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>
18 typedef void (*vhost_work_fn_t)(struct vhost_work *work);
20 #define VHOST_WORK_QUEUED 1
22 struct llist_node node;
27 /* Poll a file (eventfd or socket) */
28 /* Note: there's nothing vhost specific about this structure. */
31 wait_queue_head_t *wqh;
32 wait_queue_entry_t wait;
33 struct vhost_work work;
35 struct vhost_dev *dev;
38 void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn);
39 void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work);
40 bool vhost_has_work(struct vhost_dev *dev);
42 void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
43 __poll_t mask, struct vhost_dev *dev);
44 int vhost_poll_start(struct vhost_poll *poll, struct file *file);
45 void vhost_poll_stop(struct vhost_poll *poll);
46 void vhost_poll_flush(struct vhost_poll *poll);
47 void vhost_poll_queue(struct vhost_poll *poll);
48 void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work);
49 long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp);
56 enum vhost_uaddr_type {
63 /* The virtqueue structure describes a queue attached to a device. */
64 struct vhost_virtqueue {
65 struct vhost_dev *dev;
67 /* The actual ring of buffers. */
70 vring_desc_t __user *desc;
71 vring_avail_t __user *avail;
72 vring_used_t __user *used;
73 const struct vhost_iotlb_map *meta_iotlb[VHOST_NUM_ADDRS];
75 struct eventfd_ctx *call_ctx;
76 struct eventfd_ctx *error_ctx;
77 struct eventfd_ctx *log_ctx;
79 struct vhost_poll poll;
81 /* The routine to call when the Guest pings us, or timeout. */
82 vhost_work_fn_t handle_kick;
84 /* Last available index we saw. */
87 /* Caches available index value from user. */
90 /* Last index we used. */
96 /* Last used index value we have signalled on */
99 /* Last used index value we have signalled on */
100 bool signalled_used_valid;
102 /* Log writes to used structure. */
106 struct iovec iov[UIO_MAXIOV];
107 struct iovec iotlb_iov[64];
108 struct iovec *indirect;
109 struct vring_used_elem *heads;
110 /* Protected by virtqueue mutex. */
111 struct vhost_iotlb *umem;
112 struct vhost_iotlb *iotlb;
115 u64 acked_backend_features;
116 /* Log write descriptors */
117 void __user *log_base;
118 struct vhost_log *log;
120 /* Ring endianness. Defaults to legacy native endianness.
121 * Set to true when starting a modern virtio device. */
123 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
124 /* Ring endianness requested by userspace for cross-endian support. */
127 u32 busyloop_timeout;
130 struct vhost_msg_node {
132 struct vhost_msg msg;
133 struct vhost_msg_v2 msg_v2;
135 struct vhost_virtqueue *vq;
136 struct list_head node;
140 struct mm_struct *mm;
142 struct vhost_virtqueue **vqs;
144 struct eventfd_ctx *log_ctx;
145 struct llist_head work_list;
146 struct task_struct *worker;
147 struct vhost_iotlb *umem;
148 struct vhost_iotlb *iotlb;
149 spinlock_t iotlb_lock;
150 struct list_head read_list;
151 struct list_head pending_list;
152 wait_queue_head_t wait;
158 int (*msg_handler)(struct vhost_dev *dev,
159 struct vhost_iotlb_msg *msg);
162 bool vhost_exceeds_weight(struct vhost_virtqueue *vq, int pkts, int total_len);
163 void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs,
164 int nvqs, int iov_limit, int weight, int byte_weight,
166 int (*msg_handler)(struct vhost_dev *dev,
167 struct vhost_iotlb_msg *msg));
168 long vhost_dev_set_owner(struct vhost_dev *dev);
169 bool vhost_dev_has_owner(struct vhost_dev *dev);
170 long vhost_dev_check_owner(struct vhost_dev *);
171 struct vhost_iotlb *vhost_dev_reset_owner_prepare(void);
172 void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_iotlb *iotlb);
173 void vhost_dev_cleanup(struct vhost_dev *);
174 void vhost_dev_stop(struct vhost_dev *);
175 long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp);
176 long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp);
177 bool vhost_vq_access_ok(struct vhost_virtqueue *vq);
178 bool vhost_log_access_ok(struct vhost_dev *);
180 int vhost_get_vq_desc(struct vhost_virtqueue *,
181 struct iovec iov[], unsigned int iov_count,
182 unsigned int *out_num, unsigned int *in_num,
183 struct vhost_log *log, unsigned int *log_num);
184 void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
186 int vhost_vq_init_access(struct vhost_virtqueue *);
187 int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
188 int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads,
190 void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *,
191 unsigned int id, int len);
192 void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *,
193 struct vring_used_elem *heads, unsigned count);
194 void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *);
195 void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *);
196 bool vhost_vq_avail_empty(struct vhost_dev *, struct vhost_virtqueue *);
197 bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *);
199 int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
200 unsigned int log_num, u64 len,
201 struct iovec *iov, int count);
202 int vq_meta_prefetch(struct vhost_virtqueue *vq);
204 struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type);
205 void vhost_enqueue_msg(struct vhost_dev *dev,
206 struct list_head *head,
207 struct vhost_msg_node *node);
208 struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev,
209 struct list_head *head);
210 __poll_t vhost_chr_poll(struct file *file, struct vhost_dev *dev,
212 ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to,
214 ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
215 struct iov_iter *from);
216 int vhost_init_device_iotlb(struct vhost_dev *d, bool enabled);
218 void vhost_iotlb_map_free(struct vhost_iotlb *iotlb,
219 struct vhost_iotlb_map *map);
221 #define vq_err(vq, fmt, ...) do { \
222 pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
223 if ((vq)->error_ctx) \
224 eventfd_signal((vq)->error_ctx, 1);\
228 VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) |
229 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) |
230 (1ULL << VIRTIO_RING_F_EVENT_IDX) |
231 (1ULL << VHOST_F_LOG_ALL) |
232 (1ULL << VIRTIO_F_ANY_LAYOUT) |
233 (1ULL << VIRTIO_F_VERSION_1)
237 * vhost_vq_set_backend - Set backend.
240 * @private_data The private data.
242 * Context: Need to call with vq->mutex acquired.
244 static inline void vhost_vq_set_backend(struct vhost_virtqueue *vq,
247 vq->private_data = private_data;
251 * vhost_vq_get_backend - Get backend.
255 * Context: Need to call with vq->mutex acquired.
256 * Return: Private data previously set with vhost_vq_set_backend.
258 static inline void *vhost_vq_get_backend(struct vhost_virtqueue *vq)
260 return vq->private_data;
263 static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit)
265 return vq->acked_features & (1ULL << bit);
268 static inline bool vhost_backend_has_feature(struct vhost_virtqueue *vq, int bit)
270 return vq->acked_backend_features & (1ULL << bit);
273 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
274 static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
279 static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
281 return virtio_legacy_is_little_endian() || vq->is_le;
285 /* Memory accessors */
286 static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val)
288 return __virtio16_to_cpu(vhost_is_little_endian(vq), val);
291 static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val)
293 return __cpu_to_virtio16(vhost_is_little_endian(vq), val);
296 static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val)
298 return __virtio32_to_cpu(vhost_is_little_endian(vq), val);
301 static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val)
303 return __cpu_to_virtio32(vhost_is_little_endian(vq), val);
306 static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val)
308 return __virtio64_to_cpu(vhost_is_little_endian(vq), val);
311 static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val)
313 return __cpu_to_virtio64(vhost_is_little_endian(vq), val);