base on A Virtual Machine Monitor for modern Cloud workloads. Features include CPU, memory and device hotplug, support for running Windows and Linux guests, device offload with vhost-user and a minimal compact footprint. Written in Rust with a strong focus on security. - [1. What is Cloud Hypervisor?](#1-what-is-cloud-hypervisor) - [Objectives](#objectives) - [High Level](#high-level) - [Architectures](#architectures) - [Guest OS](#guest-os) - [2. Getting Started](#2-getting-started) - [Host OS](#host-os) - [Use Pre-built Binaries](#use-pre-built-binaries) - [Packages](#packages) - [Building from Source](#building-from-source) - [Booting Linux](#booting-linux) - [Firmware Booting](#firmware-booting) - [Custom Kernel and Disk Image](#custom-kernel-and-disk-image) - [Building your Kernel](#building-your-kernel) - [Disk image](#disk-image) - [Booting the guest VM](#booting-the-guest-vm) - [3. Status](#3-status) - [Hot Plug](#hot-plug) - [Device Model](#device-model) - [Roadmap](#roadmap) - [4. Relationship with _Rust VMM_ Project](#4-relationship-with-rust-vmm-project) - [Differences with Firecracker and crosvm](#differences-with-firecracker-and-crosvm) - [5. Community](#5-community) - [Contribute](#contribute) - [Slack](#slack) - [Mailing list](#mailing-list) - [Security issues](#security-issues) # 1. What is Cloud Hypervisor? Cloud Hypervisor is an open source Virtual Machine Monitor (VMM) that runs on top of the [KVM](https://www.kernel.org/doc/Documentation/virtual/kvm/api.txt) hypervisor and the Microsoft Hypervisor (MSHV). The project focuses on running modern, _Cloud Workloads_, on specific, common, hardware architectures. In this case _Cloud Workloads_ refers to those that are run by customers inside a Cloud Service Provider. This means modern operating systems with most I/O handled by paravirtualised devices (e.g. _virtio_), no requirement for legacy devices, and 64-bit CPUs. Cloud Hypervisor is implemented in [Rust](https://www.rust-lang.org/) and is based on the [Rust VMM](https://github.com/rust-vmm) crates. ## Objectives ### High Level - Runs on KVM or MSHV - Minimal emulation - Low latency - Low memory footprint - Low complexity - High performance - Small attack surface - 64-bit support only - CPU, memory, PCI hotplug - Machine to machine migration ### Architectures Cloud Hypervisor supports the `x86-64` and `AArch64` architectures. There are minor differences in functionality between the two architectures (see [#1125](https://github.com/cloud-hypervisor/cloud-hypervisor/issues/1125)). ### Guest OS Cloud Hypervisor supports `64-bit Linux` and Windows 10/Windows Server 2019. # 2. Getting Started The following sections describe how to build and run Cloud Hypervisor. ## Prerequisites for AArch64 - AArch64 servers (recommended) or development boards equipped with the GICv3 interrupt controller. ## Host OS For required KVM functionality and adequate performance the recommended host kernel version is 5.13. The majority of the CI currently tests with kernel version 5.15. ## Use Pre-built Binaries The recommended approach to getting started with Cloud Hypervisor is by using a pre-built binary. Binaries are available for the [latest release](https://github.com/cloud-hypervisor/cloud-hypervisor/releases/latest). Use `cloud-hypervisor-static` for `x86-64` or `cloud-hypervisor-static-aarch64` for `AArch64` platform. ## Packages For convenience, packages are also available targeting some popular Linux distributions. This is thanks to the [Open Build Service](https://build.opensuse.org). The [OBS