/*
* Vhost User library
*
* Copyright (c) 2016 Red Hat, Inc.
*
* Authors:
* Victor Kaplansky <victork@redhat.com>
* Marc-André Lureau <mlureau@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or
* later. See the COPYING file in the top-level directory.
*/
#ifndef LIBVHOST_USER_H
#define LIBVHOST_USER_H
#include <stdint.h>
#include <stdbool.h>
#include <stddef.h>
#include <sys/poll.h>
#include <linux/vhost.h>
#include "standard-headers/linux/virtio_ring.h"
/* Based on qemu/hw/virtio/vhost-user.c */
#define VHOST_USER_F_PROTOCOL_FEATURES 30
#define VHOST_LOG_PAGE 4096
#define VHOST_MAX_NR_VIRTQUEUE 8
#define VIRTQUEUE_MAX_SIZE 1024
#define VHOST_MEMORY_MAX_NREGIONS 8
enum VhostUserProtocolFeature {
VHOST_USER_PROTOCOL_F_MQ = 0,
VHOST_USER_PROTOCOL_F_LOG_SHMFD = 1,
VHOST_USER_PROTOCOL_F_RARP = 2,
VHOST_USER_PROTOCOL_F_MAX
};
#define VHOST_USER_PROTOCOL_FEATURE_MASK ((1 << VHOST_USER_PROTOCOL_F_MAX) - 1)
typedef enum VhostUserRequest {
VHOST_USER_NONE = 0,
VHOST_USER_GET_FEATURES = 1,
VHOST_USER_SET_FEATURES = 2,
VHOST_USER_SET_OWNER = 3,
VHOST_USER_RESET_OWNER = 4,
VHOST_USER_SET_MEM_TABLE = 5,
VHOST_USER_SET_LOG_BASE = 6,
VHOST_USER_SET_LOG_FD = 7,
VHOST_USER_SET_VRING_NUM = 8,
VHOST_USER_SET_VRING_ADDR = 9,
VHOST_USER_SET_VRING_BASE = 10,
VHOST_USER_GET_VRING_BASE = 11,
VHOST_USER_SET_VRING_KICK = 12,
VHOST_USER_SET_VRING_CALL = 13,
VHOST_USER_SET_VRING_ERR = 14,
VHOST_USER_GET_PROTOCOL_FEATURES = 15,
VHOST_USER_SET_PROTOCOL_FEATURES = 16,
VHOST_USER_GET_QUEUE_NUM = 17,
VHOST_USER_SET_VRING_ENABLE = 18,
VHOST_USER_SEND_RARP = 19,
VHOST_USER_INPUT_GET_CONFIG = 20,
VHOST_USER_MAX
} VhostUserRequest;
typedef struct VhostUserMemoryRegion {
uint64_t guest_phys_addr;
uint64_t memory_size;
uint64_t userspace_addr;
uint64_t mmap_offset;
} VhostUserMemoryRegion;
typedef struct VhostUserMemory {
uint32_t nregions;
uint32_t padding;
VhostUserMemoryRegion regions[VHOST_MEMORY_MAX_NREGIONS];
} VhostUserMemory;
typedef struct VhostUserLog {
uint64_t mmap_size;
uint64_t mmap_offset;
} VhostUserLog;
#if defined(_WIN32)
# define VU_PACKED __attribute__((gcc_struct, packed))
#else
# define VU_PACKED __attribute__((packed))
#endif
typedef struct VhostUserMsg {
VhostUserRequest request;
#define VHOST_USER_VERSION_MASK (0x3)
#define VHOST_USER_REPLY_MASK (0x1 << 2)
uint32_t flags;
uint32_t size; /* the following payload size */
union {
#define VHOST_USER_VRING_IDX_MASK (0xff)
#define VHOST_USER_VRING_NOFD_MASK (0x1 << 8)
uint64_t u64;
struct vhost_vring_state state;
struct vhost_vring_addr addr;
VhostUserMemory memory;
VhostUserLog log;
} payload;
int fds[VHOST_MEMORY_MAX_NREGIONS];
int fd_num;
uint8_t *data;
} VU_PACKED VhostUserMsg;
typedef struct VuDevRegion {
/* Guest Physical address. */
uint64_t gpa;
/* Memory region size. */
uint64_t size;
/* QEMU virtual address (userspace). */
uint64_t qva;
/* Starting offset in our mmaped space. */
uint64_t mmap_offset;
/* Start address of mmaped space. */
uint64_t mmap_addr;
} VuDevRegion;
typedef struct VuDev VuDev;
typedef uint64_t (*vu_get_features_cb) (VuDev *dev);
typedef void (*vu_set_features_cb) (VuDev *dev, uint64_t features);
typedef int (*vu_process_msg_cb) (VuDev *dev, VhostUserMsg *vmsg,
int *do_reply);
typedef void (*vu_queue_set_started_cb) (VuDev *dev, int qidx, bool started);
typedef struct VuDevIface {
/* called by VHOST_USER_GET_FEATURES to get the features bitmask */
