Intel CM8062101038606 Intel VT-x Features, Intel VT-d Objectives, Intel VT-d Features Supported

Technologies

3.1.2Intel VT-x Features

The processor core supports the following Intel VT-x features:

•Extended Page Tables (EPT)

—hardware assisted page table virtualization

—eliminates VM exits from guest OS to the VMM for shadow page-table maintenance

•Virtual Processor IDs (VPID)

—Ability to assign a VM ID to tag processor core hardware structures (for example, TLBs)

—This avoids flushes on VM transitions to give a lower-cost VM transition time and an overall reduction in virtualization overhead.

•Guest Preemption Timer

—Mechanism for a VMM to preempt the execution of a guest OS after an amount of time specified by the VMM. The VMM sets a timer value before entering a guest

—The feature aids VMM developers in flexibility and Quality of Service (QoS) guarantees

•Descriptor-Table Exiting

—Descriptor-table exiting allows a VMM to protect a guest OS from internal (malicious software based) attack by preventing relocation of key system data structures like IDT (interrupt descriptor table), GDT (global descriptor table), LDT (local descriptor table), and TSS (task segment selector).

—A VMM using this feature can intercept (by a VM exit) attempts to relocate these data structures and prevent them from being tampered by malicious software.

•Pause Loop Exiting (PLE)

—PLE aims to improve virtualization performance and enhance the scaling of virtual machines with multiple virtual processors

—PLE attempts to detect lock-holder preemption in a VM and helps the VMM to make better scheduling decisions

3.1.3Intel VT-d Objectives

The key Intel VT-d objectives are domain-based isolation and hardware-based virtualization. A domain can be abstractly defined as an isolated environment in a platform to which a subset of host physical memory is allocated. Virtualization allows for the creation of one or more partitions on a single system. This could be multiple partitions in the same operating system, or there can be multiple operating system instances running on the same system – offering benefits such as system consolidation, legacy migration, activity partitioning or security.

3.1.3.1Intel VT-d Features Supported

The processor supports the following Intel VT-d features:

•Root entry, context entry, and default context

•Support for 4-K page sizes only

•Support for register-based fault recording only (for single entry only) and support for MSI interrupts for faults

80	Intel® Xeon® Processor E5-1600/E5-2600/E5-4600 Product Families
	Datasheet Volume One