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  1. XenServer Org
  2. XSO-635

Wrong CPU Cores detection on Skylake processors



    • Type: Bug
    • Status: Done (View Workflow)
    • Priority: Blocker
    • Resolution: Done
    • Affects Version/s: 6.5 SP1, 7.0, Ely alpha, 7.1, 7.2
    • Fix Version/s: None
    • Component/s: API, other
    • Labels:
    • Environment:

      Mobo: Intel S1200SP
      Processor: Intel(R) Xeon(R) CPU E3-1230 v5 @ 3.40GHz
      Ram: 8GB
      Disk: 1TB (No RAID)
      SO: Xenserver 7


      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.


        1. hypervisor.log
          15 kB
        2. dmesg.txt
          55 kB
        3. hypervisor.log
          27 kB
        4. xensource.log
          262 kB
        5. xen-xso-635-v1.gz
          995 kB
        6. xl-dmesg.log
          27 kB
        7. putty.log
          29 kB
        8. dmesg-debian
          82 kB
        9. dmesg-debian
          182 kB



            SimonCro Simon Crowe
            gperez.tlp gperez.tlp
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