Pkg xen devel - Nov 2010 - Bug#604160: solution found, but vmx flag is misleading

After further investigation:

`xm dmesg' output:

(XEN) CPU0: VMX disabled by BIOS.
(XEN) VMX: failed to initialise.

I tried the following:

- updated to the latest BIOS 2.21 from Lenovo
- reboot and press `ThinkVantage' button
- under CPU, enable VMX

Rebooting into Xen, it still didn't work

After reading about this in search results, I found that many users have 
had to do a cold reboot (remove power to the machine) after changing the 
VMX settings in the BIOS.  Doing this resolved the problem and now I 
have VMX:

(XEN) VMX: Supported advanced features:
(XEN)  - APIC MMIO access virtualisation
(XEN)  - APIC TPR shadow
(XEN)  - Virtual NMI
(XEN)  - MSR direct-access bitmap
(XEN) HVM: ASIDs disabled.
(XEN) HVM: VMX enabled
(XEN) I/O virtualisation disabled
(XEN) Total of 2 processors activated.

The vmx flag in the cpuinfo output doesn't provide an accurate 
indication of BIOS status.

On 11/21/2010 03:58 AM, Daniel Pocock wrote:
> The vmx flag in the cpuinfo output doesn't provide an accurate
> indication of BIOS status.
Why do you think it should? It's there simply to tell what the processor
is capable of, not to tell what your motherboard supports!!!

Thomas