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_queue(struct vhost_poll *poll); 48 void vhost_dev_flush(struct vhost_dev *dev); 49 50 struct vhost_log { 51 u64 addr; 52 u64 len; 53 }; 54 55 enum vhost_uaddr_type { 56 VHOST_ADDR_DESC = 0, 57 VHOST_ADDR_AVAIL = 1, 58 VHOST_ADDR_USED = 2, 59 VHOST_NUM_ADDRS = 3, 60 }; 61 62 struct vhost_vring_call { 63 struct eventfd_ctx *ctx; 64 struct irq_bypass_producer producer; 65 }; 66 67 /* The virtqueue structure describes a queue attached to a device. */ 68 struct vhost_virtqueue { 69 struct vhost_dev *dev; 70 71 /* The actual ring of buffers. */ 72 struct mutex mutex; 73 unsigned int num; 74 vring_desc_t __user *desc; 75 vring_avail_t __user *avail; 76 vring_used_t __user *used; 77 const struct vhost_iotlb_map *meta_iotlb[VHOST_NUM_ADDRS]; 78 struct file *kick; 79 struct vhost_vring_call call_ctx; 80 struct eventfd_ctx *error_ctx; 81 struct eventfd_ctx *log_ctx; 82 83 struct vhost_poll poll; 84 85 /* The routine to call when the Guest pings us, or timeout. */ 86 vhost_work_fn_t handle_kick; 87 88 /* Last available index we saw. */ 89 u16 last_avail_idx; 90 91 /* Caches available index value from user. */ 92 u16 avail_idx; 93 94 /* Last index we used. */ 95 u16 last_used_idx; 96 97 /* Used flags */ 98 u16 used_flags; 99 100 /* Last used index value we have signalled on */ 101 u16 signalled_used; 102 103 /* Last used index value we have signalled on */ 104 bool signalled_used_valid; 105 106 /* Log writes to used structure. */ 107 bool log_used; 108 u64 log_addr; 109 110 struct iovec iov[UIO_MAXIOV]; 111 struct iovec iotlb_iov[64]; 112 struct iovec *indirect; 113 struct vring_used_elem *heads; 114 /* Protected by virtqueue mutex. */ 115 struct vhost_iotlb *umem; 116 struct vhost_iotlb *iotlb; 117 void *private_data; 118 u64 acked_features; 119 u64 acked_backend_features; 120 /* Log write descriptors */ 121 void __user *log_base; 122 struct vhost_log *log; 123 struct iovec log_iov[64]; 124 125 /* Ring endianness. Defaults to legacy native endianness. 126 * Set to true when starting a modern virtio device. */ 127 bool is_le; 128 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY 129 /* Ring endianness requested by userspace for cross-endian support. */ 130 bool user_be; 131 #endif 132 u32 busyloop_timeout; 133 }; 134 135 struct vhost_msg_node { 136 union { 137 struct vhost_msg msg; 138 struct vhost_msg_v2 msg_v2; 139 }; 140 struct vhost_virtqueue *vq; 141 struct list_head node; 142 }; 143 144 struct vhost_dev { 145 struct mm_struct *mm; 146 struct mutex mutex; 147 struct vhost_virtqueue **vqs; 148 int nvqs; 149 struct eventfd_ctx *log_ctx; 150 struct llist_head work_list; 151 struct task_struct *worker; 152 struct vhost_iotlb *umem; 153 struct vhost_iotlb *iotlb; 154 spinlock_t iotlb_lock; 155 struct list_head read_list; 156 struct list_head pending_list; 157 wait_queue_head_t wait; 158 int iov_limit; 159 int weight; 160 int byte_weight; 161 u64 kcov_handle; 162 bool use_worker; 163 int (*msg_handler)(struct vhost_dev *dev, u32 asid, 164 struct vhost_iotlb_msg *msg); 165 }; 166 167 bool vhost_exceeds_weight(struct vhost_virtqueue *vq, int pkts, int total_len); 168 void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, 169 int nvqs, int iov_limit, int weight, int byte_weight, 170 bool use_worker, 171 int (*msg_handler)(struct vhost_dev *dev, u32 asid, 172 struct vhost_iotlb_msg *msg)); 173 long vhost_dev_set_owner(struct vhost_dev *dev); 174 bool vhost_dev_has_owner(struct vhost_dev *dev); 175 long vhost_dev_check_owner(struct vhost_dev *); 176 struct vhost_iotlb *vhost_dev_reset_owner_prepare(void); 177 void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_iotlb *iotlb); 178 void vhost_dev_cleanup(struct vhost_dev *); 179 void vhost_dev_stop(struct vhost_dev *); 180 long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp); 181 long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp); 182 bool vhost_vq_access_ok(struct vhost_virtqueue *vq); 183 bool vhost_log_access_ok(struct vhost_dev *); 184 185 int vhost_get_vq_desc(struct vhost_virtqueue *, 186 struct iovec iov[], unsigned int iov_count, 187 unsigned int *out_num, unsigned int *in_num, 188 struct vhost_log *log, unsigned int *log_num); 189 void vhost_discard_vq_desc(struct vhost_virtqueue *, int n); 190 191 bool vhost_vq_is_setup(struct