123 					     struct vfio_device *vdev);
124 	int		(*dma_rw)(void *iommu_data, dma_addr_t user_iova,
125 				  void *data, size_t count, bool write);
126 	struct iommu_domain *(*group_iommu_domain)(void *iommu_data,
127 						   struct iommu_group *group);
128 };
129 
130 struct vfio_iommu_driver {
131 	const struct vfio_iommu_driver_ops	*ops;
132 	struct list_head			vfio_next;
133 };
134 
135 int vfio_register_iommu_driver(const struct vfio_iommu_driver_ops *ops);
136 void vfio_unregister_iommu_driver(const struct vfio_iommu_driver_ops *ops);
137 
138 struct vfio_container *vfio_container_from_file(struct file *filep);
139 int vfio_group_use_container(struct vfio_group *group);
140 void vfio_group_unuse_container(struct vfio_group *group);
141 int vfio_container_attach_group(struct vfio_container *container,
142 				struct vfio_group *group);
143 void vfio_group_detach_container(struct vfio_group *group);
144 void vfio_device_container_register(struct vfio_device *device);
145 void vfio_device_container_unregister(struct vfio_device *device);
146 int vfio_device_container_pin_pages(struct vfio_device *device,
147 				    dma_addr_t iova, int npage,
148 				    int prot, struct page **pages);
149 void vfio_device_container_unpin_pages(struct vfio_device *device,
150 				       dma_addr_t iova, int npage);
151 int vfio_device_container_dma_rw(struct vfio_device *device,
152 				 dma_addr_t iova, void *data,
153 				 size_t len, bool write);
154 
155 int __init vfio_container_init(void);
156 void vfio_container_cleanup(void);
157 #else
158 static inline struct vfio_container *
159 vfio_container_from_file(struct file *filep)
160 {
161 	return NULL;
162 }
163 
164 static inline int vfio_group_use_container(struct vfio_group *group)
165 {
166 	return -EOPNOTSUPP;
167 }
168 
169 static inline void vfio_group_unuse_container(struct vfio_group *group)
170 {
171 }
172 
173 static inline int vfio_container_attach_group(struct vfio_container *container,
174 					      struct vfio_group *group)
175 {
176 	return -EOPNOTSUPP;
177 }
178 
179 static inline void vfio_group_detach_container(struct vfio_group *group)
180 {
181 }
182 
183 static inline void vfio_device_container_register(struct vfio_device *device)
184 {
185 }
186 
187 static inline void vfio_device_container_unregister(struct vfio_device *device)
188 {
189 }
190 
191 static inline int vfio_device_container_pin_pages(struct vfio_device *device,
192 						  dma_addr_t iova, int npage,
193 						  int prot, struct page **pages)
194 {
195 	return -EOPNOTSUPP;
196 }
197 
198 static inline void vfio_device_container_unpin_pages(struct vfio_device *device,
199 						     dma_addr_t iova, int npage)
200 {
201 }
202 
203 static inline int vfio_device_container_dma_rw(struct vfio_device *device,
204 					       dma_addr_t iova, void *data,
205 					       size_t len, bool write)
206 {
207 	return -EOPNOTSUPP;
208 }
209 
210 static inline int vfio_container_init(void)
211 {
212 	return 0;
213 }
214 static inline void vfio_container_cleanup(void)
215 {
216 }
217 #endif
218 
219 #if IS_ENABLED(CONFIG_IOMMUFD)
220 int vfio_iommufd_bind(struct vfio_device *device, struct iommufd_ctx *ictx);
221 void vfio_iommufd_unbind(struct vfio_device *device);
222 #else
223 static inline int vfio_iommufd_bind(struct vfio_device *device,
224 				    struct iommufd_ctx *ictx)
225 {
226 	return -EOPNOTSUPP;
227 }
228 
229 static inline void vfio_iommufd_unbind(struct vfio_device *device)
230 {
231 }
232 #endif
233 
234 #if IS_ENABLED(CONFIG_VFIO_VIRQFD)
235 int __init vfio_virqfd_init(void);
236 void vfio_virqfd_exit(void);
237 #else
238 static inline int __init vfio_virqfd_init(void)
239 {
240 	return 0;
241 }
242 static inline void vfio_virqfd_exit(void)
243 {
244 }
245 #endif
246 
247 #ifdef CONFIG_VFIO_NOIOMMU
248 extern bool vfio_noiommu __read_mostly;
249 #else
250 enum { vfio_noiommu = false };
251 #endif
252 
253 #ifdef CONFIG_HAVE_KVM
254 void _vfio_device_get_kvm_safe(struct vfio_device *device, struct kvm *kvm);
255 void vfio_device_put_kvm(struct vfio_device *device);
256 #else
257 static inline void _vfio_device_get_kvm_safe(struct vfio_device *device,
258 					     struct kvm *kvm)
259 {
260 }
261 
262 static inline void vfio_device_put_kvm(struct vfio_device *device)
263 {
264 }
265 #endif
266 
267 #endif
268