What are the benefits of using Virtualization instructions?

Jack · Joined: 09 Oct 2007 Posts: 8

The Intel Platform provides something called virtualization instructions,
what are the benefits of using these instructions?
Some even said that these things are essential for running VM... I am not
quite convinced yet.
And you?
Thanks
Jack

Archived from group: microsoft>public>virtualpc

Colin Barnhorst · Joined: 06 Jan 2008 Posts: 210

A vm will run without hardware virtualization support but then it requires
software support to run the virtual machine's kernel mode code. With
hardware virtualization support that overhead is not required since the
virtual machine's kernel mode code can run directly on the processor. Ben
Armstrong blogged about this at
http://blogs.msdn.com/virtual_pc_guy/archive/2006/05/01/587992.aspx. This
is now a couple of years old but germane to your question.

"Jack" wrote in message @TK2MSFTNGP04.phx.gbl...
> The Intel Platform provides something called virtualization instructions,
> what are the benefits of using these instructions?
> Some even said that these things are essential for running VM... I am not
> quite convinced yet.
> And you?
> Thanks
> Jack
>

Steve Jain · Joined: 22 Aug 2007 Posts: 835

On Sun, 24 Feb 2008 13:23:58 +0800, "Jack" wrote:

>The Intel Platform provides something called virtualization instructions,
>what are the benefits of using these instructions?
>Some even said that these things are essential for running VM... I am not
>quite convinced yet.
>And you?
>Thanks
>Jack
>

Depends. If the OS has VM Tools or VM Additions for it, there's not
much of a benefit, since these will offset the hardware
virtualization. If not, like say a *nix OS on VPC, the benefits will
be significant.

--
Cheers,
Steve Jain, Virtual Machine MVP
http://vpc.essjae.com/
I do not work for Microsoft.