openstack/nova
Code Issues Proposed changes
nova/doc/source/admin/hw-emulation-architecture.rst
Jonathan Race 31ff7ce7e2 driver/secheduler/docs for Adds Pick guest CPU architecture based on 
host arch in libvirt driver support

This is split 2 of 3 for the architecture emulation feature.

This implements emulated multi-architecture support through qemu
within OpenStack Nova.

Additional config variable check to pull host architecture into
hw_architecture field for emulation checks to be made.

Adds a custom function that simply performs a check for
hw_emulation_architecture field being set, allowing for core code to
function as normal while enabling a simple check to enable emulated
architectures to follow the same path as all multi-arch support
already established for physical nodes but instead levaraging qemu
which allows for the overall emulation.

Added check for domain xml unit test to strip arch from the os tag,
as it is not required uefi checks, and only leveraged for emulation
checks.

Added additional test cases test_driver validating emulation
functionality with checking hw_emulation_architecture against the
os_arch/hw_architecture field. Added required os-traits and settings
for scheduler request_filter.

Added RISCV64 to architecture enum for better support in driver.

Implements: blueprint pick-guest-arch-based-on-host-arch-in-libvirt-driver
Closes-Bug: 1863728
Change-Id: Ia070a29186c6123cf51e1b17373c2dc69676ae7c
Signed-off-by: Jonathan Race <jrace@augusta.edu>
2022-02-24 12:25:59 -05:00

4.2 KiB
Raw Blame History

hw_emulation_architecture - Configuring QEMU instance emulation architecture

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