1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #ifndef _VHOST_H |
3 | #define _VHOST_H |
4 | |
5 | #include <linux/eventfd.h> |
6 | #include <linux/vhost.h> |
7 | #include <linux/mm.h> |
8 | #include <linux/mutex.h> |
9 | #include <linux/poll.h> |
10 | #include <linux/file.h> |
11 | #include <linux/uio.h> |
12 | #include <linux/virtio_config.h> |
13 | #include <linux/virtio_ring.h> |
14 | #include <linux/atomic.h> |
15 | #include <linux/vhost_iotlb.h> |
16 | #include <linux/irqbypass.h> |
17 | |
18 | struct vhost_work; |
19 | struct vhost_task; |
20 | typedef void (*vhost_work_fn_t)(struct vhost_work *work); |
21 | |
22 | #define VHOST_WORK_QUEUED 1 |
23 | struct vhost_work { |
24 | struct llist_node node; |
25 | vhost_work_fn_t fn; |
26 | unsigned long flags; |
27 | }; |
28 | |
29 | struct vhost_worker { |
30 | struct vhost_task *vtsk; |
31 | /* Used to serialize device wide flushing with worker swapping. */ |
32 | struct mutex mutex; |
33 | struct llist_head work_list; |
34 | u64 kcov_handle; |
35 | u32 id; |
36 | int attachment_cnt; |
37 | }; |
38 | |
39 | /* Poll a file (eventfd or socket) */ |
40 | /* Note: there's nothing vhost specific about this structure. */ |
41 | struct vhost_poll { |
42 | poll_table table; |
43 | wait_queue_head_t *wqh; |
44 | wait_queue_entry_t wait; |
45 | struct vhost_work work; |
46 | __poll_t mask; |
47 | struct vhost_dev *dev; |
48 | struct vhost_virtqueue *vq; |
49 | }; |
50 | |
51 | void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn, |
52 | __poll_t mask, struct vhost_dev *dev, |
53 | struct vhost_virtqueue *vq); |
54 | int vhost_poll_start(struct vhost_poll *poll, struct file *file); |
55 | void vhost_poll_stop(struct vhost_poll *poll); |
56 | void vhost_poll_queue(struct vhost_poll *poll); |
57 | |
58 | void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn); |
59 | void vhost_dev_flush(struct vhost_dev *dev); |
60 | |
61 | struct vhost_log { |
62 | u64 addr; |
63 | u64 len; |
64 | }; |
65 | |
66 | enum vhost_uaddr_type { |
67 | VHOST_ADDR_DESC = 0, |
68 | VHOST_ADDR_AVAIL = 1, |
69 | VHOST_ADDR_USED = 2, |
70 | VHOST_NUM_ADDRS = 3, |
71 | }; |
72 | |
73 | struct vhost_vring_call { |
74 | struct eventfd_ctx *ctx; |
75 | struct irq_bypass_producer producer; |
76 | }; |
77 | |
78 | /* The virtqueue structure describes a queue attached to a device. */ |
79 | struct vhost_virtqueue { |
80 | struct vhost_dev *dev; |
81 | struct vhost_worker __rcu *worker; |
82 | |
83 | /* The actual ring of buffers. */ |
84 | struct mutex mutex; |
85 | unsigned int num; |
86 | vring_desc_t __user *desc; |
87 | vring_avail_t __user *avail; |
88 | vring_used_t __user *used; |
89 | const struct vhost_iotlb_map *meta_iotlb[VHOST_NUM_ADDRS]; |
90 | struct file *kick; |
91 | struct vhost_vring_call call_ctx; |
92 | struct eventfd_ctx *error_ctx; |
93 | struct eventfd_ctx *log_ctx; |
94 | |
95 | struct vhost_poll poll; |
96 | |
97 | /* The routine to call when the Guest pings us, or timeout. */ |
98 | vhost_work_fn_t handle_kick; |
99 | |
100 | /* Last available index we saw. |
101 | * Values are limited to 0x7fff, and the high bit is used as |
102 | * a wrap counter when using VIRTIO_F_RING_PACKED. */ |
103 | u16 last_avail_idx; |
104 | |
105 | /* Caches available index value from user. */ |
106 | u16 avail_idx; |
107 | |
108 | /* Last index we used. |
109 | * Values are limited to 0x7fff, and the high bit is used as |
110 | * a wrap counter when using VIRTIO_F_RING_PACKED. */ |
111 | u16 last_used_idx; |
112 | |
113 | /* Used flags */ |
114 | u16 used_flags; |
115 | |
116 | /* Last used index value we have signalled on */ |
117 | u16 signalled_used; |
118 | |
119 | /* Last used index value we have signalled on */ |
120 | bool signalled_used_valid; |
121 | |
122 | /* Log writes to used structure. */ |
123 | bool log_used; |
124 | u64 log_addr; |
125 | |
126 | struct iovec iov[UIO_MAXIOV]; |
127 | struct iovec iotlb_iov[64]; |
128 | struct iovec *indirect; |
129 | struct vring_used_elem *heads; |
130 | /* Protected by virtqueue mutex. */ |
131 | struct vhost_iotlb *umem; |
