Cloud Hypervisor: What is it, Use Cases, and Set Up 

Cloud Hypervisor is a fast, open-source Type 1 hypervisor built for the cloud. It runs lean, works with the Linux kernel, and uses Rust-VMM for smooth, secure virtualization.

This guide covers the tech behind Cloud Hypervisor, how to install it, where it shines, and how it stacks up against KVM and Proxmox.

Table of Contents

1. What is a Cloud Hypervisor?
2. Core Technology
3. Common Cloud Hypervisor Use Cases
4. Installation and Set Up for Cloud Hypervisor
5. How Does Cloud Hypervisor Compare to Other Hypervisors?
6. Final Words
7. FAQs

1. What is Cloud Hypervisor?

Cloud Hypervisor is a free, open-source tool that helps manage virtual machines (VMs) for cloud tasks—thus the name. It’s built to be fast, secure, and lightweight, making it perfect for today’s cloud needs. It was written in Rust, a safe and speedy programming language.

It works on two popular systems: KVM for Linux and Microsoft Hypervisor (MSHV) for Windows. This makes it flexible for different setups. It supports 64-bit systems like x86-64 and AArch64, and it can handle both Linux and Windows as guest operating systems.

What makes Cloud Hypervisor stand out? It skips old, clunky device emulation. Instead, it keeps things simple, efficient, and secure. This makes it a top pick for modern cloud workloads—no extra baggage, just smooth performance.

Key Features:

• Rust-vmm Integration: Cloud Hypervisor was built using Rust-vmm crates. These crates let you reuse handy components like KVM wrappers, Virtio devices, and kernel loaders.
• Linux Kernel Compatibility: It runs on KVM using the /dev/kvm API. You’ll need Linux kernel 5.13 or newer. This keeps things running smoothly and ensures top-notch performance.
• Efficient Memory Management: This is a perfect feature if you require more memory on the fly. Cloud Hypervisor supports memory hotplug for dynamic resizing with minimal overhead. Plus, it handles CPU, PCI, and device hotplug for flexible resource tweaking.
• Optimized Design: It’s fast, lightweight, and secure. The design focuses on low latency and a small memory footprint (fewer ways for attackers to sneak in). It uses modern, paravirtualized I/O devices like Virtio to keep things speedy.
• Cloud Workload Optimization: Built for cloud providers. It keeps resource usage lean and mean. The idea is that it skips complicated hardware abstractions like PCI or ISA bus trees to stay simple and efficient.
• Advanced Security: Thanks to Rust’s memory safety, Cloud Hypervisor cuts down on vulnerabilities like buffer overflows. It also uses para-virtualized devices to shrink the attack surface and avoids emulating old, clunky hardware.
• Snapshot Support: You can save and restore VM states in a snap (memory, device configs, etc.) This makes recovery, live migration, and scaling up or down easier.
• Device and PCIe Passthrough: Cloud Hypervisor lets you assign host devices components like GPUs and NICs directly to VMs using VFIO and PCIe passthrough. Perfect for heavy I/O workloads and for having that near-native performance.

Community and Governance:

Cloud Hypervisor is governed by the Linux Foundation and supported by leading organizations like Intel, Microsoft, Alibaba, AMD, and Tencent Cloud. Community resources include:

• GitHub Repository for source code, roadmap, and bug reports. It also hosts development discussions.
• The Cloud Hypervisor website provides an overview, documentation, and community resources.
• Quick Start Guide: For initial setup and usage. Check the documentation section.

2. Core Technology

Rust-VMM Library

Rust-vmm is an open-source library for building lightweight ‘custom’ Virtual Machine Monitors (VMMs) in Rust. It provides modular, reusable parts—like KVM bindings, Virtio devices, and a kernel loader. Big names like Amazon, Google, Intel, and Red Hat contribute to it.

Each part is a separate crate (a Rust package). Developers can grab only what they need. This helps keep things slim, fast, and secure. By sharing these core tools, Rust-vmm makes it easier to build custom, high-performance VMMs for any use case.

