PiotrProkop 86ab1b22a3 runtime: Hotplug VFIO network devices before any container starts
A VFIO-backed network interface used to be hotplugged only as a side
effect of creating the workload container that references the VFIO
device in its OCI spec: setupNetworks() skipped VfioEndpoints when it
ran at sandbox start and applied their configuration later, on the
second invocation from createContainer(), guarded by the
hotplugNetworkConfigApplied flag.

Init containers run before that workload container, so they started
with the VFIO interface absent and thus without pod networking.

Attach the device at sandbox scope instead, from setupNetworks() at
sandbox start, before any container is created:

- Add Sandbox.hotplugVfioNetworkDevice(): resolve the VFIO device
  node backing the endpoint's host BDF, hotplug it and record the
  guest PCI path on the endpoint. When the workload container later
  references the same VFIO group through a device plugin, the device
  manager finds the device by major:minor and only bumps reference
  counts, so it is neither plugged twice nor unplugged when that
  container exits.

- Configure all endpoints, VfioEndpoints included, in a single
  setupNetworks() pass at sandbox start. The Container parameter, the
  second invocation from createContainer() and the
  hotplugNetworkConfigApplied flag are no longer needed.

Add unit tests for the hotplugVfioNetworkDevice() guard paths.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Signed-off-by: PiotrProkop <pprokop@nvidia.com>
2026-07-03 15:14:22 +02:00
2025-09-16 19:16:14 +02:00
2026-02-09 15:03:26 -08:00
2026-03-09 14:52:17 -05:00
2026-06-29 09:36:34 +01:00
2023-11-16 16:09:20 +00:00
2022-02-21 17:01:09 +00:00
2026-05-18 09:47:15 +01:00
2017-12-06 23:01:13 -06:00
2026-06-18 14:23:52 +01:00
2026-06-18 14:23:52 +01:00
2026-06-18 14:23:52 +01:00
2026-06-22 01:15:24 +02:00

CI | Publish Kata Containers payload Kata Containers Nightly CI OpenSSF Scorecard

Kata Containers

Welcome to Kata Containers!

This repository is the home of the Kata Containers code for the 2.0 and newer releases.

If you want to learn about Kata Containers, visit the main Kata Containers website.

Introduction

Kata Containers is an open source project and community working to build a standard implementation of lightweight Virtual Machines (VMs) that feel and perform like containers, but provide the workload isolation and security advantages of VMs.

License

The code is licensed under the Apache 2.0 license. See the license file for further details.

Platform support

Kata Containers currently runs on 64-bit systems supporting the following technologies:

Architecture Virtualization technology
x86_64, amd64 Intel VT-x, AMD SVM
aarch64 ("arm64") ARM Hyp
ppc64le IBM Power
s390x IBM Z & LinuxONE SIE

Hardware requirements

The Kata Containers runtime provides a command to determine if your host system is capable of running and creating a Kata Container:

$ kata-runtime check

Notes:

  • This command runs a number of checks including connecting to the network to determine if a newer release of Kata Containers is available on GitHub. If you do not wish this to check to run, add the --no-network-checks option.

  • By default, only a brief success / failure message is printed. If more details are needed, the --verbose flag can be used to display the list of all the checks performed.

  • If the command is run as the root user additional checks are run (including checking if another incompatible hypervisor is running). When running as root, network checks are automatically disabled.

Getting started

See the installation documentation.

Documentation

See the official documentation including:

Configuration

Kata Containers uses a single configuration file which contains a number of sections for various parts of the Kata Containers system including the runtime, the agent and the hypervisor.

Hypervisors

See the hypervisors document and the Hypervisor specific configuration details.

Community

To learn more about the project, its community and governance, see the community repository. This is the first place to go if you wish to contribute to the project.

Getting help

See the community section for ways to contact us.

Raising issues

Please raise an issue in this repository.

Note: If you are reporting a security issue, please follow the vulnerability reporting process

Developers

See the developer guide.

Components

Main components

The table below lists the core parts of the project:

Component Type Description
runtime core Main component run by a container manager and providing a containerd shimv2 runtime implementation.
runtime-rs core The Rust version runtime.
agent core Management process running inside the virtual machine / POD that sets up the container environment.
dragonball core An optional built-in VMM brings out-of-the-box Kata Containers experience with optimizations on container workloads
documentation documentation Documentation common to all components (such as design and install documentation).
tests tests Excludes unit tests which live with the main code.

Additional components

The table below lists the remaining parts of the project:

Component Type Description
packaging infrastructure Scripts and metadata for producing packaged binaries
(components, hypervisors, kernel and rootfs).
kernel kernel Linux kernel used by the hypervisor to boot the guest image. Patches are stored here.
osbuilder infrastructure Tool to create "mini O/S" rootfs and initrd images and kernel for the hypervisor.
kata-debug infrastructure Utility tool to gather Kata Containers debug information from Kubernetes clusters.
agent-ctl utility Tool that provides low-level access for testing the agent.
kata-ctl utility Tool that provides advanced commands and debug facilities.
trace-forwarder utility Agent tracing helper.
ci CI Continuous Integration configuration files and scripts.
ocp-ci CI Continuous Integration configuration for the OpenShift pipelines.
katacontainers.io Source for the katacontainers.io site.
Webhook utility Example of a simple admission controller webhook to annotate pods with the Kata runtime class

Packaging and releases

Kata Containers is now available natively for most distributions.

General tests

See the tests documentation.

Glossary of Terms

See the glossary of terms related to Kata Containers.

Languages
Rust 60.7%
Go 23.4%
Shell 9.1%
RPC 4.6%
Makefile 1%
Other 1.2%