Vista Tutorial - Why is Hardware Assisted Virtualisation now mandatory?

Hey there,

I'm just wondering why Hardware Assisted Virtualisation is now mandatory? I
mean tbh, whether it was enabled or disabled in Virtual PC 2007 I didn't
notice any difference in performance.

Also isn't it a little ironic, a virtualisation technology that's meant to
cut down the cost of requiring the physical hardware, when actually allot of
us are going to have to upgrade just so we can make use of the latest
releases. Wouldn't it have been good if it was an option just like it's
always been? I've got 2 computers that can't run Virtual PC Beta and one of
them is brand spanking new! lol!

Nick.

nak wrote:Maybe VPC 2007 didn't use the new technology at all, even if it was
enabled in the BIOS on the physical computer.
Yes, it is stupid. Microsoft does not (officially at least) make any
money from the sale of hardware upgrades (although they often use the
sale of a new PC as an opportunity to sell another copy of Windows at
the discounted OEM price).

Technically, the deepest core function in any VPC product is the
"hypervisor" which is responsible for making the Virtual machine think
it owns its own CPU, even though it really doesn't. This hypervisor
needs to be implemented differently (and in a more difficult way) on a
CPU without enabled hardware VT, than when much of the work can be done
by the VT feature of the CPU.

So if Microsoft was starting from scratch with no older VPC product to
upgrade, implementing VPC to run only with hardware VT would be the
easiest/cheapest solution. But Microsoft is not starting from scratch,
they have a functioning hypervisor for non-VT machines, which they could
continue to maintain, with higher level code in VPC automatically
loading either the VT or the non-VT hypervisor depending on machine
capabilities.

Note that large amounts of "auxiliary" code such as .vhd support, device
simulation, virtual BIOS, user interface, VPC additions etc. etc. could
be shared by the two hypervisor implementations, keeping the total cost
down and allowing VPC images to be shared amongst different physical
machines. It would also allow VPCs with saved state to survive a change
in the VT BIOS setting on the Host PC.

--
Jakob Bøhm, M.Sc.Eng. * jb@xxxxxx * direct tel:+45-45-90-25-33
Netop Solutions A/S * Bregnerodvej 127 * DK-3460 Birkerod * DENMARK
http://www.netop.com * tel:+45-45-90-25-25 * fax:+45-45-90-25-26
Information in this mail is hasty, not binding and may not be right.
Information in this posting may not be the official position of Netop
Solutions A/S, only the personal opinions of the author.

On May 27, 6:06*am, "nak" <a...@xxxxxx> wrote:It's only mandatory in the version of VPC for Windows 7. It remains to
be seen if MS will release a complete new version of VPC with the
option to enable/disable VT.

I think they will because for full compatibility with old programs you
cannot just have VT you need actual full emulation (which no Connectix/
VPC/Vmware product has ever done) or dynamic recompilation.

It's mandatory in VPC for Windows 7 because they wanted to make sure
that the people running it had the hardware to run it and had a good
experience running software inside of it. The people using these
programs wouldn't have any idea of what Virtual PC is so they didn't
want them to have a reason to complain about performance.


If you have a computer that is not capable of running VPC Beta then
that is your fault. You should have done the proper research on your
motherboard/processor.

Hi Ronald,
Well one product I was thinking of was Hyper-V on Windows Server 2008. I'm
mainly moaning because I purchased a small server, with the similar
performance to my desktop PC hoping that I would be able to mess about with
the SoftGrid capabilities and virtualise Visual Studio, which I was also
hoping would streamline my work process.

Unfortunately I can't even install it lol! More fool me for not checking
the capabilities of my system first, but still the question is worth asking.
I wouldn't even mind a "slower" implementation of the technologies just so I
can have a play with it and see how it effects my work.
Well tbh, my experience of the Beta of VPC for Windows 7 has been pretty
poor so far. It's dreadfully slow on my laptop that has the Hardware
Virtualsation option. The same VM on my desktop without Hardware
Virtualsation on Virtual PC 2007 is much faster. Then again it is a beta of
course so I can only hope that they do make it an optional feature because I
would like to continue to use VMs for developing in.

I'm sure people running Virtualised software would have some kind of an idea
of what's happening, and if not they would still need the hardware to be
able to do so. How many companies will upgrade every employees laptop to
Hardware Virtualisation standards to support this product? It's going to
cost a fortune.

I guess the thing here is that I don't use VM features for legacy apps, I
just do it so I can create a consistent development environment, and
technically it's the developers that are being sh*t on here. Then again we
always are! lol!

Nick.

Hi Jakob,
Well you certainly have allot of knowledge on the subject, and
understand what's going on under the hood. So it seems that technically
Microsoft are doing this abandon legacy code? Rather than just optimising it
and bringing it up to new standards, same old same old.

This is a big shame and I don't see how big companies will be able to
adobt this technology without performing the upgrade. And durning a
worldwide recession this is extremely blinkered of Microsoft.
Well I just hope one of the devs/pms might take these points on board
and reconsider their architechture. Not meaning they abandon what they have
done, just bring the legacy stuff back even stronger than it was before,
knowing Microsoft I very much doubt the code was immaculate as it was.

*fingers crossed*

Nick.

while one the reasons you are needing Virtualization support is because less needs to be done by the program to run the vm....

Virtualization support makes it possible to be able to run more "native commands" on the processor and not have to make the software do more work...

i believe they are just testing this feature in the new VPC as most of the people running XPM mode are the people running 64 bit processors that are not able to run 16 bit process in a 64 bit system (and those cryptic applications that just refuse to run because of the author for what ever reason did not support it)

i said most not all so while they will eventually support non AMD-v or Intel-VTx processors (when it goes the software suite goes "gold") or any that are motherboards that are "locked" in a sense and not be able to bring Virtualization Support on to the OS or software...

and remember this is a beta not even a RC of the product...

On 5ÔÂ27ÈÕ, ÏÂÎç6ʱ06·Ö, "nak" <a...@xxxxxx> wrote:I experiented somewhat different with the Hardware Virtualization.
The Windows XP running more smooth and speedy when it is turned on but
Windows 98 in the opposite.And some OS can only be installed with it
is turned on (For example the Blue Bottle OS) but some OS can only be
installed with it is turned off (Windows 95/ WindowsNT3.1).

"Jakob Bohm" wrote:
Jakob,

The best site for all the up to date news on the product is found at the
Windows 7 support forum, at micorsoft.com/springboard. The site will also
give you all sorts of useful information, such as the “what’s new in the
r.c.� feed….or you can also you use talkingaboutwindows.com as an additional
resource
Thanks,

Glen@xxxxxx-springboard

Another advantage of using Virtual XP is the ability to use hardware through
the USB such as a scanner when there are no 64 bit drivers but there are 32
bit drivers. I can use my old scanner that has 32 bit drivers only while I
am running Windows 7 x64.

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