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>
17 typedef void (*vhost_work_fn_t
)(struct vhost_work
*work
);
19 #define VHOST_WORK_QUEUED 1
21 struct llist_node node
;
23 wait_queue_head_t done
;
30 /* Poll a file (eventfd or socket) */
31 /* Note: there's nothing vhost specific about this structure. */
34 wait_queue_head_t
*wqh
;
35 wait_queue_entry_t wait
;
36 struct vhost_work work
;
38 struct vhost_dev
*dev
;
41 void vhost_work_init(struct vhost_work
*work
, vhost_work_fn_t fn
);
42 void vhost_work_queue(struct vhost_dev
*dev
, struct vhost_work
*work
);
43 bool vhost_has_work(struct vhost_dev
*dev
);
45 void vhost_poll_init(struct vhost_poll
*poll
, vhost_work_fn_t fn
,
46 unsigned long mask
, struct vhost_dev
*dev
);
47 int vhost_poll_start(struct vhost_poll
*poll
, struct file
*file
);
48 void vhost_poll_stop(struct vhost_poll
*poll
);
49 void vhost_poll_flush(struct vhost_poll
*poll
);
50 void vhost_poll_queue(struct vhost_poll
*poll
);
51 void vhost_work_flush(struct vhost_dev
*dev
, struct vhost_work
*work
);
52 long vhost_vring_ioctl(struct vhost_dev
*d
, int ioctl
, void __user
*argp
);
59 #define START(node) ((node)->start)
60 #define LAST(node) ((node)->last)
62 struct vhost_umem_node
{
64 struct list_head link
;
75 struct rb_root_cached umem_tree
;
76 struct list_head umem_list
;
80 enum vhost_uaddr_type
{
87 /* The virtqueue structure describes a queue attached to a device. */
88 struct vhost_virtqueue
{
89 struct vhost_dev
*dev
;
91 /* The actual ring of buffers. */
94 struct vring_desc __user
*desc
;
95 struct vring_avail __user
*avail
;
96 struct vring_used __user
*used
;
97 const struct vhost_umem_node
*meta_iotlb
[VHOST_NUM_ADDRS
];
101 struct eventfd_ctx
*call_ctx
;
102 struct eventfd_ctx
*error_ctx
;
103 struct eventfd_ctx
*log_ctx
;
105 struct vhost_poll poll
;
107 /* The routine to call when the Guest pings us, or timeout. */
108 vhost_work_fn_t handle_kick
;
110 /* Last available index we saw. */
113 /* Caches available index value from user. */
116 /* Last index we used. */
122 /* Last used index value we have signalled on */
125 /* Last used index value we have signalled on */
126 bool signalled_used_valid
;
128 /* Log writes to used structure. */
132 struct iovec iov
[UIO_MAXIOV
];
133 struct iovec iotlb_iov
[64];
134 struct iovec
*indirect
;
135 struct vring_used_elem
*heads
;
136 /* Protected by virtqueue mutex. */
137 struct vhost_umem
*umem
;
138 struct vhost_umem
*iotlb
;
141 /* Log write descriptors */
142 void __user
*log_base
;
143 struct vhost_log
*log
;
145 /* Ring endianness. Defaults to legacy native endianness.
146 * Set to true when starting a modern virtio device. */
148 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
149 /* Ring endianness requested by userspace for cross-endian support. */
152 u32 busyloop_timeout
;
155 struct vhost_msg_node
{
156 struct vhost_msg msg
;
157 struct vhost_virtqueue
*vq
;
158 struct list_head node
;
162 struct mm_struct
*mm
;
164 struct vhost_virtqueue
**vqs
;
166 struct file
*log_file
;
167 struct eventfd_ctx
*log_ctx
;
168 struct llist_head work_list
;
169 struct task_struct
*worker
;
170 struct vhost_umem
*umem
;
171 struct vhost_umem
*iotlb
;
172 spinlock_t iotlb_lock
;
173 struct list_head read_list
;
174 struct list_head pending_list
;
175 wait_queue_head_t wait
;
178 void vhost_dev_init(struct vhost_dev
*, struct vhost_virtqueue
**vqs
, int nvqs
);
179 long vhost_dev_set_owner(struct vhost_dev
*dev
);
180 bool vhost_dev_has_owner(struct vhost_dev
*dev
);
181 long vhost_dev_check_owner(struct vhost_dev
*);
182 struct vhost_umem
*vhost_dev_reset_owner_prepare(void);
183 void vhost_dev_reset_owner(struct vhost_dev
*, struct vhost_umem
*);
184 void vhost_dev_cleanup(struct vhost_dev
*, bool locked
);
185 void vhost_dev_stop(struct vhost_dev
*);
