nvme_mi_msg_hdr - Man Page

struct nvme_mi_msg_hdr {
   __u8 type;
   __u8 nmp;
   __u8 meb;
   __u8 rsvd0;
};

type

MCTP message type, will always be NVME_MI_MSGTYPE_NVME

nmp

NVMe-MI message parameters (including MI message type)

meb

Management Endpoint Buffer flag; unused for libnvme-mi implementation

rsvd0

currently reserved

Wire format shared by both request and response messages, per NVMe-MI section 3.1. This is used for all message types, MI and Admin.