®

Xen Directions

Ian Pratt

Citrix Systems and Chairman of Xen.org

1

®Outline

• A brief overview of Xen and Xen.org

• Why virtualization matters

• Xen Architecture and Roadmap

• The Xen Client Initiative

2

®The Xen Story

• Mar 1999 XenoServers HotOS paper

• Apr 2002 Xen hypervisor development starts

• Oct 2003 Xen SOSP paper

• Apr 2004 Xen 1.0 released

• Jun 2004 First Xen developer‟s summit

• Nov 2004 Xen 2.0 released

• 2004 Hardware vendors start taking Xen seriously

• 2005 RedHat, Novell, Sun and others adopt Xen

• 2006 VMware and Microsoft adopt paravirtualization

• Sep 2006 First XenEnterprise released

• May 2008 Xen embedded in Flash on HP/Dell servers3

®

Xen

Citrix, Intel, AMD, IBM, HP, Oracle,

Sun, Unisys, SGI, Samsung,

RedHat, Novell, Fujitsu, VALinux,

NTT, NEC, US DoD, NSA, many

Universities (over 60 orgs)

Xen: An Open Reference Standard

®

Xen Hypervisor

First and Best to

support new

CPU, chipset,

and Smart IO

Technologies

Pioneers of

OS “Paravirtualization”

(Hyper-V compatible)

®Unlocking Hardware Innovation

Only a hypervisor can deliver

the benefits of the new hardware

Hardware Virtualization Support

• Nested Page Tables (VT2/VMI)

• FlexPriority, FlexMigrate

• Smart NICs (e.g. VT-C/VMDq) and HBAs

Multi-core Processors

• More efficient utilization

• Hides complexity from guests

Enhanced Security

• TPM and secure boot (TXT)

• IOMMU to protect device DMA accesses

• Full Execute-Disable (NX/XD)

®Xen Tops Performance Comparisons

Keith Ward, Virtualization Review

"The Porsche of hypervisors? XenServer. Raise your hand if you saw that coming.... The pokiest? ESX.

“XenServer 5 outperforms VMware ESX 3.5 by 41% in (XenApp) user scalability tests.”

The Tolly Group

®

Xen is great. It’s powerful

and easy to use. But most

important is the very active

community around it.

That was a very big reason

for us in selecting Xen.

Xen Powers the World‟s IT Infrastructure Clouds

Werner Vogels

CTO, Amazon.com”

“

®Xen Today

• ~17% enterprise server market share (Yankee, Aug 08)

• World's largest virtualization deployments are Xen based

• Development Community: over 50 Companies,

25 Universities, from 25 Countries, ~250 developers

• More than 20,000 code submissions

• x86, IA64, ARM support

• Used in Severs, Desktops, Laptops, Storage Appliances,

Network Appliances, PDAs and Smart Phones

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®XenServer Embedded

“HP will offer the Citrix XenServer HP Select Edition as the preferred and

recommended solution for virtualization on Proliant Systems”

Scott Farrand, VP Software, HP Industry Standard Servers

• Hypervisor embedded into firmware

• Closely coupled and optimized for server h/w

• Dedicated hypervisor better able to meet the rapid h/w product cycle than a full OS, and thus best placed to fully enable new hardware features

®

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First Virtualization Benefits

• Server consolidation– Consolidate scale-out success

– Exploit multi-core CPUs

• Manageability– Secure remote console

– Reboot / power control

– Performance monitoring

• Ease of deployment– Rapid provisioning

• VM image portability– Move image between different hardware

– Disaster Recovery

®2nd Generation Virtualization Benefits

Avoid planned downtime with VM Relocation

Dynamically re-balance workload to meet app SLAs or to saver power

®2nd Generation Virtualization Benefits

Restart-HA monitors hosts and VMs to keep apps running

Hardware Fault Tolerance with deterministic replayor checkpointing

®Hypervisor Security

• Hypervisors add more s/w and thus increase the attack

surface:– Network-facing control stack

– VM containment

• True type-1 hypervisor much smaller and defensible than

an OS– Xen was designed with security as a key priority

• Principle of least privilege, layered defences approach

• Xen Security Modules developed by the US NSA

– Secure hypervisor launch using Trusted Platform Module (TPM) and

Trusted Execution Technology (TXT)

• Xen is field hardened from extensive cloud deployments

®Improving Security with Hypervisors

• Hypervisors allow administrative policy

enforcement outside the OS– Firewalls, IDS, malware scanning etc

• More robust as can not be disabled

• Provides protection within a network rather than just at borders

– Hardening OSes with immutable memory, taint tracking,

logging and replay

– Backup policy, multi-path IO, HA, FT etc

• Availability and Reliability

®Hypervisor I/O Architecture

Event Channel Virtual MMUVirtual CPU Control IF

Hardware (CPU, MMU, physical memory, Ethernet, SCSI/IDE etc)

Physical

Device

Driver

Control OS

Device

Manager &

Control s/w

VM0

Guest OS

VM1

Virtual Device Driver

Guest OS

Applications

VM2

Guest OS

Applications

VM3

Safe HW IF

Virtual Machine Monitor

Virtual Device Mux

Applications

Virtual Device Driver Device Emulation

“h/w” Device Driver

®Hardware Assisted I/O Architecture

Event Channel Virtual MMUVirtual CPU Control IF

Hardware (CPU, MMU, physical memory, Ethernet, SCSI/IDE etc)

