xref: /linux/include/linux/vfio.h (revision 20460472952043a4735e9abc1fd9de8e024d1c9e)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * VFIO API definition
4  *
5  * Copyright (C) 2012 Red Hat, Inc.  All rights reserved.
6  *     Author: Alex Williamson <alex.williamson@redhat.com>
7  */
8 #ifndef VFIO_H
9 #define VFIO_H
10 
11 
12 #include <linux/iommu.h>
13 #include <linux/mm.h>
14 #include <linux/workqueue.h>
15 #include <linux/poll.h>
16 #include <linux/cdev.h>
17 #include <uapi/linux/vfio.h>
18 #include <linux/iova_bitmap.h>
19 
20 struct kvm;
21 struct iommufd_ctx;
22 struct iommufd_device;
23 struct iommufd_access;
24 
25 /*
26  * VFIO devices can be placed in a set, this allows all devices to share this
27  * structure and the VFIO core will provide a lock that is held around
28  * open_device()/close_device() for all devices in the set.
29  */
30 struct vfio_device_set {
31 	void *set_id;
32 	struct mutex lock;
33 	struct list_head device_list;
34 	unsigned int device_count;
35 };
36 
37 struct vfio_device {
38 	struct device *dev;
39 	const struct vfio_device_ops *ops;
40 	/*
41 	 * mig_ops/log_ops is a static property of the vfio_device which must
42 	 * be set prior to registering the vfio_device.
43 	 */
44 	const struct vfio_migration_ops *mig_ops;
45 	const struct vfio_log_ops *log_ops;
46 #if IS_ENABLED(CONFIG_VFIO_GROUP)
47 	struct vfio_group *group;
48 	struct list_head group_next;
49 	struct list_head iommu_entry;
50 #endif
51 	struct vfio_device_set *dev_set;
52 	struct list_head dev_set_list;
53 	unsigned int migration_flags;
54 	struct kvm *kvm;
55 
56 	/* Members below here are private, not for driver use */
57 	unsigned int index;
58 	struct device device;	/* device.kref covers object life circle */
59 #if IS_ENABLED(CONFIG_VFIO_DEVICE_CDEV)
60 	struct cdev cdev;
61 #endif
62 	refcount_t refcount;	/* user count on registered device*/
63 	unsigned int open_count;
64 	struct completion comp;
65 	struct iommufd_access *iommufd_access;
66 	void (*put_kvm)(struct kvm *kvm);
67 	struct inode *inode;
68 #if IS_ENABLED(CONFIG_IOMMUFD)
69 	struct iommufd_device *iommufd_device;
70 	u8 iommufd_attached:1;
71 #endif
72 	u8 cdev_opened:1;
73 #ifdef CONFIG_DEBUG_FS
74 	/*
75 	 * debug_root is a static property of the vfio_device
76 	 * which must be set prior to registering the vfio_device.
77 	 */
78 	struct dentry *debug_root;
79 #endif
80 };
81 
82 /**
83  * struct vfio_device_ops - VFIO bus driver device callbacks
84  *
85  * @name: Name of the device driver.
86  * @init: initialize private fields in device structure
87  * @release: Reclaim private fields in device structure
88  * @bind_iommufd: Called when binding the device to an iommufd
89  * @unbind_iommufd: Opposite of bind_iommufd
90  * @attach_ioas: Called when attaching device to an IOAS/HWPT managed by the
91  *		 bound iommufd. Undo in unbind_iommufd if @detach_ioas is not
92  *		 called.
93  * @detach_ioas: Opposite of attach_ioas
94  * @open_device: Called when the first file descriptor is opened for this device
95  * @close_device: Opposite of open_device
96  * @read: Perform read(2) on device file descriptor
97  * @write: Perform write(2) on device file descriptor
98  * @ioctl: Perform ioctl(2) on device file descriptor, supporting VFIO_DEVICE_*
99  *         operations documented below
100  * @mmap: Perform mmap(2) on a region of the device file descriptor
101  * @request: Request for the bus driver to release the device
102  * @match: Optional device name match callback (return: 0 for no-match, >0 for
103  *         match, -errno for abort (ex. match with insufficient or incorrect
104  *         additional args)
105  * @dma_unmap: Called when userspace unmaps IOVA from the container
106  *             this device is attached to.