132 | struct vhost_iotlb *iotlb; |
133 | void *private_data; |
134 | u64 acked_features; |
135 | u64 acked_backend_features; |
136 | /* Log write descriptors */ |
137 | void __user *log_base; |
138 | struct vhost_log *log; |
139 | struct iovec log_iov[64]; |
140 | |
141 | /* Ring endianness. Defaults to legacy native endianness. |
142 | * Set to true when starting a modern virtio device. */ |
143 | bool is_le; |
144 | #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY |
145 | /* Ring endianness requested by userspace for cross-endian support. */ |
146 | bool user_be; |
147 | #endif |
148 | u32 busyloop_timeout; |
149 | }; |
150 | |
151 | struct vhost_msg_node { |
152 | union { |
153 | struct vhost_msg msg; |
154 | struct vhost_msg_v2 msg_v2; |
155 | }; |
156 | struct vhost_virtqueue *vq; |
157 | struct list_head node; |
158 | }; |
159 | |
160 | struct vhost_dev { |
161 | struct mm_struct *mm; |
162 | struct mutex mutex; |
163 | struct vhost_virtqueue **vqs; |
164 | int nvqs; |
165 | struct eventfd_ctx *log_ctx; |
166 | struct vhost_iotlb *umem; |
167 | struct vhost_iotlb *iotlb; |
168 | spinlock_t iotlb_lock; |
169 | struct list_head read_list; |
170 | struct list_head pending_list; |
171 | wait_queue_head_t wait; |
172 | int iov_limit; |
173 | int weight; |
174 | int byte_weight; |
175 | struct xarray worker_xa; |
176 | bool use_worker; |
177 | int (*msg_handler)(struct vhost_dev *dev, u32 asid, |
178 | struct vhost_iotlb_msg *msg); |
179 | }; |
180 | |
181 | bool vhost_exceeds_weight(struct vhost_virtqueue *vq, int pkts, int total_len); |
182 | void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, |
183 | int nvqs, int iov_limit, int weight, int byte_weight, |
184 | bool use_worker, |
185 | int (*msg_handler)(struct vhost_dev *dev, u32 asid, |
186 | struct vhost_iotlb_msg *msg)); |
187 | long vhost_dev_set_owner(struct vhost_dev *dev); |
188 | bool vhost_dev_has_owner(struct vhost_dev *dev); |
189 | long vhost_dev_check_owner(struct vhost_dev *); |
190 | struct vhost_iotlb *vhost_dev_reset_owner_prepare(void); |
191 | void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_iotlb *iotlb); |
192 | void vhost_dev_cleanup(struct vhost_dev *); |
193 | void vhost_dev_stop(struct vhost_dev *); |
194 | long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp); |
195 | long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp); |
196 | long vhost_worker_ioctl(struct vhost_dev *dev, unsigned int ioctl, |
197 | void __user *argp); |
198 | bool vhost_vq_access_ok(struct vhost_virtqueue *vq); |
199 | bool vhost_log_access_ok(struct vhost_dev *); |
200 | void vhost_clear_msg(struct vhost_dev *dev); |
201 | |
202 | int vhost_get_vq_desc(struct vhost_virtqueue *, |
203 | struct iovec iov[], unsigned int iov_size, |
204 | unsigned int *out_num, unsigned int *in_num, |
205 | struct vhost_log *log, unsigned int *log_num); |
206 | void vhost_discard_vq_desc(struct vhost_virtqueue *, int n); |
207 | |
208 | void vhost_vq_flush(struct vhost_virtqueue *vq); |
209 | bool vhost_vq_work_queue(struct vhost_virtqueue *vq, struct vhost_work *work); |
210 | bool vhost_vq_has_work(struct vhost_virtqueue *vq); |
211 | bool vhost_vq_is_setup(struct vhost_virtqueue *vq); |
212 | int vhost_vq_init_access(struct vhost_virtqueue *); |
213 | int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len); |
214 | int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads, |
215 | unsigned count); |
216 | void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *, |
217 | unsigned int id, int len); |
218 | void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *, |
219 | struct vring_used_elem *heads, unsigned count); |
220 | void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *); |
221 | void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *); |
222 | bool vhost_vq_avail_empty(struct vhost_dev *, struct vhost_virtqueue *); |
223 | bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *); |
224 | |
225 | int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, |
226 | unsigned int log_num, u64 len, |
