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vhost: introduce vhost_exceeds_weight()
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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>
3a4d5c94 15
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16struct vhost_work;
17typedef void (*vhost_work_fn_t)(struct vhost_work *work);
18
04b96e55 19#define VHOST_WORK_QUEUED 1
c23f3445 20struct vhost_work {
04b96e55 21 struct llist_node node;
c23f3445 22 vhost_work_fn_t fn;
04b96e55 23 unsigned long flags;
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24};
25
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26/* Poll a file (eventfd or socket) */
27/* Note: there's nothing vhost specific about this structure. */
28struct vhost_poll {
29 poll_table table;
30 wait_queue_head_t *wqh;
ac6424b9 31 wait_queue_entry_t wait;
c23f3445 32 struct vhost_work work;
58e3b602 33 __poll_t mask;
c23f3445 34 struct vhost_dev *dev;
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35};
36
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37void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn);
38void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work);
526d3e7f 39bool vhost_has_work(struct vhost_dev *dev);
163049ae 40
c23f3445 41void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
58e3b602 42 __poll_t mask, struct vhost_dev *dev);
2b8b328b 43int vhost_poll_start(struct vhost_poll *poll, struct file *file);
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44void vhost_poll_stop(struct vhost_poll *poll);
45void vhost_poll_flush(struct vhost_poll *poll);
46void vhost_poll_queue(struct vhost_poll *poll);
6ac1afbf 47void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work);
26b36604 48long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp);
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49
50struct vhost_log {
51 u64 addr;
52 u64 len;
53};
54
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55#define START(node) ((node)->start)
56#define LAST(node) ((node)->last)
57
58struct vhost_umem_node {
59 struct rb_node rb;
60 struct list_head link;
61 __u64 start;
62 __u64 last;
63 __u64 size;
64 __u64 userspace_addr;
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65 __u32 perm;
66 __u32 flags_padding;
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67 __u64 __subtree_last;
68};
69
70struct vhost_umem {
f808c13f 71 struct rb_root_cached umem_tree;
a9709d68 72 struct list_head umem_list;
6b1e6cc7 73 int numem;
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74};
75
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76enum vhost_uaddr_type {
77 VHOST_ADDR_DESC = 0,
78 VHOST_ADDR_AVAIL = 1,
79 VHOST_ADDR_USED = 2,
80 VHOST_NUM_ADDRS = 3,
81};
82
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83/* The virtqueue structure describes a queue attached to a device. */
84struct vhost_virtqueue {
85 struct vhost_dev *dev;
86
87 /* The actual ring of buffers. */
88 struct mutex mutex;
89 unsigned int num;
90 struct vring_desc __user *desc;
91 struct vring_avail __user *avail;
92 struct vring_used __user *used;
f8894913 93 const struct vhost_umem_node *meta_iotlb[VHOST_NUM_ADDRS];
3a4d5c94 94 struct file *kick;
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95 struct eventfd_ctx *call_ctx;
96 struct eventfd_ctx *error_ctx;
97 struct eventfd_ctx *log_ctx;
98
99 struct vhost_poll poll;
100
101 /* The routine to call when the Guest pings us, or timeout. */
c23f3445 102 vhost_work_fn_t handle_kick;
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103
104 /* Last available index we saw. */
105 u16 last_avail_idx;
106
107 /* Caches available index value from user. */
108 u16 avail_idx;
109
110 /* Last index we used. */
111 u16 last_used_idx;
112
113 /* Used flags */
114 u16 used_flags;
115
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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
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122 /* Log writes to used structure. */
123 bool log_used;
124 u64 log_addr;
125
e0e9b406 126 struct iovec iov[UIO_MAXIOV];
6b1e6cc7 127 struct iovec iotlb_iov[64];
e0e9b406 128 struct iovec *indirect;
e0e9b406 129 struct vring_used_elem *heads;
22fa90c7 130 /* Protected by virtqueue mutex. */
a9709d68 131 struct vhost_umem *umem;
6b1e6cc7 132 struct vhost_umem *iotlb;
22fa90c7 133 void *private_data;
bd82752a 134 u64 acked_features;
429711ae 135 u64 acked_backend_features;
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136 /* Log write descriptors */
137 void __user *log_base;
e0e9b406 138 struct vhost_log *log;
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139
140 /* Ring endianness. Defaults to legacy native endianness.