Physical

Device

Driver

Control OS

Device

Manager &

Control s/w

VM0

Guest OS

VM1

Virtual Device Driver

Guest OS

Applications

VM2

Guest OS

Applications

VM3

Safe HW IF

Virtual Machine Monitor

Virtual Device Mux

Applications

Virtual Device Driver Device Emulation

“h/w” Device Driver

H/W Accel

DriverH/W Accel

Driver

®Network Performance

Type-0

0

5

10

15

20

25

30

35

CP

U (

%)

usercopy

kern

xen1

grantcopy

kern0

xen0basic smart

NIC

SR-IOV

NIC

native

201%

100%123% 105%

• New Smart NICs reduce CPU overhead substantially

• Care must be taken with type-2/3 NICs to ensure benefits

of VM portability and live relocation are not lost

s/w only

®

• Full featured open source virtual switch for Xen

• Isolation & resource control enables hypervisor multi-tenancy

• Supports key network control plane protocols

• Full visibility into and reporting of traffic via

• Netflow

• SPAN / RSPAN

• Enhanced security through

• Replication of traffic to external IDS

• Per VM firewall & policies that migrate with the VM on live relocation

• High performance

New Distributed Virtual Switch for Xen

VMVM

VMVM

Hypervisor

®

Distributed Virtual Switch for XenServer

VMVM

VMVM

Hypervisor

VMVM

VMVM

Hypervisor

VMVM

VMVM

Hypervisor

DVS

Controller

• External DVS Controller manages per-VM and per-overlay state

• Offers enhanced security and visibility, centralized logging

• Provides a single config & management view of a distributed virtual edge switch

• Per VM firewall policies migrate with VM

• Implemented as a virtual appliance with per-flow time scale control over each host switch

®The Xen.org Xen Client Initiative

• Formed in October 2007 to develop Xen for desktops and laptop

– Develop true „bare metal‟ type-1 Hypervisor, plus interim type-2 Virtual

Machine Monitor

• Develop enhanced power management, USB, WiFi, WWAN, 3D

Graphics, fingerprint reader, multitouch etc

• Support for Intel® vPro™ technologies: TXT w/TPM, VT-d, AMT

• Tiny footprint hypervisor, Embeddable in Flash memory, or

Disk/SSD

• Citrix and Intel spearhead the Xen Client Initiative

• Aiming to make virtualization ubiquitous on client devices...

®Client Hypervisor Benefits

• Security, Manageability, Supportability, Auditability

• Building Multi-Level Secure systems– Run multiple VMs with policy controlled information flow

• E.g. Personal VM; Corporate VM; VM for web browsing; VM for banking

• Enables “out-of-band” management and policy

enforcement– Malware detection, remote access, image update, backup, VPN, etc.

• Requires a true type-1 hypervisor architecture– Trusted hypervisor provides secure isolation

®Client Virtual Machine Monitor Architectures

Type 2 VMMType 1 Hypervisor

Type-1 hypervisor

hardware

personal image corporate imageType-2 hypervisor

hardware

Personal Image

corporate image

®Type 1 vs. Type 2 Client Hypervisors

Type 1 Type 2

High Performance User Experience

No Dependency on Existing Operating

System

Low Overhead Virtualization Layer

Hardware Independence for All

Environments on the System

Fully Isolated Computing

Environments

Direct Access to Hardware

Manage All Environments as a VM

Secure Hypervisor Boot

®Intel® Trusted Execution Technology

Boots software into a known, trusted state

Isolates assigned memory partitions from other software

Closes software without exposing its data

1001010

000010111

01110100100

110011010011

Intel vPro™ Tech. Pltfm

TPM 1.2

Intel vPro™ Tech. Pltfm

TPM 1.2

Intel vPro™ Tech. Pltfm

TPM 1.2

Intel TXT

Measured Launch

Environment

Open Memory

VT-x, VT-d Isolated Memory

OS

Apps

Hardware

Unauthorized:

From 3rd party

Enabling Secure Virtualization

®

x86 Hardware

Xen Hypervisor

Control Domain

Personal VM Business VM

Audi

oGPUUSB

Disk ACPI NIC

Type 1 Client Hypervisor Architecture

TXT

TPM

®

x86 Hardware

Xen Hypervisor

Control Domain

Personal VM Business VM

Audi

oGPUUSB

Disk ACPI NIC

Hardware Isolation Operation

TXT

TPM

®

x86 Hardware

Xen Hypervisor

Control Domain

Personal VM Business VM

Audi

oUSB

Disk ACPI

GPU

NIC

Hardware Pass Through Operation

TXT

TPM

®

Laptop

Policy

BackupImages

Data Sync

Client Virtualization Possibilities

• High Performance Bare-metal Client Virtualization– Provides a High Definition User Experience

– Securely Run Multiple Hardware Independent Images

– Provide Ability to get under the client OS and manage it

• And New Way to Deliver Desktops– Use a Single Image for Initial Deployment and Ongoing Management

– Efficient Two-way Data Synchronization

– Flexible policy controls

– Integrated Encryption and Backup

®“Business” & “Personal” Environments

Business Personal

• Allows Local App Installs

• Minimal Management– Virus Scanner

– Security Patches

• No SLA– Self-Service Wipe

• Locked Down

• No Local App Installs

• Tightly Managed

• Self-Service Corporate App Installs

®

Personal

Bridge “Business” & “Personal”

Business

BusinessPersonal

®Conclusions

• Hypervisors will become ubiquitous, near zero

overhead, built in to the hardware

• Xen provides the best performance and security

• The open source community behind Xen provides

great advantages over proprietary development

• Virtualization is a really fun area to be working in!

ian.pratt@xen.org

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