1 #ifndef _VHOST_H 2 #define _VHOST_H 3 4 #include <linux/eventfd.h> 5 #include <linux/vhost.h> 6 #include <linux/mm.h> 7 #include <linux/mutex.h> 8 #include <linux/poll.h> 9 #include <linux/file.h> 10 #include <linux/uio.h> 11 #include <linux/virtio_config.h> 12 #include <linux/virtio_ring.h> 13 #include <linux/atomic.h> 14 15 struct vhost_work; 16 typedef void (*vhost_work_fn_t)(struct vhost_work *work); 17 18 struct vhost_work { 19 struct list_head node; 20 vhost_work_fn_t fn; 21 wait_queue_head_t done; 22 int flushing; 23 unsigned queue_seq; 24 unsigned done_seq; 25 }; 26 27 /* Poll a file (eventfd or socket) */ 28 /* Note: there's nothing vhost specific about this structure. */ 29 struct vhost_poll { 30 poll_table table; 31 wait_queue_head_t *wqh; 32 wait_queue_t wait; 33 struct vhost_work work; 34 unsigned long mask; 35 struct vhost_dev *dev; 36 }; 37 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); 41 42 void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn, 43 unsigned long 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, int ioctl, void __user *argp); 50 51 struct vhost_log { 52 u64 addr; 53 u64 len; 54 }; 55 56 /* The virtqueue structure describes a queue attached to a device. */ 57 struct vhost_virtqueue { 58 struct vhost_dev *dev; 59 60 /* The actual ring of buffers. */ 61 struct mutex mutex; 62 unsigned int num; 63 struct vring_desc __user *desc; 64 struct vring_avail __user *avail; 65 struct vring_used __user *used; 66 struct file *kick; 67 struct file *call; 68 struct file *error; 69 struct eventfd_ctx *call_ctx; 70 struct eventfd_ctx *error_ctx; 71 struct eventfd_ctx *log_ctx; 72 73 struct vhost_poll poll; 74 75 /* The routine to call when the Guest pings us, or timeout. */ 76 vhost_work_fn_t handle_kick; 77 78 /* Last available index we saw. */ 79 u16 last_avail_idx; 80 81 /* Caches available index value from user. */ 82 u16 avail_idx; 83 84 /* Last index we used. */ 85 u16 last_used_idx; 86 87 /* Used flags */ 88 u16 used_flags; 89 90 /* Last used index value we have signalled on */ 91 u16 signalled_used; 92 93 /* Last used index value we have signalled on */ 94 bool signalled_used_valid; 95 96 /* Log writes to used structure. */ 97 bool log_used; 98 u64 log_addr; 99 100 struct iovec iov[UIO_MAXIOV]; 101 struct iovec *indirect; 102 struct vring_used_elem *heads; 103 /* Protected by virtqueue mutex. */ 104 struct vhost_memory *memory; 105 void *private_data; 106 u64 acked_features; 107 /* Log write descriptors */ 108 void __user *log_base; 109 struct vhost_log *log; 110 111 /* Ring endianness. Defaults to legacy native endianness. 112 * Set to true when starting a modern virtio device. */ 113 bool is_le; 114 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY 115 /* Ring endianness requested by userspace for cross-endian support. */ 116 bool user_be; 117 #endif 118 u32 busyloop_timeout; 119 }; 120 121 struct vhost_dev { 122 struct vhost_memory *memory; 123 struct mm_struct *mm; 124 struct mutex mutex; 125 struct vhost_virtqueue **vqs; 126 int nvqs; 127 struct file *log_file; 128 struct eventfd_ctx *log_ctx; 129 spinlock_t work_lock; 130 struct list_head work_list; 131 struct task_struct *worker; 132 }; 133 134 void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, int nvqs); 135 long vhost_dev_set_owner(struct vhost_dev *dev); 136 bool vhost_dev_has_owner(struct vhost_dev *dev); 137 long vhost_dev_check_owner(struct vhost_dev *); 138 struct vhost_memory *vhost_dev_reset_owner_prepare(void); 139 void vhost_dev_reset_owner(struct vhost_dev *, struct vhost_memory *); 140 void vhost_dev_cleanup(struct vhost_dev *, bool locked); 141 void vhost_dev_stop(struct vhost_dev *); 142 long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp); 143 long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp); 144 int vhost_vq_access_ok(struct vhost_virtqueue *vq); 145 int vhost_log_access_ok(struct vhost_dev *); 146 147 int vhost_get_vq_desc(struct vhost_virtqueue *, 148 struct iovec iov[], unsigned int iov_count, 149 unsigned int *out_num, unsigned int *in_num, 150 struct vhost_log *log, unsigned int *log_num); 151 void vhost_discard_vq_desc(struct vhost_virtqueue *, int n); 152 153 int vhost_vq_init_access(struct vhost_virtqueue *); 154 int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len); 155 int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads, 156 unsigned count); 157 void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *, 158 unsigned int id, int len); 159 void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *, 160 struct vring_used_elem *heads, unsigned count); 161 void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *); 162 void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *); 163 bool vhost_vq_avail_empty(struct vhost_dev *, struct vhost_virtqueue *); 164 bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *); 165 166 int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, 167 unsigned int log_num, u64 len); 168 169 #define vq_err(vq, fmt, ...) do { \ 170 pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \ 171 if ((vq)->error_ctx) \ 172 eventfd_signal((vq)->error_ctx, 1);\ 173 } while (0) 174 175 enum { 176 VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | 177 (1ULL << VIRTIO_RING_F_INDIRECT_DESC) | 178 (1ULL << VIRTIO_RING_F_EVENT_IDX) | 179 (1ULL << VHOST_F_LOG_ALL) | 180 (1ULL << VIRTIO_F_ANY_LAYOUT) | 181 (1ULL << VIRTIO_F_VERSION_1) 182 }; 183 184 static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit) 185 { 186 return vq->acked_features & (1ULL << bit); 187 } 188 189 #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY 190 static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq) 191 { 192 return vq->is_le; 193 } 194 #else 195 static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq) 196 { 197 return virtio_legacy_is_little_endian() || vq->is_le; 198 } 199 #endif 200 201 /* Memory accessors */ 202 static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val) 203 { 204 return __virtio16_to_cpu(vhost_is_little_endian(vq), val); 205 } 206 207 static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val) 208 { 209 return __cpu_to_virtio16(vhost_is_little_endian(vq), val); 210 } 211 212 static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val) 213 { 214 return __virtio32_to_cpu(vhost_is_little_endian(vq), val); 215 } 216 217 static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val) 218 { 219 return __cpu_to_virtio32(vhost_is_little_endian(vq), val); 220 } 221 222 static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val) 223 { 224 return __virtio64_to_cpu(vhost_is_little_endian(vq), val); 225 } 226 227 static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val) 228 { 229 return __cpu_to_virtio64(vhost_is_little_endian(vq), val); 230 } 231 #endif 232