141 * Set to true when starting a modern virtio device. */
142 bool is_le;
143#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
144 /* Ring endianness requested by userspace for cross-endian support. */
145 bool user_be;
146#endif
03088137 147 u32 busyloop_timeout;
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148};
149
6b1e6cc7 150struct vhost_msg_node {
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151 union {
152 struct vhost_msg msg;
153 struct vhost_msg_v2 msg_v2;
154 };
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155 struct vhost_virtqueue *vq;
156 struct list_head node;
157};
158
3a4d5c94 159struct vhost_dev {
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160 struct mm_struct *mm;
161 struct mutex mutex;
3ab2e420 162 struct vhost_virtqueue **vqs;
3a4d5c94 163 int nvqs;
3a4d5c94 164 struct eventfd_ctx *log_ctx;
04b96e55 165 struct llist_head work_list;
c23f3445 166 struct task_struct *worker;
a9709d68 167 struct vhost_umem *umem;
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168 struct vhost_umem *iotlb;
169 spinlock_t iotlb_lock;
170 struct list_head read_list;
171 struct list_head pending_list;
172 wait_queue_head_t wait;
b46a0bf7 173 int iov_limit;
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174 int weight;
175 int byte_weight;
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176};
177
99a79c62 178bool vhost_exceeds_weight(struct vhost_virtqueue *vq, int pkts, int total_len);
b46a0bf7 179void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs,
99a79c62 180 int nvqs, int iov_limit, int weight, int byte_weight);
54db63c2 181long vhost_dev_set_owner(struct vhost_dev *dev);
05c05351 182bool vhost_dev_has_owner(struct vhost_dev *dev);
3a4d5c94 183long vhost_dev_check_owner(struct vhost_dev *);
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184struct vhost_umem *vhost_dev_reset_owner_prepare(void);
185void vhost_dev_reset_owner(struct vhost_dev *, struct vhost_umem *);
f6f93f75 186void vhost_dev_cleanup(struct vhost_dev *);
b211616d 187void vhost_dev_stop(struct vhost_dev *);
935cdee7 188long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp);
26b36604 189long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp);
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190bool vhost_vq_access_ok(struct vhost_virtqueue *vq);
191bool vhost_log_access_ok(struct vhost_dev *);
3a4d5c94 192
47283bef 193int vhost_get_vq_desc(struct vhost_virtqueue *,
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194 struct iovec iov[], unsigned int iov_count,
195 unsigned int *out_num, unsigned int *in_num,
196 struct vhost_log *log, unsigned int *log_num);
8dd014ad 197void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
3a4d5c94 198
80f7d030 199int vhost_vq_init_access(struct vhost_virtqueue *);
3a4d5c94 200int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
8dd014ad
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201int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads,
202 unsigned count);
3a4d5c94 203void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *,
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204 unsigned int id, int len);
205void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *,
206 struct vring_used_elem *heads, unsigned count);
207void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *);
8ea8cf89 208void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *);
d4a60603 209bool vhost_vq_avail_empty(struct vhost_dev *, struct vhost_virtqueue *);
8ea8cf89 210bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *);
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211
212int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
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213 unsigned int log_num, u64 len,
214 struct iovec *iov, int count);
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215int vq_iotlb_prefetch(struct vhost_virtqueue *vq);
216
217struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type);
218void vhost_enqueue_msg(struct vhost_dev *dev,
219 struct list_head *head,
220 struct vhost_msg_node *node);
221struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev,
222 struct list_head *head);
afc9a42b 223__poll_t vhost_chr_poll(struct file *file, struct vhost_dev *dev,
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224 poll_table *wait);
225ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to,
226 int noblock);
227ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
228 struct iov_iter *from);
229int vhost_init_device_iotlb(struct vhost_dev *d, bool enabled);
3a4d5c94 230
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231#define vq_err(vq, fmt, ...) do { \
232 pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
233 if ((vq)->error_ctx) \
234 eventfd_signal((vq)->error_ctx, 1);\
235 } while (0)
236
237enum {
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238 VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) |
239 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) |
240 (1ULL << VIRTIO_RING_F_EVENT_IDX) |
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241 (1ULL << VHOST_F_LOG_ALL) |
242 (1ULL << VIRTIO_F_ANY_LAYOUT) |
243 (1ULL << VIRTIO_F_VERSION_1)
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244};
245
bd82752a 246static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit)
3a4d5c94 247{
bd82752a 248 return vq->acked_features & (1ULL << bit);
3a4d5c94 249}
e05fd12b 250
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251static inline bool vhost_backend_has_feature(struct vhost_virtqueue *vq, int bit)
252{
253 return vq->acked_backend_features & (1ULL << bit);
254}
255
e407f39a 256#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
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257static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
258{
2751c988 259 return vq->is_le;
ab27c07f 260}
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261#else
262static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
263{
264 return virtio_legacy_is_little_endian() || vq->is_le;
265}
266#endif
ab27c07f 267
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268/* Memory accessors */
269static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val)
270{
ab27c07f 271 return __virtio16_to_cpu(vhost_is_little_endian(vq), val);
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272}
273
274static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val)
275{
ab27c07f 276 return __cpu_to_virtio16(vhost_is_little_endian(vq), val);
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277}
278
279static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val)
280{
ab27c07f 281 return __virtio32_to_cpu(vhost_is_little_endian(vq), val);
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282}
283
284static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val)
285{
ab27c07f 286 return __cpu_to_virtio32(vhost_is_little_endian(vq), val);
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287}
288
289static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val)
290{
ab27c07f 291 return __virtio64_to_cpu(vhost_is_little_endian(vq), val);
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292}
293
294static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val)
295{
ab27c07f 296 return __cpu_to_virtio64(vhost_is_little_endian(vq), val);
e05fd12b 297}
3a4d5c94 298#endif