vfio.h

  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;
 24struct vfio_info_cap;
 25
 26/*
 27 * VFIO devices can be placed in a set, this allows all devices to share this
 28 * structure and the VFIO core will provide a lock that is held around
 29 * open_device()/close_device() for all devices in the set.
 30 */
 31struct vfio_device_set {
 32	void *set_id;
 33	struct mutex lock;
 34	struct list_head device_list;
 35	unsigned int device_count;
 36};
 37
 38struct vfio_device {
 39	struct device *dev;
 40	const struct vfio_device_ops *ops;
 41	/*
 42	 * mig_ops/log_ops is a static property of the vfio_device which must
 43	 * be set prior to registering the vfio_device.
 44	 */
 45	const struct vfio_migration_ops *mig_ops;
 46	const struct vfio_log_ops *log_ops;
 47#if IS_ENABLED(CONFIG_VFIO_GROUP)
 48	struct vfio_group *group;
 49	struct list_head group_next;
 50	struct list_head iommu_entry;
 51#endif
 52	struct vfio_device_set *dev_set;
 53	struct list_head dev_set_list;
 54	unsigned int migration_flags;
 55	struct kvm *kvm;
 56
 57	/* Members below here are private, not for driver use */
 58	unsigned int index;
 59	struct device device;	/* device.kref covers object life circle */
 60#if IS_ENABLED(CONFIG_VFIO_DEVICE_CDEV)
 61	struct cdev cdev;
 62#endif
 63	refcount_t refcount;	/* user count on registered device*/
 64	unsigned int open_count;
 65	struct completion comp;
 66	struct iommufd_access *iommufd_access;
 67	void (*put_kvm)(struct kvm *kvm);
 68	struct inode *inode;
 69#if IS_ENABLED(CONFIG_IOMMUFD)
 70	struct iommufd_device *iommufd_device;
 71	struct ida pasids;
 72	u8 iommufd_attached:1;
 73#endif
 74	u8 cdev_opened:1;
 75#ifdef CONFIG_DEBUG_FS
 76	/*
 77	 * debug_root is a static property of the vfio_device
 78	 * which must be set prior to registering the vfio_device.
 79	 */
 80	struct dentry *debug_root;
 81#endif
 82};
 83
 84/**
 85 * struct vfio_device_ops - VFIO bus driver device callbacks
 86 *
 87 * @name: Name of the device driver.
 88 * @init: initialize private fields in device structure
 89 * @release: Reclaim private fields in device structure
 90 * @bind_iommufd: Called when binding the device to an iommufd
 91 * @unbind_iommufd: Opposite of bind_iommufd
 92 * @attach_ioas: Called when attaching device to an IOAS/HWPT managed by the
 93 *		 bound iommufd. Undo in unbind_iommufd if @detach_ioas is not
 94 *		 called.
 95 * @detach_ioas: Opposite of attach_ioas
 96 * @pasid_attach_ioas: The pasid variation of attach_ioas
 97 * @pasid_detach_ioas: Opposite of pasid_attach_ioas
 98 * @open_device: Called when the first file descriptor is opened for this device
 99 * @close_device: Opposite of open_device
100 * @read: Perform read(2) on device file descriptor
101 * @write: Perform write(2) on device file descriptor
102 * @ioctl: Perform ioctl(2) on device file descriptor, supporting VFIO_DEVICE_*
103 *         operations documented below
104 * @mmap: Perform mmap(2) on a region of the device file descriptor
105 * @request: Request for the bus driver to release the device
106 * @match: Optional device name match callback (return: 0 for no-match, >0 for
107 *         match, -errno for abort (ex. match with insufficient or incorrect
108 *         additional args)
109 * @match_token_uuid: Optional device token match/validation. Return 0
110 *         if the uuid is valid for the device, -errno otherwise. uuid is NULL
111 *         if none was provided.
112 * @dma_unmap: Called when userspace unmaps IOVA from the container
113 *             this device is attached to.