Powering Cloud Hypervisor

Cloud Hypervisor taps into Rust-vmm to create a secure, lightweight, and high-speed virtualization solution for the cloud. Here's how it works:

• Rust-vmm Integration – Cloud Hypervisor uses KVM wrappers, Virtio devices, and kernel loaders to simplify VMM development.
• Tight Linux Kernel Integration – Runs on KVM and Microsoft Hypervisor (MSHV), managing hardware via /dev/kvm.
• Smart Memory Management – Supports memory hotplug, letting VMs scale without wasting resources. It also skips old-school emulation (like ISA or PCI buses) for better performance.
• Optimized Device Models – Uses Virtio devices for I/O, skipping clunky legacy emulation. Features like device hotplug and vDPA (Virtio Data Path Acceleration) boost speed and make migration easier.

3. Common Coud Hypervisor Use Cases

Cloud Hypervisor is a next-gen hypervisor (running on Rust-VMM for speed and security), powered by Intel & Microsoft. It’s a lightweight, modern alternative to QEMU. It was built for today’s cloud needs. It keeps memory use low, supports device passthrough, and offers snapshots for fast recovery.

The goal? High performance with low-security risk.

Cloud hypervisors can be considered as the backbone of cloud systems. They blend virtualization with cloud power, making them perfect for virtual desktops, AI, gaming, and high-performance computing. This hypervisor gives you the flexibility and power to handle any workload (from tiny home labs to huge cloud networks)

So, what are the top 10 use cases?

1. Cloud Computing and Virtualization: Power cloud infrastructure by enabling virtualization. As any good hypervisor, it separates physical hardware from virtual resources like CPU, memory, and storage. Its design makes it perfect for managing cloud-native workloads.
2. Running Secure, Containerized Workloads: Isolate containerized applications in lightweight VMs for enhanced security. This is ideal for Kubernetes integrations like Kata Containers or KubeVirt.
3. Virtual Desktop Infrastructure (VDI): Deliver virtual desktops to users, replacing physical hardware with (isolated) virtualized environments for remote work or centralized management.
4. Development and Testing Environments: Create isolated, reproducible environments for developers to test software across different operating systems without needing multiple physical machines.
5. Disaster Recovery and Snapshots: Enable quick recovery through VM snapshots and backups. It helps capture the VM’s state for easy restoration in case of failures.
6. Server Consolidation: Run multiple VMs on fewer physical machines. In this case, Cloud Hypervisor helps reduce hardware costs, energy consumption, and maintenance overhead.
7. High-Performance Computing (HPC): Support resource-intensive workloads like AI, machine learning, or scientific computing in secure, virtualized environments.
8. Specialized Workloads (AI, Gaming, Data-Intensive Tasks): Optimized for high-performance tasks requiring direct hardware access (e.g., GPU passthrough) or low-latency operations.
9. Efficient Resource Optimization: Maximize hardware utilization by running multiple operating systems on a single host. This helps reduce waste and saving costs.
10. Small Deployments and Homelabs: Provide a lightweight, easy-to-manage alternative to larger platforms like Proxmox or OpenStack. This makes Cloud Hypervisor perfect for small-scale setups or personal labs.

4. Installation and Set Up for Cloud Hypervisor

Before you can run Cloud Hypervisor, you need to set up your system. This section will walk you through everything—system requirements, installation options, and testing your setup.

Let's get Cloud Hypervisor installed!

System Requirements

• Hardware Requirements
  • Architecture: x86-64 (Intel VT-x / AMD-V), AArch64 (ARM64 with GICv3).
  • Memory: Minimum 1GB RAM (supports hot-plugging for scaling).
  • Storage: Requires disk images in raw format (can be converted from qcow2 using qemu-img).
  • Networking: TAP networking requires CAP_NET_ADMIN permissions.
• Host OS Requirements
  • Linux Kernel: Minimum: 4.11 (for KVM functionality). Recommended: 5.6+ (for optimal performance).
  • Supported Host OS: Linux distributions with appropriate kernel versions. Or Microsoft Hypervisor (MSHV) as an alternative to KVM for Windows.
• Software Dependencies
  • Pre-built Binaries: cloud-hypervisor-static (x86-64).cloud-hypervisor-static-aarch64 (AArch64).
  • Building from Source: Requires Rust toolchain and Rust VMM crates.
  • Firmware Support: Rust Hypervisor Firmware or edk2 UEFI firmware.
  • Disk Image Management: qemu-img for image conversion (qcow2 → raw).

