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 typedef void (*vhost_work_fn_t)(struct vhost_work *work); 20 21 #define VHOST_WORK_QUEUED 1 22 struct vhost_work { 23 struct llist_node node; 24 vhost_work_fn_t fn; 25 unsigned long flags; 26 }; 27 28 /* Poll a file (eventfd or socket) */ 29 /* Note: there's nothing vhost specific about this structure. */ 30 struct vhost_poll { 31 poll_table table; 32 wait_queue_head_t *wqh; 33 wait_queue_entry_t wait; 34 struct vhost_work work; 35 __poll_t mask; 36 struct vhost_dev *dev; 37 }; 38 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); 42 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); 51 52 struct vhost_log { 53 u64 addr; 54 u64 len; 55 }; 56 57 enum vhost_uaddr_type { 58 VHOST_ADDR_DESC = 0, 59 VHOST_ADDR_AVAIL = 1, 60 VHOST_ADDR_USED = 2, 61 VHOST_NUM_ADDRS = 3, 62 }; 63 64 struct vhost_vring_call { 65 struct eventfd_ctx *ctx; 66 struct irq_bypass_producer producer; 67 }; 68 69 /* The virtqueue structure describes a queue attached to a device. */ 70 struct vhost_virtqueue { 71 struct vhost_dev *dev; 72 73 /* The actual ring of buffers. */ 74 struct mutex mutex; 75 unsigned int num; 76 vring_desc_t __user *desc; 77 vring_avail_t __user *avail; 78 vring_used_t __user *used; 79 const struct vhost_iotlb_map *meta_iotlb[VHOST_NUM_ADDRS]; 80 struct file *kick; 81 struct vhost_vring_call call_ctx; 82 struct eventfd_ctx *error_ctx; 83 struct eventfd_ctx *log_ctx; 84 85 struct vhost_poll poll; 86 87 /* The routine to call when the Guest pings us, or timeout. */ 88 vhost_work_fn_t handle_kick; 89 90 /* Last available index we saw. */ 91 u16 last_avail_idx; 92 93 /* Caches available index value from user. */ 94 u16 avail_idx; 95 96 /* Last index we used. */ 97 u16 last_used_idx; 98 99 /* Used flags */ 100 u16 used_flags; 101 102 /* Last used index value we have signalled on */ 103 u16 signalled_used; 104 105 /* Last used index value we have signalled on */ 106 bool signalled_used_valid; 107 108 /* Log writes to used structure. */ 109 bool log_used; 110 u64 log_addr; 111 112 struct iovec iov[UIO_MAXIOV]; 113 struct iovec iotlb_iov[64]; 114 struct iovec *indirect; 115 struct vring_used_elem *heads; 116 /* Protected by virtqueue mutex. */ 117 struct vhost_iotlb *umem; 118 struct vhost_iotlb *iotlb; 119 void *private_data; 120 u64 acked_features; 121 u64 acked_backend_features; 122 /* Log write descriptors */ 123 void __user *log_base; 124 struct vhost_log *log; 125 struct iovec log_iov[64]; 126 127 /* Ring endianness. Defaults to legacy native endianness. 128 * Set to true when starting a modern virtio device. */ 129 bool is_le; 130 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY 131 /* Ring endianness requested by userspace for cross-endian support. */ 132 bool user_be; 133 #endif 134 u32 busyloop_timeout; 135 }; 136 137 struct vhost_msg_node { 138 union { 139 struct vhost_msg msg; 140 struct vhost_msg_v2 msg_v2; 141 }; 142 struct vhost_virtqueue *vq; 143 struct list_head node; 144 }; 145 146 struct vhost_dev { 147 struct mm_struct *mm; 148 struct mutex mutex; 149 struct vhost_virtqueue **vqs; 150 int nvqs; 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; 160 int iov_limit; 161 int weight; 162 int byte_weight; 163 u64 kcov_handle; 164 bool use_worker; 165 int (*msg_handler)(struct vhost_dev *dev, 166 struct vhost_iotlb_msg *msg); 167 }; 168 169 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, 172 bool use_worker, 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 *); 186 187 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); 192 193 bool vhost_vq_is_setup(struct vhost_virtqueue *vq); 194 int vhost_vq_init_access(struct vhost_virtqueue *); 195 int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len); 196 int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads, 197 unsigned count); 198 void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *, 199 unsigned int id, int