On Wed, Nov 09, 2022, Xin Li wrote: > +__visible noinstr void external_interrupt(struct pt_regs *regs, > + unsigned int vector) > +{ > + unsigned int sysvec = vector - FIRST_SYSTEM_VECTOR; > + > + BUG_ON(vector < FIRST_EXTERNAL_VECTOR); Why not return an error up the stack? KVM and/or CPU bugs aren't unheard of. Dropping an IRQ obviously isn't ideal, but there's a non-zero chance that letting KVM WARN and kill the VM will keep the host alive and thus other VMs running. A somewhat sophisticated setup might even react to the VM being killed by migrating other VMs off the system and initiating host maintenance.