3.4 [aarch64] CPU hotplug functionality not functional in KVM

Although CPU hotplug functionality is available in QEMU, the aarch64 Linux kernel is not yet able to handle the addition of new virtual CPUs to a running virtual machine. When QEMU is used to add a virtual CPU to a running virtual machine in KVM, and error is returned:

kvm_init_vcpu failed: Device or resource busy

CPU hotplug functionality is currently unavailable for UEK R5 on 64-bit Arm platforms. (Bug ID 28140386)