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Anyone actually using Intel VT? (particuarly Xen)

Posted: Sun Apr 29, 2007 6:47 pm
by jbinto
Hello everyone,

I've ordered my T60 with a Core2Duo T5600 and am awaiting for it impatiently.

Just wanted to see if anyone here is using actually making good use of the virtualization capability of their Thinkpads. From what I could tell, the R60 and Z60 lines have this option disabled regardless of whether the CPU supports it or not, and the T60 has a quite a few models with CPUs that do not support it (t2300e, t5500(edit) comes to mind). The ones that do, apparently require a BIOS flash.

I intend to use Xen under Linux to run multiple other distributions of linux/bsd and windows xp for some development work.

If anyone is using it, or knows anything about Intel VT on Thinkpads, let me know:

- what type of Core(2)Duo chip you have,
- what type of Thinkpad and BIOS version,
- whether it is enabled in BIOS and what you had to do to get it that way (flash?)
- what solution you're using (Xen on linux? VMWare ESX on linux or windows? Virtual PC on windows?)
- how happy you are with it (no longer really thinkpad specific- but does your solution rival the Parallels experience on MacOSX?)

Thanks in advance,

- eager, prospective mobile virtual machine user, aka jbinto

Posted: Mon Apr 30, 2007 12:40 pm
by arni
I have a T60 200763G Model and i could enable Intel VT in bios.

There are different stories around if it will help you with virtualization or not. Vmware e.g. doesn't recommend turing on VT for their products. On the other hand some MS folks, particularly from the Virtualization team are all in for VT with VirtualPC and VirtualServer.

You can read about it here http://blogs.technet.com/jhoward/archiv ... 27210.aspx
and here http://blogs.technet.com/jhoward/archiv ... 27210.aspx .

Posted: Mon Apr 30, 2007 1:18 pm
by Ivan Ivankovic
when my T60p arrives (a week or so until arrival) I'll be using VMware almost all the time (Fedora & Solaris under WinXP).
I'm also interested in this topic so if anyone could shed some light I'd appreciate it.

Posted: Mon Apr 30, 2007 1:42 pm
by Oaklodge
According to VMWare you can have an x32 host and if VT is enabled run x64 guests.

Posted: Mon Apr 30, 2007 1:44 pm
by bim
I have tried Vmware server and MS virtual server, but I didn't notice any difference if VT enabled (T2500). I had problems to enable 2 cores in virtual server, but that's another story.

Posted: Mon Apr 30, 2007 1:53 pm
by Oaklodge
Hmm, don't know about the VMWare Server product ... but VMWare Workstation 5.5 and greater should work.

Posted: Mon Apr 30, 2007 3:55 pm
by axiom
used XP pro through KVM to file my tax
core duo t2700, with the same virtualization extension found on t7x00
Only thing I had to do was to enable it in the bios and load the kvm-intel module, then everything works like a charm, but doesn't feel any impressive performance. Probably xen will be better, haven't tried that.

By the way, I am not sure if t5x00 has the same level of virtualization extension as t7x00 or not.

Posted: Mon Apr 30, 2007 4:01 pm
by axiom
axiom wrote:...
By the way, I am not sure if t5x00 has the same level of virtualization extension as t7x00 or not....
Nevermind
t5600 or above is fine

Posted: Mon Apr 30, 2007 10:47 pm
by WPWoodJr
arni wrote:I have a T60 200763G Model and i could enable Intel VT in bios.

There are different stories around if it will help you with virtualization or not. Vmware e.g. doesn't recommend turing on VT for their products. On the other hand some MS folks, particularly from the Virtualization team are all in for VT with VirtualPC and VirtualServer.

You can read about it here http://blogs.technet.com/jhoward/archiv ... 27210.aspx
and here http://blogs.technet.com/jhoward/archiv ... 27210.aspx .
Can you link to where VMWare says not to use VT? I turned it on in my bios and VMWare is working fine. I don't know if its faster though.

Posted: Tue May 01, 2007 9:00 am
by Dodge DeBoulet
WPWoodJr wrote:Can you link to where VMWare says not to use VT? I turned it on in my bios and VMWare is working fine. I don't know if its faster though.
Support for VT is experimental in VMWare Workstation, so I think the inference is that for maximum stability, you wouldn't want to use it.

A Wikipedia entry on virtualization makes the claim that there's a negative performance impact for VMWare workstation for most tasks, but that enabling it is the only way to run 64 bit guests on a 32 bit host OS.

Posted: Tue May 01, 2007 11:14 am
by taob
I've been playing with XenEnterprise 3.2 since the weekend, though not on a Thinkpad. I'm thinking of repartitioning and reinstalling the drive that holds OS X 10.4.8 anyway, so maybe I'll make room for a Xen install. I can tell you that it does work fabulously well on an IBM X3650 server with dual quad-core X5355's and 16GB of RAM. :lol:

Posted: Wed May 02, 2007 10:37 pm
by evforme
How can I be sure that VT is enabled? I checked the BIOS and under the "Current Setting" it says Disabled, but the field is grayed out so I can't modify it. I have T60p 2623DDU btw.

Posted: Thu May 03, 2007 1:54 pm
by WPWoodJr
evforme wrote:How can I be sure that VT is enabled? I checked the BIOS and under the "Current Setting" it says Disabled, but the field is grayed out so I can't modify it. I have T60p 2623DDU btw.
My guess is that since you have a Core Duo and not a Core 2 Duo that virtualization is not available.

