// SPDX-License-Identifier: GPL-2.0-or-later
/* Vhost-user protocol */

#ifndef __VHOST_USER_H__
#define __VHOST_USER_H__

/* Message flags */
#define VHOST_USER_FLAG_REPLY           BIT(2)
#define VHOST_USER_FLAG_NEED_REPLY      BIT(3)
/* Feature bits */
#define VHOST_USER_F_PROTOCOL_FEATURES  30
/* Protocol feature bits */
#define VHOST_USER_PROTOCOL_F_MQ                        0
#define VHOST_USER_PROTOCOL_F_REPLY_ACK                 3
#define VHOST_USER_PROTOCOL_F_SLAVE_REQ                 5
#define VHOST_USER_PROTOCOL_F_CONFIG                    9
#define VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS      14
/* Vring state index masks */
#define VHOST_USER_VRING_INDEX_MASK     0xff
#define VHOST_USER_VRING_POLL_MASK      BIT(8)

/* Supported version */
#define VHOST_USER_VERSION              1
/* Supported transport features */
#define VHOST_USER_SUPPORTED_F          BIT_ULL(VHOST_USER_F_PROTOCOL_FEATURES)
/* Supported protocol features */
#define VHOST_USER_SUPPORTED_PROTOCOL_F (BIT_ULL(VHOST_USER_PROTOCOL_F_MQ) | \
                                         BIT_ULL(VHOST_USER_PROTOCOL_F_REPLY_ACK) | \
                                         BIT_ULL(VHOST_USER_PROTOCOL_F_SLAVE_REQ) | \
                                         BIT_ULL(VHOST_USER_PROTOCOL_F_CONFIG) | \
                                         BIT_ULL(VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS))

enum vhost_user_request {
        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_NET_SEND_MTU = 20,
        VHOST_USER_SET_SLAVE_REQ_FD = 21,
        VHOST_USER_IOTLB_MSG = 22,
        VHOST_USER_SET_VRING_ENDIAN = 23,
        VHOST_USER_GET_CONFIG = 24,
        VHOST_USER_SET_CONFIG = 25,
        VHOST_USER_VRING_KICK = 35,
};

enum vhost_user_slave_request {
        VHOST_USER_SLAVE_IOTLB_MSG = 1,
        VHOST_USER_SLAVE_CONFIG_CHANGE_MSG = 2,
        VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG = 3,
        VHOST_USER_SLAVE_VRING_CALL = 4,
};

struct vhost_user_header {
        /*
         * Use enum vhost_user_request for outgoing messages,
         * uses enum vhost_user_slave_request for incoming ones.
         */
        u32 request;
        u32 flags;
        u32 size;
} __packed;

struct vhost_user_config {
        u32 offset;
        u32 size;
        u32 flags;
        u8 payload[]; /* Variable length */
} __packed;

struct vhost_user_vring_state {
        u32 index;
        u32 num;
} __packed;

struct vhost_user_vring_addr {
        u32 index;
        u32 flags;
        u64 desc, used, avail, log;
} __packed;

struct vhost_user_mem_region {
        u64 guest_addr;
        u64 size;
        u64 user_addr;
        u64 mmap_offset;
} __packed;

struct vhost_user_mem_regions {
        u32 num;
        u32 padding;
        struct vhost_user_mem_region regions[2]; /* Currently supporting 2 */
} __packed;

union vhost_user_payload {
        u64 integer;
        struct vhost_user_config config;
        struct vhost_user_vring_state vring_state;
        struct vhost_user_vring_addr vring_addr;
        struct vhost_user_mem_regions mem_regions;
};

struct vhost_user_msg {
        struct vhost_user_header header;
        union vhost_user_payload payload;
} __packed;

#endif