CTB HXG MESSAGE(9)

💖 CTB HXG Message 💖

okay bestie, this is the CTB HXG Message(9) page from the Kernel API Manual — and it’s literally the bit layout for the HXG message. The table has two columns, Bits and Description, and here’s the tea ☕:

• 0, bits 31:16 — FENCE
• 0, bits 15:12 — FORMAT = GUC_CTB_FORMAT_HXG_
• 0, bits 11:8 — RESERVED = MBZ
• 0, bits 7:0 — NUM_DWORDS = length (in dwords) of the embedded HXG message

Then you get the embedded part, and it’s giving entries 1 through n, all with bits 31:0:

┌────────────────────────────────────────────┐
│     1     31:0                             │
│     ...          [Embedded `HXG Message`_] │
│     n     31:0                             │
└────────────────────────────────────────────┘

so yeah, entry 1 bits 31:0 … entry n bits 31:0, with the embedded HXG Message in the middle — periodt. 💅

🌈 SEE ALSO 🌈

• Kernel file ./drivers/gpu/drm/xe/abi/guc_communication_ctb_abi.h
• CT Buffer(9)
• CTB Descriptor(9)
• CTB Message(9)
• CTB based communication(9)

🎀 that’s the entire page, bestie! source/version: ./drivers/gpu/drm/xe/abi · date: October 2026 — mwah 💋 🎀