libnvme(9)

💖 libnvme(9) — struct nvme_mi_admin_req_hdr 💖

okay bestie, buckle up, because this is the libnvme API manual and today's main character is struct nvme_mi_admin_req_hdr — the Admin command request header. yes, the whole page is literally just this one struct and honestly? it ate. let's get into it 🫶

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✨ NAME ✨

struct nvme_mi_admin_req_hdr — Admin command request header. that's it, that's the vibe 💅

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🌸 SYNOPSIS 🌸

bestie here's the whole thing, look at her:

struct nvme_mi_admin_req_hdr {
    struct nvme_mi_msg_hdr hdr;
    __u8 opcode;
    __u8 flags;
    __le16 ctrl_id;
    __le32 cdw1, cdw2, cdw3, cdw4, cdw5;
    __le32 doff;
    __le32 dlen;
    __le32 rsvd0, rsvd1;
    __le32 cdw10, cdw11, cdw12, cdw13, cdw14, cdw15;
 };

like, no cap, that's the entire struct. sixteen-ish fields of pure Admin command energy ⭐

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🎀 Members 🎀

time for the member-by-member vibe check, and yes we're doing all of them, i would never gatekeep 🙈

• hdr — the Generic MI message header. it's giving "generic but essential" 💜
• opcode — Admin command opcode, and it's using enum nvme_admin_opcode. iconic, lowkey 🦋
• flags — Command Flags, and what they do is indicate dlen and doff validity. but heads up bestie: this is Only defined in NVMe-MI version 1.1 💀 there are no fields defined in 1.2 (where the dlen/doff are always considered valid). so like, version check your vibes, fr fr
• ctrl_id — Controller ID target of command. it's giving "who is this for" energy 👑
• cdw1 — Submission Queue Entry doubleword 1 ✨
• cdw2 — Submission Queue Entry doubleword 2 ✨
• cdw3 — Submission Queue Entry doubleword 3 ✨
• cdw4 — Submission Queue Entry doubleword 4 ✨
• cdw5 — Submission Queue Entry doubleword 5 ✨
• doff — Offset of data to return from command. that's your little pointer to the good stuff 🍓
• dlen — Length of sent/returned data. size matters, periodt 💅
• rsvd0 — Reserved. not for you bestie, hands off 🙅
• rsvd1 — Reserved. also not for you, also hands off 🙅
• cdw10 — Submission Queue Entry doubleword 10 🌈
• cdw11 — Submission Queue Entry doubleword 11 🌈
• cdw12 — Submission Queue Entry doubleword 12 🌈
• cdw13 — Submission Queue Entry doubleword 13 🌈
• cdw14 — Submission Queue Entry doubleword 14 🌈
• cdw15 — Submission Queue Entry doubleword 15 🌈

ok real talk for a sec: cdw1 through cdw5 and cdw10 through cdw15 are all Submission Queue Entry doublewords. notice how cdw6–cdw9 are just… not here? anyway, not my struct, not my problem 🧚

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🦋 Description 🦋

so what is this thing? it's the Wire format for Admin command message headers, defined in section 6 of NVMe-MI. and that's the whole description, bestie — short, mysterious, main character energy. genuinely obsessed with how it says so much by saying so little 😭🔥

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and that's the page!! this gorgeous little slice of API manual is from libnvme(9), it covers struct nvme_mi_admin_req_hdr, and it's dated October 2026 — go forth and structure your admin requests, queen 💖✨🎀