README](https://github.com/cloud-hypervisor/obs-packaging) explains how to enable the repository in a supported Linux distribution and install Cloud Hypervisor and accompanying packages. Please report any packaging issues in the [obs-packaging](https://github.com/cloud-hypervisor/obs-packaging) repository. ## Building from Source Please see the [instructions for building from source](docs/building.md) if you do not wish to use the pre-built binaries. ## Booting Linux Cloud Hypervisor supports direct kernel boot (the x86-64 kernel requires the kernel built with PVH support or a bzImage) or booting via a firmware (either [Rust Hypervisor Firmware](https://github.com/cloud-hypervisor/rust-hypervisor-firmware) or an edk2 UEFI firmware called `CLOUDHV` / `CLOUDHV_EFI`.) Binary builds of the firmware files are available for the latest release of [Rust Hypervisor Firmware](https://github.com/cloud-hypervisor/rust-hypervisor-firmware/releases/latest) and [our edk2 repository](https://github.com/cloud-hypervisor/edk2/releases/latest) The choice of firmware depends on your guest OS choice; some experimentation may be required. ### Firmware Booting Cloud Hypervisor supports booting disk images containing all needed components to run cloud workloads, a.k.a. cloud images. The following sample commands will download an Ubuntu Cloud image, converting it into a format that Cloud Hypervisor can use and a firmware to boot the image with. ```shell $ wget https://cloud-images.ubuntu.com/focal/current/focal-server-cloudimg-amd64.img $ qemu-img convert -p -f qcow2 -O raw focal-server-cloudimg-amd64.img focal-server-cloudimg-amd64.raw $ wget https://github.com/cloud-hypervisor/rust-hypervisor-firmware/releases/download/0.4.2/hypervisor-fw ``` The Ubuntu cloud images do not ship with a default password so it necessary to use a `cloud-init` disk image to customise the image on the first boot. A basic `cloud-init` image is generated by this [script](scripts/create-cloud-init.sh). This seeds the image with a default username/password of `cloud/cloud123`. It is only necessary to add this disk image on the first boot. Script also assigns default IP address using `test_data/cloud-init/ubuntu/local/network-config` details with `--net "mac=12:34:56:78:90:ab,tap="` option. Then the matching mac address interface will be enabled as per `network-config` details. ```shell $ sudo setcap cap_net_admin+ep ./cloud-hypervisor $ ./create-cloud-init.sh $ ./cloud-hypervisor \ --kernel ./hypervisor-fw \ --disk path=focal-server-cloudimg-amd64.raw path=/tmp/ubuntu-cloudinit.img \ --cpus boot=4 \ --memory size=1024M \ --net "tap=,mac=,ip=,mask=" ``` If access to the firmware messages or interaction with the boot loader (e.g. GRUB) is required then it necessary to switch to the serial console instead of `virtio-console`. ```shell $ ./cloud-hypervisor \ --kernel ./hypervisor-fw \ --disk path=focal-server-cloudimg-amd64.raw path=/tmp/ubuntu-cloudinit.img \ --cpus boot=4 \ --memory size=1024M \ --net "tap=,mac=,ip=,mask=" \ --serial tty \ --console off ``` ### Custom Kernel and Disk Image #### Building your Kernel Cloud Hypervisor also supports direct kernel boot. For x86-64, a `vmlinux` ELF kernel (compiled with PVH support) or a regular bzImage are supported. In order to support development there is a custom branch; however provided the required options are enabled any recent kernel will suffice. To build the kernel: ```shell # Clone the Cloud Hypervisor Linux branch $ git clone --depth 1 https://github.com/cloud-hypervisor/linux.git -b ch-6.2 linux-cloud-hypervisor $ pushd