Wrong CPU Cores detection on Skylake processors

I've been having this issue only with this processor/chipset. I can install XenServer, but when it boots doesn't recognize all the cores that it should be. The processor has 4 Physycal CPUs and it has Hyperthreading enabled on the BIOS (VT-d and VT-x also are activated), so it has 8 logical cores. Once installed /proc/cpuinfo shows 4 cores, and xl info show only one. In XenCenter, shows only one CPU available, and it generates the imposibility to give more than one core to a VM. There is a post on the forum that explains and gives more info of the problem: http://discussions.citrix.com/topic/381364-xen-detects-only-one-cpu/

I'm referring this here because it's a very big issue for us, basically we cannot use Xenserver on this hardware, and it seems to be related to the Xen Kernel, but i cannot find any solution, and in the forum, i couldn't find any help. Bear in mind that almost all the hardware available right now belongs to the "Skylake" family, so this issue is a real blocker . I've tested this on 6.5 & 7 and it's the same, also another person tried it on "Ely" and doesn't seems to be solved.