Merge tag 'locking-core-2023-05-05' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-block.git] / drivers / vhost / vhost.h
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b2441318 1/* SPDX-License-Identifier: GPL-2.0 */
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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>
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9#include <linux/poll.h>
10#include <linux/file.h>
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11#include <linux/uio.h>
12#include <linux/virtio_config.h>
13#include <linux/virtio_ring.h>
60063497 14#include <linux/atomic.h>
0bbe3066 15#include <linux/vhost_iotlb.h>
265a0ad8 16#include <linux/irqbypass.h>
3a4d5c94 17
c23f3445 18struct vhost_work;
6e890c5d 19struct vhost_task;
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20typedef void (*vhost_work_fn_t)(struct vhost_work *work);
21
04b96e55 22#define VHOST_WORK_QUEUED 1
c23f3445 23struct vhost_work {
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24 struct llist_node node;
25 vhost_work_fn_t fn;
26 unsigned long flags;
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27};
28
1a5f8090 29struct vhost_worker {
6e890c5d 30 struct vhost_task *vtsk;
1a5f8090 31 struct llist_head work_list;
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32 u64 kcov_handle;
33};
34
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35/* Poll a file (eventfd or socket) */
36/* Note: there's nothing vhost specific about this structure. */
37struct vhost_poll {
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38 poll_table table;
39 wait_queue_head_t *wqh;
40 wait_queue_entry_t wait;
41 struct vhost_work work;
42 __poll_t mask;
43 struct vhost_dev *dev;
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44};
45
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46void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn);
47void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work);
526d3e7f 48bool vhost_has_work(struct vhost_dev *dev);
163049ae 49
c23f3445 50void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
58e3b602 51 __poll_t mask, struct vhost_dev *dev);
2b8b328b 52int vhost_poll_start(struct vhost_poll *poll, struct file *file);
3a4d5c94 53void vhost_poll_stop(struct vhost_poll *poll);
3a4d5c94 54void vhost_poll_queue(struct vhost_poll *poll);
b2ffa407 55void vhost_dev_flush(struct vhost_dev *dev);
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56
57struct vhost_log {
58 u64 addr;
59 u64 len;
60};
61
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62enum vhost_uaddr_type {
63 VHOST_ADDR_DESC = 0,
64 VHOST_ADDR_AVAIL = 1,
65 VHOST_ADDR_USED = 2,
66 VHOST_NUM_ADDRS = 3,
67};
68
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69struct vhost_vring_call {
70 struct eventfd_ctx *ctx;
71 struct irq_bypass_producer producer;
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72};
73
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74/* The virtqueue structure describes a queue attached to a device. */
75struct vhost_virtqueue {
76 struct vhost_dev *dev;
77
78 /* The actual ring of buffers. */
79 struct mutex mutex;
80 unsigned int num;
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81 vring_desc_t __user *desc;
82 vring_avail_t __user *avail;
83 vring_used_t __user *used;
0bbe3066 84 const struct vhost_iotlb_map *meta_iotlb[VHOST_NUM_ADDRS];
3a4d5c94 85 struct file *kick;
265a0ad8 86 struct vhost_vring_call call_ctx;
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87 struct eventfd_ctx *error_ctx;
88 struct eventfd_ctx *log_ctx;
89
90 struct vhost_poll poll;
91
92 /* The routine to call when the Guest pings us, or timeout. */
c23f3445 93 vhost_work_fn_t handle_kick;
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94
95 /* Last available index we saw. */
96 u16 last_avail_idx;
97
98 /* Caches available index value from user. */
99 u16 avail_idx;
100
101 /* Last index we used. */
102 u16 last_used_idx;
103
104 /* Used flags */
105 u16 used_flags;
106
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107 /* Last used index value we have signalled on */
108 u16 signalled_used;
109
110 /* Last used index value we have signalled on */
111 bool signalled_used_valid;
112
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113 /* Log writes to used structure. */
114 bool log_used;
115 u64 log_addr;
116
e0e9b406 117 struct iovec iov[UIO_MAXIOV];
6b1e6cc7 118 struct iovec iotlb_iov[64];
e0e9b406 119 struct iovec *indirect;
e0e9b406 120 struct vring_used_elem *heads;
22fa90c7 121 /* Protected by virtqueue mutex. */
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122 struct vhost_iotlb *umem;
123 struct vhost_iotlb *iotlb;
22fa90c7 124 void *private_data;
bd82752a 125 u64 acked_features;
429711ae 126 u64 acked_backend_features;
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127 /* Log write descriptors */
128 void __user *log_base;
e0e9b406 129 struct vhost_log *log;
5e5e8736 130 struct iovec log_iov[64];
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131
132 /* Ring endianness. Defaults to legacy native endianness.
