msr_set_bit(9)

📦 version 7.3.1, in nixpkgs unstable

✨ msr_set_bit ✨

okay so bestie, welcome to the msr_set_bit(9) page from the Kernel API Manual — yes that's the manual name, we're fancy now 💅 — and honestly? this little guy is doing exactly what it says on the tin and I respect it so much.

🌸 NAME 🌸

msr_set_bit — sets @bit in a MSR @msr. that's it. that's the whole vibe. short, sweet, main character energy 🎀

🦋 SYNOPSIS 🦋

int msr_set_bit (u32 msr , u8 bit );

look at that signature. clean. iconic. no notes 🔥

💖 ARGUMENTS 💖

  • msr — the MSR you're writing to. this is the destination, the moment, the whole point 🫶
  • bit — the bit number you wanna set. like, which little guy are we flipping ✨

👑 RETURN 👑

the return value is literally telling you a whole story, so listen up:

  • < 0 — an error was encountered 😭 something went wrong, tragedy, we don't love that.
  • = 0 — the bit was already set. no cap, it was already living its best life, nothing changed 💀
  • > 0 — hardware accepted the MSR write. SLAAAAY 🔥 the machine said yes, we ate.
fr fr, pay attention to which of these three you get back — they mean completely different things and the vibe check depends on it 👀

🌈 SEE ALSO 🌈

the kernel file ./arch/x86/lib/msr.c, plus the whole friend group:

go say hi, they're all in the same friend group bestie 🧚

💜 and that's the page!! this one lives in ./arch/x86/lib, dated October 2026 — so yeah, mark your calendar, this is the version you're reading 🍓 byeee, go set some bits responsibly ✨

📦 where this page comes from