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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/skbuff.h>
11#include <linux/uio.h>
12#include <linux/virtio_config.h>
13#include <linux/virtio_ring.h>
14#include <linux/atomic.h>
15
16/* This is for zerocopy, used buffer len is set to 1 when lower device DMA
17 * done */
18#define VHOST_DMA_DONE_LEN 1
19#define VHOST_DMA_CLEAR_LEN 0
20
21struct vhost_device;
22
23struct vhost_work;
24typedef void (*vhost_work_fn_t)(struct vhost_work *work);
25
26struct vhost_work {
27 struct list_head node;
28 vhost_work_fn_t fn;
29 wait_queue_head_t done;
30 int flushing;
31 unsigned queue_seq;
32 unsigned done_seq;
33};
34
35/* Poll a file (eventfd or socket) */
36/* Note: there's nothing vhost specific about this structure. */
37struct vhost_poll {
38 poll_table table;
39 wait_queue_head_t *wqh;
40 wait_queue_t wait;
41 struct vhost_work work;
42 unsigned long mask;
43 struct vhost_dev *dev;
44};
45
46void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
47 unsigned long mask, struct vhost_dev *dev);
48void vhost_poll_start(struct vhost_poll *poll, struct file *file);
49void vhost_poll_stop(struct vhost_poll *poll);
50void vhost_poll_flush(struct vhost_poll *poll);
51void vhost_poll_queue(struct vhost_poll *poll);
52
53struct vhost_log {
54 u64 addr;
55 u64 len;
56};
57
58struct vhost_virtqueue;
59
60struct vhost_ubuf_ref {
61 struct kref kref;
62 wait_queue_head_t wait;
63 struct vhost_virtqueue *vq;
64};
65
66struct vhost_ubuf_ref *vhost_ubuf_alloc(struct vhost_virtqueue *, bool zcopy);
67void vhost_ubuf_put(struct vhost_ubuf_ref *);
68void vhost_ubuf_put_and_wait(struct vhost_ubuf_ref *);
69
70/* The virtqueue structure describes a queue attached to a device. */
71struct vhost_virtqueue {
72 struct vhost_dev *dev;
73
74 /* The actual ring of buffers. */
75 struct mutex mutex;
76 unsigned int num;
77 struct vring_desc __user *desc;
78 struct vring_avail __user *avail;
79 struct vring_used __user *used;
80 struct file *kick;
81 struct file *call;
82 struct file *error;
83 struct eventfd_ctx *call_ctx;
84 struct eventfd_ctx *error_ctx;
85 struct eventfd_ctx *log_ctx;
86
87 struct vhost_poll poll;
88
89 /* The routine to call when the Guest pings us, or timeout. */
90 vhost_work_fn_t handle_kick;
91
92 /* Last available index we saw. */
93 u16 last_avail_idx;
94
95 /* Caches available index value from user. */
96 u16 avail_idx;
97
98 /* Last index we used. */
99 u16 last_used_idx;
100
101 /* Used flags */
102 u16 used_flags;
103
104 /* Last used index value we have signalled on */
105 u16 signalled_used;
106
107 /* Last used index value we have signalled on */
108 bool signalled_used_valid;
109
110 /* Log writes to used structure. */
111 bool log_used;
112 u64 log_addr;
113
114 struct iovec iov[UIO_MAXIOV];
115 /* hdr is used to store the virtio header.
116 * Since each iovec has >= 1 byte length, we never need more than
117 * header length entries to store the header. */
118 struct iovec hdr[sizeof(struct virtio_net_hdr_mrg_rxbuf)];
119 struct iovec *indirect;
120 size_t vhost_hlen;
121 size_t sock_hlen;
122 struct vring_used_elem *heads;
123 /* We use a kind of RCU to access private pointer.
124 * All readers access it from worker, which makes it possible to
125 * flush the vhost_work instead of synchronize_rcu. Therefore readers do
126 * not need to call rcu_read_lock/rcu_read_unlock: the beginning of
127 * vhost_work execution acts instead of rcu_read_lock() and the end of
128 * vhost_work execution acts instead of rcu_read_unlock().
