GUC OPT IN FEATURE KLVS(9)

💅 GuC OPT IN FEATURE KLVs 💅

okay so welcome to GuC Opt In Feature KLVs(9) — that's section 9 of the Kernel API Manual, bestie, and it's literally just the cheat sheet for the opt-in feature keys 🎀

✨ DESCRIPTION ✨

These are the GuC KLV_ keys you're allowed to use with OPT_IN_FEATURE_KLV — like, this is the guest list and only these keys get in 🫶

• GUC_KLV_OPT_IN_FEATURE_EXT_CAT_ERR_TYPE : 0x4001 — this one adds an extra dword to the XE_GUC_ACTION_NOTIFY_MEMORY_CAT_ERROR G2H, and that dword carries the type of the CAT error. cute, right? 🙈 but bestie listen — on HW that doesn't support reporting the CAT error type, that extra dword gets set to 0xdeadbeef 💀 so don't go reading it like it's real data, iykyk.
• GUC_KLV_OPT_IN_FEATURE_DYNAMIC_INHIBIT_CONTEXT_SWITCH : 0x4003 — this KLV turns on the Dynamic Inhibit Context Switch optimization ✨ and here's what that actually means: the GuC sets the CTX_CTRL_INHIBIT_SYN_CTX_SWITCH bit to zero in the CTX_CONTEXT_CONTROL register of LRCs that are submitted to an oversubscribed engine 👑 so those contexts get switched out immediately if they hit an unsatisfied semaphore wait, instead of sitting there waiting the full timeslice duration. no cap, that's the whole glow-up. but the bit gets set to one instead when a single context is queued on the engine — because then you don't want it switched out if there isn't another context that can run in its place 🦋 it's giving "know when to hold 'em".
• GUC_KLV_OPT_IN_FEATURE_UNCORRECTABLE_LOCAL_ERROR_NOTIFICATION : 0x4004 — this flag enables notification from GuC to KMD via the G2H message GUC_ACTION_GUC2HOST_NOTIFY_UNCORRECTABLE_LOCAL_ERROR when it receives the same interrupt from the CS 🚨 like, the GuC hears the interrupt and immediately tells KMD about it. iconic behavior fr.

🌈 SEE ALSO 🌈

• Kernel file ./drivers/gpu/drm/xe/abi/guc_klvs_abi.h
• GuC KLV(9)
• GuC Global Config KLVs(9)
• GuC Self Config KLVs(9)
• GuC Scheduling Policies KLVs(9)
• GuC VGT Policy KLVs(9)
• GuC VF Configuration KLVs(9)
• GuC Reserved KLVs(9)

and that's the whole page, bestie, you ate that 💖 this lil section lives out of ./drivers/gpu/drm/xe/abi, dated October 2026 — mwah, go forth and opt in responsibly 🧚‍♀️⭐