107  * @device_feature: Optional, fill in the VFIO_DEVICE_FEATURE ioctl
108  */
109 struct vfio_device_ops {
110 	char	*name;
111 	int	(*init)(struct vfio_device *vdev);
112 	void	(*release)(struct vfio_device *vdev);
113 	int	(*bind_iommufd)(struct vfio_device *vdev,
114 				struct iommufd_ctx *ictx, u32 *out_device_id);
115 	void	(*unbind_iommufd)(struct vfio_device *vdev);
116 	int	(*attach_ioas)(struct vfio_device *vdev, u32 *pt_id);
117 	void	(*detach_ioas)(struct vfio_device *vdev);
118 	int	(*open_device)(struct vfio_device *vdev);
119 	void	(*close_device)(struct vfio_device *vdev);
120 	ssize_t	(*read)(struct vfio_device *vdev, char __user *buf,
121 			size_t count, loff_t *ppos);
122 	ssize_t	(*write)(struct vfio_device *vdev, const char __user *buf,
123 			 size_t count, loff_t *size);
124 	long	(*ioctl)(struct vfio_device *vdev, unsigned int cmd,
125 			 unsigned long arg);
126 	int	(*mmap)(struct vfio_device *vdev, struct vm_area_struct *vma);
127 	void	(*request)(struct vfio_device *vdev, unsigned int count);
128 	int	(*match)(struct vfio_device *vdev, char *buf);
129 	void	(*dma_unmap)(struct vfio_device *vdev, u64 iova, u64 length);
130 	int	(*device_feature)(struct vfio_device *device, u32 flags,
131 				  void __user *arg, size_t argsz);
132 };
133 
134 #if IS_ENABLED(CONFIG_IOMMUFD)
135 struct iommufd_ctx *vfio_iommufd_device_ictx(struct vfio_device *vdev);
136 int vfio_iommufd_get_dev_id(struct vfio_device *vdev, struct iommufd_ctx *ictx);
137 int vfio_iommufd_physical_bind(struct vfio_device *vdev,
138 			       struct iommufd_ctx *ictx, u32 *out_device_id);
139 void vfio_iommufd_physical_unbind(struct vfio_device *vdev);
140 int vfio_iommufd_physical_attach_ioas(struct vfio_device *vdev, u32 *pt_id);
141 void vfio_iommufd_physical_detach_ioas(struct vfio_device *vdev);
142 int vfio_iommufd_emulated_bind(struct vfio_device *vdev,
143 			       struct iommufd_ctx *ictx, u32 *out_device_id);
144 void vfio_iommufd_emulated_unbind(struct vfio_device *vdev);
145 int vfio_iommufd_emulated_attach_ioas(struct vfio_device *vdev, u32 *pt_id);
146 void vfio_iommufd_emulated_detach_ioas(struct vfio_device *vdev);
147 #else
148 static inline struct iommufd_ctx *
149 vfio_iommufd_device_ictx(struct vfio_device *vdev)
150 {
151 	return NULL;
152 }
153 
154 static inline int
155 vfio_iommufd_get_dev_id(struct vfio_device *vdev, struct iommufd_ctx *ictx)
156 {
157 	return VFIO_PCI_DEVID_NOT_OWNED;
158 }
159 
160 #define vfio_iommufd_physical_bind                                      \
161 	((int (*)(struct vfio_device *vdev, struct iommufd_ctx *ictx,   \
162 		  u32 *out_device_id)) NULL)
163 #define vfio_iommufd_physical_unbind \
164 	((void (*)(struct vfio_device *vdev)) NULL)
165 #define vfio_iommufd_physical_attach_ioas \
166 	((int (*)(struct vfio_device *vdev, u32 *pt_id)) NULL)
167 #define vfio_iommufd_physical_detach_ioas \
168 	((void (*)(struct vfio_device *vdev)) NULL)
169 #define vfio_iommufd_emulated_bind                                      \
170 	((int (*)(struct vfio_device *vdev, struct iommufd_ctx *ictx,   \
171 		  u32 *out_device_id)) NULL)
172 #define vfio_iommufd_emulated_unbind \
173 	((void (*)(struct vfio_device *vdev)) NULL)
174 #define vfio_iommufd_emulated_attach_ioas \
175 	((int (*)(struct vfio_device *vdev, u32 *pt_id)) NULL)
176 #define vfio_iommufd_emulated_detach_ioas \
177 	((void (*)(struct vfio_device *vdev)) NULL)
178 #endif
179 
180 static inline bool vfio_device_cdev_opened(struct vfio_device *device)
181 {
182 	return device->cdev_opened;
183 }
184 
185 /**
186  * struct vfio_migration_ops - VFIO bus device driver migration callbacks
187  *
188  * @migration_set_state: Optional callback to change the migration state for
189  *         devices that support migration. It's mandatory for
190  *         VFIO_DEVICE_FEATURE_MIGRATION migration support.