linux-cloud-hypervisor # Use the x86-64 cloud-hypervisor kernel config to build your kernel for x86-64 $ wget https://raw.githubusercontent.com/cloud-hypervisor/cloud-hypervisor/main/resources/linux-config-x86_64 # Use the AArch64 cloud-hypervisor kernel config to build your kernel for AArch64 $ wget https://raw.githubusercontent.com/cloud-hypervisor/cloud-hypervisor/main/resources/linux-config-aarch64 $ cp linux-config-x86_64 .config # x86-64 $ cp linux-config-aarch64 .config # AArch64 # Do native build of the x86-64 kernel $ KCFLAGS="-Wa,-mx86-used-note=no" make bzImage -j `nproc` # Do native build of the AArch64 kernel $ make -j `nproc` $ popd ``` For x86-64, the `vmlinux` kernel image will then be located at `linux-cloud-hypervisor/arch/x86/boot/compressed/vmlinux.bin`. For AArch64, the `Image` kernel image will then be located at `linux-cloud-hypervisor/arch/arm64/boot/Image`. #### Disk image For the disk image the same Ubuntu image as before can be used. This contains an `ext4` root filesystem. ```shell $ wget https://cloud-images.ubuntu.com/focal/current/focal-server-cloudimg-amd64.img # x86-64 $ wget https://cloud-images.ubuntu.com/focal/current/focal-server-cloudimg-arm64.img # AArch64 $ qemu-img convert -p -f qcow2 -O raw focal-server-cloudimg-amd64.img focal-server-cloudimg-amd64.raw # x86-64 $ qemu-img convert -p -f qcow2 -O raw focal-server-cloudimg-arm64.img focal-server-cloudimg-arm64.raw # AArch64 ``` #### Booting the guest VM These sample commands boot the disk image using the custom kernel whilst also supplying the desired kernel command line. - x86-64 ```shell $ sudo setcap cap_net_admin+ep ./cloud-hypervisor $ ./create-cloud-init.sh $ ./cloud-hypervisor \ --kernel ./linux-cloud-hypervisor/arch/x86/boot/compressed/vmlinux.bin \ --disk path=focal-server-cloudimg-amd64.raw path=/tmp/ubuntu-cloudinit.img \ --cmdline "console=hvc0 root=/dev/vda1 rw" \ --cpus boot=4 \ --memory size=1024M \ --net "tap=,mac=,ip=,mask=" ``` - AArch64 ```shell $ sudo setcap cap_net_admin+ep ./cloud-hypervisor $ ./create-cloud-init.sh $ ./cloud-hypervisor \ --kernel ./linux-cloud-hypervisor/arch/arm64/boot/Image \ --disk path=focal-server-cloudimg-arm64.raw path=/tmp/ubuntu-cloudinit.img \ --cmdline "console=hvc0 root=/dev/vda1 rw" \ --cpus boot=4 \ --memory size=1024M \ --net "tap=,mac=,ip=,mask=" ``` If earlier kernel messages are required the serial console should be used instead of `virtio-console`. - x86-64 ```shell $ ./cloud-hypervisor \ --kernel ./linux-cloud-hypervisor/arch/x86/boot/compressed/vmlinux.bin \ --console off \ --serial tty \ --disk path=focal-server-cloudimg-amd64.raw \ --cmdline "console=ttyS0 root=/dev/vda1 rw" \ --cpus boot=4 \ --memory size=1024M \ --net "tap=,mac=,ip=,mask=" ``` - AArch64 ```shell $ ./cloud-hypervisor \ --kernel ./linux-cloud-hypervisor/arch/arm64/boot/Image \ --console off \ --serial tty \ --disk path=focal-server-cloudimg-arm64.raw \ --cmdline "console=ttyAMA0 root=/dev/vda1 rw" \ --cpus boot=4 \ --memory size=1024M \ --net "tap=,mac=,ip=,mask=" ``` # 3. Status Cloud Hypervisor is under active development. The following stability guarantees are currently made: * The API (including command line options) will not be removed or changed in a breaking way without a minimum of 2 major releases notice. Where possible warnings will be given about the use of deprecated functionality and the deprecations will be documented in the release notes. * Point releases will be made between individual releases where there are substantial bug fixes or security issues that need to be fixed. These