Run 64-bit linux on Intel processor, x86 platform. My use case: other cores (may run other OS) will send the IPI to core#0 (linux), the interrupt need be caught/addressed.

I can catch the inter processor interrupts via the kernel hacking.

But I am not successful to register the interrupt handler to catch the IPI using the linux kernel driver. The below APIs were tested but failed: request_irq/setup_irq/probe_irq_on/off. I can get some IRQ reigsterred. But unable to the catch the interrupt.

How do I generate the interrupt on core#0? Just write the APIC ICR with the destination core id, and vector number.

Any help is highly appreciated.

You are better to call some API to setup IPI interrupt instead of writing APIC ICR register directly.

I am now able to use requestt_irq/free_irq for IPI. It seemed that the irq/interrupt vector delta is about 0x30. Verified on 2 systems.

However I cannot use any send_IPI_mask provided by the kernel API. They are not exported. Correct me if I were wrong.

Let me make this clear: The above IRQ/Interrupt vector delta (0x30) is tested/verified within a very limited range, less than 0xf. IRQ shall be dynamically allocated, I don't have the answer on which code decides the gap. It just dirty work with a little lucky.

Welcome to the elegant approach or suggestions.

Why do you need to capture/address IPI interrupt? Is your Linux kernel generic or dedicated?

Sorry for late reply. The linux kernel is standard but only running core #0. Other cores will run other Operating system (non-linux). That's why need do IPI.

If Linux kernel is standard. You are better find out another way to capture IPI.