191  *         The returned FD is used for data transfer according to the FSM
192  *         definition. The driver is responsible to ensure that FD reaches end
193  *         of stream or error whenever the migration FSM leaves a data transfer
194  *         state or before close_device() returns.
195  * @migration_get_state: Optional callback to get the migration state for
196  *         devices that support migration. It's mandatory for
197  *         VFIO_DEVICE_FEATURE_MIGRATION migration support.
198  * @migration_get_data_size: Optional callback to get the estimated data
199  *          length that will be required to complete stop copy. It's mandatory for
200  *          VFIO_DEVICE_FEATURE_MIGRATION migration support.
201  */
202 struct vfio_migration_ops {
203 	struct file *(*migration_set_state)(
204 		struct vfio_device *device,
205 		enum vfio_device_mig_state new_state);
206 	int (*migration_get_state)(struct vfio_device *device,
207 				   enum vfio_device_mig_state *curr_state);
208 	int (*migration_get_data_size)(struct vfio_device *device,
209 				       unsigned long *stop_copy_length);
210 };
211 
212 /**
213  * struct vfio_log_ops - VFIO bus device driver logging callbacks
214  *
215  * @log_start: Optional callback to ask the device start DMA logging.
216  * @log_stop: Optional callback to ask the device stop DMA logging.
217  * @log_read_and_clear: Optional callback to ask the device read
218  *         and clear the dirty DMAs in some given range.
219  *
220  * The vfio core implementation of the DEVICE_FEATURE_DMA_LOGGING_ set
221  * of features does not track logging state relative to the device,
222  * therefore the device implementation of vfio_log_ops must handle
223  * arbitrary user requests. This includes rejecting subsequent calls
224  * to log_start without an intervening log_stop, as well as graceful
225  * handling of log_stop and log_read_and_clear from invalid states.
226  */
227 struct vfio_log_ops {
228 	int (*log_start)(struct vfio_device *device,
229 		struct rb_root_cached *ranges, u32 nnodes, u64 *page_size);
230 	int (*log_stop)(struct vfio_device *device);
231 	int (*log_read_and_clear)(struct vfio_device *device,
232 		unsigned long iova, unsigned long length,
233 		struct iova_bitmap *dirty);
234 };
235 
236 /**
237  * vfio_check_feature - Validate user input for the VFIO_DEVICE_FEATURE ioctl
238  * @flags: Arg from the device_feature op
239  * @argsz: Arg from the device_feature op
240  * @supported_ops: Combination of VFIO_DEVICE_FEATURE_GET and SET the driver
241  *                 supports
242  * @minsz: Minimum data size the driver accepts
243  *
244  * For use in a driver's device_feature op. Checks that the inputs to the
245  * VFIO_DEVICE_FEATURE ioctl are correct for the driver's feature. Returns 1 if
246  * the driver should execute the get or set, otherwise the relevant
247  * value should be returned.
