kvm_age_gfn(9)

💅 kvm_age_gfn — clear young

okay so bestie, welcome to the Kernel API Manual ✨ — this one's about kvm_age_gfn(9), and no cap it's a little baby function with a very specific job. sit down, hydrate, let's get into it 🫶

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🌸 NAME 🌸

kvm_age_gfn — clear young 🧚

like, literally just that. clear young. it's giving "one job and it does it" 💅

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✨ SYNOPSIS ✨

bool kvm_age_gfn (struct kvm *kvm , struct kvm_gfn_range *range );

that's the whole vibe check right there 👑 two args, one bool coming back at you.

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🎀 ARGUMENTS 🎀

• kvm — the kvm instance 🦋 like, the actual KVM you're working with. the main character, if you will.
• range — the range of guest addresses whose young status needs to be cleared 🌈 yes bestie, the young status. it's gotta go. we're clearing it.

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💜 CONTEXT 💜

so, when does this even run? it's called by KVM common code without holding the kvm mmu lock 😭 — and that part is highkey important, so don't go assuming the lock's already in your hand. noted, remembered, internalized 🫡

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⭐ RETURN ⭐

it hands you back true if any page in the given range was young 🔥 otherwise, 0.

that's it. that's the return. short, sweet, iconic.

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👑 SEE ALSO 👑

the kernel file we're repping here is:

./arch/s390/kvm/s390/s390.c

and the whole friend group of related calls 💖:

• kvm_s390_update_topology_change_report(9)
• kvm_s390_cpus_from_pv(9)
• kvm_s390_cpus_to_pv(9)
• kvm_arch_vcpu_pre_fault_memory(9)
• kvm_test_age_gfn(9)
• kvm_unmap_gfn_range(9)

go read those too, iykyk 📚💅

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💀 reminder bestie: range is about guest addresses and their young status getting cleared. don't get it twisted.

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and that's a wrap, gorgeous 🌸 this lil page came from ./arch/s390/kvm/s390, dated October 2026, and it's literally titled kvm_age_gfn(9) — so you know exactly where it lives 🎀 bye bestie, go clear some young 💖🦋✨