Since xen 4.3, the hypervisor is no longer supported on x86_32. But fear not,
you can actually use the x86_64 xen hypervisor, even when using a 32bit kernel
and system. This is because the hypervisor is loaded before the kernel and OS.
Keep in mind that a x86_64 capable processor is still required, but then if
you are installing a hypervisor, you really should be using 64bit anyway.