UNION MSI_INSTANCE_COOKIE(9)

💅 union msi_instance_cookie(9) 💅

Okay so this is the Kernel API Manual, bestie 💖 — and we're talking about union msi_instance_cookie(9), which is lowkey iconic in the MSI universe. No cap.

🌸 NAME 🌸

union msi_instance_cookie — MSI instance cookie ✨

🦋 SYNOPSIS 🦋

       union msi_instance_cookie {
           u64 value;
           void *ptr;
        };

🎀 Members 🎀

• value — u64 value store 🫶 — yes, that is literally what it says, bestie.
• ptr — Pointer to usage site specific data 👑

✨ Description ✨

This cookie is handed to the IMS allocation function and stored in the MSI descriptor for the interrupt chip callbacks. 💫

The content of this cookie is MSI domain implementation defined. For PCI/IMS implementations this could be a PASID or a pointer to queue memory. 🧚

🔥 SEE ALSO 🔥

• Kernel file ./include/linux/msi_api.h
• msi_get_virq(9)

That's the whole vibe, bestie 🫶 Source/version: ./include/linux; date: October 2026; page: union msi_instance_cookie(9). Stay hydrated and don't leak your queue memory 💜🌈