VF2GUC_VF_RESET(9)

✨ VF2GUC_VF_RESET ✨

okay so bestie, this is a page from the Kernel API Manual and it's all about VF2GUC_VF_RESET — say that five times fast, i literally cannot 😭

💅 what it even does

This action is used by VF to reset GuC's VF state. that's the whole vibe. reset the state, move on, slay.

🫶 important detail before you go anywhere: this message must be sent as MMIO HXG Message_ — like, non-negotiable, that's the transport, periodt.

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📨 the request message, bit by bit

here's the layout, and yes every single bit is accounted for, no cap:

• 0 / bits 31 — ORIGIN = GUC_HXG_ORIGIN_HOST_
• 0 / bits 30:28 — TYPE = GUC_HXG_TYPE_REQUEST_
• 0 / bits 27:16 — DATA0 = MBZ
• 0 / bits 15:0 — ACTION = _GUC_ACTION_VF2GUC_VF_RESET = 0x5507

that 0x5507 is literally the whole personality of this message btw 🔥

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🦋 the response message (the glow-up reply)

when it comes back, it looks like this:

• 0 / bits 31 — ORIGIN = GUC_HXG_ORIGIN_GUC_
• 0 / bits 30:28 — TYPE = GUC_HXG_TYPE_RESPONSE_SUCCESS_
• 0 / bits 27:0 — DATA0 = MBZ

RESPONSE_SUCCESS_ — we love a happy ending 💖

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🌈 SEE ALSO

the kernel file that lives and breathes this:

• ./drivers/gpu/drm/xe/abi/guc_actions_sriov_abi.h

and the whole friend group, all in one groupchat:

• GUC2PF_RELAY_FROM_VF(9)
• PF2GUC_RELAY_TO_VF(9)
• GUC2VF_RELAY_FROM_PF(9)
• VF2GUC_RELAY_TO_PF(9)
• GUC2PF_ADVERSE_EVENT(9)
• GUC2PF_VF_STATE_NOTIFY(9)
• VF2GUC_MATCH_VERSION(9)
• PF2GUC_UPDATE_VGT_POLICY(9)
• PF2GUC_UPDATE_VF_CFG(9)
• PF2GUC_VF_CONTROL(9)
• VF2GUC_RESFIX_DONE(9)
• VF2GUC_QUERY_SINGLE_KLV(9)
• PF2GUC_SAVE_RESTORE_VF(9)
• VF2GUC_RESFIX_START(9)

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and that's the page!! 🎀 this icon came from ./drivers/gpu/drm/xe/abi, dated October 2026, and it's filed under VF2GUC_VF_RESET(9) — go read the rest of the docs bestie, ily, bye 💜