186 long vhost_dev_ioctl(struct vhost_dev
*, unsigned int ioctl
, void __user
*argp
);
187 long vhost_vring_ioctl(struct vhost_dev
*d
, int ioctl
, void __user
*argp
);
188 int vhost_vq_access_ok(struct vhost_virtqueue
*vq
);
189 int vhost_log_access_ok(struct vhost_dev
*);
191 int vhost_get_vq_desc(struct vhost_virtqueue
*,
192 struct iovec iov
[], unsigned int iov_count
,
193 unsigned int *out_num
, unsigned int *in_num
,
194 struct vhost_log
*log
, unsigned int *log_num
);
195 void vhost_discard_vq_desc(struct vhost_virtqueue
*, int n
);
197 int vhost_vq_init_access(struct vhost_virtqueue
*);
198 int vhost_add_used(struct vhost_virtqueue
*, unsigned int head
, int len
);
199 int vhost_add_used_n(struct vhost_virtqueue
*, struct vring_used_elem
*heads
,
201 void vhost_add_used_and_signal(struct vhost_dev
*, struct vhost_virtqueue
*,
202 unsigned int id
, int len
);
203 void vhost_add_used_and_signal_n(struct vhost_dev
*, struct vhost_virtqueue
*,
204 struct vring_used_elem
*heads
, unsigned count
);
205 void vhost_signal(struct vhost_dev
*, struct vhost_virtqueue
*);
206 void vhost_disable_notify(struct vhost_dev
*, struct vhost_virtqueue
*);
207 bool vhost_vq_avail_empty(struct vhost_dev
*, struct vhost_virtqueue
*);
208 bool vhost_enable_notify(struct vhost_dev
*, struct vhost_virtqueue
*);
210 int vhost_log_write(struct vhost_virtqueue
*vq
, struct vhost_log
*log
,
211 unsigned int log_num
, u64 len
);
212 int vq_iotlb_prefetch(struct vhost_virtqueue
*vq
);
214 struct vhost_msg_node
*vhost_new_msg(struct vhost_virtqueue
*vq
, int type
);
215 void vhost_enqueue_msg(struct vhost_dev
*dev
,
216 struct list_head
*head
,
217 struct vhost_msg_node
*node
);
218 struct vhost_msg_node
*vhost_dequeue_msg(struct vhost_dev
*dev
,
219 struct list_head
*head
);
220 unsigned int vhost_chr_poll(struct file
*file
, struct vhost_dev
*dev
,
222 ssize_t
vhost_chr_read_iter(struct vhost_dev
*dev
, struct iov_iter
*to
,
224 ssize_t
vhost_chr_write_iter(struct vhost_dev
*dev
,
225 struct iov_iter
*from
);
226 int vhost_init_device_iotlb(struct vhost_dev
*d
, bool enabled
);
228 #define vq_err(vq, fmt, ...) do { \
229 pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
230 if ((vq)->error_ctx) \
231 eventfd_signal((vq)->error_ctx, 1);\
235 VHOST_FEATURES
= (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY
) |
236 (1ULL << VIRTIO_RING_F_INDIRECT_DESC
) |
237 (1ULL << VIRTIO_RING_F_EVENT_IDX
) |
238 (1ULL << VHOST_F_LOG_ALL
) |
239 (1ULL << VIRTIO_F_ANY_LAYOUT
) |
240 (1ULL << VIRTIO_F_VERSION_1
)
243 static inline bool vhost_has_feature(struct vhost_virtqueue
*vq
, int bit
)
245 return vq
->acked_features
& (1ULL << bit
);
248 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
249 static inline bool vhost_is_little_endian(struct vhost_virtqueue
*vq
)
254 static inline bool vhost_is_little_endian(struct vhost_virtqueue
*vq
)
256 return virtio_legacy_is_little_endian() || vq
->is_le
;
260 /* Memory accessors */
261 static inline u16
vhost16_to_cpu(struct vhost_virtqueue
*vq
, __virtio16 val
)
263 return __virtio16_to_cpu(vhost_is_little_endian(vq
), val
);
266 static inline __virtio16
cpu_to_vhost16(struct vhost_virtqueue
*vq
, u16 val
)
268 return __cpu_to_virtio16(vhost_is_little_endian(vq
), val
);
271 static inline u32
vhost32_to_cpu(struct vhost_virtqueue
*vq
, __virtio32 val
)
273 return __virtio32_to_cpu(vhost_is_little_endian(vq
), val
);
276 static inline __virtio32
cpu_to_vhost32(struct vhost_virtqueue
*vq
, u32 val
)
278 return __cpu_to_virtio32(vhost_is_little_endian(vq
), val
);
281 static inline u64
vhost64_to_cpu(struct vhost_virtqueue
*vq
, __virtio64 val
)
283 return __virtio64_to_cpu(vhost_is_little_endian(vq
), val
);
286 static inline __virtio64
cpu_to_vhost64(struct vhost_virtqueue
*vq
, u64 val
)
288 return __cpu_to_virtio64(vhost_is_little_endian(vq
), val
);