hw_emulation_architecture - Configuring QEMU instance emulation architecture

New in version 25.0.0: (Yoga)

The libvirt driver now allows for handling of specific cpu architectures when defined within the image metadata properties, to be emulated through QEMU.

Added hw_emulation_architecture as an available image_meta property.

Note

The following only applies to environments using libvirt compute hosts. and should be considered experimental in its entirety, during its first release as a feature.

Introduction

This capability is to fill a need with environments that do not have the capability to support the various cpu architectures that are present today with physical hardware. A small subset of architectures that are supported both within libvirt and QEMU have been selected as prime candidates for emulation support.

While support has been added for the below base architectures, this does not guarantee that every subset or custom operating system that leverages one of these architectures will function.

Configure

QEMU Binary Support

To ensure that libvirt and QEMU can properly handle the level of cpu emulation desired by the end-user, you are required to install the specific qemu-system-XXX, qemu-efi-arm, qemu-efi-aarch64 binaries on the compute nodes that will be providing support.

Console Support

Consideration need to be made in regards to which architectures you want to support, as there are limitations on support through spice, novnc, and serial. All testing and validation has been done to ensure that spice and serial connections function as expected.

  • AARCH64 - Spice & Serial

  • S390X - Serial

  • PPC64LE - Spice & Serial

  • MIPSEL - untested

Supported Emulated Architectures

The supported emulated architectures require specific image meta properties to be set in order to trigger the proper settings to be configured by libvirtd.

For end users the emulation architecture of an instance is controlled by the selection of an image with the hw_emulation_architecture image metadata property set.

AARCH64

Tested and Validated as functional

$ openstack image set --property hw_emulation_architecture=aarch64 $IMAGE
$ openstack image set --property hw_machine_type=virt $IMAGE
$ openstack image set --property hw_firmware_type=uefi $IMAGE

S390x

Tested and Validated as functional

$ openstack image set --property hw_emulation_architecture=s390x $IMAGE
$ openstack image set --property hw_machine_type=s390-ccw-virtio $IMAGE
$ openstack image set --property hw_video_model=virtio $IMAGE

PPC64LE

Tested and Validated as functional

$ openstack image set --property hw_emulation_architecture=ppc64le $IMAGE
$ openstack image set --property hw_machine_type=pseries $IMAGE

MIPSEL

Testing and validation is ongoing to overcome PCI issues

Note

Support is currently impacted, one current method for support is manually patching and compiling as defined in libvirt bug XML error: No PCI buses available.

$ openstack image set --property hw_emulation_architecture=mipsel $IMAGE
$ openstack image set --property hw_machine_type=virt $IMAGE