vu_get_features_cb get_features;
/* enable vhost implementation features */
vu_set_features_cb set_features;
/* get the protocol feature bitmask from the underlying vhost
* implementation */
vu_get_features_cb get_protocol_features;
/* enable protocol features in the underlying vhost implementation. */
vu_set_features_cb set_protocol_features;
/* process_msg is called for each vhost-user message received */
/* skip libvhost-user processing if return value != 0 */
vu_process_msg_cb process_msg;
/* tells when queues can be processed */
vu_queue_set_started_cb queue_set_started;
} VuDevIface;
typedef void (*vu_queue_handler_cb) (VuDev *dev, int qidx);
typedef struct VuRing {
unsigned int num;
struct vring_desc *desc;
struct vring_avail *avail;
struct vring_used *used;
uint64_t log_guest_addr;
uint32_t flags;
} VuRing;
typedef struct VuVirtq {
VuRing vring;
/* Next head to pop */
uint16_t last_avail_idx;
/* Last avail_idx read from VQ. */
uint16_t shadow_avail_idx;
uint16_t used_idx;
/* Last used index value we have signalled on */
uint16_t signalled_used;
/* Last used index value we have signalled on */
bool signalled_used_valid;
/* Notification enabled? */
bool notification;
int inuse;
vu_queue_handler_cb handler;
int call_fd;
int kick_fd;
int err_fd;
unsigned int enable;
bool started;
} VuVirtq;
enum VuWatchCondtion {
VU_WATCH_IN = POLLIN,
VU_WATCH_OUT = POLLOUT,
VU_WATCH_PRI = POLLPRI,
VU_WATCH_ERR = POLLERR,
VU_WATCH_HUP = POLLHUP,
};
typedef void (*vu_panic_cb) (VuDev *dev, const char *err);
typedef void (*vu_watch_cb) (VuDev *dev, int condition, void *data);
typedef void (*vu_set_watch_cb) (VuDev *dev, int fd, int condition,
vu_watch_cb cb, void *data);
typedef void (*vu_remove_watch_cb) (VuDev *dev, int fd);
struct VuDev {
int sock;
uint32_t nregions;
VuDevRegion regions[VHOST_MEMORY_MAX_NREGIONS];
VuVirtq vq[VHOST_MAX_NR_VIRTQUEUE];
int log_call_fd;
uint64_t log_size;
uint8_t *log_table;
uint64_t features;
uint64_t protocol_features;
bool broken;
/* @set_watch: add or update the given fd to the watch set,
* call cb when condition is met */
vu_set_watch_cb set_watch;
/* @remove_watch: remove the given fd from the watch set */
vu_remove_watch_cb remove_watch;
/* @panic: encountered an unrecoverable error, you may try to
* re-initialize */
vu_panic_cb panic;
const VuDevIface *iface;
};
typedef struct VuVirtqElement {
unsigned int index;
unsigned int out_num;
unsigned int in_num;
struct iovec *in_sg;
struct iovec *out_sg;
} VuVirtqElement;
/**
* vu_init:
* @dev: a VuDev context
* @socket: the socket connected to vhost-user master
* @panic: a panic callback
* @set_watch: a set_watch callback
* @remove_watch: a remove_watch callback
* @iface: a VuDevIface structure with vhost-user device callbacks
*
* Intializes a VuDev vhost-user context.
**/
void vu_init(VuDev *dev,
int socket,
vu_panic_cb panic,
vu_set_watch_cb set_watch,
vu_remove_watch_cb remove_watch,
const VuDevIface *iface);
/**
* vu_deinit:
* @dev: a VuDev context
*
* Cleans up the VuDev context
*/
void vu_deinit(VuDev *dev);
/**
* vu_dispatch:
* @dev: a VuDev context
*
* Process one vhost-user message.
*
* Returns: TRUE on success, FALSE on failure.
*/
bool vu_dispatch(VuDev *dev);
/**
* vu_gpa_to_va:
* @dev: a VuDev context
* @guest_addr: guest address
*
* Translate a guest address to a pointer. Returns NULL on failure.
