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 18struct vhost_work; 19typedef void (*vhost_work_fn_t)(struct vhost_work *work); 20 21#define VHOST_WORK_QUEUED 1 22struct 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. */ 30struct 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 39void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn); 40void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work); 41bool vhost_has_work(struct vhost_dev *dev); 42 43void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn, 44 __poll_t mask, struct vhost_dev *dev); 45int vhost_poll_start(struct vhost_poll *poll, struct file *file); 46void vhost_poll_stop(struct vhost_poll *poll); 47void vhost_poll_flush(struct vhost_poll *poll); 48void vhost_poll_queue(struct vhost_poll *poll); 49void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work); 50long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp); 51 52struct vhost_log { 53 u64 addr; 54 u64 len; 55}; 56 57enum 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 64struct 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. */ 70struct 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 * Values are limited to 0x7fff, and the high bit is used as 92 * a wrap counter when using VIRTIO_F_RING_PACKED. */ 93 u16 last_avail_idx; 94 95 /* Caches available index value from user. */ 96 u16 avail_idx; 97 98 /* Last index we used. 99 * Values are limited to 0x7fff, and the high bit is used as 100 * a wrap counter when using VIRTIO_F_RING_PACKED. */ 101 u16 last_used_idx; 102 103 /* Used flags */ 104 u16 used_flags; 105 106 /* Last used index value we have signalled on */ 107 u16 signalled_used; 108 109 /* Last used index value we have signalled on */ 110 bool signalled_used_valid; 111 112 /* Log writes to used structure. */ 113 bool log_used; 114 u64 log_addr; 115 116 struct iovec iov[UIO_MAXIOV]; 117 struct iovec iotlb_iov[64]; 118 struct iovec *indirect; 119 struct vring_used_elem *heads; 120 /* Protected by virtqueue mutex. */ 121 struct vhost_iotlb *umem; 122 struct vhost_iotlb *iotlb; 123 void *private_data; 124 u64 acked_features; 125 u64 acked_backend_features; 126 /* Log write descriptors */ 127 void __user *log_base; 128 struct vhost_log *log; 129 struct iovec log_iov[64]; 130 131 /* Ring endianness. Defaults to legacy native endianness. 132 * Set to true when starting a modern virtio device. */ 133 bool is_le; 134#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY 135 /* Ring endianness requested by userspace for cross-endian support. */ 136 bool user_be; 137#endif 138 u32 busyloop_timeout; 139}; 140 141struct vhost_msg_node { 142 union { 143 struct vhost_msg msg; 144 struct vhost_msg_v2 msg_v2; 145 }; 146 struct vhost_virtqueue *vq; 147 struct list_head node; 148}; 149 150struct vhost_dev { 151 struct mm_struct *mm; 152 struct mutex mutex; 153 struct vhost_virtqueue **vqs; 154 int nvqs; 155 struct eventfd_ctx *log_ctx; 156 struct llist_head work_list; 157 struct task_struct *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 u64 kcov_handle; 168 bool use_worker; 169 int (*msg_handler)(struct vhost_dev *dev, 170 struct vhost_iotlb_msg *msg); 171}; 172 173bool vhost_exceeds_weight(struct vhost_virtqueue *vq, int pkts, int total_len); 174void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, 175 int nvqs, int iov_limit, int weight, int byte_weight, 176 bool use_worker, 177 int (*msg_handler)(struct vhost_dev *dev, 178 struct vhost_iotlb_msg *msg)); 179long vhost_dev_set_owner(struct vhost_dev *dev); 180bool vhost_dev_has_owner(struct vhost_dev *dev); 181long vhost_dev_check_owner(struct vhost_dev *); 182struct vhost_iotlb *vhost_dev_reset_owner_prepare(void); 183void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_iotlb *iotlb); 184void vhost_dev_cleanup(struct vhost_dev *); 185void vhost_dev_stop(struct vhost_dev *); 186long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp); 187long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp); 188bool vhost_vq_access_ok(struct vhost_virtqueue *vq); 189bool vhost_log_access_ok(struct vhost_dev *); 190void vhost_clear_msg(struct vhost_dev *dev); 191 192int vhost_get_vq_desc(struct vhost_virtqueue *, 193 struct iovec iov[], unsigned int iov_count, 194 unsigned int *out_num, unsigned int *in_num, 195 struct vhost_log *log, unsigned int *log_num); 196void