QEMU 2.1.0 RC2, a generic open source emulator and virtualizer that can run OSes and programs made for a different machine, has been released and is available for download.
QEMU supports virtualization when executing under the Xen hypervisor or using the KVM kernel module in Linux. It's not the only software that is able to pull this off, but it's one of the best.
According to the changelog, the TCE entry permission has been fixed, the use of huge pages has been enabled, the RMA memory region registration code has been moved, the number of threads per core limit has been corrected, a laio resource leak has been closed, PC PCI endianness glitches have been fixed, the memory regions are now removed from BAR before destroying them, a bypass error action and I/O accounting on invalid r/w have been fixed, a new compiler error that occurred with -Wclobbered has been fixed, and incorrect KVM T&E references have been removed.
Remember that this is a development version and it should NOT be installed on production machines. It is intended for testing purposes only.