You seem to be laboring under some serious misapprehensions here. QEMU is very much a virtualization solution. It calls itself an emulator because it's older than the name 'virtualization.' KVM is merely the kernel infrastructure that enables ring-0 access for faster hardware access. For many years it was called qemu-kmod; to this day the actual process that you run is called 'kvm-qemu.'
You are overstating the difference between 'virtualization' and 'emulation.' There really isn't one. What used to be called 'emulation' is nowadays called 'full-virtualization' as opposed to 'paravirtualization.' QEMU, KVM, and XenKVM are full-virt, while traditional Xen is paravirt.
KVM is not a hypervisor; libvirt is. Xen blurs the line between virtualization platform and hypervisor because both pieces ship within the same project. Either libvirt or Xen can act as hypervisor for QEMU or KVM.
QEMU's lack of hard-dependency on a specific gui is in fact its strength, not its weakness. This makes it much easier to modularize and deploy at scale, which is what OpenStack does, for instance. Every QEMU VM is capable of listening on a given port for VNC connections, which means you don't even particularly need a GUI for basic use. More featureful guis can be found in the libvirt project (e.g. virt-manager).
QEMU is not particularly fast at cross-architecture stuff because that was not its original focus. However, it was one of the first packages available for linux that even made that possible at all, which is why it is still known for this functionality.
You are overstating the difference between 'virtualization' and 'emulation.' There really isn't one. What used to be called 'emulation' is nowadays called 'full-virtualization' as opposed to 'paravirtualization.' QEMU, KVM, and XenKVM are full-virt, while traditional Xen is paravirt.
KVM is not a hypervisor; libvirt is. Xen blurs the line between virtualization platform and hypervisor because both pieces ship within the same project. Either libvirt or Xen can act as hypervisor for QEMU or KVM.
QEMU's lack of hard-dependency on a specific gui is in fact its strength, not its weakness. This makes it much easier to modularize and deploy at scale, which is what OpenStack does, for instance. Every QEMU VM is capable of listening on a given port for VNC connections, which means you don't even particularly need a GUI for basic use. More featureful guis can be found in the libvirt project (e.g. virt-manager).
QEMU is not particularly fast at cross-architecture stuff because that was not its original focus. However, it was one of the first packages available for linux that even made that possible at all, which is why it is still known for this functionality.