Introduction

The Linux Kernel Virtual Machine (KVM) is a hypervisor that allows multiple virtual machines to run on a single Linux host machine. KVM is an open-source technology that is integrated into the Linux kernel and supports various hardware platforms, including x86, ARM, and PowerPC.

In this article, we will discuss the key features and benefits of KVM, how it works, and how to install and configure KVM on a Linux machine.

Features and Benefits

KVM offers several key features and benefits, including:

Performance

KVM uses hardware virtualization support built into modern CPUs to achieve near-native performance. This means that virtual machines running on KVM can achieve similar performance to running on bare metal hardware.

Security

KVM uses a combination of hardware-enforced isolation and software-based access controls to ensure that virtual machines are isolated from each other and from the host machine. KVM also supports virtual Trusted Platform Modules (TPMs) that can be used to secure virtual machines.

Scalability

KVM can support a large number of virtual machines on a single host machine. This makes it an ideal solution for organizations that need to run multiple virtual machines on a single physical machine.

Open-source

KVM is an open-source technology that is integrated into the Linux kernel. This means that it is freely available and can be customized to meet specific needs.

Interoperability

KVM supports a wide range of operating systems, including Linux, Windows, and various UNIX variants. This makes it an ideal choice for organizations that need to run multiple operating systems on a single host machine.

How KVM Works

KVM uses hardware virtualization support built into modern CPUs to create and manage virtual machines. KVM consists of a kernel module that provides the core virtualization functionality and a userspace component that provides management tools and interfaces.

When a virtual machine is started, KVM creates a new process in userspace that runs the virtual machine. KVM then allocates memory and CPU resources to the virtual machine and begins running the guest operating system.

KVM provides a range of management tools and interfaces, including command-line tools and graphical user interfaces. These tools allow administrators to create, manage, and monitor virtual machines on the host machine.

Installing and Configuring KVM

To install and configure KVM on a Linux machine, follow these steps:

  1. Check hardware virtualization support: Before installing KVM, ensure that your CPU supports hardware virtualization. You can check this by running the egrep -c ‘(svm|vmx)’ /proc/cpuinfo command. If the output is greater than zero, your CPU supports hardware virtualization.

  2. Install KVM packages: Install the KVM packages using the package manager of your Linux distribution. On Ubuntu, you can install KVM by running the sudo apt install qemu-kvm libvirt-daemon-system libvirt-clients bridge-utils command.

  3. Configure networking: Configure networking for the virtual machines by creating a bridge interface. You can create a bridge interface using the brctl command or by using the network configuration tool of your Linux distribution.

  4. Create virtual machines: Create virtual machines using the virt-install command or a graphical user interface such as virt-manager.

  5. Manage virtual machines: Manage virtual machines using the virsh command or a graphical user interface such as virt-manager.

Conclusion

KVM is a powerful virtualization solution that provides high performance, flexibility, and scalability. With its hardware-assisted virtualization capabilities, KVM allows multiple operating systems to run simultaneously on a single host machine, making it a popular choice for data centers, cloud computing environments, and other virtualization use cases. If you’re looking for a virtualization solution for your Linux environment, KVM is definitely worth considering.