133 * Set to true when starting a modern virtio device. */
134 bool is_le;
135#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
136 /* Ring endianness requested by userspace for cross-endian support. */
137 bool user_be;
138#endif
03088137 139 u32 busyloop_timeout;
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140};
141
6b1e6cc7 142struct vhost_msg_node {
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143 union {
144 struct vhost_msg msg;
145 struct vhost_msg_v2 msg_v2;
146 };
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147 struct vhost_virtqueue *vq;
148 struct list_head node;
149};
150
3a4d5c94 151struct vhost_dev {
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152 struct mm_struct *mm;
153 struct mutex mutex;
3ab2e420 154 struct vhost_virtqueue **vqs;
3a4d5c94 155 int nvqs;
3a4d5c94 156 struct eventfd_ctx *log_ctx;
1a5f8090 157 struct vhost_worker *worker;
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158 struct vhost_iotlb *umem;
159 struct vhost_iotlb *iotlb;
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160 spinlock_t iotlb_lock;
161 struct list_head read_list;
162 struct list_head pending_list;
163 wait_queue_head_t wait;
b46a0bf7 164 int iov_limit;
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165 int weight;
166 int byte_weight;
01fcb1cb 167 bool use_worker;
91233ad7 168 int (*msg_handler)(struct vhost_dev *dev, u32 asid,
792a4f2e 169 struct vhost_iotlb_msg *msg);
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170};
171
e82b9b07 172bool vhost_exceeds_weight(struct vhost_virtqueue *vq, int pkts, int total_len);
b46a0bf7 173void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs,
792a4f2e 174 int nvqs, int iov_limit, int weight, int byte_weight,
01fcb1cb 175 bool use_worker,
91233ad7 176 int (*msg_handler)(struct vhost_dev *dev, u32 asid,
792a4f2e 177 struct vhost_iotlb_msg *msg));
54db63c2 178long vhost_dev_set_owner(struct vhost_dev *dev);
05c05351 179bool vhost_dev_has_owner(struct vhost_dev *dev);
3a4d5c94 180long vhost_dev_check_owner(struct vhost_dev *);
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181struct vhost_iotlb *vhost_dev_reset_owner_prepare(void);
182void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_iotlb *iotlb);
f6f93f75 183void vhost_dev_cleanup(struct vhost_dev *);
b211616d 184void vhost_dev_stop(struct vhost_dev *);
935cdee7 185long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp);
26b36604 186long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp);
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187bool vhost_vq_access_ok(struct vhost_virtqueue *vq);
188bool vhost_log_access_ok(struct vhost_dev *);
9526f9a2 189void vhost_clear_msg(struct vhost_dev *dev);
3a4d5c94 190
47283bef 191int vhost_get_vq_desc(struct vhost_virtqueue *,
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192 struct iovec iov[], unsigned int iov_count,
193 unsigned int *out_num, unsigned int *in_num,
194 struct vhost_log *log, unsigned int *log_num);
8dd014ad 195void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
3a4d5c94 196
6bcf3422 197bool vhost_vq_is_setup(struct vhost_virtqueue *vq);
80f7d030 198int vhost_vq_init_access(struct vhost_virtqueue *);
3a4d5c94 199int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
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200int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads,
201 unsigned count);
3a4d5c94 202void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *,
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203 unsigned int id, int len);
204void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *,
205 struct vring_used_elem *heads, unsigned count);
206void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *);
8ea8cf89 207void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *);
d4a60603 208bool vhost_vq_avail_empty(struct vhost_dev *, struct vhost_virtqueue *);
8ea8cf89 209bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *);
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210
211int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
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212 unsigned int log_num, u64 len,
213 struct iovec *iov, int count);
9b5e830b 214int vq_meta_prefetch(struct vhost_virtqueue *vq);
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215
216struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type);
