setup_apcb00(9)

💅 setup_apcb00(9) — from the Kernel API Manual, bestie ✨

okay so real talk, this one lives in the Kernel API Manual and it's a tiny little helper that does exactly one job and does it cute. no cap 🎀

✨ NAME ✨

setup_apcb00 — Copy to APCB FORMAT0 from APCB FORMAT0 🫶

like, it copies FORMAT0 into FORMAT0. yes bestie, that's literally what it says. iconic behavior, we don't question it 💅

✨ SYNOPSIS ✨

int setup_apcb00 (struct kvm_vcpu *vcpu , unsigned long *apcb_s ,
unsigned long crycb_gpa , unsigned long *apcb_h );

that's the whole vibe check right there ⭐

🌸 ARGUMENTS 🌸

• vcpu — pointer to the virtual CPU 👑 like, the main character of this whole situation
• apcb_s — pointer to start of apcb in the shadow crycb 🦋 (the s is for shadow, iykyk)
• crycb_gpa — guest physical address to start of original guest crycb 📍 location drop
• apcb_h — pointer to start of apcb in the guest1 💖 yes, guest1, that's the name, we're keeping it

💜 DESCRIPTION 💜

so what happens is: it does the copy. and then — this is the important part, don't skip it — it returns 0 on success and -EFAULT on error reading guest apcb 😭 so if you see -EFAULT you know the guest apcb read went sideways, no cap.

fr fr, that's the whole function. no hidden lore, no extra flags, nothing. it's giving "small but mighty" energy 🔥

🌈 SEE ALSO 🌈

• Kernel file ./arch/s390/kvm/s390/vsie.c
• setup_apcb11(9)
• setup_apcb(9)
• shadow_crycb(9)

and that's a wrap bestie 🧚 this page came straight out of ./arch/s390/kvm/s390, dated October 2026 — slay, obsessed, periodt 💅💖