Datasheet

Intel
®
Xeon
®
Processor C5500/C3500 Series
February 2010 Datasheet, Volume 1
Order Number: 323103-001 307
Technologies
4.1.2 Intel
®
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 (e.g. TLBs).
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.
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 the relocation of key system
data structures like interrupt descriptor table (IDT), global descriptor table
(GDT), local descriptor table (LDT), and task segment selector (TSS).
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.
4.1.3 Intel
®
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 OS or multiple operating system instances running on the same
system, offering benefits such as system consolidation, legacy migration, activity
partitioning, or security.