227 | struct iovec *iov, int count); |
228 | int vq_meta_prefetch(struct vhost_virtqueue *vq); |
229 | |
230 | struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type); |
231 | void vhost_enqueue_msg(struct vhost_dev *dev, |
232 | struct list_head *head, |
233 | struct vhost_msg_node *node); |
234 | struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev, |
235 | struct list_head *head); |
236 | void vhost_set_backend_features(struct vhost_dev *dev, u64 features); |
237 | |
238 | __poll_t vhost_chr_poll(struct file *file, struct vhost_dev *dev, |
239 | poll_table *wait); |
240 | ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to, |
241 | int noblock); |
242 | ssize_t vhost_chr_write_iter(struct vhost_dev *dev, |
243 | struct iov_iter *from); |
244 | int vhost_init_device_iotlb(struct vhost_dev *d); |
245 | |
246 | void vhost_iotlb_map_free(struct vhost_iotlb *iotlb, |
247 | struct vhost_iotlb_map *map); |
248 | |
249 | #define vq_err(vq, fmt, ...) do { \ |
250 | pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \ |
251 | if ((vq)->error_ctx) \ |
252 | eventfd_signal((vq)->error_ctx, 1);\ |
253 | } while (0) |
254 | |
255 | enum { |
256 | VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | |
257 | (1ULL << VIRTIO_RING_F_INDIRECT_DESC) | |
258 | (1ULL << VIRTIO_RING_F_EVENT_IDX) | |
259 | (1ULL << VHOST_F_LOG_ALL) | |
260 | (1ULL << VIRTIO_F_ANY_LAYOUT) | |
261 | (1ULL << VIRTIO_F_VERSION_1) |
262 | }; |
263 | |
264 | /** |
265 | * vhost_vq_set_backend - Set backend. |
266 | * |
267 | * @vq Virtqueue. |
268 | * @private_data The private data. |
269 | * |
270 | * Context: Need to call with vq->mutex acquired. |
271 | */ |
272 | static inline void vhost_vq_set_backend(struct vhost_virtqueue *vq, |
273 | void *private_data) |
274 | { |
275 | vq->private_data = private_data; |
276 | } |
277 | |
278 | /** |
279 | * vhost_vq_get_backend - Get backend. |
280 | * |
281 | * @vq Virtqueue. |
282 | * |
283 | * Context: Need to call with vq->mutex acquired. |
284 | * Return: Private data previously set with vhost_vq_set_backend. |
285 | */ |
286 | static inline void *vhost_vq_get_backend(struct vhost_virtqueue *vq) |
287 | { |
288 | return vq->private_data; |
289 | } |
290 | |
291 | static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit) |
292 | { |
293 | return vq->acked_features & (1ULL << bit); |
294 | } |
295 | |
296 | static inline bool vhost_backend_has_feature(struct vhost_virtqueue *vq, int bit) |
297 | { |
298 | return vq->acked_backend_features & (1ULL << bit); |
299 | } |
300 | |
301 | #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY |
302 | static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq) |
303 | { |
304 | return vq->is_le; |
305 | } |
306 | #else |
307 | static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq) |
308 | { |
309 | return virtio_legacy_is_little_endian() || vq->is_le; |
310 | } |
311 | #endif |
312 | |
313 | /* Memory accessors */ |
314 | static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val) |
315 | { |
316 | return __virtio16_to_cpu(little_endian: vhost_is_little_endian(vq), val); |
317 | } |
318 | |
319 | static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val) |
320 | { |
321 | return __cpu_to_virtio16(little_endian: vhost_is_little_endian(vq), val); |
322 | } |
323 | |
324 | static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val) |
325 | { |
326 | return __virtio32_to_cpu(little_endian: vhost_is_little_endian(vq), val); |
327 | } |
328 | |
329 | static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val) |
330 | { |
331 | return __cpu_to_virtio32(little_endian: vhost_is_little_endian(vq), val); |
332 | } |
333 | |
334 | static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val) |
335 | { |
336 | return __virtio64_to_cpu(little_endian: vhost_is_little_endian(vq), val); |
337 | } |
338 | |
339 | static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val) |
340 | { |
341 | return __cpu_to_virtio64(little_endian: vhost_is_little_endian(vq), val); |
342 | } |
343 | #endif |
344 | |