xref: /openbmc/linux/include/linux/vfio.h (revision d63670d2)
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 <uapi/linux/vfio.h>
17 
18 /*
19  * VFIO devices can be placed in a set, this allows all devices to share this
20  * structure and the VFIO core will provide a lock that is held around
21  * open_device()/close_device() for all devices in the set.
22  */
23 struct vfio_device_set {
24 	void *set_id;
25 	struct mutex lock;
26 	struct list_head device_list;
27 	unsigned int device_count;
28 };
29 
30 struct vfio_device {
31 	struct device *dev;
32 	const struct vfio_device_ops *ops;
33 	struct vfio_group *group;
34 	struct vfio_device_set *dev_set;
35 	struct list_head dev_set_list;
36 	unsigned int migration_flags;
37 
38 	/* Members below here are private, not for driver use */
39 	refcount_t refcount;
40 	unsigned int open_count;
41 	struct completion comp;
42 	struct list_head group_next;
43 };
44 
45 /**
46  * struct vfio_device_ops - VFIO bus driver device callbacks
47  *
48  * @open_device: Called when the first file descriptor is opened for this device
49  * @close_device: Opposite of open_device
50  * @read: Perform read(2) on device file descriptor
51  * @write: Perform write(2) on device file descriptor
52  * @ioctl: Perform ioctl(2) on device file descriptor, supporting VFIO_DEVICE_*
53  *         operations documented below
54  * @mmap: Perform mmap(2) on a region of the device file descriptor
55  * @request: Request for the bus driver to release the device
56  * @match: Optional device name match callback (return: 0 for no-match, >0 for
57  *         match, -errno for abort (ex. match with insufficient or incorrect
58  *         additional args)
59  * @device_feature: Optional, fill in the VFIO_DEVICE_FEATURE ioctl
60  * @migration_set_state: Optional callback to change the migration state for
61  *         devices that support migration. It's mandatory for
62  *         VFIO_DEVICE_FEATURE_MIGRATION migration support.
63  *         The returned FD is used for data transfer according to the FSM
64  *         definition. The driver is responsible to ensure that FD reaches end
65  *         of stream or error whenever the migration FSM leaves a data transfer
66  *         state or before close_device() returns.
67  * @migration_get_state: Optional callback to get the migration state for
68  *         devices that support migration. It's mandatory for
69  *         VFIO_DEVICE_FEATURE_MIGRATION migration support.
70  */
71 struct vfio_device_ops {
72 	char	*name;
73 	int	(*open_device)(struct vfio_device *vdev);
74 	void	(*close_device)(struct vfio_device *vdev);
75 	ssize_t	(*read)(struct vfio_device *vdev, char __user *buf,
76 			size_t count, loff_t *ppos);
77 	ssize_t	(*write)(struct vfio_device *vdev, const char __user *buf,
78 			 size_t count, loff_t *size);
79 	long	(*ioctl)(struct vfio_device *vdev, unsigned int cmd,
80 			 unsigned long arg);
81 	int	(*mmap)(struct vfio_device *vdev, struct vm_area_struct *vma);
82 	void	(*request)(struct vfio_device *vdev, unsigned int count);
83 	int	(*match)(struct vfio_device *vdev, char *buf);
84 	int	(*device_feature)(struct vfio_device *device, u32 flags,
85 				  void __user *arg, size_t argsz);
86 	struct file *(*migration_set_state)(
87 		struct vfio_device *device,
88 		enum vfio_device_mig_state new_state);
89 	int (*migration_get_state)(struct vfio_device *device,
90 				   enum vfio_device_mig_state *curr_state);
91 };
92 
93 /**
94  * vfio_check_feature - Validate user input for the VFIO_DEVICE_FEATURE ioctl
95  * @flags: Arg from the device_feature op
96  * @argsz: Arg from the device_feature op
97  * @supported_ops: Combination of VFIO_DEVICE_FEATURE_GET and SET the driver
98  *                 supports
99  * @minsz: Minimum data size the driver accepts
100  *
101  * For use in a driver's device_feature op. Checks that the inputs to the
102  * VFIO_DEVICE_FEATURE ioctl are correct for the driver's feature. Returns 1 if
103  * the driver should execute the get or set, otherwise the relevant
104  * value should be returned.
