STRUCT TD_INFO(9)

💖 struct td_info(9) 💖

okay so bestie, we're in the Kernel API Manual today and the main character is struct td_info — it's giving "TDX guest measurements and configuration" and honestly? iconic. 🫶

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✨ NAME ✨

struct td_info — TDX guest measurements and configuration. no cap, that's literally what it is 💅

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🎀 SYNOPSIS 🎀

struct td_info {
    __u8 attr[8];
    __u64 xfam;
    __u64 mrtd[6];
    __u64 mrconfigid[6];
    __u64 mrowner[6];
    __u64 mrownerconfig[6];
    __u64 rtmr[24];
    __u64 reserved[14];
 };

like, that's the whole vibe right there ⬆️ every field, exactly as written, don't come for me 🧚

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🌸 Members 🌸

• attr — the TDX Guest attributes (things like debug, spet_disable, etc). the little personality traits of the guest, basically 🐛
• xfam — Extended features allowed mask. it's the "yes queen you may" list of features ✨
• mrtd — Build time measurement register. the moment the guest was born, frozen in time 😭
• mrconfigid — Software-defined ID for non-owner-defined configuration of the guest — e.g., run-time or OS configuration. so like, the stuff that's not the owner's business 🎀
• mrowner — Software-defined ID for the guest owner. hi, this is the owner's whole identity 👑
• mrownerconfig — Software-defined ID for owner-defined configuration of the guest — e.g., specific to the workload. the owner's personal aesthetic choices, workload edition 🌈
• rtmr — Run time measurement registers. these ones keep growing and extending as the guest lives its life, main character energy fr fr 🔥
• reserved — Added for future extension. it's literally saving seats for the future besties 💜

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🌟 Description 🌟

so what is this thing actually for? it contains the measurements and initial configuration of the TDX guest — the ones that got locked at initialization (yes, locked, no takebacks 💀) — plus a whole set of measurement registers that are run-time extendable (those ones keep going, we love a flexible king 🦋).

and if you want the full lore drop, more details can be found in the TDX v1.0 Module specification, section titled "TDINFO_STRUCT". go read it, iykyk 📖

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🌈 SEE ALSO 🌈

• Kernel file ./tools/testing/selftests/tdx/tdx_guest_test.c
• struct tdreport_type(9)
• struct reportmac(9)

go check those out too, they're in the same friend group 🫶

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okay that's the whole page bestie, every single member accounted for, nothing skipped, periodt 💅✨

from ./tools/testing/selftests/tdx, dated October 2026 — mwah, love u, bye 👋🍓