Cloud Hypervisor Installation

Option 1: Use Pre-built Binaries

• Visit the Releases page: Look in Cloud Hypervisor Releases for the latest stable release and make sure cloud-hypervisor-static is included in Assets.
• Download the binary: wget https://github.com/cloud-hypervisor/cloud-hypervisor/releases/download/v43.0/cloud-hypervisor-static
• Make the binary executable:
  • chmod +x cloud-hypervisor-static

• Optional: Move the Binary to Your PATH: To make it easier to use, move it to /usr/local/bin:
  • sudo mv cloud-hypervisor-static /usr/local/bin/cloud-hypervisor
• Verify Installation: Check if the installation was successful:
  • cloud-hypervisor –version

Option 2: From Source

• Install Rust and Cargo:
  • curl –proto ‘=https' –tlsv1.2 -sSf https://sh.rustup.rs | sh

• Verify that Rust and Cargo are installed:
  • You can look for the output: Rust is installed now. Great!
  • Or, you can also verify the installation and check the version by running:
  • rustc –version
  • cargo –version

• Clone the repository:
  • git clone https://github.com/cloud-hypervisor/cloud-hypervisor.git
  • cd cloud-hypervisor
  • cargo build –release
• The binary will be located at target/release/cloud-hypervisor.

• Additional Requirements: 
  • Firmware: Download compatible firmware such as Rust Hypervisor Firmware or EDK2:
  • https://github.com/cloud-hypervisor/rust-hypervisor-firmware/releases/download//hypervisor-fw
  • Replace in the URL with the desired firmware version. For example, if the version is 0.4.0, run:
  • Change the permissions to make the downloaded file executable: chmod +x hypervisor-fw

Configuration and Testing

• Prepare a Disk Image: Download and convert a cloud-ready OS image (e.g., Ubuntu):
  • Wget https://cloud-images.ubuntu.com/focal/current/focal-server-cloudimg-amd64.img
  • qemu-img convert -p -f qcow2 -O raw
    /home/user/focal-server-cloudimg-amd64.img
    /home/user/focal-server-cloudimg-amd64.raw

• Booting a Guest VM: Example command for starting a VM:
  ./cloud-hypervisor \
  –kernel ./hypervisor-fw \
  –disk path=focal-server-cloudimg-amd64.raw \
  –cpus boot=4 \
  –memory size=1024M \
  –net “tap=,mac=,ip=,mask=”
• An example of net: “tap=tap0,mac=52:54:00:12:34:56,ip=192.168.1.100,mask=255.255.255.0” –
• Testing the Setup:
  • Verify successful VM boot by checking the console output or connecting to the guest using SSH.
  • Use snapshot features to save and restore VM states to ensure functionality.

5. How does a Cloud Hypervisor compare to Other Hypervisors?

Most hypervisors, like KVM or Proxmox, handle all kinds of virtual machines. Cloud Hypervisor is different. It's built specifically for cloud-native workloads.

Cloud Hypervisor is secure, fast, and flexible. One, Rust’s memory safety reduces risks. Two, Linux kernel components boost speed. Three, device passthrough supports hardware access. And the best part? Rust-VMM keeps it modular.

Want to see how it stacks up against Proxmox, KVM, or QEMU? Check out the comparison table below.

Cloud Hypervisor vs. Other Hypervisors

Summary:

• Cloud Hypervisor: Lightweight, secure, and cloud-focused.
• Proxmox VE: Enterprise-friendly with GUI.
• KVM: Minimal and powerful for custom setups.
• QEMU: Best for emulation and testing.

6. Final Words

Cloud Hypervisor represents the future of cloud-native virtualization. Thanks to the combination of Rust’s security and Linux’s efficiency, Cloud hypervisor can deliver a lightweight, high-performance solution.

Need to scale apps, deploy at the edge, or lock down security? Cloud Hypervisor delivers the speed and control to keep everything running smoothly.

So, are you ready to get started? Visit the official GitHub repository to explore documentation, contribute to the project, or download the latest release.

Cloud Hypervisor FAQs