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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 | #ifndef _VHOST_H #define _VHOST_H #include <linux/eventfd.h> #include <linux/vhost.h> #include <linux/mm.h> #include <linux/mutex.h> #include <linux/poll.h> #include <linux/file.h> #include <linux/skbuff.h> #include <linux/uio.h> #include <linux/virtio_config.h> #include <linux/virtio_ring.h> #include <linux/atomic.h> /* This is for zerocopy, used buffer len is set to 1 when lower device DMA * done */ #define VHOST_DMA_DONE_LEN 1 #define VHOST_DMA_CLEAR_LEN 0 struct vhost_device; struct vhost_work; typedef void (*vhost_work_fn_t)(struct vhost_work *work); struct vhost_work { struct list_head node; vhost_work_fn_t fn; wait_queue_head_t done; int flushing; unsigned queue_seq; unsigned done_seq; }; /* Poll a file (eventfd or socket) */ /* Note: there's nothing vhost specific about this structure. */ struct vhost_poll { poll_table table; wait_queue_head_t *wqh; wait_queue_t wait; struct vhost_work work; unsigned long mask; struct vhost_dev *dev; }; void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn, unsigned long mask, struct vhost_dev *dev); void vhost_poll_start(struct vhost_poll *poll, struct file *file); void vhost_poll_stop(struct vhost_poll *poll); void vhost_poll_flush(struct vhost_poll *poll); void vhost_poll_queue(struct vhost_poll *poll); struct vhost_log { u64 addr; u64 len; }; struct vhost_virtqueue; struct vhost_ubuf_ref { struct kref kref; wait_queue_head_t wait; struct vhost_virtqueue *vq; }; struct vhost_ubuf_ref *vhost_ubuf_alloc(struct vhost_virtqueue *, bool zcopy); void vhost_ubuf_put(struct vhost_ubuf_ref *); void vhost_ubuf_put_and_wait(struct vhost_ubuf_ref *); /* The virtqueue structure describes a queue attached to a device. */ struct vhost_virtqueue { struct vhost_dev *dev; /* The actual ring of buffers. */ struct mutex mutex; unsigned int num; struct vring_desc __user *desc; struct vring_avail __user *avail; struct vring_used __user *used; struct file *kick; struct file *call; struct file *error; struct eventfd_ctx *call_ctx; struct eventfd_ctx *error_ctx; struct eventfd_ctx *log_ctx; struct vhost_poll poll; /* The routine to call when the Guest pings us, or timeout. */ vhost_work_fn_t handle_kick; /* Last available index we saw. */ u16 last_avail_idx; /* Caches available index value from user. */ u16 avail_idx; /* Last index we used. */ u16 last_used_idx; /* Used flags */ u16 used_flags; /* Last used index value we have signalled on */ u16 signalled_used; /* Last used index value we have signalled on */ bool signalled_used_valid; /* Log writes to used structure. */ bool log_used; u64 log_addr; struct iovec iov[UIO_MAXIOV]; /* hdr is used to store the virtio header. * Since each iovec has >= 1 byte length, we never need more than * header length entries to store the header. */ struct iovec hdr[sizeof(struct virtio_net_hdr_mrg_rxbuf)]; struct iovec *indirect; size_t vhost_hlen; size_t sock_hlen; struct vring_used_elem *heads; /* We use a kind of RCU to access private pointer. * All readers access it from worker, which makes it possible to * flush the vhost_work instead of synchronize_rcu. Therefore readers do * not need to call rcu_read_lock/rcu_read_unlock: the beginning of * vhost_work execution acts instead of rcu_read_lock() and the end of * vhost_work execution acts instead of rcu_read_unlock(). * Writers use virtqueue mutex. */ void __rcu *private_data; /* Log write descriptors */ void __user *log_base; struct vhost_log *log; /* vhost zerocopy support fields below: */ /* last used idx for outstanding DMA zerocopy buffers */ int upend_idx; /* first used idx for DMA done zerocopy buffers */ int done_idx; /* an array of userspace buffers info */ struct ubuf_info *ubuf_info; /* Reference counting for outstanding ubufs. * Protected by vq mutex. Writers must also take device mutex. */ struct vhost_ubuf_ref *ubufs; }; struct vhost_dev { /* Readers use RCU to access memory table pointer * log base pointer and features. * Writers use mutex below.*/ struct vhost_memory __rcu *memory; struct mm_struct *mm; struct mutex mutex; unsigned acked_features; struct vhost_virtqueue *vqs; int nvqs; struct file *log_file; struct eventfd_ctx *log_ctx; spinlock_t work_lock; struct list_head work_list; struct task_struct *worker; }; long vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue *vqs, int nvqs); long vhost_dev_check_owner(struct vhost_dev *); long vhost_dev_reset_owner(struct vhost_dev *); void vhost_dev_cleanup(struct vhost_dev *, bool locked); long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, unsigned long arg); int vhost_vq_access_ok(struct vhost_virtqueue *vq); int vhost_log_access_ok(struct vhost_dev *); int vhost_get_vq_desc(struct vhost_dev *, struct vhost_virtqueue *, struct iovec iov[], unsigned int iov_count, unsigned int *out_num, unsigned int *in_num, struct vhost_log *log, unsigned int *log_num); void vhost_discard_vq_desc(struct vhost_virtqueue *, int n); int vhost_init_used(struct vhost_virtqueue *); int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len); int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads, unsigned count); void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *, unsigned int id, int len); void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *, struct vring_used_elem *heads, unsigned count); void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *); void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *); bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *); int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, unsigned int log_num, u64 len); void vhost_zerocopy_callback(struct ubuf_info *); int vhost_zerocopy_signal_used(struct vhost_virtqueue *vq); #define vq_err(vq, fmt, ...) do { \ pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \ if ((vq)->error_ctx) \ eventfd_signal((vq)->error_ctx, 1);\ } while (0) enum { VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | (1ULL << VIRTIO_RING_F_INDIRECT_DESC) | (1ULL << VIRTIO_RING_F_EVENT_IDX) | (1ULL << VHOST_F_LOG_ALL) | (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) | (1ULL << VIRTIO_NET_F_MRG_RXBUF), }; static inline int vhost_has_feature(struct vhost_dev *dev, int bit) { unsigned acked_features; /* TODO: check that we are running from vhost_worker or dev mutex is * held? */ acked_features = rcu_dereference_index_check(dev->acked_features, 1); return acked_features & (1 << bit); } void vhost_enable_zcopy(int vq); #endif |