Intel’s VT-x technology and the secrets of virtualization

Quoting from Intel DevX Software Network:

There’s a problem with virtualization. It’s not a huge problem, but it’s an impediment, in my opinion, to some large-scale deployments of virtualization technology across the enterprise data center. The problem is that the venerable x86 architecture wasn’t designed for virtualization. Operating systems have complete control over the processor and the hardware; they understand the full instruction set, and can exercise every mode, use every interrupt, access every page of memory. That makes it hard for a virtual machine monitor (VMM) to exercise supervision over operating systems running in virtual machines, often called guest operating systems.

If the guest OS is trying to access physical memory, physical devices, or invoke specific interrupts, a software-based VMM is largely powerless to stop it. If there are multiple guest operating systems running in different virtual machines, the VMM has to work really hard to trick those guest operating systems into playing nicely with each other, and not stomping all over each other’s resources. These workarounds waste CPU cycles, lowering overall efficiency. They’re also not always perfect.

In this article, we’re going to talk about what I see as the biggest challenge facing virtualization, which is the ring privilege problem. VT-x neatly solves this problem…

Read the whole article at source.

Thanks to VMTN Blog for the news.