*/
void *vu_gpa_to_va(VuDev *dev, uint64_t guest_addr);
/**
* vu_get_queue:
* @dev: a VuDev context
* @qidx: queue index
*
* Returns the queue number @qidx.
*/
VuVirtq *vu_get_queue(VuDev *dev, int qidx);
/**
* vu_set_queue_handler:
* @dev: a VuDev context
* @vq: a VuVirtq queue
* @handler: the queue handler callback
*
* Set the queue handler. This function may be called several times
* for the same queue. If called with NULL @handler, the handler is
* removed.
*/
void vu_set_queue_handler(VuDev *dev, VuVirtq *vq,
vu_queue_handler_cb handler);
/**
* vu_queue_set_notification:
* @dev: a VuDev context
* @vq: a VuVirtq queue
* @enable: state
*
* Set whether the queue notifies (via event index or interrupt)
*/
void vu_queue_set_notification(VuDev *dev, VuVirtq *vq, int enable);
/**
* vu_queue_enabled:
* @dev: a VuDev context
* @vq: a VuVirtq queue
*
* Returns: whether the queue is enabled.
*/
bool vu_queue_enabled(VuDev *dev, VuVirtq *vq);
/**
* vu_queue_empty:
* @dev: a VuDev context
* @vq: a VuVirtq queue
*
* Returns: true if the queue is empty or not ready.
*/
bool vu_queue_empty(VuDev *dev, VuVirtq *vq);
/**
* vu_queue_notify:
* @dev: a VuDev context
* @vq: a VuVirtq queue
*
* Request to notify the queue via callfd (skipped if unnecessary)
*/
void vu_queue_notify(VuDev *dev, VuVirtq *vq);
/**
* vu_queue_pop:
* @dev: a VuDev context
* @vq: a VuVirtq queue
* @sz: the size of struct to return (must be >= VuVirtqElement)
*
* Returns: a VuVirtqElement filled from the queue or NULL.
*/
void *vu_queue_pop(VuDev *dev, VuVirtq *vq, size_t sz);
/**
* vu_queue_rewind:
* @dev: a VuDev context
* @vq: a VuVirtq queue
* @num: number of elements to push back
*
* Pretend that elements weren't popped from the virtqueue. The next
* virtqueue_pop() will refetch the oldest element.
*
* Returns: true on success, false if @num is greater than the number of in use
* elements.
*/
bool vu_queue_rewind(VuDev *dev, VuVirtq *vq, unsigned int num);
/**
* vu_queue_fill:
* @dev: a VuDev context
* @vq: a VuVirtq queue
* @elem: a VuVirtqElement
* @len: length in bytes to write
* @idx: optional offset for the used ring index (0 in general)
*
* Fill the used ring with @elem element.
*/
void vu_queue_fill(VuDev *dev, VuVirtq *vq,
const VuVirtqElement *elem,
unsigned int len, unsigned int idx);
/**
* vu_queue_push:
* @dev: a VuDev context
* @vq: a VuVirtq queue
* @elem: a VuVirtqElement
* @len: length in bytes to write
*
* Helper that combines vu_queue_fill() with a vu_queue_flush().
*/
void vu_queue_push(VuDev *dev, VuVirtq *vq,
const VuVirtqElement *elem, unsigned int len);
/**
* vu_queue_flush:
* @dev: a VuDev context
* @vq: a VuVirtq queue
* @num: number of elements to flush
*
* Mark the last number of elements as done (used.idx is updated by
* num elements).
*/
void vu_queue_flush(VuDev *dev, VuVirtq *vq, unsigned int num);
/**
* vu_queue_get_avail_bytes:
* @dev: a VuDev context
* @vq: a VuVirtq queue
* @in_bytes: in bytes
* @out_bytes: out bytes
* @max_in_bytes: stop counting after max_in_bytes
* @max_out_bytes: stop counting after max_out_bytes
*
* Count the number of available bytes, up to max_in_bytes/max_out_bytes.
*/
void vu_queue_get_avail_bytes(VuDev *vdev, VuVirtq *vq, unsigned int *in_bytes,
unsigned int *out_bytes,
unsigned max_in_bytes, unsigned max_out_bytes);
/**
* vu_queue_avail_bytes:
* @dev: a VuDev context
* @vq: a VuVirtq queue
* @in_bytes: expected in bytes
* @out_bytes: expected out bytes
*
* Returns: true if in_bytes <= in_total && out_bytes <= out_total
*/
bool vu_queue_avail_bytes(VuDev *dev, VuVirtq *vq, unsigned int in_bytes,
unsigned int out_bytes);
#endif /* LIBVHOST_USER_H */