114 * @device_feature: Optional, fill in the VFIO_DEVICE_FEATURE ioctl
115 */
116struct vfio_device_ops {
117	char	*name;
118	int	(*init)(struct vfio_device *vdev);
119	void	(*release)(struct vfio_device *vdev);
120	int	(*bind_iommufd)(struct vfio_device *vdev,
121				struct iommufd_ctx *ictx, u32 *out_device_id);
122	void	(*unbind_iommufd)(struct vfio_device *vdev);
123	int	(*attach_ioas)(struct vfio_device *vdev, u32 *pt_id);
124	void	(*detach_ioas)(struct vfio_device *vdev);
125	int	(*pasid_attach_ioas)(struct vfio_device *vdev, u32 pasid,
126				     u32 *pt_id);
127	void	(*pasid_detach_ioas)(struct vfio_device *vdev, u32 pasid);
128	int	(*open_device)(struct vfio_device *vdev);
129	void	(*close_device)(struct vfio_device *vdev);
130	ssize_t	(*read)(struct vfio_device *vdev, char __user *buf,
131			size_t count, loff_t *ppos);
132	ssize_t	(*write)(struct vfio_device *vdev, const char __user *buf,
133			 size_t count, loff_t *size);
134	long	(*ioctl)(struct vfio_device *vdev, unsigned int cmd,
135			 unsigned long arg);
136	int	(*get_region_info_caps)(struct vfio_device *vdev,
137					struct vfio_region_info *info,
138					struct vfio_info_cap *caps);
139	int	(*mmap)(struct vfio_device *vdev, struct vm_area_struct *vma);
140	void	(*request)(struct vfio_device *vdev, unsigned int count);
141	int	(*match)(struct vfio_device *vdev, char *buf);
142	int	(*match_token_uuid)(struct vfio_device *vdev, const uuid_t *uuid);
143	void	(*dma_unmap)(struct vfio_device *vdev, u64 iova, u64 length);
144	int	(*device_feature)(struct vfio_device *device, u32 flags,
145				  void __user *arg, size_t argsz);
146};
147
148#if IS_ENABLED(CONFIG_IOMMUFD)
149struct iommufd_ctx *vfio_iommufd_device_ictx(struct vfio_device *vdev);
150int vfio_iommufd_get_dev_id(struct vfio_device *vdev, struct iommufd_ctx *ictx);
151int vfio_iommufd_physical_bind(struct vfio_device *vdev,
152			       struct iommufd_ctx *ictx, u32 *out_device_id);
153void vfio_iommufd_physical_unbind(struct vfio_device *vdev);
154int vfio_iommufd_physical_attach_ioas(struct vfio_device *vdev, u32 *pt_id);
155void vfio_iommufd_physical_detach_ioas(struct vfio_device *vdev);
156int vfio_iommufd_physical_pasid_attach_ioas(struct vfio_device *vdev,
157					    u32 pasid, u32 *pt_id);
158void vfio_iommufd_physical_pasid_detach_ioas(struct vfio_device *vdev,
159					     u32 pasid);
160int vfio_iommufd_emulated_bind(struct vfio_device *vdev,
161			       struct iommufd_ctx *ictx, u32 *out_device_id);
162void vfio_iommufd_emulated_unbind(struct vfio_device *vdev);
163int vfio_iommufd_emulated_attach_ioas(struct vfio_device *vdev, u32 *pt_id);
164void vfio_iommufd_emulated_detach_ioas(struct vfio_device *vdev);
165#else
166static inline struct iommufd_ctx *
167vfio_iommufd_device_ictx(struct vfio_device *vdev)
168{
169	return NULL;
170}
171
172static inline int
173vfio_iommufd_get_dev_id(struct vfio_device *vdev, struct iommufd_ctx *ictx)
174{
175	return VFIO_PCI_DEVID_NOT_OWNED;
176}
177
178#define vfio_iommufd_physical_bind                                      \
179	((int (*)(struct vfio_device *vdev, struct iommufd_ctx *ictx,   \
180		  u32 *out_device_id)) NULL)
181#define vfio_iommufd_physical_unbind \
182	((void (*)(struct vfio_device *vdev)) NULL)
183#define vfio_iommufd_physical_attach_ioas \
184	((int (*)(struct vfio_device *vdev, u32 *pt_id)) NULL)
185#define vfio_iommufd_physical_detach_ioas \
186	((void (*)(struct vfio_device *vdev)) NULL)
187#define vfio_iommufd_physical_pasid_attach_ioas \
188	((int (*)(struct vfio_device *vdev, u32 pasid, u32 *pt_id)) NULL)
189#define vfio_iommufd_physical_pasid_detach_ioas \
190	((void (*)(struct vfio_device *vdev, u32 pasid)) NULL)
191#define vfio_iommufd_emulated_bind                                      \
192	((int (*)(struct vfio_device *vdev, struct iommufd_ctx *ictx,   \
193		  u32 *out_device_id)) NULL)
194#define vfio_iommufd_emulated_unbind \
195	((void (*)(struct vfio_device *vdev)) NULL)
196#define vfio_iommufd_emulated_attach_ioas \
197	((int (*)(struct vfio_device *vdev, u32 *pt_id)) NULL)
198#define vfio_iommufd_emulated_detach_ioas \
199	((void (*)(struct vfio_device *vdev)) NULL)
200#endif
201
202static inline bool vfio_device_cdev_opened(struct vfio_device *device)
203{
204	return device->cdev_opened;
205}
206
207/**
208 * struct vfio_migration_ops - VFIO bus device driver migration callbacks
209 *
210 * @migration_set_state: Optional callback to change the migration state for
211 *         devices that support migration. It's mandatory for
212 *         VFIO_DEVICE_FEATURE_MIGRATION migration support.
