nak wrote:
Quote:
> 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.
>
Maybe VPC 2007 didn't use the new technology at all, even if it was
enabled in the BIOS on the physical computer.
Quote:
> 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!
>
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.