bento/ubuntu-22.04 libvirt CPU host-passthrough fails

[ryan-ronnander]

Version

bento/ubuntu-22.04 (libvirt, 202502.21.0, (amd64))

Environment

OS: openSUSE Tumbleweed x86_64
Kernel: 6.18.2-1-default
Vagrant 2.4.9
vagrant-libvirt 0.12.2

Scenario

Cannot bring up a box with host-passthrough CPU option. However, bento/ubuntu-24.04 works as expected, bento/ubuntu-22.04 does not.

Steps to Reproduce

Set `libvirt..cpu_mode = 'host-passthrough' for the libirt provider section:

# Libvirt Provider specifics
node.vm.provider "libvirt" do |l|
  l.cpu_mode = 'host-passthrough'  # enable nested virtualization
  end
end

Expected Result

Expect a booted VM ready for nested virtualization.

Actual Result

Boot fails with

Call to virDomainCreate failed: unsupported configuration: CPU mode 'host-passthrough' for x86_64 qemu domain on x86_64 host is not supported by hypervisor (Libvirt::Error)

Likely related to #1581, as boot fails without CPU mode 'host-passthrough' as well.