能否在Azure Linux VM中运行KVM VM？嵌套虚拟化技术咨询

Great question! The short answer is yes—you absolutely can run KVM virtual machines within an Azure Linux VM, but there are specific requirements and configurations you need to meet first. Here’s a breakdown of what you need to know:

Key Requirements & Setup Steps #

• Use a Compatible Azure VM Size: Not all Azure VM sizes support nested virtualization. For Linux, you’ll need to pick a size from generation 3+ series like Dv3, Ev3, Dv4, Ev4, Dv5, Ev5, or high-performance options like M-series. These sizes expose the necessary hardware virtualization extensions (Intel VT-x/AMD-V) to the guest VM, which KVM relies on.

• Enable Nested Virtualization on Your Azure VM: Before installing KVM, you have to enable nested virtualization at the Azure VM level. You can do this via Azure CLI or the Azure Portal:

  1. First, stop your VM (you can’t enable this on a running VM):

     az vm stop --resource-group your-resource-group-name --name your-vm-name
     

  2. Enable nested virtualization:

     az vm update --resource-group your-resource-group-name --name your-vm-name --set hardwareProfile.virtualMachineSizeProperties.nestedVirtualizationEnabled=true
     

  3. Start your VM back up:

     az vm start --resource-group your-resource-group-name --name your-vm-name
     

• Install & Configure KVM on the Linux Guest: Once nested virtualization is enabled, setting up KVM works just like it would on a physical Linux server. For example, on Ubuntu/Debian-based systems:

  1. Install the required packages:

     sudo apt update && sudo apt install qemu-kvm libvirt-daemon-system libvirt-clients bridge-utils
     

  2. Add your user account to the kvm and libvirt groups to avoid needing root for every KVM operation:

     sudo adduser $USER kvm && sudo adduser $USER libvirt
     

  3. Log out and back in, then verify the installation with:

     virsh list --all
     

     This should return an empty list (no VMs created yet), confirming KVM is ready to use.

Quick Notes #

• Performance Overhead: Nested virtualization adds a small performance hit, so make sure your Azure VM has enough CPU and memory allocated to support both the host OS and any nested KVM VMs you plan to run.
• Networking: For nested VMs to access the network, you’ll need to set up a bridge interface on the Azure Linux host or use NAT-based networking (the default for KVM is often NAT, but bridges are better for direct network access).

内容的提问来源于stack exchange，提问作者Daniel Plas Rivera