Updates the ipi_optimize test to use 4 CPUs for qemu_x86_64. This provides enough CPUs for the test to verify the recently added directed IPI support for x86_64. Signed-off-by: Peter Mitsis <peter.mitsis@intel.com>
Adds several tests to verify that IPIs can be appropriately targeted to specific CPUs. Signed-off-by: Peter Mitsis <peter.mitsis@intel.com>