read_guest_with_key(9)

📦 version 7.3.1, in nixpkgs unstable

💖 read_guest_with_key(9) 💖

okay so bestie, welcome to the Kernel API Manual ✨ — this is the page for read_guest_with_key(9), and honestly? it's giving "tiny function, big responsibilities" and i'm obsessed 🎀

🌸 NAME 🌸

read_guest_with_key — copy data from guest space to kernel space 💫

like literally that's the whole job. copy the data. move it over. slay 💅

✨ SYNOPSIS ✨

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

one function, six arguments, no notes 👑 (jk there are notes, they're right below 🫶)

🦋 ARGUMENTS 🦋

  • vcpu — virtual cpu. the whole entire vibe of this operation, lowkey the main character here 💜
  • ga — guest address. this is where in guest space we're reading from, iykyk 📍
  • ar — access register. yes bestie it's exactly what it sounds like 🌈
  • data — destination address in kernel space. the data's new home 🏠✨
  • len — number of bytes to copy. not one more, not one less, we're precise here fr fr 🔢
  • access_key — access key the storage key needs to match. it's a whole vibe check for keys 🔑💅

🧚 DESCRIPTION 🧚

so the tea is: copy len bytes from ga (guest address) over to data (kernel space). that's it. that's the function. short king behavior honestly 👑🫶

and here's the iconic part — the behaviour of read_guest_with_key is identical to write_guest_with_key, except that data will be copied from guest space to kernel space. 🔄 like yes they're twins but this one reads instead of writes, periodt 💫

ngl it's a beautiful little family of functions and this one knows exactly which direction it's going 😭🌷

🔥 SEE ALSO 🔥

Kernel file ./arch/s390/kvm/s390/gaccess.h 📁 — go read the header if you want the full lore, it's a whole rabbit hole 🐇💜

then the rest of the squad, all iconic, all linked, no cap:

anyway bestie that's the page 💖 live your truth, read your guest bytes, and remember: it's len bytes, not a suggestion 💅

🎀 mwah, bye bestie! this manual page lives at ./arch/s390/kvm/s390 and it was dated October 2026 — keep that in your notes, it's the receipt 🧾✨ 🦋🌸💜
📦 where this page comes from