is_eva_am_mapped(9)

💅 is_eva_am_mapped — a Kernel API Manual moment 💅

okay bestie so you've wandered into the is_eva_am_mapped(9) page — that's the Kernel API Manual btw, we're in kernel-land now 🎀 — and honestly? it's giving "tiny function, big responsibilities." Let's get into it.

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✨ NAME ✨

is_eva_am_mapped — literally just: figure out whether an access mode is mapped. that's the whole vibe check. 🦋

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🌸 SYNOPSIS 🌸

bool is_eva_am_mapped (struct kvm_vcpu *vcpu , unsigned int am , bool eu
);

three args, one bool back. clean. no notes. 👑

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💖 ARGUMENTS 💖

• vcpu — the KVM VCPU state. yes, that VCPU. the main character of this whole operation 🌟
• am — a 3-bit encoded access mode. three bits! tiny! iconic! 🧚
• eu — whether the segment becomes unmapped and uncached when Status.ERL=1. two things at once, she's multitasking 💅

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🫶 DESCRIPTION 🫶

so what it does is: it decodes am to find whether it encodes a mapped segment for the current VCPU state. like, context matters, bestie — it's not a one-size-fits-all answer 🌈

and where necessary, eu and the actual instruction causing the fault get taken into account too, to make the decision. so it's not just vibes — it's looking at the real faulting instruction. no cap. 🔥

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😭 RETURN 😭

returns whether the VCPU faulted on a TLB mapped address. that's it. that's the answer. 🍓

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🌺 SEE ALSO 🌺

everything lives in the kernel file ./arch/mips/kvm/vz.c — go read it, iykyk 👀 — and also these absolute legends:

• kvm_vz_should_use_htimer(9)
• _kvm_vz_restore_stimer(9)
• _kvm_vz_restore_htimer(9)
• kvm_vz_restore_timer(9)
• kvm_vz_acquire_htimer(9)
• _kvm_vz_save_htimer(9)
• kvm_vz_save_timer(9)
• kvm_vz_lose_htimer(9)
• is_eva_access(9)
• kvm_vz_gva_to_gpa(9)
• kvm_vz_badvaddr_to_gpa(9)
• kvm_trap_vz_handle_cop_unusable(9)
• kvm_trap_vz_handle_msa_disabled(9)
• kvm_vz_resize_guest_vtlb(9)

like… a whole friend group of timer functions and trap handlers. the way they all show up together 🫶✨

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💀 reminder that eu is about the segment becoming unmapped and uncached when Status.ERL=1 — that's a real hardware behaviour thing, not just a cute flag name. don't sleep on it.

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and that's the page, bestie!! 🎀 source vibes come from ./arch/mips/kvm, dated October 2026, and this whole manual page is filed under is_eva_am_mapped(9) — slay, go map some access modes, ily, bye! 💜🦋🌸