97951a2d12
kata-containers/pulls#3771 added TDX support for Cloud Hypervisor, but two big things got overlooked while doing that. 1. virtio-fs, as of now, cannot be part of the trust boundary, so the Confidential Guest will not be using it. 2. virtio-block hotplug should be enabled in order to use virtio-block for the rootfs (used with the devmapper plugin). When trying to use cloud-hypervisor with TDX using virtio-fs, we're facing the following error on the guest kernel: ``` virtiofs virtio2: device must provide VIRTIO_F_ACCESS_PLATFORM ``` After checking and double-checking with virtiofs and cloud-hypervisor developers, it happens as confidential containers might put some limitations on the device, so it can't access all of the guests' memory and that's where this restriction seems to be coming from. Vivek mentioned that virtiofsd do not support VIRTIO_F_ACCESS_PLATFORM (aka VIRTIO_F_IOMMU_PLATFORM) yet, and that for ecrypted guests virtiofs may not be the best solution at the moment. @sboeuf put this in a very nice way: "if the virtio-fs driver doesn't support VIRTIO_F_ACCESS_PLATFORM, then the pages corresponding to the virtqueues and the buffers won't be marked as SHARED, meaning the VMM won't have access to it". Interestingly enough, it works with QEMU, and it may be due to some change done on the patched QEMU that @devimc is packaging, but we won't take the path to figure out what was the change and patch cloud-hypervisor on the same way, because of 1. Fixes: #3810 Signed-off-by: Fabiano Fidêncio <fabiano.fidencio@intel.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. |
| agent | core | Management process running inside the virtual machine / POD that sets up the container environment. |
| 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. |
agent-ctl |
utility | Tool that provides low-level access for testing the agent. |
trace-forwarder |
utility | Agent tracing helper. |
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. However, packaging scripts and metadata are still used to generate snap and GitHub releases. See the components section for further details.
Glossary of Terms
See the glossary of terms related to Kata Containers.