Examples may forward an input/output (IO) request with use of kernel-level instructions. Examples may receive the IO request via a port of a standby controller, generate an alternate version of the IO request using at least kernel-level instructions of the standby controller, and provide the alternate version of the IO request to physical memory of the active controller by providing the alternate version of the IO request to a designated region of physical memory of the standby controller that is mapped to a designated region of the physical memory of the active controller.