sony-vaio-z-series team mailing list archive

[Easter Master <dariomas@xxxxxxxxx>]

Hello!

On Mon, Aug 10, 2009 at 03:19, Raphael
Gradenwitz<raphael@xxxxxxxxxxxxxxxxx> wrote:
> Am Mittwoch, den 29.07.2009, 17:20 -0400 schrieb Roberto Lublinerman:
>> It might be of interest of this community to know that a guy found a way
>> to enable VT on Vaio Z machines. You can read the story and download the
>> software you need to enable vt here (http://feature-enable.blogspot.com/)
>>
>> I have now enabled VT on my Z (Z590) and on my brother's (z790) with
>> success; happy to see all those virtual horses unleashed.
>
> Q: is VT not already enabled on sony z-series under Linux completely
> independent from bios?
>
> Simple test on cpu flag 'vmx' like:
>
>  # begin test
> echo; echo -n "  Full-Virtualization is ";\
> grep '^flags.*vmx' /proc/cpuinfo || echo -n "not ";\
> echo "suported by your CPU"; echo
>  # end test

The CPU Flags are only flags, indicates the capabilities available on
the Processor.
To check if that capabilities are enabled you need to check the MSR register.

In Linux you can use the "msr-tools" package; with the "rdmsr" utility
you can check the VMX MSR register numbered 0x3A:

$ rdmsr 0x3A
5

That shows bit-2 (0x04) and bit-0 (0x01) of MSR 0x3A are set. bit-2 is
the VT enable bit.


>
> and a working kvm (out of the box) makes me suspect that it does..

A working virtualization environment does not means that you are using
the processor capabilities to support virtualization.

Try loading the Linux KVM modules

$ sudo modprobe kvm-intel
$ lsmod | grep kvm
kvm_intel              47768  0
kvm                   152984  1 kvm_intel

If VT wasn't enabled, there are error reports in /var/log/kern.log  or
/var/log/messages:

kernel:  kvm: disabled by bios


>
> The report this link [2] is pointing to is speaking about bios. But one
> can eg. completely bypass any bios update by simply installing the
> newest Linux Processor Microcode Data File from Intel [1]:
>
> sudo apt-get install intel-microcode microcode.ctl

An updated CPU microcode is very useful to correct processor bugs but
it cannot enable a disabled MSR register and cannot add capabilities
not available on the processor.
The BIOS updates correct firmware bugs and not only Processor microcode.

>
> But even without the newest microcode installed I have got full
> virtualisation support on my VGN-Z21MN (ubuntu-jaunty and -karmic).
> Without any changes to the bios.
>
> Or did I just misunderstood everything?

Maybe you are using "software only" virtualization; you can be sure
only checking the VMX MSR register (after checking the CPU Flags).
Hope that this is more clear, anyway ask here anything you don't understand.

>
> Raphael
>
> [1] http://downloadcenter.intel.com/Detail_Desc.aspx?ProductID=483&DwnldID=14303
> [2] https://lists.launchpad.net/sony-vaio-z-series/msg00035.html
>
>
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>



-- 
Ciao,
   alla prossima_