Tag Archives: open source

Celebrating 15 Years of the Xen Project and Our Future

In the 1990s, Xen was a part of a research project to build a public computing infrastructure on the Internet led by Ian Pratt and Keir Fraser at The University of Cambridge Computer Laboratory. The Xen Project is now one of the most popular open source hypervisors and amasses more than 10 million users, and this October marks our 15th anniversary.

From its beginnings, Xen technology focused on building a modular and flexible architecture, a high degree of customizability, and security. This security mindset from the outset led to inclusion of non-core security technologies, which eventually allowed the Xen Project to excel outside of the data center and be a trusted source for security and embedded vendors (ex. Qubes, Bromium, Bitdefender, Star Labs, Zentific, Dornerworks, Bosch, BAE systems), and also
a leading hypervisor contender for the automotive space.

As the Xen Project looks to a future of virtualization everywhere, we reflect back on some of our major achievements over the last 15 years. To celebrate, we’ve created an infographic that captures some of our key milestones share it on social.

A few community members also weighed in on some of their favorite Xen Project moments and what’s to come:

“Xen offers best-in-class isolation and separation while preserving nearly bare-metal performance on x86 and ARM platforms. The growing market for a secure hypervisor ensures Xen will continue to grow in multiple markets to meet users demands.”
– Doug Goldstein, Software Developer V, Hypervisors at Rackspace

“Xen started life at the University of Cambridge Computer Laboratory, as part of the XenoServers research project to build a public computing infrastructure on the Internet. It’s been fantastic to see the impact of Xen, and the role it’s played at the heart of what we now call Infrastructure as a Service Cloud Computing. It’s been an incredible journey from Xen’s early beginnings in the University, to making our first open source release in 2003, to building a strong community of contributors around the project, and then Xen’s growth beyond server virtualization into end-user systems and now embedded devices. Xen is a great example of the power of open source to enable cooperation and drive technological progress.”
– Ian Pratt, Founder and President at Bromium, and Xen Project Founder

“From its beginnings as a research project, able to run just a handful of Linux VMs, through being the foundation of many of the world’s largest clouds, to being the open-source hypervisor of choice for many next-generation industrial, automotive and aeronautical applications, Xen Project has shown its adaptability, flexibility and pioneering spirit for 15 years. Today, at Citrix, Xen remains the core of our Citrix Hypervisor platform, powering the secure delivery of applications and data to organizations across the globe. Xen Project Hypervisor allows our customers to run thousands of virtual desktops per server, many of them using Xen’s ground-breaking GPU virtualization capabilities. Happy birthday, Xen!”
– James Bulpin, Senior Director of Technology at Citrix

“The Xen open source community is a vibrant and diverse platform for collaboration, something which is important to Arm and vital to the ongoing success of our ecosystem. We’ve contributed to the Xen open source hypervisor across a range of markets starting with mobile, moving into the strategic enablement that allowed the deployment of Arm-based cloud servers, and more recently focusing on the embedded space, exploring computing in safety-sensitive environments such as connected vehicles.”
– Mark Hambleton, Vice President of Open Source Software, Arm

“I – like many others – associate cloud computing with Xen. All my cloud-related projects are tied to companies running large deployments of Xen. These days even my weekend binge-watching needs are satisfied by a Xen instance somewhere. With Xen making its way into cars, rocket launch operations and satellites, it’s safe to say the industry at large recognizes it as a solid foundation for building the future, and I’m excited to be a part of it.”
– Mihai Dontu, Chief Linux Officer at Bitdefender

“Xen was the first open source hypervisor for the data center, the very foundation of the cloud as we know it. Later, it pioneered virtualization for embedded and IoT, making its way into set-top boxes and smaller ARM devices. Now, we are discussing automotive, medical and industrial devices. It is incredibly exciting to be part of a ground-breaking project that has been at the forefront of open source innovation since its inception.”
– Stefano Stabellini, Principal Engineer, Tech Lead at Xilinx and Xen on ARM Committer and Maintainer

“Congratulations to the Xen Project on this milestone anniversary. As the first open source data center hypervisor, Xen played a key role in defining what virtualization technology could deliver and has been the foundation for many advancements in the modern data center and cloud computing. Intel has been involved with Xen development since the early days and enjoys strong collaboration with the Xen community, which helped make Xen the first hypervisor to include Intel® Virtualization Technology (VT-x) support, providing a more secure, efficient platform for server workload consolidation and the growth of cloud computing.”
– Susie Li, Director of Open Source Virtualization Engineering, Intel Corp.

