This is the next release of OSv since the previous one 0.52.0 was crafted. Unlike previous one this release does deliver new exciting feature - it supports running OSv on new lightweight hypervisor firecracker which makes possible to boot OSv Read-Only FS image in as low as 5ms per bootchart. We hope next release will happen before end of second quarter of 2019.

Features Highlights

• Enhanced OSv to run on firecracker (for details please see here)
  • OSv can boot as vmlinux (64-bit ELF - please see loader.elf attached)
  • OSv does not require ACPI to run
  • Added support of virtio mmio devices
• Added support of both legacy and modern virtio 1.0 PCI devices (for details please see here)
• Further reduced minimal memory to run OSv to 18MB (25% reduction)
• Fixed critical bug affecting apps doing heavy floating point computations like ffmpeg (see issues #1019, #1020, #1010, #1018, #536)
• Implemented some missing syscalls to better support Golang apps
• Enhanced Python 3 app to support including modules
• Upgraded tomcat app to version 9
• Added support of graalvm apps

Specifics

• Refactored virtio layer to support legacy and modern PCI and mmio devices
• Implemented modern virtio PCI device
• Enhanced OSv to boot without ACPI present
• Enhanced OSv to discover SMP information by reading MP table if ACPI is not present
• Made OSv bootable as a vmlinux 64-bit ELF
• Added boot option to disable PCI enumeration
• Added virtio mmio implementation
• Made httpserver-api configuration file configurable
• Enhanced ELF dynamic loader to support position dependent shared libraries (Graal VM)
• Deleted “assigned virtio driver"
• Made memory allocation more efficient
  • Handles small memory allocations ( < 16 bytes) more space efficiently
  • Implemented more space-efficient early memory allocation scheme (reduced memory utilization by 6MB - see #270)

Closed issues

• #1030 - Test failure with Fedora Java 8
• #1029 - Debug build fails because tracepoint sections are discarded
• #1028 - scripts/firecracker.py doesn't pass input to OSv
• #1020 - Maybe need to reset fpu status word on context switch
• #1019 - Maybe need to reset fpu state after saving it
• #1018 - OSv crashes sporadically with page fault when transcoding video with ffmpeg
• #1017 - upload_manifest.py opens a port to the world, and always the same port
• #1011 - Make allocations < 16 bytes more space efficient
• #1010 - Memory access fault when OSv pounded by periodic /os/threads REST call
• #1006 - Missing function fcntl64
• #1004 - Handle (either support correctly, or forbid) non-fPIC shared objects
• #956 - Missing readlinkat()
• #536 - Cassandra with CLI crash with cassandra stress
• #270 - Wasted memory in early malloc()

List of contributors alphabetically

• Felix Yan (@felixonmars) - 1 patch
• Nadav Har'El (@nyh) - 8 patches
• Przemek Pikuła (@pshem) - 4 patches
• Waldemar Kozaczuk (@wkozaczuk )- 45 patches
• Geraldo Netto (@geraldo-netto) - 6 patches
• Vinícius Fraga (@viniciusmsfra) - 1 patch

Acknowledgments

We want to thank all contributors to the project. But the special thanks go to:

• Nadav Har’El for contributing and reviewing many patches and providing guidance for many others
• Waldemar Kozaczuk for contributing most patches

Artifacts

This time we are only publishing kernel artifacts and capstan packages for Python 3 and REST API httpserver.