1 /* SPDX-License-Identifier: GPL-2.0 */
5 #include <linux/eventfd.h>
6 #include <linux/vhost.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 #include <linux/irqbypass.h>
19 typedef void (*vhost_work_fn_t
)(struct vhost_work
*work
);
21 #define VHOST_WORK_QUEUED 1
23 struct llist_node node
;
28 /* Poll a file (eventfd or socket) */
29 /* Note: there's nothing vhost specific about this structure. */
32 wait_queue_head_t
*wqh
;
33 wait_queue_entry_t wait
;
34 struct vhost_work work
;
36 struct vhost_dev
*dev
;
39 void vhost_work_init(struct vhost_work
*work
, vhost_work_fn_t fn
);
40 void vhost_work_queue(struct vhost_dev
*dev
, struct vhost_work
*work
);
41 bool vhost_has_work(struct vhost_dev
*dev
);
43 void vhost_poll_init(struct vhost_poll
*poll
, vhost_work_fn_t fn
,
44 __poll_t mask
, struct vhost_dev
*dev
);
45 int vhost_poll_start(struct vhost_poll
*poll
, struct file
*file
);
46 void vhost_poll_stop(struct vhost_poll
*poll
);
47 void vhost_poll_flush(struct vhost_poll
*poll
);
48 void vhost_poll_queue(struct vhost_poll
*poll
);
49 void vhost_work_flush(struct vhost_dev
*dev
, struct vhost_work
*work
);
50 long vhost_vring_ioctl(struct vhost_dev
*d
, unsigned int ioctl
, void __user
*argp
);
57 enum vhost_uaddr_type
{
64 struct vhost_vring_call
{
65 struct eventfd_ctx
*ctx
;
66 struct irq_bypass_producer producer
;
70 /* The virtqueue structure describes a queue attached to a device. */
71 struct vhost_virtqueue
{
72 struct vhost_dev
*dev
;
74 /* The actual ring of buffers. */
77 vring_desc_t __user
*desc
;
78 vring_avail_t __user
*avail
;
79 vring_used_t __user
*used
;
80 const struct vhost_iotlb_map
*meta_iotlb
[VHOST_NUM_ADDRS
];
82 struct vhost_vring_call call_ctx
;
83 struct eventfd_ctx
*error_ctx
;
84 struct eventfd_ctx
*log_ctx
;
86 struct vhost_poll poll
;
88 /* The routine to call when the Guest pings us, or timeout. */
89 vhost_work_fn_t handle_kick
;
91 /* Last available index we saw. */
94 /* Caches available index value from user. */
97 /* Last index we used. */
103 /* Last used index value we have signalled on */
106 /* Last used index value we have signalled on */
107 bool signalled_used_valid
;
109 /* Log writes to used structure. */
113 struct iovec iov
[UIO_MAXIOV
];
114 struct iovec iotlb_iov
[64];
115 struct iovec
*indirect
;
116 struct vring_used_elem
*heads
;
117 /* Protected by virtqueue mutex. */
118 struct vhost_iotlb
*umem
;
119 struct vhost_iotlb
*iotlb
;
122 u64 acked_backend_features
;
123 /* Log write descriptors */
124 void __user
*log_base
;
125 struct vhost_log
*log
;
127 /* Ring endianness. Defaults to legacy native endianness.
128 * Set to true when starting a modern virtio device. */
130 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
131 /* Ring endianness requested by userspace for cross-endian support. */
134 u32 busyloop_timeout
;
137 struct vhost_msg_node
{
139 struct vhost_msg msg
;
140 struct vhost_msg_v2 msg_v2
;
142 struct vhost_virtqueue
*vq
;
143 struct list_head node
;
147 struct mm_struct
*mm
;
149 struct vhost_virtqueue
**vqs
;
151 struct eventfd_ctx
*log_ctx
;
152 struct llist_head work_list
;
153 struct task_struct
*worker
;
154 struct vhost_iotlb
*umem
;
155 struct vhost_iotlb
*iotlb
;
156 spinlock_t iotlb_lock
;
157 struct list_head read_list
;
158 struct list_head pending_list
;
159 wait_queue_head_t wait
;
165 int (*msg_handler
)(struct vhost_dev
*dev
,
166 struct vhost_iotlb_msg
*msg
);
169 bool vhost_exceeds_weight(struct vhost_virtqueue
*vq
, int pkts
, int total_len
);
170 void vhost_dev_init(struct vhost_dev
*, struct vhost_virtqueue
**vqs
,
171 int nvqs
, int iov_limit
, int weight
, int byte_weight
,
173 int (*msg_handler
)(struct vhost_dev
*dev
,
174 struct vhost_iotlb_msg
*msg
));
175 long vhost_dev_set_owner(struct vhost_dev
*dev
);
176 bool vhost_dev_has_owner(struct vhost_dev
*dev
);
177 long vhost_dev_check_owner(struct vhost_dev
*);
178 struct vhost_iotlb
*vhost_dev_reset_owner_prepare(void);
179 void vhost_dev_reset_owner(struct vhost_dev
*dev
, struct vhost_iotlb
*iotlb
);
180 void vhost_dev_cleanup(struct vhost_dev
*);
181 void vhost_dev_stop(struct vhost_dev
*);
182 long vhost_dev_ioctl(struct vhost_dev
*, unsigned int ioctl
, void __user
*argp
);
183 long vhost_vring_ioctl(struct vhost_dev
*d
, unsigned int ioctl
, void __user
*argp
);
184 bool vhost_vq_access_ok(struct vhost_virtqueue
*vq
);
185 bool vhost_log_access_ok(struct vhost_dev
*);
