[Bug]: virtual fact not working on Linux on Proxmox

[matejzero]

Is this a critical security issue?

• This is not a security issue.

Describe the Bug

When using Linux on Proxmox hosts, facter reports VMs as physical.

Example for the manufacture under proxmoxr: QEMU

# facter dmi
{
  bios => {
    release_date => "04/01/2014",
    vendor => "SeaBIOS",
    version => "rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org"
  },
  chassis => {
    type => "Other"
  },
  manufacturer => "QEMU",
  product => {
    name => "Standard PC (i440FX + PIIX, 1996)",
    uuid => "4806f36a-e9dc-4cb7-a107-4945edb2733d",
    version => "pc-i440fx-10.1"
  }
}

Similar issues on Windows in BSD:

• #128 windows virtual fact support for proxmox/qemu #129
• Detect QEMU and Yandex hypervisors to yield correct {is_,}virtual facts #62

Expected Behavior

Linux on Proxmox should return virtual = kvm

Steps to Reproduce

Use proxmox / kvm as a hypervisor
use linux as your guest OS
fact returns physical

Environment

Facter: 5.6.1
OS: AlmaLinux 10
Proxmox: 9.1.1

Additional Context

I can try and make a PR, but I'm no ruby guy so I might need some guidance.

I check the code really quick. Should manufacturer check be done in

openfact/lib/facter/facts/linux/hypervisors/kvm.rb

Lines 37 to 47 in c617902

	def kvm?
	product_name = discover_hypervisor
	bios_vendor = Facter::Resolvers::Linux::DmiBios.resolve(:bios_vendor)
	@log.debug("Detected bios vendor: #{bios_vendor}")
	Facter::Resolvers::VirtWhat.resolve(:vm) == 'kvm' ||
	Facter::Resolvers::Lspci.resolve(:vm) == 'kvm' ||
	bios_vendor&.include?('Amazon EC2') ||
	bios_vendor&.include?('Google') ||
	product_name&.include?('OpenStack')
	end

like it is for windows version: https://github.com/Hedius/openfact/blob/8e7c3e146aba26ec0002ec9d62d69dea34e1058d/lib/facter/resolvers/windows/virtualization.rb#L52

Relevant log output

[Hedius]

I do not have that issue on Debian and RHEL/RockyLinux hmmm. not sure why you get here physical
Rocky as an example

x:~# facter dmi
{
  bios => {
    release_date => "11/13/2025",
    vendor => "Proxmox distribution of EDK II",
    version => "4.2025.05-2"
  },
  chassis => {
    type => "Other"
  },
  manufacturer => "QEMU",
  product => {
    name => "Standard PC (i440FX + PIIX, 1996)",
    uuid => "423e6748-5eee-3090-c4dc-83d765c03a35",
    version => "pc-i440fx-10.1"
  }
}
x:~# facter virtual
kvm
x:~# uname -a
Linux x 5.14.0-687.15.1.el9_8.x86_64 #1 SMP PREEMPT_DYNAMIC Thu Jun 11 16:33:25 UTC 2026 x86_64 x86_64 x86_64 GNU/Linux

[Hedius]

On Linux there are a lot of checks here. One of them should return the kvm hmmm

https://github.com/OpenVoxProject/openfact/blob/main/lib/facter/util/facts/posix/virtual_detector.rb#L9-L14

[matejzero]

I had a look at the checks and I can fix my problem with installing pciutils which then provides the correct fact. But pciutils is not installed by default (at least not on our servers which use minimal install).

I think depending on info from dmi manufacturer field would be a safer option since it's always present. bios.vendor obviously has different values as well and we can't depend on tha.

[bzed]

The fact should just use systemd-detect-virt if available.