Virtualization solutions allow multiple operating systems and applications to run in independent partitions all on a single computer. Using virtualization capabilities, one physical computer system can function as multiple "virtual" systems. Intel® Virtualization Technology (Intel VT) improves the performance and robustness of today's virtual machine solutions by adding hardware support for efficient virtual machines.
I've received a fair number of questions on the Intel Virtualization and Software Development Forum about VT-d -- enough to justify a few words on this note in the blogging sphere.
"VT-d" stands for "Intel Virtualization Technology for Directed I/O". The relationship between VT and VT-d is that the former is an "umbrella" term referring to all Intel virtualization technologies and the latter is a particular solution within a suite of solutions under this umbrella.
IOMMU's or Input/Output Memory Management Unit is a new entrant to the x86 world. This is something which has existed in the risc based systems for quite some time. You can get a brief introduction on the concept of what an IOMMU is all about from the
Basically an IOMMU brokers any DMA request on behalf of an IO device translating IO virtual address much the same way as the processor MMU complex performs translation of a virtual address to physical address.
This guide shows step by step instructions on how to "direct assign" Intel 85276 NIC to a virtual machine using Intel's VT-d technology. For this guide I am using the following hardware and software:
- Supermicro X8DTN+ Server with Intel Core i7 X5570 processors, American Megatrends BIOS R1.1
- VMware's ESX Server 4.0 as the hypervisor