248  */
249 static inline int vfio_check_feature(u32 flags, size_t argsz, u32 supported_ops,
250 				    size_t minsz)
251 {
252 	if ((flags & (VFIO_DEVICE_FEATURE_GET | VFIO_DEVICE_FEATURE_SET)) &
253 	    ~supported_ops)
254 		return -EINVAL;
255 	if (flags & VFIO_DEVICE_FEATURE_PROBE)
256 		return 0;
257 	/* Without PROBE one of GET or SET must be requested */
258 	if (!(flags & (VFIO_DEVICE_FEATURE_GET | VFIO_DEVICE_FEATURE_SET)))
259 		return -EINVAL;
260 	if (argsz < minsz)
261 		return -EINVAL;
262 	return 1;
263 }
264 
265 struct vfio_device *_vfio_alloc_device(size_t size, struct device *dev,
266 				       const struct vfio_device_ops *ops);
267 #define vfio_alloc_device(dev_struct, member, dev, ops)				\
268 	container_of(_vfio_alloc_device(sizeof(struct dev_struct) +		\
269 					BUILD_BUG_ON_ZERO(offsetof(		\
270 						struct dev_struct, member)),	\
271 					dev, ops),				\
272 		     struct dev_struct, member)
273 
274 static inline void vfio_put_device(struct vfio_device *device)
275 {
276 	put_device(&device->device);
277 }
278 
279 int vfio_register_group_dev(struct vfio_device *device);
280 int vfio_register_emulated_iommu_dev(struct vfio_device *device);
281 void vfio_unregister_group_dev(struct vfio_device *device);
282 
283 int vfio_assign_device_set(struct vfio_device *device, void *set_id);
284 unsigned int vfio_device_set_open_count(struct vfio_device_set *dev_set);
285 struct vfio_device *
286 vfio_find_device_in_devset(struct vfio_device_set *dev_set,
287 			   struct device *dev);
288 
289 int vfio_mig_get_next_state(struct vfio_device *device,
290 			    enum vfio_device_mig_state cur_fsm,
291 			    enum vfio_device_mig_state new_fsm,
292 			    enum vfio_device_mig_state *next_fsm);
293 
294 void vfio_combine_iova_ranges(struct rb_root_cached *root, u32 cur_nodes,
295 			      u32 req_nodes);
296 
297 /*
298  * External user API
299  */
300 struct iommu_group *vfio_file_iommu_group(struct file *file);
301 
302 #if IS_ENABLED(CONFIG_VFIO_GROUP)
303 bool vfio_file_is_group(struct file *file);
304 bool vfio_file_has_dev(struct file *file, struct vfio_device *device);
305 #else
306 static inline bool vfio_file_is_group(struct file *file)
307 {
308 	return false;
309 }
310 
311 static inline bool vfio_file_has_dev(struct file *file, struct vfio_device *device)
312 {
313 	return false;
314 }
315 #endif
316 bool vfio_file_is_valid(struct file *file);
317 bool vfio_file_enforced_coherent(struct file *file);
318 void vfio_file_set_kvm(struct file *file, struct kvm *kvm);
319 
320 #define VFIO_PIN_PAGES_MAX_ENTRIES	(PAGE_SIZE/sizeof(unsigned long))
321 
322 int vfio_pin_pages(struct vfio_device *device, dma_addr_t iova,
323 		   int npage, int prot, struct page **pages);
324 void vfio_unpin_pages(struct vfio_device *device, dma_addr_t iova, int npage);
325 int vfio_dma_rw(struct vfio_device *device, dma_addr_t iova,
326 		void *data, size_t len, bool write);
327 
328 /*
329  * Sub-module helpers
330  */
331 struct vfio_info_cap {
332 	struct vfio_info_cap_header *buf;
333 	size_t size;
334 };
335 struct vfio_info_cap_header *vfio_info_cap_add(struct vfio_info_cap *caps,
336 					       size_t size, u16 id,
337 					       u16 version);
338 void vfio_info_cap_shift(struct vfio_info_cap *caps, size_t offset);
339 
340 int vfio_info_add_capability(struct vfio_info_cap *caps,
341 			     struct vfio_info_cap_header *cap, size_t size);
342 
343 int vfio_set_irqs_validate_and_prepare(struct vfio_irq_set *hdr,
344 				       int num_irqs, int max_irq_type,
345 				       size_t *data_size);
346 
347 /*
348  * IRQfd - generic
349  */
350 struct virqfd {
351 	void			*opaque;
352 	struct eventfd_ctx	*eventfd;
353 	int			(*handler)(void *, void *);
354 	void			(*thread)(void *, void *);
355 	void			*data;
356 	struct work_struct	inject;
357 	wait_queue_entry_t		wait;
358 	poll_table		pt;
359 	struct work_struct	shutdown;
360 	struct work_struct	flush_inject;
361 	struct virqfd		**pvirqfd;
362 };
363 
364 int vfio_virqfd_enable(void *opaque, int (*handler)(void *, void *),
365 		       void (*thread)(void *, void *), void *data,
366 		       struct virqfd **pvirqfd, int fd);
367 void vfio_virqfd_disable(struct virqfd **pvirqfd);
368 void vfio_virqfd_flush_thread(struct virqfd **pvirqfd);
369 
370 #endif /* VFIO_H */
371