Hi Ido,

The below warning should be introduced by this commit at tip/master:

commit c00679af441c5be76e195deed2c76fef65a5d102
Author:     Ido Yariv <ido@wizery.com>
CommitDate: Wed Aug 22 10:48:05 2012 +0200

    x86/vsmp: Use hypervisor layer for initialization
   
[    0.000000] tsc: Detected 3200.098 MHz processor
[    0.000000] ------------[ cut here ]------------
[    0.000000] WARNING: at /c/kernel-tests/src/tip/arch/x86/kernel/vsmp_64.c:158 is_vsmp_box+0xa1/0xb0()
[    0.000000] Hardware name: Bochs
[    0.000000] Pid: 0, comm: swapper/0 Not tainted 3.6.0-rc2-01612-g595b3f3 #292
[    0.000000] Call Trace:
[    0.000000]  [<ffffffff8105a12a>] ? warn_slowpath_common+0x7a/0xb0
[    0.000000]  [<ffffffff810339f1>] ? is_vsmp_box+0xa1/0xb0
[    0.000000]  [<ffffffff818125d5>] ? apic_is_clustered_box+0x34/0x4c
[    0.000000]  [<ffffffff8180baa4>] ? unsynchronized_tsc+0x23/0x71
[    0.000000]  [<ffffffff81f8330c>] ? tsc_init+0xc2/0xed
[    0.000000]  [<ffffffff81f7cc0d>] ? start_kernel+0x3fd/0x47a
[    0.000000]  [<ffffffff81f7c627>] ? repair_env_string+0x5b/0x5b
[    0.000000]  [<ffffffff81f7c436>] ? x86_64_start_kernel+0x105/0x114

Thanks,
Fengguang