vhost_user.h

/*-
 *   BSD LICENSE
 *
 *   Copyright (c) Intel Corporation.
 *   Copyright (c) Cloudbyte Corporation.
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 *
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 *       notice, this list of conditions and the following disclaimer.
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 *       notice, this list of conditions and the following disclaimer in
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 *       distribution.
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 *       from this software without specific prior written permission.
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 */

#ifndef VHOST_USER_H_
#define VHOST_USER_H_

#include <stdint.h>

#define	VHOST_MEMORY_MAX_NREGIONS	8

// Structures and defines imported from the Linux headers.

/* The Host uses this in used->flags to advise the Guest: don't kick me when
 * you add a buffer.  It's unreliable, so it's simply an optimization.  Guest
 * will still kick if it's out of buffers. */
#define VRING_USED_F_NO_NOTIFY	1
/* The Guest uses this in avail->flags to advise the Host: don't interrupt me
 * when you consume a buffer.  It's unreliable, so it's simply an
 * optimization.  */
#define VRING_AVAIL_F_NO_INTERRUPT	1

/* We support indirect buffer descriptors */
#define VIRTIO_RING_F_INDIRECT_DESC 28
/* The Guest publishes the used index for which it expects an interrupt
 * at the end of the avail ring. Host should ignore the avail->flags field. */
/* The Host publishes the avail index for which it expects a kick
 * at the end of the used ring. Guest should ignore the used->flags field. */
#define VIRTIO_RING_F_EVENT_IDX     29
#define VHOST_USER_F_PROTOCOL_FEATURES  30
#define VIRTIO_F_VERSION_1  32

struct vhost_vring_state { unsigned int index, num; };
struct vhost_vring_file { unsigned int index; int fd; };
struct vhost_vring_addr {
	unsigned int index, flags;
	uint64_t desc_user_addr, used_user_addr;
	uint64_t avail_user_addr, log_guest_addr;
};

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 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_MAX
} VhostUserRequest;

typedef struct VhostUserMsg {
    VhostUserRequest request;

#define VHOST_USER_VERSION_MASK     (0x3)
#define VHOST_USER_REPLY_MASK       (0x1<<2)
    uint32_t flags;
    uint32_t size; /* 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;
    };
}  __attribute__((packed)) VhostUserMsg;

#define MEMB_SIZE(t, m)     (sizeof(((t*)0)->m))
#define VHOST_USER_HDR_SIZE (MEMB_SIZE(VhostUserMsg,request) \
                            + MEMB_SIZE(VhostUserMsg,flags) \
                            + MEMB_SIZE(VhostUserMsg,size))

/* The version of the protocol we support */
#define VHOST_USER_VERSION    (0x1)

// end of import from linux

int vhost_user_send_fds(int fd, const VhostUserMsg *msg, int *fds,
    size_t fd_num);
int vhost_user_recv_fds(int fd, const VhostUserMsg *msg, int *fds,
    size_t *fd_num);
int vhost_ioctl(int sock, VhostUserRequest request, void *arg);

#endif /* VHOST_USER_H_ */