en 4.4 was released on March 10, after 8 months of development, and was one of our most stable, most tested releases ever. This talk will go over what happened, what didn't happen, what went well and what might have gone better for the 4.4 development cycle.

1. Xen Development
and 4.4 Retrospective
George Dunlap

2. Principles of community development
• Risk of using / contributing: Project direction
• Principles for building trust
• Technical meritocracy
• All important decisions made in the open
• The more you contribute the more influence you have

3. 4.4 Development Window
• Opened July 2013
• Goal: 6 month release cycle
• Scheduled release: January 2014
• Actual release: March 2014

4. 4.4 Highlights: Core
• Testing: osstest and XenRT
• Event channel scalability
• libxl device script daemon

5. 4.4 Highlights: x86
• PVH domU support (experimental)
• Nested virtualization (tech preview)
• SPICE support for HVM guests

6. 4.4 Highlights: ARM
• Stable ABI declared
• ARM server class hardware in osstest
• Automatic device tree generation
• Many new platforms supported

7. 4.4 Highlights: Linux
• PV block: Indirect descriptors
• Improved kexec

8. 4.4 Highlights: External
• libvirt support for libxl
• pvgrub2