1. A method, comprising: mapping, by a hypervisor being executed by a processing device of a host computer system, a plurality of interrupt controller registers of the host computer system into a memory address space of a virtual machine being executed by the host computer system; mapping, into the memory address space of the virtual machine, a task mapping data structure comprising a plurality of records, each record associating a task with a processor of the host computer system; and mapping, into the memory address space of the virtual machine, a notification code module to be invoked by the virtual machine for writing a notification message into an interrupt controller register associated with the processor identified using the task mapping data structure.