write_guest(9)

🌸 NAME 🌸

okay so bestie, welcome to write_guest(9) from the Kernel API Manual — the function whose whole job is literally copy data from kernel space to guest space. no cap, that's the vibe 💅✨

✨ SYNOPSIS ✨

int write_guest (struct kvm_vcpu *vcpu , unsigned long ga , u8 ar , void
       *data , unsigned long len );

🎀 ARGUMENTS 🎀

• vcpu — virtual cpu, the main character 💖
• ga — guest address, where the guest lore happens 🦋
• ar — access register, iconic little parameter ✨
• data — source address in kernel space, the origin story 🌸
• len — number of bytes to copy, the count, periodt 🔢

🦋 DESCRIPTION 🦋

the behaviour of write_guest is identical to write_guest_with_key, lowkey exactly the same — except that the PSW access key is used instead of an explicit argument. that's the whole plot twist, iykyk 💫

🔥 SEE ALSO 🔥

Kernel file: ./arch/s390/kvm/s390/gaccess.h 👀 — and the whole friend group is here:

• kvm_s390_real_to_abs(9)
• _kvm_s390_logical_to_effective(9)
• kvm_s390_logical_to_effective(9)
• put_guest_lc(9)
• write_guest_lc(9)
• read_guest_lc(9)
• write_guest_with_key(9)
• read_guest_with_key(9)
• read_guest(9)
• read_guest_instr(9)
• write_guest_abs(9)
• read_guest_abs(9)
• write_guest_real(9)
• read_guest_real(9)

xoxo, your Unix bestie 💖 — source/version: ./arch/s390/kvm/s390; date: October 2026. slay ✨