handle_external_interrupt(9)

💖 NAME 💖

handle_external_interrupt — used for external interruption interceptions. Welcome to the Kernel API Manual, bestie, this one’s giving very specific s390 KVM energy ✨

🎀 SYNOPSIS 🎀

int handle_external_interrupt (struct kvm_vcpu *vcpu );

🦋 ARGUMENTS 🦋

• vcpu — virtual cpu. That’s the whole argument, and honestly? Iconic minimalism 🫶

🌸 DESCRIPTION 🌸

Okay so this interception occurs if either of these two situations is happening:

• The CPUSTAT_EXT_INT bit was already set when the external interrupt occurred. In this case, the interrupt needs to be injected manually to preserve interrupt priority.
• The external new PSW has external interrupts enabled, which will cause an interruption loop. We drop to userspace in this case.

The latter case can be detected by inspecting the external mask bit in the external new psw.

Under PV, only the latter case can occur, since interrupt priorities are handled in the ultravisor.

🌈 SEE ALSO 🌈

• Kernel file ./arch/s390/kvm/s390/intercept.c
• handle_mvpg_pei(9)

Mwah 💋 — xoxo, your kernel bestie. Source/version: ./arch/s390/kvm/s390; date: October 2026; page: handle_external_interrupt(9). periodt 💅