“It is amazing how a project that started 15 years ago has not lost any of its original appeal, despite the constant evolution of hardware architectures and new applications that were unimaginable when the Xen Project started. In certain segments, e.g. power management, the pace of innovation in Xen is just accelerating and serves as the ultimate reference for all other virtualization efforts. Happy quinceañera (sweet 15) Xen!”
– Vojin Zivojnovic, CEO and Co-Founder of Aggios

Building the Journey Towards the Next 15 Years; Sneak Peek into Xen Project 4.12
The next Xen Project release is set for March 2019. The release continues to support the Xen Project’s efforts around security with cloud environments and rich features and architectural changes for automotive and embedded use cases. Expect:

  • Deprivileged Device Model: Under tech preview in QEMU 3.0, the feature adds extra restrictions to a device model running in domain 0 in order to prevent a compromised device model to attack the rest of the system.  
  • Capability to compile a PV-only version of Xen giving cloud providers simplified management, reducing the surface of attack, and the ability to build a Xen Project hypervisor configuration with no “classic” PV support at all.
  • Xen to boot multiple domains in parallel on Arm, in addition to dom0 enabling booting of domains in less than 1 second. This is the first step towards a dom0-less Xen, which impacts statically configured embedded systems that require very fast boot times.  
  • Reduction of codesize to 46 KSLOC for safety certification and the first phase of making the codebase MISRA C compliant.
    • MISRA C is a set of software development guidelines for the C programming language developed by the Motor Industry Software Reliability Association with the aim to facilitate code safety, security, portability, and reliability in the context of embedded systems.

Thank you for the last 15 years and for the next 15+ to come!
Lars Kurth, Chairperson of the Xen Project

P.S. If you want more insight on why Xen has been so successful, check out this recent talk from Open Source Summit Europe!


Xen 3.3 a Finalist for 2009 CODIE Awards from SIIA

Congrats to the Xen Community as the Xen 3.3 release was named a finalist in the 2009 CODIE awards in the Best Open Source Solution Category.

A second round of judging will begin on March 16. Approximately 400+ SIIA members will begin voting on the finalists and are allowed one vote per company in each category. Following, SIIA members will cast ballots online during the CODiE Finalist Showcase on May 4 and winners will be announced on May 5 at the CODiE Awards gala.

The complete list of categories and finalists is here. The press release on the finalists being announced is here.

Xen Document Project Update

For those of you curious about the Xen Document project, you can see the latest at http://wiki.xensource.com/xenwiki/Xen3.xDocumentUpdateProject. All documentation requests are posted on the site along with people who are working on the updates and status of those changes. Please contact me if you have any questions.

As an update on the Xen 3.3 User Guide, I have a new version posted with all the cosmetic changes complete. The next set of changes are requested on the Wiki page.

Xen 3.3 Feature – C & P State Power Management

One of the notable features of Xen 3.3 is to incorporate full support for processor power management features, C-states and P-states. Power management is getting more crucial not only for clients, but also for servers. C/P is from ACPI nomenclature which stand for different set of power/thermal technologies. Combining both, Xen 3.3 is now expected to achieve far better performance per watt.

The Xen 3.3 idle governor can support full line of C-states with great power reduction, especially for idle power consumption. The idle governor is triggered when the CPU is fully idle, and then the governor chooses the appropriate low power state based on the power budget and latency tolerance accordingly. The deeper C-state is, less power is consumed with longer entry/exit latency. The previous Xen releases only supported C1, as triggered by the HLT instruction.

The Xen 3.3 on-demand governor monitors CPU utilization in small intervals and dynamically chooses a suitable operation point with lower power and negligible performance impacts. P-states are set of operation points about CPU frequency/voltage, which can help reach optimal performance at the lowest power even when the system is in load line. Unlike C-states, P-state transitions can be triggered at fine-grained level, upon fast-changing workload characteristics. CPU vendors provide smart hardware level enhancements  to ensure fast on-demand frequency/voltage change, like Intel’s Enhanced Intel SpeedStep@ and AMD’s PowerNow!@.

Xen 3.3 Press Release

The official Xen.org Press Release announcing Xen 3.3 has been posted here. There are many partner quotes in the release from Oracle, Novell, Intel, AMD, Sun, IBM, Fujitsu, Samsung, Neocleus, Citrix, SignaCert, etc and I encourage everyone in the community to take a look. I just got a Google News email with the word “Xen” in the search and there are a lot of public news groups promoting the release (e.g. MarketWatch,  Sys-Con, OStatic, Redmond Developer News, etc).

Congrats again on the great community effort in getting this release out to the world…

Xen 3.3 Feature: Optimized HVM Video Memory Tracking

From Samuel Thibault:

When having a look at how much CPU time is used when an HVM guest is idle, one can notice that the ioemu process used to permanently take something like 7%. This is because ioemu used to keep checking the content of the HVM video RAM for modifications, because setting up a trap on each guest video write would slow guest video operations awfully down.  In Xen 3.3, ioemu requests the hypervisor to track video memory modification.  The hypervisor can do it more efficiently since it has access to the dirty bit that the processor automatically sets in the page table flags on write accesses to pages.  As a result, instead of regularly comparing 8MB of video memory, ioemu just makes a hypercall to read the list of dirty pages.  As an additional optimization, if no modification has occurred for two seconds, the entire video memory write access is dropped until the guest writes to video memory again, hence saving the page table walk itself.

The result is that the CPU time goes down around 0.3%!