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Using EFI mode for virtual machines

You can boot a virtual machine (VM) in Extensible Firmware Interface (EFI) mode.

About EFI mode for virtual machines

Extensible Firmware Interface (EFI), like legacy BIOS, initializes hardware components and operating system image files when a computer starts. EFI supports more modern features and customization options than BIOS, enabling faster boot times.

It stores all the information about initialization and startup in a file with a .efi extension, which is stored on a special partition called EFI System Partition (ESP). The ESP also contains the boot loader programs for the operating system that is installed on the computer.

Booting virtual machines in EFI mode

You can configure a virtual machine to boot in EFI mode by editing the VM manifest.

Prerequisites

  • Install the OpenShift CLI (oc).

Procedure

  1. Create a YAML file that defines a VM object. Use the firmware stanza of the example YAML file:

    Booting in EFI mode with secure boot active
    apiversion: kubevirt.io/v1
kind: VirtualMachine
metadata:
  labels:
    special: vm-secureboot
  name: vm-secureboot
spec:
  template:
    metadata:
      labels:
        special: vm-secureboot
    spec:
      domain:
        devices:
          disks:
          - disk:
              bus: virtio
            name: containerdisk
        features:
          acpi: {}
          smm:
            enabled: true (1)
        firmware:
          bootloader:
            efi:
              secureBoot: true (2)
#...
    1 OKD Virtualization requires System Management Mode (SMM) to be enabled for Secure Boot in EFI mode to occur.
    2 OKD Virtualization supports a VM with or without Secure Boot when using EFI mode. If Secure Boot is enabled, then EFI mode is required. However, EFI mode can be enabled without using Secure Boot.

  2. Apply the manifest to your cluster by running the following command:

    $ oc create -f <file_name>.yaml