e477ed0e86
First of all, this is a controversial piece, and I know that. In this commit we're trying to make a less greedy approach regards the amount of vCPUs we allocate for the VMM, which will be advantageous mainly when using the `static_sandbox_resource_mgmt` feature, which is used by the confidential guests. The current approach we have basically does: * Gets the amount of vCPUs set in the config (an integer) * Gets the amount of vCPUs set as limit (an integer) * Sum those up * Starts / Updates the VMM to use that total amount of vCPUs The fact we're dealing with integers is logical, as we cannot request 500m vCPUs to the VMMs. However, it leads us to, in several cases, be wasting one vCPU. Let's take the example that we know the VMM requires 500m vCPUs to be running, and the workload sets 250m vCPUs as a resource limit. In that case, we'd do: * Gets the amount of vCPUs set in the config: 1 * Gets the amount of vCPUs set as limit: ceil(0.25) * 1 + ceil(0.25) = 1 + 1 = 2 vCPUs * Starts / Updates the VMM to use 2 vCPUs With the logic changed here, what we're doing is considering everything as float till just before we start / update the VMM. So, the flow describe above would be: * Gets the amount of vCPUs set in the config: 0.5 * Gets the amount of vCPUs set as limit: 0.25 * ceil(0.5 + 0.25) = 1 vCPUs * Starts / Updates the VMM to use 1 vCPUs In the way I've written this patch we introduce zero regressions, as the default values set are still the same, and those will only be changed for the TEE use cases (although I can see firecracker, or any other user of `static_sandbox_resource_mgmt=true` taking advantage of this). There's, though, an implicit assumption in this patch that we'd need to make explicit, and that's that the default_vcpus / default_memory is the amount of vcpus / memory required by the VMM, and absolutely nothing else. Also, the amount set there should be reflected in the podOverhead for the specific runtime class. One other possible approach, which I am not that much in favour of taking as I think it's **less clear**, is that we could actually get the podOverhead amount, subtract it from the default_vcpus (treating the result as a float), then sum up what the user set as limit (as a float), and finally ceil the result. It could work, but IMHO this is **less clear**, and **less explicit** on what we're actually doing, and how the default_vcpus / default_memory should be used. Fixes: #6909 Signed-off-by: Fabiano Fidêncio <fabiano.fidencio@intel.com> Signed-off-by: Christophe de Dinechin <dinechin@redhat.com>
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-checksoption.By default, only a brief success / failure message is printed. If more details are needed, the
--verboseflag can be used to display the list of all the checks performed.If the command is run as the
rootuser additional checks are run (including checking if another incompatible hypervisor is running). When running asroot, 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. |
log-parser-rs |
utility | Tool that aid in analyzing logs from the kata runtime. |
trace-forwarder |
utility | Agent tracing helper. |
runk |
utility | Standard OCI container runtime based on the agent. |
ci |
CI | Continuous Integration configuration files and scripts. |
katacontainers.io |
Source for the katacontainers.io site. |
Packaging and releases
Kata Containers is now available natively for most distributions.
Metrics tests
See the metrics documentation.
Glossary of Terms
See the glossary of terms related to Kata Containers.