217void vhost_enqueue_msg(struct vhost_dev *dev,
218 struct list_head *head,
219 struct vhost_msg_node *node);
220struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev,
221 struct list_head *head);
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222void vhost_set_backend_features(struct vhost_dev *dev, u64 features);
223
afc9a42b 224__poll_t vhost_chr_poll(struct file *file, struct vhost_dev *dev,
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225 poll_table *wait);
226ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to,
227 int noblock);
228ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
229 struct iov_iter *from);
759aba1e 230int vhost_init_device_iotlb(struct vhost_dev *d);
3a4d5c94 231
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232void vhost_iotlb_map_free(struct vhost_iotlb *iotlb,
233 struct vhost_iotlb_map *map);
234
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235#define vq_err(vq, fmt, ...) do { \
236 pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
237 if ((vq)->error_ctx) \
238 eventfd_signal((vq)->error_ctx, 1);\
239 } while (0)
240
241enum {
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242 VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) |
243 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) |
244 (1ULL << VIRTIO_RING_F_EVENT_IDX) |
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245 (1ULL << VHOST_F_LOG_ALL) |
246 (1ULL << VIRTIO_F_ANY_LAYOUT) |
247 (1ULL << VIRTIO_F_VERSION_1)
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248};
249
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250/**
251 * vhost_vq_set_backend - Set backend.
252 *
253 * @vq Virtqueue.
254 * @private_data The private data.
255 *
256 * Context: Need to call with vq->mutex acquired.
257 */
258static inline void vhost_vq_set_backend(struct vhost_virtqueue *vq,
259 void *private_data)
260{
261 vq->private_data = private_data;
262}
263
264/**
265 * vhost_vq_get_backend - Get backend.
266 *
267 * @vq Virtqueue.
268 *
269 * Context: Need to call with vq->mutex acquired.
270 * Return: Private data previously set with vhost_vq_set_backend.
271 */
272static inline void *vhost_vq_get_backend(struct vhost_virtqueue *vq)
273{
274 return vq->private_data;
275}
276
bd82752a 277static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit)
3a4d5c94 278{
bd82752a 279 return vq->acked_features & (1ULL << bit);
3a4d5c94 280}
e05fd12b 281
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282static inline bool vhost_backend_has_feature(struct vhost_virtqueue *vq, int bit)
283{
284 return vq->acked_backend_features & (1ULL << bit);
285}
286
e407f39a 287#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
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288static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
289{
2751c988 290 return vq->is_le;
ab27c07f 291}
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292#else
293static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
294{
295 return virtio_legacy_is_little_endian() || vq->is_le;
296}
297#endif
ab27c07f 298
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299/* Memory accessors */
300static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val)
301{
ab27c07f 302 return __virtio16_to_cpu(vhost_is_little_endian(vq), val);
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303}
304
305static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val)
306{
ab27c07f 307 return __cpu_to_virtio16(vhost_is_little_endian(vq), val);
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308}
309
310static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val)
311{
ab27c07f 312 return __virtio32_to_cpu(vhost_is_little_endian(vq), val);
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313}
314
315static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val)
316{
ab27c07f 317 return __cpu_to_virtio32(vhost_is_little_endian(vq), val);
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318}
319
320static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val)
321{
ab27c07f 322 return __virtio64_to_cpu(vhost_is_little_endian(vq), val);
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323}
324
325static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val)
326{
ab27c07f 327 return __cpu_to_virtio64(vhost_is_little_endian(vq), val);
e05fd12b 328}
3a4d5c94 329#endif