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