linaro connect asia 13 : citrix - xen on arm plenary session
DESCRIPTION
The Xen on ARM effort has had a short, but impressive, history. In late 2011, Citrix seeded a Xen.org community project to port Xen to ARMv7 with virtualization extensions targeting the Cortex A15 as the reference platform. In 2012, the project scope was expanded to include the ARMv8 architecture. Linux 3.7 was the first kernel release to run on Xen on ARM as Dom0 and DomU. Very soon now (Q2 2013), Xen 4.3 will fully support several different ARM platforms, including Samsung Chromebooks, Versatile Express Cortex A15 and Arndale development boards. In this talk, we will outline how virtualization enabled server consolidation and cloud computing, as well as innovative and secure solutions for both desktops and mobile devices. We will explain why Citrix saw the need for the project, and why it is highly relevant in today’s cloud-centric virtualization landscape. We will discuss the opportunities this has brought to the Xen ecosystem, and then peek into the future possibilities which Xen on ARM will enable. While Xen is best known as technology powering some of the biggest clouds in the industry, but could also be powering virtual machines on devices that fit in your pocket. The talk will also include a brief overview of the Xen on ARM architecture, including the key design principles employed. The techniques pioneered during the ARM port will allow the Xen community to remove many legacy components from the Xen code base, streamlining both the ARM and x86 implementations. We will share some data on the challenges in porting Xen to new ARM boards. Due to full reliance on Device Tree and to the minimal hardware requirements of the hypervisor, ports to new boards require surprisingly little effort. Finally, the talk will conclude by outlining the immediate roadmap for Xen on ARM.TRANSCRIPT
Mark Heath, VP Products XenServer, Citrix
Lars Kurth, Xen.org Community Manager, Citrix
Citrix is a cloud
computing
company that
enables mobile
workstyles
Gartner, 2012
m o b i l e w o r k s t y l e s & c l o u d s e r v i c e s
• Efficient resource utilization
• Faster provisioning
• Workload mobility
• Increased uptime
• Enhanced security
Mark Moerdler, Bernstein 2012
• Less Space
• Less Energy
• Reduced Cost
• Even Less Space
• Greener Datacentres
• Even Less Cost
UBS Global Investment Research, August 7, 2012, James F. Hillier.
XenServer
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• GPLv2 with DCO
• Governance similar to Linux Kernel
• Citrix is the steward of Xen.org
• 30% code developed by Citrix
• > 10M open source users
• Xen powers the largest clouds in production
HW CPUs Memory I/O
VM1
Guest OS
Applications
VM0 (or Dom0)
Dom0 Kernel
Drivers
VM2 VMn
Applications
Guest OS
Applications
Guest OS
Toolstack
Scheduler MMU Timers Interrupts Config
back PV front
• Make optimum use of the ARM SOC
• Supports 32 and 64 bit
• Small code base
• Avoid x86 “baggage”
ARM SOC
GIC
v2 GT
2 stage
MMU
I/O
Device Tree describes …
ARM Architecture Features for Virtualization
Hypervisor mode: EL2
Kernel mode: EL1
User mode: EL0
HVC
ARM SOC
GIC
v2 GT
2 stage
MMU
I/O
Device Tree describes …
ARM Architecture Features for Virtualization
Hypervisor mode: EL2
Kernel mode: EL1
User mode: EL0
HVC
Xen Hypervisor
Dom0
only
Any Xen Guest VM (including Dom0)
Kernel
User Space
HVC
I/O
PV back
PV front
I/O
• One virtualization mode
• No user space run-time on data path
• No need for Device Emulation
• Xen is easy to port
Stefano Stabellini, Linux Xen ARM Maintainer,2013
• Fully functional for ARM v7 & v8 (64bit dom0, 32bit guests)
• ARM v7: Versatile Express, Arndale & Samsung Chromebook
• ARM v8: Fast Model
• Will be released in Xen 4.3
m o b i l e w o r k s t y l e s & c l o u d s e r v i c e s
m o b i l e w o r k s t y l e s & c l o u d s e r v i c e s
• Good Technology Match
• Platform First
• Creates Opportunities …
– for Citrix
– for the Xen Community
– for the Linaro Community