187 int vhost_get_vq_desc(struct vhost_virtqueue
*,
188 struct iovec iov
[], unsigned int iov_count
,
189 unsigned int *out_num
, unsigned int *in_num
,
190 struct vhost_log
*log
, unsigned int *log_num
);
191 void vhost_discard_vq_desc(struct vhost_virtqueue
*, int n
);
193 int vhost_vq_init_access(struct vhost_virtqueue
*);
194 int vhost_add_used(struct vhost_virtqueue
*, unsigned int head
, int len
);
195 int vhost_add_used_n(struct vhost_virtqueue
*, struct vring_used_elem
*heads
,
197 void vhost_add_used_and_signal(struct vhost_dev
*, struct vhost_virtqueue
*,
198 unsigned int id
, int len
);
199 void vhost_add_used_and_signal_n(struct vhost_dev
*, struct vhost_virtqueue
*,
200 struct vring_used_elem
*heads
, unsigned count
);
201 void vhost_signal(struct vhost_dev
*, struct vhost_virtqueue
*);
202 void vhost_disable_notify(struct vhost_dev
*, struct vhost_virtqueue
*);
203 bool vhost_vq_avail_empty(struct vhost_dev
*, struct vhost_virtqueue
*);
204 bool vhost_enable_notify(struct vhost_dev
*, struct vhost_virtqueue
*);
206 int vhost_log_write(struct vhost_virtqueue
*vq
, struct vhost_log
*log
,
207 unsigned int log_num
, u64 len
,
208 struct iovec
*iov
, int count
);
209 int vq_meta_prefetch(struct vhost_virtqueue
*vq
);
211 struct vhost_msg_node
*vhost_new_msg(struct vhost_virtqueue
*vq
, int type
);
212 void vhost_enqueue_msg(struct vhost_dev
*dev
,
213 struct list_head
*head
,
214 struct vhost_msg_node
*node
);
215 struct vhost_msg_node
*vhost_dequeue_msg(struct vhost_dev
*dev
,
216 struct list_head
*head
);
217 void vhost_set_backend_features(struct vhost_dev
*dev
, u64 features
);
219 __poll_t
vhost_chr_poll(struct file
*file
, struct vhost_dev
*dev
,
221 ssize_t
vhost_chr_read_iter(struct vhost_dev
*dev
, struct iov_iter
*to
,
223 ssize_t
vhost_chr_write_iter(struct vhost_dev
*dev
,
224 struct iov_iter
*from
);
225 int vhost_init_device_iotlb(struct vhost_dev
*d
, bool enabled
);
227 void vhost_iotlb_map_free(struct vhost_iotlb
*iotlb
,
228 struct vhost_iotlb_map
*map
);
230 #define vq_err(vq, fmt, ...) do { \
231 pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
232 if ((vq)->error_ctx) \
233 eventfd_signal((vq)->error_ctx, 1);\
237 VHOST_FEATURES
= (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY
) |
238 (1ULL << VIRTIO_RING_F_INDIRECT_DESC
) |
239 (1ULL << VIRTIO_RING_F_EVENT_IDX
) |
240 (1ULL << VHOST_F_LOG_ALL
) |
241 (1ULL << VIRTIO_F_ANY_LAYOUT
) |
242 (1ULL << VIRTIO_F_VERSION_1
)
246 * vhost_vq_set_backend - Set backend.
249 * @private_data The private data.
251 * Context: Need to call with vq->mutex acquired.
253 static inline void vhost_vq_set_backend(struct vhost_virtqueue
*vq
,
256 vq
->private_data
= private_data
;
260 * vhost_vq_get_backend - Get backend.
264 * Context: Need to call with vq->mutex acquired.
265 * Return: Private data previously set with vhost_vq_set_backend.
267 static inline void *vhost_vq_get_backend(struct vhost_virtqueue
*vq
)
269 return vq
->private_data
;
272 static inline bool vhost_has_feature(struct vhost_virtqueue
*vq
, int bit
)
274 return vq
->acked_features
& (1ULL << bit
);
277 static inline bool vhost_backend_has_feature(struct vhost_virtqueue
*vq
, int bit
)
279 return vq
->acked_backend_features
& (1ULL << bit
);
282 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
283 static inline bool vhost_is_little_endian(struct vhost_virtqueue
*vq
)
288 static inline bool vhost_is_little_endian(struct vhost_virtqueue
*vq
)
290 return virtio_legacy_is_little_endian() || vq
->is_le
;
294 /* Memory accessors */
295 static inline u16
vhost16_to_cpu(struct vhost_virtqueue
*vq
, __virtio16 val
)
297 return __virtio16_to_cpu(vhost_is_little_endian(vq
), val
);
300 static inline __virtio16
cpu_to_vhost16(struct vhost_virtqueue
*vq
, u16 val
)
302 return __cpu_to_virtio16(vhost_is_little_endian(vq
), val
);
305 static inline u32
vhost32_to_cpu(struct vhost_virtqueue
*vq
, __virtio32 val
)
307 return __virtio32_to_cpu(vhost_is_little_endian(vq
), val
);
310 static inline __virtio32
cpu_to_vhost32(struct vhost_virtqueue
*vq
, u32 val
)
312 return __cpu_to_virtio32(vhost_is_little_endian(vq
), val
);
315 static inline u64
vhost64_to_cpu(struct vhost_virtqueue
*vq
, __virtio64 val
)
317 return __virtio64_to_cpu(vhost_is_little_endian(vq
), val
);
320 static inline __virtio64
cpu_to_vhost64(struct vhost_virtqueue
*vq
, u64 val
)
322 return __cpu_to_virtio64(vhost_is_little_endian(vq
), val
);