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/workqueue.h> 9 #include <linux/poll.h> 10 #include <linux/file.h> 11 #include <linux/skbuff.h> 12 #include <linux/uio.h> 13 #include <linux/virtio_config.h> 14 #include <linux/virtio_ring.h> 15 16 struct vhost_device; 17 18 enum { 19 /* Enough place for all fragments, head, and virtio net header. */ 20 VHOST_NET_MAX_SG = MAX_SKB_FRAGS + 2, 21 }; 22 23 /* Poll a file (eventfd or socket) */ 24 /* Note: there's nothing vhost specific about this structure. */ 25 struct vhost_poll { 26 poll_table table; 27 wait_queue_head_t *wqh; 28 wait_queue_t wait; 29 /* struct which will handle all actual work. */ 30 struct work_struct work; 31 unsigned long mask; 32 }; 33 34 void vhost_poll_init(struct vhost_poll *poll, work_func_t func, 35 unsigned long mask); 36 void vhost_poll_start(struct vhost_poll *poll, struct file *file); 37 void vhost_poll_stop(struct vhost_poll *poll); 38 void vhost_poll_flush(struct vhost_poll *poll); 39 void vhost_poll_queue(struct vhost_poll *poll); 40 41 struct vhost_log { 42 u64 addr; 43 u64 len; 44 }; 45 46 /* The virtqueue structure describes a queue attached to a device. */ 47 struct vhost_virtqueue { 48 struct vhost_dev *dev; 49 50 /* The actual ring of buffers. */ 51 struct mutex mutex; 52 unsigned int num; 53 struct vring_desc __user *desc; 54 struct vring_avail __user *avail; 55 struct vring_used __user *used; 56 struct file *kick; 57 struct file *call; 58 struct file *error; 59 struct eventfd_ctx *call_ctx; 60 struct eventfd_ctx *error_ctx; 61 struct eventfd_ctx *log_ctx; 62 63 struct vhost_poll poll; 64 65 /* The routine to call when the Guest pings us, or timeout. */ 66 work_func_t handle_kick; 67 68 /* Last available index we saw. */ 69 u16 last_avail_idx; 70 71 /* Caches available index value from user. */ 72 u16 avail_idx; 73 74 /* Last index we used. */ 75 u16 last_used_idx; 76 77 /* Used flags */ 78 u16 used_flags; 79 80 /* Log writes to used structure. */ 81 bool log_used; 82 u64 log_addr; 83 84 struct iovec indirect[VHOST_NET_MAX_SG]; 85 struct iovec iov[VHOST_NET_MAX_SG]; 86 struct iovec hdr[VHOST_NET_MAX_SG]; 87 size_t hdr_size; 88 /* We use a kind of RCU to access private pointer. 89 * All readers access it from workqueue, which makes it possible to 90 * flush the workqueue instead of synchronize_rcu. Therefore readers do 91 * not need to call rcu_read_lock/rcu_read_unlock: the beginning of 92 * work item execution acts instead of rcu_read_lock() and the end of 93 * work item execution acts instead of rcu_read_lock(). 94 * Writers use virtqueue mutex. */ 95 void *private_data; 96 /* Log write descriptors */ 97 void __user *log_base; 98 struct vhost_log log[VHOST_NET_MAX_SG]; 99 }; 100 101 struct vhost_dev { 102 /* Readers use RCU to access memory table pointer 103 * log base pointer and features. 104 * Writers use mutex below.*/ 105 struct vhost_memory *memory; 106 struct mm_struct *mm; 107 struct mutex mutex; 108 unsigned acked_features; 109 struct vhost_virtqueue *vqs; 110 int nvqs; 111 struct file *log_file; 112 struct eventfd_ctx *log_ctx; 113 }; 114 115 long vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue *vqs, int nvqs); 116 long vhost_dev_check_owner(struct vhost_dev *); 117 long vhost_dev_reset_owner(struct vhost_dev *); 118 void vhost_dev_cleanup(struct vhost_dev *); 119 long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, unsigned long arg); 120 int vhost_vq_access_ok(struct vhost_virtqueue *vq); 121 int vhost_log_access_ok(struct vhost_dev *); 122 123 unsigned vhost_get_vq_desc(struct vhost_dev *, struct vhost_virtqueue *, 124 struct iovec iov[], unsigned int iov_count, 125 unsigned int *out_num, unsigned int *in_num, 126 struct vhost_log *log, unsigned int *log_num); 127 void vhost_discard_vq_desc(struct vhost_virtqueue *); 128 129 int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len); 130 void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *); 131 void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *, 132 unsigned int head, int len); 133 void vhost_disable_notify(struct vhost_virtqueue *); 134 bool vhost_enable_notify(struct vhost_virtqueue *); 135 136 int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, 137 unsigned int log_num, u64 len); 138 139 int vhost_init(void); 140 void vhost_cleanup(void); 141 142 #define vq_err(vq, fmt, ...) do { \ 143 pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \ 144 if ((vq)->error_ctx) \ 145 eventfd_signal((vq)->error_ctx, 1);\ 146 } while (0) 147 148 enum { 149 VHOST_FEATURES = (1 << VIRTIO_F_NOTIFY_ON_EMPTY) | 150 (1 << VIRTIO_RING_F_INDIRECT_DESC) | 151 (1 << VHOST_F_LOG_ALL) | 152 (1 << VHOST_NET_F_VIRTIO_NET_HDR), 153 }; 154 155 static inline int vhost_has_feature(struct vhost_dev *dev, int bit) 156 { 157 unsigned acked_features = rcu_dereference(dev->acked_features); 158 return acked_features & (1 << bit); 159 } 160 161 #endif 162