tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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
18struct vhost_work {
19 struct list_head node;
20 vhost_work_fn_t fn;
21 wait_queue_head_t done;
22 int flushing;
23 unsigned queue_seq;
24 unsigned done_seq;
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_t wait;
33 struct vhost_work work;
34 unsigned long 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);
40
41void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
42 unsigned long mask, struct vhost_dev *dev);
43int vhost_poll_start(struct vhost_poll *poll, struct file *file);
44void vhost_poll_stop(struct vhost_poll *poll);
45void vhost_poll_flush(struct vhost_poll *poll);
46void vhost_poll_queue(struct vhost_poll *poll);
47void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work);
48long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp);
49
50struct vhost_log {
51 u64 addr;
52 u64 len;
53};
54
55/* The virtqueue structure describes a queue attached to a device. */
56struct vhost_virtqueue {
57 struct vhost_dev *dev;
58
59 /* The actual ring of buffers. */
60 struct mutex mutex;
61 unsigned int num;
62 struct vring_desc __user *desc;
63 struct vring_avail __user *avail;
64 struct vring_used __user *used;
65 struct file *kick;
66 struct file *call;
67 struct file *error;
68 struct eventfd_ctx *call_ctx;
69 struct eventfd_ctx *error_ctx;
70 struct eventfd_ctx *log_ctx;
71
72 struct vhost_poll poll;
73
74 /* The routine to call when the Guest pings us, or timeout. */
75 vhost_work_fn_t handle_kick;
76
77 /* Last available index we saw. */
78 u16 last_avail_idx;
79
80 /* Caches available index value from user. */
81 u16 avail_idx;
82
83 /* Last index we used. */
84 u16 last_used_idx;
85
86 /* Used flags */
87 u16 used_flags;
88
89 /* Last used index value we have signalled on */
90 u16 signalled_used;
91
92 /* Last used index value we have signalled on */
93 bool signalled_used_valid;
94
95 /* Log writes to used structure. */
96 bool log_used;
97 u64 log_addr;
98
99 struct iovec iov[UIO_MAXIOV];
100 struct iovec *indirect;
101 struct vring_used_elem *heads;
102 /* Protected by virtqueue mutex. */
103 struct vhost_memory *memory;
104 void *private_data;
105 u64 acked_features;
106 /* Log write descriptors */
107 void __user *log_base;
108 struct vhost_log *log;
109
110 /* Ring endianness. Defaults to legacy native endianness.
111 * Set to true when starting a modern virtio device. */
112 bool is_le;
113#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
114 /* Ring endianness requested by userspace for cross-endian support. */
115 bool user_be;
116#endif
117};
118
119struct vhost_dev {
120 struct vhost_memory *memory;
121 struct mm_struct *mm;
122 struct mutex mutex;
123 struct vhost_virtqueue **vqs;
124 int nvqs;
125 struct file *log_file;
126 struct eventfd_ctx *log_ctx;
127 spinlock_t work_lock;
128 struct list_head work_list;
129 struct task_struct *worker;
130};
131
132void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, int nvqs);
133long vhost_dev_set_owner(struct vhost_dev *dev);
134bool vhost_dev_has_owner(struct vhost_dev *dev);
135long vhost_dev_check_owner(struct vhost_dev *);
136struct vhost_memory *vhost_dev_reset_owner_prepare(void);
137void vhost_dev_reset_owner(struct vhost_dev *, struct vhost_memory *);
138void vhost_dev_cleanup(struct vhost_dev *, bool locked);
139void vhost_dev_stop(struct vhost_dev *);
140long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp);
141long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp);
142int vhost_vq_access_ok(struct vhost_virtqueue *vq);
143int vhost_log_access_ok(struct vhost_dev *);
144
145int vhost_get_vq_desc(struct vhost_virtqueue *,
146 struct iovec iov[], unsigned int iov_count,
147 unsigned int *out_num, unsigned int *in_num,
148 struct vhost_log *log, unsigned int *log_num);
149void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
150
151int vhost_init_used(struct vhost_virtqueue *);
152int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
153int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads,
154 unsigned count);
155void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *,
156 unsigned int id, int len);
157void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *,
158 struct vring_used_elem *heads, unsigned count);
159void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *);
160void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *);
161bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *);
162
163int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
164 unsigned int log_num, u64 len);
165
166#define vq_err(vq, fmt, ...) do { \
167 pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
168 if ((vq)->error_ctx) \
169 eventfd_signal((vq)->error_ctx, 1);\
170 } while (0)
171
172enum {
173 VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) |
174 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) |
175 (1ULL << VIRTIO_RING_F_EVENT_IDX) |
176 (1ULL << VHOST_F_LOG_ALL) |
177 (1ULL << VIRTIO_F_ANY_LAYOUT) |
178 (1ULL << VIRTIO_F_VERSION_1)
179};
180
181static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit)
182{
183 return vq->acked_features & (1ULL << bit);
184}
185
186#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
187static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
188{
189 return vq->is_le;
190}
191#else
192static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
193{
194 return virtio_legacy_is_little_endian() || vq->is_le;
195}
196#endif
197
198/* Memory accessors */
199static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val)
200{
201 return __virtio16_to_cpu(vhost_is_little_endian(vq), val);
202}
203
204static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val)
205{
206 return __cpu_to_virtio16(vhost_is_little_endian(vq), val);
207}
208
209static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val)
210{
211 return __virtio32_to_cpu(vhost_is_little_endian(vq), val);
212}
213
214static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val)
215{
216 return __cpu_to_virtio32(vhost_is_little_endian(vq), val);
217}
218
219static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val)
220{
221 return __virtio64_to_cpu(vhost_is_little_endian(vq), val);
222}
223
224static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val)
225{
226 return __cpu_to_virtio64(vhost_is_little_endian(vq), val);
227}
228#endif