1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _VHOST_H 3 #define _VHOST_H 4 5 #include <linux/eventfd.h> 6 #include <linux/vhost.h> 7 #include <linux/mm.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> 17 18 struct vhost_work; 19 struct vhost_task; 20 typedef void (*vhost_work_fn_t)(struct vhost_work *work); 21 22 #define VHOST_WORK_QUEUED 1 23 struct vhost_work { 24 struct llist_node node; 25 vhost_work_fn_t fn; 26 unsigned long flags; 27 }; 28 29 struct vhost_worker { 30 struct vhost_task *vtsk; 31 struct llist_head work_list; 32 u64 kcov_handle; 33 }; 34 35 /* Poll a file (eventfd or socket) */ 36 /* Note: there's nothing vhost specific about this structure. */ 37 struct vhost_poll { 38 poll_table table; 39 wait_queue_head_t *wqh; 40 wait_queue_entry_t wait; 41 struct vhost_work work; 42 __poll_t mask; 43 struct vhost_dev *dev; 44 }; 45 46 void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn); 47 void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work); 48 bool vhost_has_work(struct vhost_dev *dev); 49 50 void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn, 51 __poll_t mask, struct vhost_dev *dev); 52 int vhost_poll_start(struct vhost_poll *poll, struct file *file); 53 void vhost_poll_stop(struct vhost_poll *poll); 54 void vhost_poll_queue(struct vhost_poll *poll); 55 void vhost_dev_flush(struct vhost_dev *dev); 56 57 struct vhost_log { 58 u64 addr; 59 u64 len; 60 }; 61 62 enum vhost_uaddr_type { 63 VHOST_ADDR_DESC = 0, 64 VHOST_ADDR_AVAIL = 1, 65 VHOST_ADDR_USED = 2, 66 VHOST_NUM_ADDRS = 3, 67 }; 68 69 struct vhost_vring_call { 70 struct eventfd_ctx *ctx; 71 struct irq_bypass_producer producer; 72 }; 73 74 /* The virtqueue structure describes a queue attached to a device. */ 75 struct vhost_virtqueue { 76 struct vhost_dev *dev; 77 78 /* The actual ring of buffers. */ 79 struct mutex mutex; 80 unsigned int num; 81 vring_desc_t __user *desc; 82 vring_avail_t __user *avail; 83 vring_used_t __user *used; 84 const struct vhost_iotlb_map *meta_iotlb[VHOST_NUM_ADDRS]; 85 struct file *kick; 86 struct vhost_vring_call call_ctx; 87 struct eventfd_ctx *error_ctx; 88 struct eventfd_ctx *log_ctx; 89 90 struct vhost_poll poll; 91 92 /* The routine to call when the Guest pings us, or timeout. */ 93 vhost_work_fn_t handle_kick; 94 95 /* Last available index we saw. */ 96 u16 last_avail_idx; 97 98 /* Caches available index value from user. */ 99 u16 avail_idx; 100 101 /* Last index we used. */ 102 u16 last_used_idx; 103 104 /* Used flags */ 105 u16 used_flags; 106 107 /* Last used index value we have signalled on */ 108 u16 signalled_used; 109 110 /* Last used index value we have signalled on */ 111 bool signalled_used_valid; 112 113 /* Log writes to used structure. */ 114 bool log_used; 115 u64 log_addr; 116 117 struct iovec iov[UIO_MAXIOV]; 118 struct iovec iotlb_iov[64]; 119 struct iovec *indirect; 120 struct vring_used_elem *heads; 121 /* Protected by virtqueue mutex. */ 122 struct vhost_iotlb *umem; 123 struct vhost_iotlb *iotlb; 124 void *private_data; 125 u64 acked_features; 126 u64 acked_backend_features; 127 /* Log write descriptors */ 128 void __user *log_base; 129 struct vhost_log *log; 130 struct iovec log_iov[64]; 131 132 /* Ring endianness. Defaults to legacy native endianness. 133 * Set to true when starting a modern virtio device. */ 134 bool is_le; 135 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY 136 /* Ring endianness requested by userspace for cross-endian support. */ 137 bool user_be; 138 #endif 139 u32 busyloop_timeout; 140 }; 141 142 struct vhost_msg_node { 143 union { 144 struct vhost_msg msg; 145 struct vhost_msg_v2 msg_v2; 146 }; 147 struct vhost_virtqueue *vq; 148 struct list_head node; 149 }; 150 151 struct vhost_dev { 152 struct mm_struct *mm; 153 struct mutex mutex; 154 struct vhost_virtqueue **vqs; 155 int nvqs; 156 struct eventfd_ctx *log_ctx; 157 struct vhost_worker *worker; 158 struct vhost_iotlb *umem; 159 struct vhost_iotlb *iotlb; 160 spinlock_t iotlb_lock; 161 struct list_head read_list; 162 struct list_head pending_list; 163 wait_queue_head_t wait; 164 int iov_limit; 165 int weight; 166 int byte_weight; 167 bool use_worker; 168 int (*msg_handler)(struct vhost_dev *dev, u32 asid, 169 struct vhost_iotlb_msg *msg); 170 }; 171 172 bool vhost_exceeds_weight(struct vhost_virtqueue *vq, int pkts, int total_len); 173 void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, 174 int nvqs, int iov_limit, int weight, int byte_weight, 175 bool use_worker, 176 int (*msg_handler)(struct vhost_dev *dev, u32 asid, 177 struct vhost_iotlb_msg *msg)); 178 long vhost_dev_set_owner(struct vhost_dev *dev); 179 bool vhost_dev_has_owner(struct vhost_dev *dev); 180 long vhost_dev_check_owner(struct vhost_dev *); 181 struct vhost_iotlb *vhost_dev_reset_owner_prepare(void); 182 void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_iotlb *iotlb); 183 void vhost_dev_cleanup(struct vhost_dev *); 184 void vhost_dev_stop(struct vhost_dev *); 185 long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp); 186 long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp); 187 bool vhost_vq_access_ok(struct vhost_virtqueue *vq); 188 bool vhost_log_access_ok(struct vhost_dev *); 189 void vhost_clear_msg(struct vhost_dev *dev); 190 191 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); 196 197 bool vhost_vq_is_setup(struct vhost_virtqueue *vq); 198 int vhost_vq_init_access(struct vhost_virtqueue *); 199 int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len); 200 int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads, 201 unsigned count); 202 void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *, 203 unsigned int id, int len); 204 void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *, 205 struct vring_used_elem *heads, unsigned count); 206 void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *); 207 void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *); 208 bool vhost_vq_avail_empty(struct vhost_dev *, struct vhost_virtqueue *); 209 bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *); 210 211 int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, 212 unsigned int log_num, u64 len, 213 struct iovec *iov, int count); 214 int vq_meta_prefetch(struct vhost_virtqueue *vq); 215 216 struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type); 217 void vhost_enqueue_msg(struct vhost_dev *dev, 218 struct list_head *head, 219 struct vhost_msg_node *node); 220 struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev, 221 struct list_head *head); 222 void vhost_set_backend_features(struct vhost_dev *dev, u64 features); 223 224 __poll_t vhost_chr_poll(struct file *file, struct vhost_dev *dev, 225 poll_table *wait); 226 ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to, 227 int noblock); 228 ssize_t vhost_chr_write_iter(struct vhost_dev *dev, 229 struct iov_iter *from); 230 int vhost_init_device_iotlb(struct vhost_dev *d); 231 232 void vhost_iotlb_map_free(struct vhost_iotlb *iotlb, 233 struct vhost_iotlb_map *map); 234 235 #define vq_err(vq, fmt, ...) do { \ 236 pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \ 237 if ((vq)->error_ctx) \ 238 eventfd_signal((vq)->error_ctx, 1);\ 239 } while (0) 240 241 enum { 242 VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | 243 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) | 244 (1ULL << VIRTIO_RING_F_EVENT_IDX) | 245 (1ULL << VHOST_F_LOG_ALL) | 246 (1ULL << VIRTIO_F_ANY_LAYOUT) | 247 (1ULL << VIRTIO_F_VERSION_1) 248 }; 249 250 /** 251 * vhost_vq_set_backend - Set backend. 252 * 253 * @vq Virtqueue. 254 * @private_data The private data. 255 * 256 * Context: Need to call with vq->mutex acquired. 257 */ 258 static inline void vhost_vq_set_backend(struct vhost_virtqueue *vq, 259 void *private_data) 260 { 261 vq->private_data = private_data; 262 } 263 264 /** 265 * vhost_vq_get_backend - Get backend. 266 * 267 * @vq Virtqueue. 268 * 269 * Context: Need to call with vq->mutex acquired. 270 * Return: Private data previously set with vhost_vq_set_backend. 271 */ 272 static inline void *vhost_vq_get_backend(struct vhost_virtqueue *vq) 273 { 274 return vq->private_data; 275 } 276 277 static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit) 278 { 279 return vq->acked_features & (1ULL << bit); 280 } 281 282 static inline bool vhost_backend_has_feature(struct vhost_virtqueue *vq, int bit) 283 { 284 return vq->acked_backend_features & (1ULL << bit); 285 } 286 287 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY 288 static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq) 289 { 290 return vq->is_le; 291 } 292 #else 293 static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq) 294 { 295 return virtio_legacy_is_little_endian() || vq->is_le; 296 } 297 #endif 298 299 /* Memory accessors */ 300 static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val) 301 { 302 return __virtio16_to_cpu(vhost_is_little_endian(vq), val); 303 } 304 305 static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val) 306 { 307 return __cpu_to_virtio16(vhost_is_little_endian(vq), val); 308 } 309 310 static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val) 311 { 312 return __virtio32_to_cpu(vhost_is_little_endian(vq), val); 313 } 314 315 static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val) 316 { 317 return __cpu_to_virtio32(vhost_is_little_endian(vq), val); 318 } 319 320 static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val) 321 { 322 return __virtio64_to_cpu(vhost_is_little_endian(vq), val); 323 } 324 325 static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val) 326 { 327 return __cpu_to_virtio64(vhost_is_little_endian(vq), val); 328 } 329 #endif 330