point releases will only include bug fixes. Currently the following items are **not** guaranteed across updates: * Snapshot/restore is not supported across different versions * Live migration is not supported across different versions * The following features are considered experimental and may change substantially between releases: TDX, vfio-user, vDPA. Further details can be found in the [release documentation](docs/releases.md). As of 2023-01-03, the following cloud images are supported: - [Ubuntu Focal](https://cloud-images.ubuntu.com/focal/current/) (focal-server-cloudimg-{amd64,arm64}.img) - [Ubuntu Jammy](https://cloud-images.ubuntu.com/jammy/current/) (jammy-server-cloudimg-{amd64,arm64}.img ) - [Fedora 36](https://fedora.mirrorservice.org/fedora/linux/releases/36/Cloud/) ([Fedora-Cloud-Base-36-1.5.x86_64.raw.xz](https://fedora.mirrorservice.org/fedora/linux/releases/36/Cloud/x86_64/images/) / [Fedora-Cloud-Base-36-1.5.aarch64.raw.xz](https://fedora.mirrorservice.org/fedora/linux/releases/36/Cloud/aarch64/images/)) Direct kernel boot to userspace should work with a rootfs from most distributions although you may need to enable exotic filesystem types in the reference kernel configuration (e.g. XFS or btrfs.) ## Hot Plug Cloud Hypervisor supports hotplug of CPUs, passthrough devices (VFIO), `virtio-{net,block,pmem,fs,vsock}` and memory resizing. This [document](docs/hotplug.md) details how to add devices to a running VM. ## Device Model Details of the device model can be found in this [documentation](docs/device_model.md). ## Roadmap The project roadmap is tracked through a [GitHub project](https://github.com/orgs/cloud-hypervisor/projects/6). # 4. Relationship with _Rust VMM_ Project In order to satisfy the design goal of having a high-performance, security-focused hypervisor the decision was made to use the [Rust](https://www.rust-lang.org/) programming language. The language's strong focus on memory and thread safety makes it an ideal candidate for implementing VMMs. Instead of implementing the VMM components from scratch, Cloud Hypervisor is importing the [Rust VMM](https://github.com/rust-vmm) crates, and sharing code and architecture together with other VMMs like e.g. Amazon's [Firecracker](https://firecracker-microvm.github.io/) and Google's [crosvm](https://chromium.googlesource.com/chromiumos/platform/crosvm/). Cloud Hypervisor embraces the _Rust VMM_ project's goals, which is to be able to share and re-use as many virtualization crates as possible. ## Differences with Firecracker and crosvm A large part of the Cloud Hypervisor code is based on either the Firecracker or the crosvm project's implementations. Both of these are VMMs written in Rust with a focus on safety and security, like Cloud Hypervisor. The goal of the Cloud Hypervisor project differs from the aforementioned projects in that it aims to be a general purpose VMM for _Cloud Workloads_ and not limited to container/serverless or client workloads. The Cloud Hypervisor community thanks the communities of both the Firecracker and crosvm projects for their excellent work. # 5. Community The Cloud Hypervisor project follows the governance, and community guidelines described in the [Community](https://github.com/cloud-hypervisor/community) repository. ## Contribute The project strongly believes in building a global, diverse and collaborative community around the Cloud Hypervisor project. Anyone who is interested in [contributing](CONTRIBUTING.md) to the project is welcome to participate. Contributing to a open source project like Cloud