read_guest_abs(9)

read_guest_abs(9) 💅✨

okay bestie, this page is from the Kernel API Manual, and it's all about read_guest_abs — the function that copies data from guest space absolute to kernel space. no cap, the name is literally the plot. 🎀

🌸 NAME 🌸

read_guest_abs — copy data from guest space absolute to kernel space. that's the whole vibe. 🦋

✨ SYNOPSIS ✨

int read_guest_abs (struct kvm_vcpu *vcpu , unsigned long gpa , void *data , unsigned long len );

🫶 ARGUMENTS 🫶

okay here's the cast, bestie:

• vcpu — virtual cpu. main character energy.
• gpa — guest physical (absolute) address. not a grades GPA, keep up 💅
• data — destination address in kernel space.
• len — number of bytes to copy.

💖 DESCRIPTION 💖

so what it does: copies len bytes from gpa (the guest absolute address) to data (kernel space). literally the whole point. ✨

bestie, huge caveat: it is up to the caller to ensure that the entire guest memory range is valid memory before calling this function. also, guest key protection is not checked. periodt. 🫶

It returns zero on success or -EFAULT on error.

and if an error occurs, data may have been copied partially to kernel space 😭 — partial copy is a thing, don't act surprised.

🌈 SEE ALSO 🌈

Kernel file ./arch/s390/kvm/s390/gaccess.h — plus the whole cross-reference friend group:

• 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)
• write_guest(9)
• read_guest_with_key(9)
• read_guest(9)
• read_guest_instr(9)
• write_guest_abs(9)
• write_guest_real(9)
• read_guest_real(9)

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mwah 💋 source/version: ./arch/s390/kvm/s390; date: October 2026. bye bestie 🫶