https://en.wikipedia.org/wiki/Hypervisor#Classification says QEMU is type 2 hypervisor, and KVM can be both type 1 and 2 hypervisor:
The distinction between these two types is not always clear. For instance, Linux's Kernel-based Virtual Machine (KVM) and FreeBSD's bhyve are kernel modules that effectively convert the host operating system to a type-1 hypervisor. At the same time, since Linux distributions and FreeBSD are still general-purpose operating systems, with applications competing with each other for VM resources, KVM and bhyve can also be categorized as type-2 hypervisors.
How is "Linux distributions and FreeBSD are still general-purpose operating systems, with applications competing with each other for VM resources" the reason for KVM to be a type 2 hypervisor?
By itself, KVM does not perform any emulation. Instead, it exposes the /dev/kvm interface, which a userspace host can then use to:
- Set up the guest VM's address space. The host must also supply a firmware image (usually a custom BIOS when emulating PCs) that the guest can use to bootstrap into its main OS.
- Feed the guest simulated I/O.
- Map the guest's video display back onto the system host.
On Linux, QEMU versions 0.10.1 and later is one such userspace host. QEMU uses KVM when available to virtualize guests at near-native speeds, but otherwise falls back to software-only emulation.
If "KVM does not perform any emulation", can KVM be a hypervisor
A hypervisor or virtual machine monitor (VMM) is computer software, firmware or hardware that creates and runs virtual machines.
Can KVM work as a hypervisor without another hypervisor like QEMU?
Can libvirt also work directly with KVM, without QEMU?