HXG REQUEST(9)

💅 HXG Request 💅

okay so you're in the Kernel API Manual (section 9, we love a classic) and the page is HXG Request — and ngl bestie, this one is kind of a big deal. 🎀

The HXG Request message is the one you send when you want to initiate synchronous activity for which confirmation or return data is expected. like, you're not just posting into the group chat and hoping — you actually want a reply. fr fr. ✨

🫶 how the reply situation works

The recipient of this message shall use HXG Response, HXG Failure or HXG Retry as a definite reply — no ghosting, no leaving you on read, that's the whole vibe check 💀.

They may also use HXG Busy as an intermediate reply, which is basically the "bestie i'm typing…" of kernel messages 🙈.

heads up: the format of DATA0 and all the DATAn fields depends on the ACTION code. so do not go assuming the payload shape, check the action first 👑.

✨ the bits, bestie ✨

here's the whole "Bits / Description" situation, laid out so it actually makes sense:

• row 0 — the first 32-bit chunk:
  • bits 31 — ORIGIN
  • bits 30:28 — TYPE = GUC_HXG_TYPE_REQUEST_
  • bits 27:16 — DATA0 — request data (depends on ACTION)
  • bits 15:0 — ACTION — requested action code
• rows 1 … n — the extra chunks, all 31:0:
  • bits 31:0 — DATAn — optional data (depends on ACTION)

so yeah, DATA0 is doing main character energy up in bits 27:16, and everything else after that is optional vibes depending on the action. iykyk 🌸

👀 SEE ALSO

• the kernel file ./drivers/gpu/drm/xe/abi/guc_messages_abi.h (go read it, it's giving source of truth 💜)
• HXG Message(9)
• HXG Fast Request(9)
• HXG Event(9)
• HXG Busy(9)
• HXG Retry(9)
• HXG Failure(9)
• HXG Response(9)

mwah 💋 this whole page lives under ./drivers/gpu/drm/xe/abi, it's dated October 2026, and it's filed as HXG Request(9) — slay, go send some synchronous messages responsibly. 🌈💖