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_entry_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_cached umem_tree;
75 struct list_head umem_list;
76 int numem;
77};
78
79enum vhost_uaddr_type {
80 VHOST_ADDR_DESC = 0,
81 VHOST_ADDR_AVAIL = 1,
82 VHOST_ADDR_USED = 2,
83 VHOST_NUM_ADDRS = 3,
84};
85
86/* The virtqueue structure describes a queue attached to a device. */
87struct vhost_virtqueue {
88 struct vhost_dev *dev;
89
90 /* The actual ring of buffers. */
91 struct mutex mutex;
92 unsigned int num;
93 struct vring_desc __user *desc;
94 struct vring_avail __user *avail;
95 struct vring_used __user *used;
96 const struct vhost_umem_node *meta_iotlb[VHOST_NUM_ADDRS];
97 struct file *kick;
98 struct file *call;
99 struct file *error;
100 struct eventfd_ctx *call_ctx;
101 struct eventfd_ctx *error_ctx;
102 struct eventfd_ctx *log_ctx;
103
104 struct vhost_poll poll;
105
106 /* The routine to call when the Guest pings us, or timeout. */
107 vhost_work_fn_t handle_kick;
108
109 /* Last available index we saw. */
110 u16 last_avail_idx;
111
112 /* Caches available index value from user. */
113 u16 avail_idx;
114
115 /* Last index we used. */
116 u16 last_used_idx;
117
118 /* Used flags */
119 u16 used_flags;
120
121 /* Last used index value we have signalled on */
122 u16 signalled_used;
123
124 /* Last used index value we have signalled on */
125 bool signalled_used_valid;
126
127 /* Log writes to used structure. */
128 bool log_used;
129 u64 log_addr;
130
131 struct iovec iov[UIO_MAXIOV];
132 struct iovec iotlb_iov[64];
133 struct iovec *indirect;
134 struct vring_used_elem *heads;
135 /* Protected by virtqueue mutex. */
136 struct vhost_umem *umem;
137 struct vhost_umem *iotlb;
138 void *private_data;
139 u64 acked_features;
140 /* Log write descriptors */
141 void __user *log_base;
142 struct vhost_log *log;
143
144 /* Ring endianness. Defaults to legacy native endianness.
145 * Set to true when starting a modern virtio device. */
146 bool is_le;
147#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
148 /* Ring endianness requested by userspace for cross-endian support. */
149 bool user_be;
150#endif
151 u32 busyloop_timeout;
152};
153
154struct vhost_msg_node {
155 struct vhost_msg msg;
156 struct vhost_virtqueue *vq;
157 struct list_head node;
158};
159
160struct vhost_dev {
161 struct mm_struct *mm;
162 struct mutex mutex;
163 struct vhost_virtqueue **vqs;
164 int nvqs;
165 struct file *log_file;
166 struct eventfd_ctx *log_ctx;
167 struct llist_head work_list;
168 struct task_struct *worker;
169 struct vhost_umem *umem;
170 struct vhost_umem *iotlb;
171 spinlock_t iotlb_lock;
172 struct list_head read_list;
173 struct list_head pending_list;
174 wait_queue_head_t wait;
175};
176
177void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, int nvqs);
178long vhost_dev_set_owner(struct vhost_dev *dev);
179bool vhost_dev_has_owner(struct vhost_dev *dev);
180long vhost_dev_check_owner(struct vhost_dev *);
181struct vhost_umem *vhost_dev_reset_owner_prepare(void);
182void vhost_dev_reset_owner(struct vhost_dev *, struct vhost_umem *);
183void vhost_dev_cleanup(struct vhost_dev *, bool locked);
184void vhost_dev_stop(struct vhost_dev *);
185long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp);
186long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp);
187int vhost_vq_access_ok(struct vhost_virtqueue *vq);
188int vhost_log_access_ok(struct vhost_dev *);
189
190int vhost_get_vq_desc(struct vhost_virtqueue *,
191 struct iovec iov[], unsigned int iov_count,
192 unsigned int *out_num, unsigned int *in_num,
193 struct vhost_log *log, unsigned int *log_num);
194void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
195
196int vhost_vq_init_access(struct vhost_virtqueue *);
197int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
198int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads,
199 unsigned count);
200void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *,
201 unsigned int id, int len);
202void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *,
203 struct vring_used_elem *heads, unsigned count);
204void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *);
205void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *);
206bool vhost_vq_avail_empty(struct vhost_dev *, struct vhost_virtqueue *);
207bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *);
208
209int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
210 unsigned int log_num, u64 len);
211int vq_iotlb_prefetch(struct vhost_virtqueue *vq);
212
213struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type);
214void vhost_enqueue_msg(struct vhost_dev *dev,
215 struct list_head *head,
216 struct vhost_msg_node *node);
217struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev,
218 struct list_head *head);
219unsigned int vhost_chr_poll(struct file *file, struct vhost_dev *dev,
220 poll_table *wait);
221ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to,
222 int noblock);
223ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
224 struct iov_iter *from);
225int vhost_init_device_iotlb(struct vhost_dev *d, bool enabled);
226
227#define vq_err(vq, fmt, ...) do { \
228 pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
229 if ((vq)->error_ctx) \
230 eventfd_signal((vq)->error_ctx, 1);\
231 } while (0)
232
233enum {
234 VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) |
235 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) |
236 (1ULL << VIRTIO_RING_F_EVENT_IDX) |
237 (1ULL << VHOST_F_LOG_ALL) |
238 (1ULL << VIRTIO_F_ANY_LAYOUT) |
239 (1ULL << VIRTIO_F_VERSION_1)
240};
241
242static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit)
243{
244 return vq->acked_features & (1ULL << bit);
245}
246
247#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
248static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
249{
250 return vq->is_le;
251}
252#else
253static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
254{
255 return virtio_legacy_is_little_endian() || vq->is_le;
256}
257#endif
258
259/* Memory accessors */
260static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val)
261{
262 return __virtio16_to_cpu(vhost_is_little_endian(vq), val);
263}
264
265static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val)
266{
267 return __cpu_to_virtio16(vhost_is_little_endian(vq), val);
268}
269
270static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val)
271{
272 return __virtio32_to_cpu(vhost_is_little_endian(vq), val);
273}
274
275static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val)
276{
277 return __cpu_to_virtio32(vhost_is_little_endian(vq), val);
278}
279
280static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val)
281{
282 return __virtio64_to_cpu(vhost_is_little_endian(vq), val);
283}
284
285static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val)
286{
287 return __cpu_to_virtio64(vhost_is_little_endian(vq), val);
288}
289#endif