Kernel-based Virtual Machine (KVM) is a Linux kernel virtualization infrastructure. KVM is a full virtualization solution for Linux on x86 hardware containing virtualization extensions Intel VT (vmx) or AMD-V (svm). It consists of a loadable kernel module, kvm.ko, that provides the core virtualization infrastructure and a processor specific module, kvm-intel.ko or kvm-amd.ko. KVM also requires a modified QEMU although work is underway to get the required changes upstream.
KVM is a free opensource virtualization software and is included in Linux Kernel version 2.6.20 and above. Using KVM, one can run multiple virtual machines running unmodified Linux or Windows images. Each virtual machine has private virtualized hardware: a network card, disk, graphics adapter, etc.