vhost_discard_vq_desc(struct vhost_virtqueue *, int n); 197 198bool vhost_vq_is_setup(struct vhost_virtqueue *vq); 199int vhost_vq_init_access(struct vhost_virtqueue *); 200int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len); 201int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads, 202 unsigned count); 203void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *, 204 unsigned int id, int len); 205void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *, 206 struct vring_used_elem *heads, unsigned count); 207void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *); 208void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *); 209bool vhost_vq_avail_empty(struct vhost_dev *, struct vhost_virtqueue *); 210bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *); 211 212int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, 213 unsigned int log_num, u64 len, 214 struct iovec *iov, int count); 215int vq_meta_prefetch(struct vhost_virtqueue *vq); 216 217struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type); 218void vhost_enqueue_msg(struct vhost_dev *dev, 219 struct list_head *head, 220 struct vhost_msg_node *node); 221struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev, 222 struct list_head *head); 223void vhost_set_backend_features(struct vhost_dev *dev, u64 features); 224 225__poll_t vhost_chr_poll(struct file *file, struct vhost_dev *dev, 226 poll_table *wait); 227ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to, 228 int noblock); 229ssize_t vhost_chr_write_iter(struct vhost_dev *dev, 230 struct iov_iter *from); 231int vhost_init_device_iotlb(struct vhost_dev *d, bool enabled); 232 233void vhost_iotlb_map_free(struct vhost_iotlb *iotlb, 234 struct vhost_iotlb_map *map); 235 236#define vq_err(vq, fmt, ...) do { \ 237 pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \ 238 if ((vq)->error_ctx) \ 239 eventfd_signal((vq)->error_ctx, 1);\ 240 } while (0) 241 242enum { 243 VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | 244 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) | 245 (1ULL << VIRTIO_RING_F_EVENT_IDX) | 246 (1ULL << VHOST_F_LOG_ALL) | 247 (1ULL << VIRTIO_F_ANY_LAYOUT) | 248 (1ULL << VIRTIO_F_VERSION_1) 249}; 250 251/** 252 * vhost_vq_set_backend - Set backend. 253 * 254 * @vq Virtqueue. 255 * @private_data The private data. 256 * 257 * Context: Need to call with vq->mutex acquired. 258 */ 259static inline void vhost_vq_set_backend(struct vhost_virtqueue *vq, 260 void *private_data) 261{ 262 vq->private_data = private_data; 263} 264 265/** 266 * vhost_vq_get_backend - Get backend. 267 * 268 * @vq Virtqueue. 269 * 270 * Context: Need to call with vq->mutex acquired. 271 * Return: Private data previously set with vhost_vq_set_backend. 272 */ 273static inline void *vhost_vq_get_backend(struct vhost_virtqueue *vq) 274{ 275 return vq->private_data; 276} 277 278static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit) 279{ 280 return vq->acked_features & (1ULL << bit); 281} 282 283static inline bool vhost_backend_has_feature(struct vhost_virtqueue *vq, int bit) 284{ 285 return vq->acked_backend_features & (1ULL << bit); 286} 287 288#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY 289static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq) 290{ 291 return vq->is_le; 292} 293#else 294static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq) 295{ 296 return virtio_legacy_is_little_endian() || vq->is_le; 297} 298#endif 299 300/* Memory accessors */ 301static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val) 302{ 303 return __virtio16_to_cpu(vhost_is_little_endian(vq), val); 304} 305 306static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val) 307{ 308 return __cpu_to_virtio16(vhost_is_little_endian(vq), val); 309} 310 311static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val) 312{ 313 return __virtio32_to_cpu(vhost_is_little_endian(vq), val); 314} 315 316static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val) 317{ 318 return __cpu_to_virtio32(vhost_is_little_endian(vq), val); 319} 320 321static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val) 322{ 323 return __virtio64_to_cpu(vhost_is_little_endian(vq), val); 324} 325 326static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val) 327{ 328 return __cpu_to_virtio64(vhost_is_little_endian(vq), val); 329} 330#endif 331