kvm_handle_wfx(9)

💅 kvm_handle_wfx(9) — like, the whole vibe

okay so bestie, welcome to the Kernel API Manual ✨ this one's kvm_handle_wfx(9) and it's literally about what happens when a guest CPU is like "mm k bye, wake me when something happens" 🫶

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🌸 NAME 🌸

kvm_handle_wfx — handle a wait-for-interrupts or wait-for-event instruction executed by a guest

like yes, the guest is being dramatic and taking a nap, and we have to deal with it 💀

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✨ SYNOPSIS ✨

int kvm_handle_wfx (struct kvm_vcpu *vcpu );

short, iconic, no notes 👑

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🎀 ARGUMENTS 🎀

• vcpu — the vcpu pointer. yes it's just the pointer. that's the whole thing. it's giving minimalist 🦋

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🔥 DESCRIPTION 🔥

okay so there's three-ish flavours of "guest wants to sleep" and each one hits different:

• WFE[T] — yields the CPU, and comes back to this vcpu when the scheduler decides to. so the scheduler is the one holding the aux cord here 🎧
• WFI — simply calls kvm_vcpu_halt, which will halt execution of world-switches and schedule other host processes until there's an incoming IRQ or FIQ to the VM. so basically it's napping until someone pings it 😴
• WFIT — same as WFI, with a timed wakeup implemented as a background timer. so it's WFI with an alarm clock ⏰

and here's the little detail nobody says out loud: WF{I,E}T can immediately return if the deadline has already expired. like, bestie, the time's already up, no point sleeping, we're up immediately 🧚

ngl this is the whole function. three cases, one early return, and we're out. ate and left no crumbs 💅

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🌈 SEE ALSO 🌈

• Kernel file ./arch/arm64/kvm/handle_exit.c
• kvm_handle_guest_debug(9)

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k you're caught up, go read handle_exit.c, iykyk 💖

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that's the whole page bestie ✨ brought to you by the fine folks over at ./arch/arm64/kvm, from October 2026, and it's kvm_handle_wfx(9) — periodt 🎀🦋💜