Posted: Thu May 03, 2007 7:27 pm
by dbertoni5000
My T60 (200768U) has the same T2500 Core Duo chip and I have VT enabled.

I don't know why the OP can't enable it in the BIOS. Perhaps a BIOS upgrade is needed.

Posted: Fri May 04, 2007 7:27 am
by Ivan Ivankovic
dbertoni5000 wrote:I don't know why the OP can't enable it in the BIOS. Perhaps a BIOS upgrade is needed.
I vote for that, too.

Posted: Fri May 04, 2007 8:15 am
by Rizo
Ivan Ivankovic wrote:
dbertoni5000 wrote:I don't know why the OP can't enable it in the BIOS. Perhaps a BIOS upgrade is needed.
I vote for that, too.
OP doesnt have his laptop yet, he just ordered it.
I cannot enable it in BIOS with the latest version loaded with my R60 because they dont give the R models the option, regardless of chip.

Posted: Fri May 04, 2007 9:44 am
by Dodge DeBoulet
Dodge DeBoulet wrote:Support for VT is experimental in VMWare Workstation, so I think the inference is that for maximum stability, you wouldn't want to use it.
Interesting observation . . . my new T60 arrived yesterday, and I got around to installing VMWare 5.5.4 build 44386 on it this morning.

I copied my VMs over from my old laptop, and when I launched one, got a pop-up complaining that, although I had a VT-capable laptop, VT wasn't enabled in my BIOS (and it wasn't; one thing at a time :)).

So even though the support is experimental, VMWare seems to prefer that it be on. When I have a chance to reboot, I'll enable it and report any differences I find.

Posted: Sat May 05, 2007 7:30 am
by steveg47
Dodge DeBoulet wrote: A Wikipedia entry on virtualization makes the claim that there's a negative performance impact for VMWare workstation for most tasks, but that enabling it is the only way to run 64 bit guests on a 32 bit host OS.
Wrong. 64 bit guests run on a 32 bit host OS without enabling VT. The only requirement is that the host be running a 64bit cpu such as a core 2 duo. This is true on vmware 5.5 and 6 beta as I have tested both with 64 bit versions of XP and Vista.
Also, I have not noticed(subjectively) any significant difference when VT is enabled or disabled in the bios.

Posted: Sat May 05, 2007 8:29 am
by Dodge DeBoulet
steveg47 wrote:
Dodge DeBoulet wrote: A Wikipedia entry on virtualization makes the claim that there's a negative performance impact for VMWare workstation for most tasks, but that enabling it is the only way to run 64 bit guests on a 32 bit host OS.
Wrong. 64 bit guests run on a 32 bit host OS without enabling VT. The only requirement is that the host be running a 64bit cpu such as a core 2 duo. This is true on vmware 5.5 and 6 beta as I have tested both with 64 bit versions of XP and Vista.
Also, I have not noticed(subjectively) any significant difference when VT is enabled or disabled in the bios.
It's Wikipedia. You can fix it :D

Posted: Sat May 05, 2007 9:52 am
by steveg47
Dodge DeBoulet wrote: It's Wikipedia. You can fix it :D
I wouldn't waste my time. Wikipedia is flawed by its' very philosophy. IMO

Posted: Sat May 05, 2007 9:58 am
by Dodge DeBoulet
steveg47 wrote:
Dodge DeBoulet wrote: It's Wikipedia. You can fix it :D
I wouldn't waste my time. Wikipedia is flawed by its' very philosophy. IMO
To be fair, the Wikipedia entry on this topic does cite VMWare's own KB. See this article.

An extract:

Details

I want to use Workstation or VMware Server to run virtual machines with 64-bit guest operating systems. What are the hardware and firmware requirements for the host machine?

Solution

VMware's virtual machine monitor has traditionally used segmentation to provide isolation between the guest operating system and the virtual machine monitor. This is necessary because the guest operating system and virtual machine monitor share the linear address space.

AMD

Segmentation support is missing from the initial AMD64 processors (that is, revision C and earlier) while running in long mode. As a result, AMD64 processors prior to revision D do not have an efficient mechanism for isolating the virtual machine monitor from 64-bit guest operating systems.

A limited form of segmentation was reintroduced in long mode, in revision D AMD64 processors. As a result, AMD64 processors must be revision D or later to run 64-bit guest operating systems.

Note: Because AMD Opteron and Turion processors do not ship in revision D, AMD Opteron and Turion 64 processors must be revision E or later to run 64-bit guest operating systems.

Intel

Intel CPUs require EM64T and VT support in the chip and in the BIOS.

Intel EM64T CPUs do not have segmentation support in long mode. If the Intel EM64T CPU is VT-capable, it comes with hardware virtualization support (Intel's Vanderpool Technology). This hardware virtualization support allows Workstation and VMware Server to work around the lack of segmentation, making it possible to run 64-bit guest operating systems on Intel EM64T VT-capable CPUs.

Note: Firmware/BIOS support is required to enable Intel Virtualization Technology. Some systems (particularly laptops) do not have the necessary firmware/BIOS support to enable Intel Virtualization Technology, and cannot run 64-bit guest operating systems.