diff options
Diffstat (limited to 'drivers/vhost/vhost.h')
| -rw-r--r-- | drivers/vhost/vhost.h | 298 |
1 files changed, 298 insertions, 0 deletions
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h new file mode 100644 index 000000000..27a78a9b8 --- /dev/null +++ b/drivers/vhost/vhost.h @@ -0,0 +1,298 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#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/uio.h> +#include <linux/virtio_config.h> +#include <linux/virtio_ring.h> +#include <linux/atomic.h> + +struct vhost_work; +typedef void (*vhost_work_fn_t)(struct vhost_work *work); + +#define VHOST_WORK_QUEUED 1 +struct vhost_work { + struct llist_node node; + vhost_work_fn_t fn; + unsigned long flags; +}; + +/* 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_entry_t wait; + struct vhost_work work; + __poll_t mask; + struct vhost_dev *dev; +}; + +void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn); +void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work); +bool vhost_has_work(struct vhost_dev *dev); + +void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn, + __poll_t mask, struct vhost_dev *dev); +int 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); +void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work); +long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp); + +struct vhost_log { + u64 addr; + u64 len; +}; + +#define START(node) ((node)->start) +#define LAST(node) ((node)->last) + +struct vhost_umem_node { + struct rb_node rb; + struct list_head link; + __u64 start; + __u64 last; + __u64 size; + __u64 userspace_addr; + __u32 perm; + __u32 flags_padding; + __u64 __subtree_last; +}; + +struct vhost_umem { + struct rb_root_cached umem_tree; + struct list_head umem_list; + int numem; +}; + +enum vhost_uaddr_type { + VHOST_ADDR_DESC = 0, + VHOST_ADDR_AVAIL = 1, + VHOST_ADDR_USED = 2, + VHOST_NUM_ADDRS = 3, +}; + +/* 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; + const struct vhost_umem_node *meta_iotlb[VHOST_NUM_ADDRS]; + struct file *kick; + 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]; + struct iovec iotlb_iov[64]; + struct iovec *indirect; + struct vring_used_elem *heads; + /* Protected by virtqueue mutex. */ + struct vhost_umem *umem; + struct vhost_umem *iotlb; + void *private_data; + u64 acked_features; + u64 acked_backend_features; + /* Log write descriptors */ + void __user *log_base; + struct vhost_log *log; + + /* Ring endianness. Defaults to legacy native endianness. + * Set to true when starting a modern virtio device. */ + bool is_le; +#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY + /* Ring endianness requested by userspace for cross-endian support. */ + bool user_be; +#endif + u32 busyloop_timeout; +}; + +struct vhost_msg_node { + union { + struct vhost_msg msg; + struct vhost_msg_v2 msg_v2; + }; + struct vhost_virtqueue *vq; + struct list_head node; +}; + +struct vhost_dev { + struct mm_struct *mm; + struct mutex mutex; + struct vhost_virtqueue **vqs; + int nvqs; + struct eventfd_ctx *log_ctx; + struct llist_head work_list; + struct task_struct *worker; + struct vhost_umem *umem; + struct vhost_umem *iotlb; + spinlock_t iotlb_lock; + struct list_head read_list; + struct list_head pending_list; + wait_queue_head_t wait; + int iov_limit; + int weight; + int byte_weight; +}; + +bool vhost_exceeds_weight(struct vhost_virtqueue *vq, int pkts, int total_len); +void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, + int nvqs, int iov_limit, int weight, int byte_weight); +long vhost_dev_set_owner(struct vhost_dev *dev); +bool vhost_dev_has_owner(struct vhost_dev *dev); +long vhost_dev_check_owner(struct vhost_dev *); +struct vhost_umem *vhost_dev_reset_owner_prepare(void); +void vhost_dev_reset_owner(struct vhost_dev *, struct vhost_umem *); +void vhost_dev_cleanup(struct vhost_dev *); +void vhost_dev_stop(struct vhost_dev *); +long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp); +long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp); +bool vhost_vq_access_ok(struct vhost_virtqueue *vq); +bool vhost_log_access_ok(struct vhost_dev *); + +int vhost_get_vq_desc(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_vq_init_access(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_vq_avail_empty(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, + struct iovec *iov, int count); +int vq_iotlb_prefetch(struct vhost_virtqueue *vq); + +struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type); +void vhost_enqueue_msg(struct vhost_dev *dev, + struct list_head *head, + struct vhost_msg_node *node); +struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev, + struct list_head *head); +__poll_t vhost_chr_poll(struct file *file, struct vhost_dev *dev, + poll_table *wait); +ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to, + int noblock); +ssize_t vhost_chr_write_iter(struct vhost_dev *dev, + struct iov_iter *from); +int vhost_init_device_iotlb(struct vhost_dev *d, bool enabled); + +#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 << VIRTIO_F_ANY_LAYOUT) | + (1ULL << VIRTIO_F_VERSION_1) +}; + +static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit) +{ + return vq->acked_features & (1ULL << bit); +} + +static inline bool vhost_backend_has_feature(struct vhost_virtqueue *vq, int bit) +{ + return vq->acked_backend_features & (1ULL << bit); +} + +#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY +static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq) +{ + return vq->is_le; +} +#else +static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq) +{ + return virtio_legacy_is_little_endian() || vq->is_le; +} +#endif + +/* Memory accessors */ +static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val) +{ + return __virtio16_to_cpu(vhost_is_little_endian(vq), val); +} + +static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val) +{ + return __cpu_to_virtio16(vhost_is_little_endian(vq), val); +} + +static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val) +{ + return __virtio32_to_cpu(vhost_is_little_endian(vq), val); +} + +static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val) +{ + return __cpu_to_virtio32(vhost_is_little_endian(vq), val); +} + +static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val) +{ + return __virtio64_to_cpu(vhost_is_little_endian(vq), val); +} + +static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val) +{ + return __cpu_to_virtio64(vhost_is_little_endian(vq), val); +} +#endif |