213 *         The returned FD is used for data transfer according to the FSM
214 *         definition. The driver is responsible to ensure that FD reaches end
215 *         of stream or error whenever the migration FSM leaves a data transfer
216 *         state or before close_device() returns.
217 * @migration_get_state: Optional callback to get the migration state for
218 *         devices that support migration. It's mandatory for
219 *         VFIO_DEVICE_FEATURE_MIGRATION migration support.
220 * @migration_get_data_size: Optional callback to get the estimated data
221 *          length that will be required to complete stop copy. It's mandatory for
222 *          VFIO_DEVICE_FEATURE_MIGRATION migration support.
223 */
224struct vfio_migration_ops {
225	struct file *(*migration_set_state)(
226		struct vfio_device *device,
227		enum vfio_device_mig_state new_state);
228	int (*migration_get_state)(struct vfio_device *device,
229				   enum vfio_device_mig_state *curr_state);
230	int (*migration_get_data_size)(struct vfio_device *device,
231				       unsigned long *stop_copy_length);
232};
233
234/**
235 * struct vfio_log_ops - VFIO bus device driver logging callbacks
236 *
237 * @log_start: Optional callback to ask the device start DMA logging.
238 * @log_stop: Optional callback to ask the device stop DMA logging.
239 * @log_read_and_clear: Optional callback to ask the device read
240 *         and clear the dirty DMAs in some given range.
241 *
242 * The vfio core implementation of the DEVICE_FEATURE_DMA_LOGGING_ set
243 * of features does not track logging state relative to the device,
244 * therefore the device implementation of vfio_log_ops must handle
245 * arbitrary user requests. This includes rejecting subsequent calls
246 * to log_start without an intervening log_stop, as well as graceful
247 * handling of log_stop and log_read_and_clear from invalid states.
248 */
249struct vfio_log_ops {
250	int (*log_start)(struct vfio_device *device,
251		struct rb_root_cached *ranges, u32 nnodes, u64 *page_size);
252	int (*log_stop)(struct vfio_device *device);
253	int (*log_read_and_clear)(struct vfio_device *device,
254		unsigned long iova, unsigned long length,
255		struct iova_bitmap *dirty);
256};
257
258/**
259 * vfio_check_feature - Validate user input for the VFIO_DEVICE_FEATURE ioctl
260 * @flags: Arg from the device_feature op
261 * @argsz: Arg from the device_feature op
262 * @supported_ops: Combination of VFIO_DEVICE_FEATURE_GET and SET the driver
263 *                 supports
264 * @minsz: Minimum data size the driver accepts
265 *
266 * For use in a driver's device_feature op. Checks that the inputs to the
267 * VFIO_DEVICE_FEATURE ioctl are correct for the driver's feature. Returns 1 if
268 * the driver should execute the get or set, otherwise the relevant
269 * value should be returned.