129 * Writers use virtqueue mutex. */
130 void __rcu *private_data;
131 /* Log write descriptors */
132 void __user *log_base;
133 struct vhost_log *log;
134 /* vhost zerocopy support fields below: */
135 /* last used idx for outstanding DMA zerocopy buffers */
136 int upend_idx;
137 /* first used idx for DMA done zerocopy buffers */
138 int done_idx;
139 /* an array of userspace buffers info */
140 struct ubuf_info *ubuf_info;
141 /* Reference counting for outstanding ubufs.
142 * Protected by vq mutex. Writers must also take device mutex. */
143 struct vhost_ubuf_ref *ubufs;
144};
145
146struct vhost_dev {
147 /* Readers use RCU to access memory table pointer
148 * log base pointer and features.
149 * Writers use mutex below.*/
150 struct vhost_memory __rcu *memory;
151 struct mm_struct *mm;
152 struct mutex mutex;
153 unsigned acked_features;
154 struct vhost_virtqueue *vqs;
155 int nvqs;
156 struct file *log_file;
157 struct eventfd_ctx *log_ctx;
158 spinlock_t work_lock;
159 struct list_head work_list;
160 struct task_struct *worker;
161};
162
163long vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue *vqs, int nvqs);
164long vhost_dev_check_owner(struct vhost_dev *);
165long vhost_dev_reset_owner(struct vhost_dev *);
166void vhost_dev_cleanup(struct vhost_dev *);
167long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, unsigned long arg);
168int vhost_vq_access_ok(struct vhost_virtqueue *vq);
169int vhost_log_access_ok(struct vhost_dev *);
170
171int vhost_get_vq_desc(struct vhost_dev *, struct vhost_virtqueue *,
172 struct iovec iov[], unsigned int iov_count,
173 unsigned int *out_num, unsigned int *in_num,
174 struct vhost_log *log, unsigned int *log_num);
175void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
176
177int vhost_init_used(struct vhost_virtqueue *);
178int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
179int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads,
180 unsigned count);
181void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *,
182 unsigned int id, int len);
183void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *,
184 struct vring_used_elem *heads, unsigned count);
185void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *);
186void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *);
187bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *);
188
189int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
190 unsigned int log_num, u64 len);
191void vhost_zerocopy_callback(void *arg);
192int vhost_zerocopy_signal_used(struct vhost_virtqueue *vq);
193
194#define vq_err(vq, fmt, ...) do { \
195 pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
196 if ((vq)->error_ctx) \
197 eventfd_signal((vq)->error_ctx, 1);\
198 } while (0)
199
200enum {
201 VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) |
202 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) |
203 (1ULL << VIRTIO_RING_F_EVENT_IDX) |
204 (1ULL << VHOST_F_LOG_ALL) |
205 (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) |
206 (1ULL << VIRTIO_NET_F_MRG_RXBUF),
207};
208
209static inline int vhost_has_feature(struct vhost_dev *dev, int bit)
210{
211 unsigned acked_features;
212
213 /* TODO: check that we are running from vhost_worker or dev mutex is
214 * held? */
215 acked_features = rcu_dereference_index_check(dev->acked_features, 1);
216 return acked_features & (1 << bit);
217}
218
219void vhost_enable_zcopy(int vq);
220
221#endif
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);
40bool vhost_has_work(struct vhost_dev *dev);
41
42void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
43 unsigned long 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, int ioctl, void __user *argp);
50
51struct vhost_log {
52 u64 addr;
53 u64 len;
54};
55
56/* The virtqueue structure describes a queue attached to a device. */
57struct vhost_virtqueue {
58 struct vhost_dev *dev;
59
60 /* The actual ring of buffers. */
61 struct mutex mutex;
62 unsigned int num;
63 struct vring_desc __user *desc;
64 struct vring_avail __user *avail;
65 struct vring_used __user *used;
66 struct file *kick;
67 struct file *call;
68 struct file *error;
69 struct eventfd_ctx *call_ctx;
70 struct eventfd_ctx *error_ctx;
71 struct eventfd_ctx *log_ctx;
72
73 struct vhost_poll poll;
74
75 /* The routine to call when the Guest pings us, or timeout. */
76 vhost_work_fn_t handle_kick;
77
78 /* Last available index we saw. */
79 u16 last_avail_idx;
80
81 /* Caches available index value from user. */
82 u16 avail_idx;
83
84 /* Last index we used. */
85 u16 last_used_idx;
86
87 /* Used flags */
88 u16 used_flags;
89
90 /* Last used index value we have signalled on */
91 u16 signalled_used;
92
93 /* Last used index value we have signalled on */
94 bool signalled_used_valid;
95
96 /* Log writes to used structure. */
97 bool log_used;
98 u64 log_addr;
99
100 struct iovec iov[UIO_MAXIOV];
101 struct iovec *indirect;
102 struct vring_used_elem *heads;
103 /* Protected by virtqueue mutex. */
104 struct vhost_memory *memory;
105 void *private_data;
106 u64 acked_features;
107 /* Log write descriptors */
108 void __user *log_base;
109 struct vhost_log *log;
110
111 /* Ring endianness. Defaults to legacy native endianness.
