Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1#ifndef _VHOST_H
2#define _VHOST_H
3
4#include <linux/eventfd.h>
5#include <linux/vhost.h>
6#include <linux/mm.h>
7#include <linux/mutex.h>
8#include <linux/poll.h>
9#include <linux/file.h>
10#include <linux/uio.h>
11#include <linux/virtio_config.h>
12#include <linux/virtio_ring.h>
13#include <linux/atomic.h>
14
15struct vhost_work;
16typedef void (*vhost_work_fn_t)(struct vhost_work *work);
17
18#define VHOST_WORK_QUEUED 1
19struct vhost_work {
20 struct llist_node node;
21 vhost_work_fn_t fn;
22 wait_queue_head_t done;
23 int flushing;
24 unsigned queue_seq;
25 unsigned done_seq;
26 unsigned long flags;
27};
28
29/* Poll a file (eventfd or socket) */
30/* Note: there's nothing vhost specific about this structure. */
31struct vhost_poll {
32 poll_table table;
33 wait_queue_head_t *wqh;
34 wait_queue_t wait;
35 struct vhost_work work;
36 unsigned long mask;
37 struct vhost_dev *dev;
38};
39
40void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn);
41void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work);
42bool vhost_has_work(struct vhost_dev *dev);
43
44void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
45 unsigned long mask, struct vhost_dev *dev);
46int vhost_poll_start(struct vhost_poll *poll, struct file *file);
47void vhost_poll_stop(struct vhost_poll *poll);
48void vhost_poll_flush(struct vhost_poll *poll);
49void vhost_poll_queue(struct vhost_poll *poll);
50void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work);
51long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp);
52
53struct vhost_log {
54 u64 addr;
55 u64 len;
56};
57
58#define START(node) ((node)->start)
59#define LAST(node) ((node)->last)
60
61struct vhost_umem_node {
62 struct rb_node rb;
63 struct list_head link;
64 __u64 start;
65 __u64 last;
66 __u64 size;
67 __u64 userspace_addr;
68 __u32 perm;
69 __u32 flags_padding;
70 __u64 __subtree_last;
71};
72
73struct vhost_umem {
74 struct rb_root umem_tree;
75 struct list_head umem_list;
76 int numem;
77};
78
79/* The virtqueue structure describes a queue attached to a device. */
80struct vhost_virtqueue {
81 struct vhost_dev *dev;
82
83 /* The actual ring of buffers. */
84 struct mutex mutex;
85 unsigned int num;
86 struct vring_desc __user *desc;
87 struct vring_avail __user *avail;
88 struct vring_used __user *used;
89 struct file *kick;
90 struct file *call;
91 struct file *error;
92 struct eventfd_ctx *call_ctx;
93 struct eventfd_ctx *error_ctx;
94 struct eventfd_ctx *log_ctx;
95
96 struct vhost_poll poll;
97
98 /* The routine to call when the Guest pings us, or timeout. */
99 vhost_work_fn_t handle_kick;
100
101 /* Last available index we saw. */
102 u16 last_avail_idx;
103
104 /* Caches available index value from user. */
105 u16 avail_idx;
106
107 /* Last index we used. */
108 u16 last_used_idx;
109
110 /* Last used evet we've seen */
111 u16 last_used_event;
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_umem *umem;
132 struct vhost_umem *iotlb;
133 void *private_data;
134 u64 acked_features;
135 /* Log write descriptors */
136 void __user *log_base;
137 struct vhost_log *log;
138
139 /* Ring endianness. Defaults to legacy native endianness.
140 * Set to true when starting a modern virtio device. */
141 bool is_le;
142#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
143 /* Ring endianness requested by userspace for cross-endian support. */
144 bool user_be;
145#endif
146 u32 busyloop_timeout;
147};
148
149struct vhost_msg_node {
150 struct vhost_msg msg;
151 struct vhost_virtqueue *vq;
152 struct list_head node;
153};
154
155struct vhost_dev {
156 struct mm_struct *mm;
157 struct mutex mutex;
158 struct vhost_virtqueue **vqs;
159 int nvqs;
160 struct file *log_file;
161 struct eventfd_ctx *log_ctx;
162 struct llist_head work_list;
163 struct task_struct *worker;
164 struct vhost_umem *umem;
165 struct vhost_umem *iotlb;
166 spinlock_t iotlb_lock;
167 struct list_head read_list;
168 struct list_head pending_list;
169 wait_queue_head_t wait;
170};
171
172void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, int nvqs);
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_umem *vhost_dev_reset_owner_prepare(void);
177void vhost_dev_reset_owner(struct vhost_dev *, struct vhost_umem *);
178void vhost_dev_cleanup(struct vhost_dev *, bool locked);
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, int ioctl, void __user *argp);
182int vhost_vq_access_ok(struct vhost_virtqueue *vq);
183int 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
191int vhost_vq_init_access(struct vhost_virtqueue *);
192int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
193int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads,
194 unsigned count);
195void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *,
196 unsigned int id, int len);
197void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *,
198 struct vring_used_elem *heads, unsigned count);
199void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *);
200void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *);
201bool vhost_vq_avail_empty(struct vhost_dev *, struct vhost_virtqueue *);
202bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *);
203
204int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
205 unsigned int log_num, u64 len);
206int vq_iotlb_prefetch(struct vhost_virtqueue *vq);
207
208struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type);
209void vhost_enqueue_msg(struct vhost_dev *dev,
210 struct list_head *head,
211 struct vhost_msg_node *node);
212struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev,
213 struct list_head *head);
214unsigned int vhost_chr_poll(struct file *file, struct vhost_dev *dev,
215 poll_table *wait);
216ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to,
217 int noblock);
218ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
219 struct iov_iter *from);
220int vhost_init_device_iotlb(struct vhost_dev *d, bool enabled);
221
222#define vq_err(vq, fmt, ...) do { \
223 pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
224 if ((vq)->error_ctx) \
225 eventfd_signal((vq)->error_ctx, 1);\
226 } while (0)
227
228enum {
229 VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) |
230 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) |
231 (1ULL << VIRTIO_RING_F_EVENT_IDX) |
232 (1ULL << VHOST_F_LOG_ALL) |
233 (1ULL << VIRTIO_F_ANY_LAYOUT) |
234 (1ULL << VIRTIO_F_VERSION_1)
235};
236
237static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit)
238{
239 return vq->acked_features & (1ULL << bit);
240}
241
242#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
243static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
244{
245 return vq->is_le;
246}
247#else
248static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
249{
250 return virtio_legacy_is_little_endian() || vq->is_le;
251}
252#endif
253
254/* Memory accessors */
255static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val)
256{
257 return __virtio16_to_cpu(vhost_is_little_endian(vq), val);
258}
259
260static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val)
261{
262 return __cpu_to_virtio16(vhost_is_little_endian(vq), val);
263}
264
265static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val)
266{
267 return __virtio32_to_cpu(vhost_is_little_endian(vq), val);
268}
269
270static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val)
271{
272 return __cpu_to_virtio32(vhost_is_little_endian(vq), val);
273}
274
275static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val)
276{
277 return __virtio64_to_cpu(vhost_is_little_endian(vq), val);
278}
279
280static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val)
281{
282 return __cpu_to_virtio64(vhost_is_little_endian(vq), val);
283}
284#endif