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