gisa_set_iam(9)

💅 gisa_set_iam(9) — like, the Kernel API Manual obviously 🎀

okay bestie, gather round, because today we're talking about gisa_set_iam — the little function that goes "hey, new IAM value, who dis?" and swaps out the GISA interruption alert mask for you. It's giving low-level s390 KVM realness and honestly? Iconic. ✨

---

🌸 SYNOPSIS 🌸

int gisa_set_iam (struct kvm_s390_gisa *gisa , u8 iam );

That's the whole vibe check right there — two args, one int back. No cap. 🫶

---

🦋 ARGUMENTS 🦋

• gisa — the GISA you're operating on, aka the main character of this whole operation 💖
• iam — the new IAM value to use. Fresh out the box, ready to slay ✨

---

👑 DESCRIPTION 👑

So here's the tea, bestie: this changes the IAM atomically together with the next alert address and the IPM of the GISA — but only if the GISA is not part of the GIB alert list. Like, it's a package deal, all three or nothing, no half-sending. 🔥

And where do all three fields live? They're all chillin' in the first long word of the GISA. One word, three fields, very efficient, very demure. 🎀

Fr fr though — the atomicity is the whole point here. Don't be out here thinking you can do these fields one at a time, because that's not the move. 💀

---

⭐ RETURN ⭐

• 0 — success, we ate, periodt 💅
• -EBUSY — in case the gisa is part of the alert list. Like sorry babe, it's occupied, try again later 🙈

---

🌈 SEE ALSO 🌈

Kernel file ./arch/s390/kvm/s390/interrupt.c — go read the source bestie, it's right there 🦋

And these icons, obviously, you should also check out:

• gisa_clear_ipm(9)
• gisa_get_ipm_or_restore_iam(9)
• kvm_s390_gisc_register(9)
• kvm_s390_gisc_unregister(9)

---

okay that's the whole page, you're welcome, go be a kernel girlie 💜

stay hydrated, read your structs, and ship it 🌸

— with love, from ./arch/s390/kvm/s390, October 2026, gisa_set_iam(9) 🫶✨