kvm_s390_upd...hange_report(9)

✨ kvm_s390_upd...hange_report(9) ✨

okay so bestie, buckle up — we're in the Kernel API Manual today (yes, the Kernel API Manual, we're fancy now 💅) and this page is about kvm_s390_update_topology_change_report. i know, i know, the title in the header got cut off like kvm_s390_upd...hange_report(9) — that's just the man page being dramatic and truncating, don't panic 🫶

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🌸 NAME 🌸

kvm_s390_update_topology_change_report — update CPU topology change report

like. it updates the report. about topology changes. for CPUs. iconic behavior honestly ✨

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🎀 SYNOPSIS 🎀

void kvm_s390_update_topology_change_report (struct kvm *kvm , bool val );

that's the whole thing!! void return, two args, no cap 💖

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🦋 ARGUMENTS 🦋

• kvm — the guest KVM description. literally the whole vibe of the guest, hand it over please 🫶
• val — set or clear the MTCR bit. yes it's just a bool deciding whether we're setting or clearing, main character energy fr 🔥

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🌈 DESCRIPTION 🌈

okay so what this does: it updates the Multiprocessor Topology-Change-Report bit, and the whole point is to signal the guest that a topology change happened. like a little "hey girl, something moved 👀" nudge to the guest.

but — and this is important, bestie — it's only relevant if the topology facility is present. no facility, no relevance. that's the vibe check and it passed (or didn't, depending on the facility) 💀

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👑 SEE ALSO 👑

kernal file ./arch/s390/kvm/s390/s390.c — go read it, it's giving source material ✨

and the whole friend group of related functions:

• 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_age_gfn(9)
• kvm_unmap_gfn_range(9)

they all show up together, it's a whole squad 🫶💜

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and that's the page!! shoutout to the source/version tag ./arch/s390/kvm/s390 and the date October 2026 — that's the cute little sign-off at the bottom, mwah 💋 see u next man page bestie 🎀⭐