105  */
106 static inline int vfio_check_feature(u32 flags, size_t argsz, u32 supported_ops,
107 				    size_t minsz)
108 {
109 	if ((flags & (VFIO_DEVICE_FEATURE_GET | VFIO_DEVICE_FEATURE_SET)) &
110 	    ~supported_ops)
111 		return -EINVAL;
112 	if (flags & VFIO_DEVICE_FEATURE_PROBE)
113 		return 0;
114 	/* Without PROBE one of GET or SET must be requested */
115 	if (!(flags & (VFIO_DEVICE_FEATURE_GET | VFIO_DEVICE_FEATURE_SET)))
116 		return -EINVAL;
117 	if (argsz < minsz)
118 		return -EINVAL;
119 	return 1;
120 }
121 
122 void vfio_init_group_dev(struct vfio_device *device, struct device *dev,
123 			 const struct vfio_device_ops *ops);
124 void vfio_uninit_group_dev(struct vfio_device *device);
125 int vfio_register_group_dev(struct vfio_device *device);
126 int vfio_register_emulated_iommu_dev(struct vfio_device *device);
127 void vfio_unregister_group_dev(struct vfio_device *device);
128 extern struct vfio_device *vfio_device_get_from_dev(struct device *dev);
129 extern void vfio_device_put(struct vfio_device *device);
130 
131 int vfio_assign_device_set(struct vfio_device *device, void *set_id);
132 
133 int vfio_mig_get_next_state(struct vfio_device *device,
134 			    enum vfio_device_mig_state cur_fsm,
135 			    enum vfio_device_mig_state new_fsm,
136 			    enum vfio_device_mig_state *next_fsm);
137 
138 /*
139  * External user API
140  */
141 extern struct vfio_group *vfio_group_get_external_user(struct file *filep);
142 extern void vfio_group_put_external_user(struct vfio_group *group);
143 extern struct vfio_group *vfio_group_get_external_user_from_dev(struct device
144 								*dev);
145 extern bool vfio_external_group_match_file(struct vfio_group *group,
146 					   struct file *filep);
147 extern int vfio_external_user_iommu_id(struct vfio_group *group);
148 extern long vfio_external_check_extension(struct vfio_group *group,
149 					  unsigned long arg);
150 
151 #define VFIO_PIN_PAGES_MAX_ENTRIES	(PAGE_SIZE/sizeof(unsigned long))
152 
153 extern int vfio_pin_pages(struct device *dev, unsigned long *user_pfn,
154 			  int npage, int prot, unsigned long *phys_pfn);
155 extern int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn,
156 			    int npage);
157 
158 extern int vfio_group_pin_pages(struct vfio_group *group,
159 				unsigned long *user_iova_pfn, int npage,
160 				int prot, unsigned long *phys_pfn);
161 extern int vfio_group_unpin_pages(struct vfio_group *group,
162 				  unsigned long *user_iova_pfn, int npage);
163 
164 extern int vfio_dma_rw(struct vfio_group *group, dma_addr_t user_iova,
165 		       void *data, size_t len, bool write);
166 
167 extern struct iommu_domain *vfio_group_iommu_domain(struct vfio_group *group);
168 
169 /* each type has independent events */
170 enum vfio_notify_type {
171 	VFIO_IOMMU_NOTIFY = 0,
172 	VFIO_GROUP_NOTIFY = 1,
173 };
174 
175 /* events for VFIO_IOMMU_NOTIFY */
176 #define VFIO_IOMMU_NOTIFY_DMA_UNMAP	BIT(0)
177 
178 /* events for VFIO_GROUP_NOTIFY */
179 #define VFIO_GROUP_NOTIFY_SET_KVM	BIT(0)
180 
181 extern int vfio_register_notifier(struct device *dev,
182 				  enum vfio_notify_type type,
183 				  unsigned long *required_events,
184 				  struct notifier_block *nb);
185 extern int vfio_unregister_notifier(struct device *dev,
186 				    enum vfio_notify_type type,
187 				    struct notifier_block *nb);
188 
189 struct kvm;
190 extern void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm);
191 
192 /*
193  * Sub-module helpers
194  */
195 struct vfio_info_cap {
196 	struct vfio_info_cap_header *buf;
197 	size_t size;
198 };
199 extern struct vfio_info_cap_header *vfio_info_cap_add(
200 		struct vfio_info_cap *caps, size_t size, u16 id, u16 version);
201 extern void vfio_info_cap_shift(struct vfio_info_cap *caps, size_t offset);
202 
203 extern int vfio_info_add_capability(struct vfio_info_cap *caps,
204 				    struct vfio_info_cap_header *cap,
205 				    size_t size);
206 
207 extern int vfio_set_irqs_validate_and_prepare(struct vfio_irq_set *hdr,
208 					      int num_irqs, int max_irq_type,
209 					      size_t *data_size);
210 
211 struct pci_dev;
212 #if IS_ENABLED(CONFIG_VFIO_SPAPR_EEH)
213 extern void vfio_spapr_pci_eeh_open(struct pci_dev *pdev);
214 extern void vfio_spapr_pci_eeh_release(struct pci_dev *pdev);
215 extern long vfio_spapr_iommu_eeh_ioctl(struct iommu_group *group,
216 				       unsigned int cmd,
217 				       unsigned long arg);
218 #else
219 static inline void vfio_spapr_pci_eeh_open(struct pci_dev *pdev)
220 {
221 }
222 
223 static inline void vfio_spapr_pci_eeh_release(struct pci_dev *pdev)
224 {
225 }
226 
227 static inline long vfio_spapr_iommu_eeh_ioctl(struct iommu_group *group,
228 					      unsigned int cmd,
229 					      unsigned long arg)
230 {
231 	return -ENOTTY;
232 }
233 #endif /* CONFIG_VFIO_SPAPR_EEH */
234 
235 /*
236  * IRQfd - generic
237  */
238 struct virqfd {
239 	void			*opaque;
240 	struct eventfd_ctx	*eventfd;
241 	int			(*handler)(void *, void *);
242 	void			(*thread)(void *, void *);
243 	void			*data;
244 	struct work_struct	inject;
245 	wait_queue_entry_t		wait;
246 	poll_table		pt;
247 	struct work_struct	shutdown;
248 	struct virqfd		**pvirqfd;
249 };
250 
251 extern int vfio_virqfd_enable(void *opaque,
252 			      int (*handler)(void *, void *),
253 			      void (*thread)(void *, void *),
254 			      void *data, struct virqfd **pvirqfd, int fd);
255 extern void vfio_virqfd_disable(struct virqfd **pvirqfd);
256 
257 #endif /* VFIO_H */
258