270 */
271static inline int vfio_check_feature(u32 flags, size_t argsz, u32 supported_ops,
272				    size_t minsz)
273{
274	if ((flags & (VFIO_DEVICE_FEATURE_GET | VFIO_DEVICE_FEATURE_SET)) &
275	    ~supported_ops)
276		return -EINVAL;
277	if (flags & VFIO_DEVICE_FEATURE_PROBE)
278		return 0;
279	/* Without PROBE one of GET or SET must be requested */
280	if (!(flags & (VFIO_DEVICE_FEATURE_GET | VFIO_DEVICE_FEATURE_SET)))
281		return -EINVAL;
282	if (argsz < minsz)
283		return -EINVAL;
284	return 1;
285}
286
287struct vfio_device *_vfio_alloc_device(size_t size, struct device *dev,
288				       const struct vfio_device_ops *ops);
289#define vfio_alloc_device(dev_struct, member, dev, ops)				\
290	container_of(_vfio_alloc_device(sizeof(struct dev_struct) +		\
291					BUILD_BUG_ON_ZERO(offsetof(		\
292						struct dev_struct, member)),	\
293					dev, ops),				\
294		     struct dev_struct, member)
295
296static inline void vfio_put_device(struct vfio_device *device)
297{
298	put_device(&device->device);
299}
300
301int vfio_register_group_dev(struct vfio_device *device);
302int vfio_register_emulated_iommu_dev(struct vfio_device *device);
303void vfio_unregister_group_dev(struct vfio_device *device);
304bool vfio_device_try_get_registration(struct vfio_device *device);
305void vfio_device_put_registration(struct vfio_device *device);
306
307int vfio_assign_device_set(struct vfio_device *device, void *set_id);
308unsigned int vfio_device_set_open_count(struct vfio_device_set *dev_set);
309struct vfio_device *
310vfio_find_device_in_devset(struct vfio_device_set *dev_set,
311			   struct device *dev);
312
313int vfio_mig_get_next_state(struct vfio_device *device,
314			    enum vfio_device_mig_state cur_fsm,
315			    enum vfio_device_mig_state new_fsm,
316			    enum vfio_device_mig_state *next_fsm);
317
318void vfio_combine_iova_ranges(struct rb_root_cached *root, u32 cur_nodes,
319			      u32 req_nodes);
320
321/*
322 * External user API
323 */
324struct iommu_group *vfio_file_iommu_group(struct file *file);
325
326#if IS_ENABLED(CONFIG_VFIO_GROUP)
327bool vfio_file_is_group(struct file *file);
328bool vfio_file_has_dev(struct file *file, struct vfio_device *device);
329#else
330static inline bool vfio_file_is_group(struct file *file)
331{
332	return false;
333}
334
335static inline bool vfio_file_has_dev(struct file *file, struct vfio_device *device)
336{
337	return false;
338}
339#endif
340bool vfio_file_is_valid(struct file *file);
341bool vfio_file_enforced_coherent(struct file *file);
342void vfio_file_set_kvm(struct file *file, struct kvm *kvm);
343
344#define VFIO_PIN_PAGES_MAX_ENTRIES	(PAGE_SIZE/sizeof(unsigned long))
345
346int vfio_pin_pages(struct vfio_device *device, dma_addr_t iova,
347		   int npage, int prot, struct page **pages);
348void vfio_unpin_pages(struct vfio_device *device, dma_addr_t iova, int npage);
349int vfio_dma_rw(struct vfio_device *device, dma_addr_t iova,
350		void *data, size_t len, bool write);
351
352/*
353 * Sub-module helpers
354 */
355struct vfio_info_cap {
356	struct vfio_info_cap_header *buf;
357	size_t size;
358};
359struct vfio_info_cap_header *vfio_info_cap_add(struct vfio_info_cap *caps,
360					       size_t size, u16 id,
361					       u16 version);
362void vfio_info_cap_shift(struct vfio_info_cap *caps, size_t offset);
363
364int vfio_info_add_capability(struct vfio_info_cap *caps,
365			     struct vfio_info_cap_header *cap, size_t size);
366
367int vfio_set_irqs_validate_and_prepare(struct vfio_irq_set *hdr,
368				       int num_irqs, int max_irq_type,
369				       size_t *data_size);
370
371/*
372 * IRQfd - generic
373 */
374struct virqfd {
375	void			*opaque;
376	struct eventfd_ctx	*eventfd;
377	int			(*handler)(void *, void *);
378	void			(*thread)(void *, void *);
379	void			*data;
380	struct work_struct	inject;
381	wait_queue_entry_t		wait;
382	poll_table		pt;
383	struct work_struct	shutdown;
384	struct work_struct	flush_inject;
385	struct virqfd		**pvirqfd;
386};
387
388int vfio_virqfd_enable(void *opaque, int (*handler)(void *, void *),
389		       void (*thread)(void *, void *), void *data,
390		       struct virqfd **pvirqfd, int fd);
391void vfio_virqfd_disable(struct virqfd **pvirqfd);
392void vfio_virqfd_flush_thread(struct virqfd **pvirqfd);
393
394#endif /* VFIO_H */