Hypervisor covers a lot more than just sending code. Testing, documentation, pull request reviews, bug reports, feature requests, project improvement suggestions, etc, are all equal and welcome means of contribution. See the [CONTRIBUTING](CONTRIBUTING.md) document for more details. ## Slack Get an [invite to our Slack channel](https://join.slack.com/t/cloud-hypervisor/shared_invite/enQtNjY3MTE3MDkwNDQ4LWQ1MTA1ZDVmODkwMWQ1MTRhYzk4ZGNlN2UwNTI3ZmFlODU0OTcwOWZjMTkwZDExYWE3YjFmNzgzY2FmNDAyMjI), [join us on Slack](https://cloud-hypervisor.slack.com/), and [participate in our community activities](https://cloud-hypervisor.slack.com/archives/C04R5DUQVBN). ## Mailing list Please report bugs using the [GitHub issue tracker](https://github.com/cloud-hypervisor/cloud-hypervisor/issues) but for broader community discussions you may use our [mailing list](https://lists.cloudhypervisor.org/g/dev/). ## Security issues Please contact the maintainers listed in the MAINTAINERS.md file with security issues. ", Assign "at most 3 tags" to the expected json: {"id":"2252","tags":[]} "only from the tags list I provide: [{"id":77,"name":"3d"},{"id":89,"name":"agent"},{"id":17,"name":"ai"},{"id":54,"name":"algorithm"},{"id":24,"name":"api"},{"id":44,"name":"authentication"},{"id":3,"name":"aws"},{"id":27,"name":"backend"},{"id":60,"name":"benchmark"},{"id":72,"name":"best-practices"},{"id":39,"name":"bitcoin"},{"id":37,"name":"blockchain"},{"id":1,"name":"blog"},{"id":45,"name":"bundler"},{"id":58,"name":"cache"},{"id":21,"name":"chat"},{"id":49,"name":"cicd"},{"id":4,"name":"cli"},{"id":64,"name":"cloud-native"},{"id":48,"name":"cms"},{"id":61,"name":"compiler"},{"id":68,"name":"containerization"},{"id":92,"name":"crm"},{"id":34,"name":"data"},{"id":47,"name":"database"},{"id":8,"name":"declarative-gui "},{"id":9,"name":"deploy-tool"},{"id":53,"name":"desktop-app"},{"id":6,"name":"dev-exp-lib"},{"id":59,"name":"dev-tool"},{"id":13,"name":"ecommerce"},{"id":26,"name":"editor"},{"id":66,"name":"emulator"},{"id":62,"name":"filesystem"},{"id":80,"name":"finance"},{"id":15,"name":"firmware"},{"id":73,"name":"for-fun"},{"id":2,"name":"framework"},{"id":11,"name":"frontend"},{"id":22,"name":"game"},{"id":81,"name":"game-engine "},{"id":23,"name":"graphql"},{"id":84,"name":"gui"},{"id":91,"name":"http"},{"id":5,"name":"http-client"},{"id":51,"name":"iac"},{"id":30,"name":"ide"},{"id":78,"name":"iot"},{"id":40,"name":"json"},{"id":83,"name":"julian"},{"id":38,"name":"k8s"},{"id":31,"name":"language"},{"id":10,"name":"learning-resource"},{"id":33,"name":"lib"},{"id":41,"name":"linter"},{"id":28,"name":"lms"},{"id":16,"name":"logging"},{"id":76,"name":"low-code"},{"id":90,"name":"message-queue"},{"id":42,"name":"mobile-app"},{"id":18,"name":"monitoring"},{"id":36,"name":"networking"},{"id":7,"name":"node-version"},{"id":55,"name":"nosql"},{"id":57,"name":"observability"},{"id":46,"name":"orm"},{"id":52,"name":"os"},{"id":14,"name":"parser"},{"id":74,"name":"react"},{"id":82,"name":"real-time"},{"id":56,"name":"robot"},{"id":65,"name":"runtime"},{"id":32,"name":"sdk"},{"id":71,"name":"search"},{"id":63,"name":"secrets"},{"id":25,"name":"security"},{"id":85,"name":"server"},{"id":86,"name":"serverless"},{"id":70,"name":"storage"},{"id":75,"name":"system-design"},{"id":79,"name":"terminal"},{"id":29,"name":"testing"},{"id":12,"name":"ui"},{"id":50,"name":"ux"},{"id":88,"name":"video"},{"id":20,"name":"web-app"},{"id":35,"name":"web-server"},{"id":43,"name":"webassembly"},{"id":69,"name":"workflow"},{"id":87,"name":"yaml"}]" returns me the "expected json"