112 * Set to true when starting a modern virtio device. */
113 bool is_le;
114#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
115 /* Ring endianness requested by userspace for cross-endian support. */
116 bool user_be;
117#endif
118 u32 busyloop_timeout;
119};
120
121struct vhost_dev {
122 struct vhost_memory *memory;
123 struct mm_struct *mm;
124 struct mutex mutex;
125 struct vhost_virtqueue **vqs;
126 int nvqs;
127 struct file *log_file;
128 struct eventfd_ctx *log_ctx;
129 spinlock_t work_lock;
130 struct list_head work_list;
131 struct task_struct *worker;
132};
133
134void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, int nvqs);
135long vhost_dev_set_owner(struct vhost_dev *dev);
136bool vhost_dev_has_owner(struct vhost_dev *dev);
137long vhost_dev_check_owner(struct vhost_dev *);
138struct vhost_memory *vhost_dev_reset_owner_prepare(void);
139void vhost_dev_reset_owner(struct vhost_dev *, struct vhost_memory *);
140void vhost_dev_cleanup(struct vhost_dev *, bool locked);
141void vhost_dev_stop(struct vhost_dev *);
142long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp);
143long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp);
144int vhost_vq_access_ok(struct vhost_virtqueue *vq);
145int vhost_log_access_ok(struct vhost_dev *);
146
147int vhost_get_vq_desc(struct vhost_virtqueue *,
148 struct iovec iov[], unsigned int iov_count,
149 unsigned int *out_num, unsigned int *in_num,
150 struct vhost_log *log, unsigned int *log_num);
151void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
152
153int vhost_vq_init_access(struct vhost_virtqueue *);
154int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
155int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads,
156 unsigned count);
157void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *,
158 unsigned int id, int len);
159void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *,
160 struct vring_used_elem *heads, unsigned count);
161void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *);
162void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *);
163bool vhost_vq_avail_empty(struct vhost_dev *, struct vhost_virtqueue *);
164bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *);
165
166int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
167 unsigned int log_num, u64 len);
168
169#define vq_err(vq, fmt, ...) do { \
170 pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
171 if ((vq)->error_ctx) \
172 eventfd_signal((vq)->error_ctx, 1);\
173 } while (0)
174
175enum {
176 VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) |
177 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) |
178 (1ULL << VIRTIO_RING_F_EVENT_IDX) |
179 (1ULL << VHOST_F_LOG_ALL) |
180 (1ULL << VIRTIO_F_ANY_LAYOUT) |
181 (1ULL << VIRTIO_F_VERSION_1)
182};
183
184static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit)
185{
186 return vq->acked_features & (1ULL << bit);
187}
188
189#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
190static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
191{
192 return vq->is_le;
193}
194#else
195static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
196{
197 return virtio_legacy_is_little_endian() || vq->is_le;
198}
199#endif
200
201/* Memory accessors */
202static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val)
203{
204 return __virtio16_to_cpu(vhost_is_little_endian(vq), val);
205}
206
207static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val)
208{
209 return __cpu_to_virtio16(vhost_is_little_endian(vq), val);
210}
211
212static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val)
213{
214 return __virtio32_to_cpu(vhost_is_little_endian(vq), val);
215}
216
217static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val)
218{
219 return __cpu_to_virtio32(vhost_is_little_endian(vq), val);
220}
221
222static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val)
223{
224 return __virtio64_to_cpu(vhost_is_little_endian(vq), val);
225}
226
227static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val)
228{
229 return __cpu_to_virtio64(vhost_is_little_endian(vq), val);
230}
231#endif