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