[Xen-users] domU machines hang when Hyperthreading enabled in BIOS

["Samuel Torton" <samuel@xxxxxxxxxx>]

Hi,

I can't get rid of an annoying domU machines hanging issue with
Hyperthreading enabled in my BIOS.

Hardware config: IBM x325 series
                 2 * CPUs Intel Xeon 3.06 Ghz

Xen version:     3.0.0
Kernel version:  2.6.12.6
Linux distrib:   Debian Sarge 3.1 r1

I run 1 domU machine on my dom0, here is my Xen config:
  . xen0:
   /etc/xen/xend-config.sxp : (dom0-num-cpus 0)
  . xenU:
   /etc/xen/myxenU.cfg      : vcpus = 2


- First case:  . BIOS Hyperthreading : DISABLED
               . xen0 kernel config  : SMT enabled
               . xenU kernel config  : SMT enabled or disabled (whatever)
  When I reboot the physical machine, and run the command "xm list" :
   . dom0 is visible and works fine
     --> I see 2 cpus.
   . domU is visible and works fine
     --> I see 2 cpus;
         I can console the xenU machine and work inside.

- Second case: . BIOS Hyperthreading : ENABLED
               . xen0 kernel config  : SMT enabled
               . xenU kernel config  : SMT enabled or disabled (whatever)
  --> When I reboot the physical machine, and run the command "xm list" :
   . dom0 is visible and works fine
      --> I see 4 cpus.
   . domU is visible and SEEMS to work fine (!)
      --> I see 2 cpus;
          If I console the xenU machine, I see the machine
          has booted but is hanged before finishing the boot !!! :-(

Would you have any idea, any clue ? Do you have any experience ?
  - Where to search in log files in order to detect the problem ?
  - Which kernel parameter would I have forgotten ?
  - I don't even know whether the problem comes from xen0 or xenU kernel
conf !
  - etc... ?

Thank you in advance...
... please, don't advise me I have to disable Hyperthreading in BIOS !;-)

Regards,
Samuel


_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users