Use an authorized administrative account on the intended self-managed host. Confirm operating-system and processor support and arrange firmware/console access for physical hardware. Read-only checks can be run first without altering existing guests.

1. Inspect lscpu for the architecture and virtualization information. On x86, the relevant CPU capabilities are commonly Intel VT-x or AMD-V, but a displayed flag alone does not validate the whole stack.
2. Install the distribution-supported libvirt validation tooling if absent, using its official package repositories.
3. Run sudo virt-host-validate qemu and read each result. Distinguish a missing mandatory KVM capability from an optional warning unrelated to your intended guest features.
4. Check that /dev/kvm exists and is accessible to the authorized virtualization service. Inspect kernel logs if the KVM module failed to initialize.
5. If firmware virtualization is disabled, change it through the supported firmware management process during a maintenance window. For a nested host, obtain the outer provider-supported configuration instead of attempting to bypass it.
6. After correcting prerequisites, rerun validation and boot one disposable guest with hardware acceleration explicitly enabled.

On a Linux machine you are authorised to use as a virtualization host, run the installed libvirt host validator. This evaluates host prerequisites and does not create a guest or alter firmware settings. A rented VPS may not expose nested virtualization.

sudo virt-host-validate qemu
ls -l /dev/kvm

Read the result: Review each PASS, WARN or FAIL in context. A missing /dev/kvm or unavailable hardware virtualization requires checking the host platform, loaded modules and provider support. Some warnings relate to optional features rather than blocking every guest configuration.

Confirm that the service plan permits the intended virtualization role and that storage, networking and capacity are suitable. CPU flags alone do not establish a supported production hypervisor. Resolve the specific failed prerequisite before copying another host's libvirt configuration or attempting to run nested guests.

QEMU can emulate some systems without KVM, but performance and compatibility differ. Do not silently deploy an emulated production service when the plan depends on hardware-accelerated virtualization.

Confirm the test guest uses KVM acceleration and completes a normal shutdown and restart. Record the validation output and host package/kernel versions. Validate networking and storage separately before considering the host ready for production.

A permission failure can reflect the account or service context rather than unsupported hardware. Avoid making device nodes world-writable. A secure-guest or IOMMU warning may relate to optional features, while lack of KVM acceleration is fundamental for the intended KVM workload. Investigate the exact failed check rather than hiding all warnings.

• Choosing a libvirt NAT network or bridge for a virtual machine
• Creating and attaching a libvirt storage volume
• Diagnosing CPU, memory and disk contention on a KVM host
• Installing Virtualizor on a supported clean virtualization host

• libvirt: Virt Host Validate
• docs.oracle.com: Kvm Validatingthehostsystem

• libvirt virsh reference