Boot From UEFI image

The nova compute libvirt driver does not support booting from UEFI images. This is a problem because there is a slow but steady trend for OSes to move to the UEFI format and in some cases to make the UEFI format their only format. Microsoft Windows is moving in this direction and Clear Linux is already in this category. Given this, we propose enabling UEFI boot with the libvirt driver. Additionally, we propose using the well tested and battle hardened Open Virtual Machine Firmware (OVMF) as the VM firmware for x86_64.

Unified Extensible Firmware Interface (UEFI) is a standard firmware designed to replace BIOS. Booting a VM using UEFI/OVMF is supported by libvirt since version 1.2.9.

OVMF is a port of Intel’s tianocore firmware to qemu virtual machine, in other words this project enables UEFI support for Virtual Machines.

Problem description

Platform vendors have been increasingly adopting UEFI for the platform firmware over traditional BIOS. This, in part, is leading to OS vendors also shifting to support or provide UEFI images. However, as adoption of UEFI for OS images increases, it has become apparent that OpenStack through its Nova compute Libvirt driver, does not support UEFI image boot. This is problematic and needs to be resolved.

Use Cases

1. User wants to launch a VM with UEFI. In this case the user needs to be able to tell Nova everything that is needed to launch the desired VM. The only additional information that should be required is new image properties indicating which kind of firmware type will be used, uefi or bios.

Proposed change

Add missing elements when generating XML definition in libvirt driver to support OVMF firmware. Add also a new image metadata value to specify which firmware type will be used.

The following is the new metadata value.

  • ‘hw_firmware_type’: fields.EnumField()

This indicates that which kind of firmware type will be used to boot VM. This property can be set to ‘uefi’ or ‘bios’. ‘uefi’ will indicate that uefi firmware will be used. If the property is not set, ‘bios’ firmware will be used.



Data model impact


REST API impact


Security impact


Notifications impact


Other end user impact


Performance Impact


Other deployer impact

The following packages should be added to the system:

  • ovmf

Developer impact




Primary assignee: qiaowei-ren

Other contributors: Victor Morales <> Xin Xiaohui <>

Work Items

The primary work items are

  • Add the ‘hw_firmware_type’ field to the ImageMetaProps object

  • Update the libvirt guest XML configuration when the UEFI image property is present


This spec only implements uefi boot for x86_64 and arm64. And this spec will depend on the following libraries:

  • libvirt >= 1.2.9

  • OVMF from EDK2


Would need new unit tests. Without some kind of functional testing, there is a warning emitted when this is used saying it’s untested and therefore considered experimental.

Documentation Impact

Some minor additions for launching a UEFI image with Nova, note on extra config option and metadata property, Operator / installation information for the UEFI firmware. In addition, hypervisor support matrix should be also updated.




Release Name