len); 200 void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *, 201 struct vring_used_elem *heads, unsigned count); 202 void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *); 203 void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *); 204 bool vhost_vq_avail_empty(struct vhost_dev *, struct vhost_virtqueue *); 205 bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *); 206 207 int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, 208 unsigned int log_num, u64 len, 209 struct iovec *iov, int count); 210 int vq_meta_prefetch(struct vhost_virtqueue *vq); 211 212 struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type); 213 void vhost_enqueue_msg(struct vhost_dev *dev, 214 struct list_head *head, 215 struct vhost_msg_node *node); 216 struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev, 217 struct list_head *head); 218 void vhost_set_backend_features(struct vhost_dev *dev, u64 features); 219 220 __poll_t vhost_chr_poll(struct file *file, struct vhost_dev *dev, 221 poll_table *wait); 222 ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to, 223 int noblock); 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); 227 228 void vhost_iotlb_map_free(struct vhost_iotlb *iotlb, 229 struct vhost_iotlb_map *map); 230 231 #define vq_err(vq, fmt, ...) do { \ 232 pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \ 233 if ((vq)->error_ctx) \ 234 eventfd_signal((vq)->error_ctx, 1);\ 235 } while (0) 236 237 enum { 238 VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | 239 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) | 240 (1ULL << VIRTIO_RING_F_EVENT_IDX) | 241 (1ULL << VHOST_F_LOG_ALL) | 242 (1ULL << VIRTIO_F_ANY_LAYOUT) | 243 (1ULL << VIRTIO_F_VERSION_1) 244 }; 245 246 /** 247 * vhost_vq_set_backend - Set backend. 248 * 249 * @vq Virtqueue. 250 * @private_data The private data. 251 * 252 * Context: Need to call with vq->mutex acquired. 253 */ 254 static inline void vhost_vq_set_backend(struct vhost_virtqueue *vq, 255 void *private_data) 256 { 257 vq->private_data = private_data; 258 } 259 260 /** 261 * vhost_vq_get_backend - Get backend. 262 * 263 * @vq Virtqueue. 264 * 265 * Context: Need to call with vq->mutex acquired. 266 * Return: Private data previously set with vhost_vq_set_backend. 267 */ 268 static inline void *vhost_vq_get_backend(struct vhost_virtqueue *vq) 269 { 270 return vq->private_data; 271 } 272 273 static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit) 274 { 275 return vq->acked_features & (1ULL << bit); 276 } 277 278 static inline bool vhost_backend_has_feature(struct vhost_virtqueue *vq, int bit) 279 { 280 return vq->acked_backend_features & (1ULL << bit); 281 } 282 283 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY 284 static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq) 285 { 286 return vq->is_le; 287 } 288 #else 289 static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq) 290 { 291 return virtio_legacy_is_little_endian() || vq->is_le; 292 } 293 #endif 294 295 /* Memory accessors */ 296 static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val) 297 { 298 return __virtio16_to_cpu(vhost_is_little_endian(vq), val); 299 } 300 301 static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val) 302 { 303 return __cpu_to_virtio16(vhost_is_little_endian(vq), val); 304 } 305 306 static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val) 307 { 308 return __virtio32_to_cpu(vhost_is_little_endian(vq), val); 309 } 310 311 static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val) 312 { 313 return __cpu_to_virtio32(vhost_is_little_endian(vq), val); 314 } 315 316 static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val) 317 { 318 return __virtio64_to_cpu(vhost_is_little_endian(vq), val); 319 } 320 321 static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val) 322 { 323 return __cpu_to_virtio64(vhost_is_little_endian(vq), val); 324 } 325 #endif 326