Qemu

An OEM licence for the Fisher-Price OS (Windows) lives in the PC’s firmware as an ACPI table called MSDM, and QEMU will pass any such table to a guest without checking it. This covers what the table holds, a validator that refuses malformed tables before QEMU silently repairs their headers, storing them in the private half of the Proxmox cluster filesystem, Microsoft’s terms on moving an OEM licence, the one case they plainly allow, taking the table straight from the host when the licensed machine is the hypervisor, and why MAK, KMS, Active Directory and AVMA activation never touch the table.

A stock Proxmox VM shows Proxmox’s logo at boot, says Proxmox in its firmware vendor string and calls itself QEMU in every SMBIOS table. This replaces all of it with your product’s name: SMBIOS types 0, 1, 2, 3 and 11 with the serial number and SKU filled from the VM’s own name and size, the SeaBIOS splash and its colour trap, a branded OVMF built from Proxmox’s own tree or an option ROM driver that replaces the logo and the BGRT under Secure Boot without touching the firmware, and the web interface logo. Every change is placed so an upgrade cannot quietly undo it, and the one an upgrade can leave dangerously stale, the firmware, gets a hook that says so.

“Is Proxmox enterprise grade?” is a question about the hypervisor, and Proxmox VE does not contain one. The hypervisor is KVM — the same kernel module underneath EC2, Google Cloud, Alibaba Cloud, Nutanix AHV and OpenShift Virtualisation. What Proxmox really maintains, why the type 1 argument is aimed at the wrong line, and what the shared foundation does not buy you.

QEMU can emulate a real NVMe controller, so the guest uses its own in-box NVMe driver with no VirtIO media required. It is also unmigratable by design, invisible to Proxmox backups, and no faster than VirtIO SCSI. Here is how to add one and when it is worth it.

A virtual machine’s clock is built on an assumption virtualisation breaks: that the CPU keeps counting. Why guest time drifts on every hypervisor, what the skew actually breaks — Kerberos, TLS, Ceph, Windows — and how ptp_kvm fixes it properly on QEMU/KVM.

The two QEMU virtual chipsets are not interchangeable. Q35 provides a proper PCIe topology that passthrough, modern Windows, and the wider KVM ecosystem all depend on.