vhost_virtqueue *vq); 192 int vhost_vq_init_access(struct vhost_virtqueue *); 193 int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len); 194 int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads, 195 unsigned count); 196 void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *, 197 unsigned int id, int len); 198 void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *, 199 struct vring_used_elem *heads, unsigned count); 200 void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *); 201 void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *); 202 bool vhost_vq_avail_empty(struct vhost_dev *, struct vhost_virtqueue *); 203 bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *); 204 205 int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, 206 unsigned int log_num, u64 len, 207 struct iovec *iov, int count); 208 int vq_meta_prefetch(struct vhost_virtqueue *vq); 209 210 struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type); 211 void vhost_enqueue_msg(struct vhost_dev *dev, 212 struct list_head *head, 213 struct vhost_msg_node *node); 214 struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev, 215 struct list_head *head); 216 void vhost_set_backend_features(struct vhost_dev *dev, u64 features); 217 218 __poll_t vhost_chr_poll(struct file *file, struct vhost_dev *dev, 219 poll_table *wait); 220 ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to, 221 int noblock); 222 ssize_t vhost_chr_write_iter(struct vhost_dev *dev, 223 struct iov_iter *from); 224 int vhost_init_device_iotlb(struct vhost_dev *d, bool enabled); 225 226 void vhost_iotlb_map_free(struct vhost_iotlb *iotlb, 227 struct vhost_iotlb_map *map); 228 229 #define vq_err(vq, fmt, ...) do { \ 230 pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \ 231 if ((vq)->error_ctx) \ 232 eventfd_signal((vq)->error_ctx, 1);\ 233 } while (0) 234 235 enum { 236 VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | 237 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) | 238 (1ULL << VIRTIO_RING_F_EVENT_IDX) | 239 (1ULL << VHOST_F_LOG_ALL) | 240 (1ULL << VIRTIO_F_ANY_LAYOUT) | 241 (1ULL << VIRTIO_F_VERSION_1) 242 }; 243 244 /** 245 * vhost_vq_set_backend - Set backend. 246 * 247 * @vq Virtqueue. 248 * @private_data The private data. 249 * 250 * Context: Need to call with vq->mutex acquired. 251 */ 252 static inline void vhost_vq_set_backend(struct vhost_virtqueue *vq, 253 void *private_data) 254 { 255 vq->private_data = private_data; 256 } 257 258 /** 259 * vhost_vq_get_backend - Get backend. 260 * 261 * @vq Virtqueue. 262 * 263 * Context: Need to call with vq->mutex acquired. 264 * Return: Private data previously set with vhost_vq_set_backend. 265 */ 266 static inline void *vhost_vq_get_backend(struct vhost_virtqueue *vq) 267 { 268 return vq->private_data; 269 } 270 271 static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit) 272 { 273 return vq->acked_features & (1ULL << bit); 274 } 275 276 static inline bool vhost_backend_has_feature(struct vhost_virtqueue *vq, int bit) 277 { 278 return vq->acked_backend_features & (1ULL << bit); 279 } 280 281 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY 282 static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq) 283 { 284 return vq->is_le; 285 } 286 #else 287 static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq) 288 { 289 return virtio_legacy_is_little_endian() || vq->is_le; 290 } 291 #endif 292 293 /* Memory accessors */ 294 static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val) 295 { 296 return __virtio16_to_cpu(vhost_is_little_endian(vq), val); 297 } 298 299 static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val) 300 { 301 return __cpu_to_virtio16(vhost_is_little_endian(vq), val); 302 } 303 304 static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val) 305 { 306 return __virtio32_to_cpu(vhost_is_little_endian(vq), val); 307 } 308 309 static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val) 310 { 311 return __cpu_to_virtio32(vhost_is_little_endian(vq), val); 312 } 313 314 static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val) 315 { 316 return __virtio64_to_cpu(vhost_is_little_endian(vq), val); 317 } 318 319 static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val) 320 { 321 return __cpu_to_virtio64(vhost_is_little_endian(vq), val); 322 } 323 #endif 324