QEMU 0.15 offers full Xen support
The QEMU project has released version 0.15 of its system emulator. The software, which can be used as a stand-alone desktop virtualisation product, but is also used for emulating guest hardware by the Xen and KVM virtualisation solutions, now offers full Xen support. Since version 3.0, the kernel has included all the essential components for working with the Xen hypervisor, the new QEMU release means distributions now have everything, apart from the Xen hypervisor, they need to set up a Xen host using already installed components.
The KVM support in QEMU has also matured. Although QEMU has supported KVM for a while, distributions currently tend to use the qemu-kvm fork of QEMU to provide virtualisation via the kernel's own hypervisor. Numerous corrections from the KVM-optimised fork have been ported to the upstream QEMU; both are now said to share the same core code and therefore should offer the same quality. The developers also say they have fully synchronised QEMU's threading model with that of qemu-kvm.
The new version also supports the Lattice Mico32 (LM32) and UniCore32 architectures. There are some performance improvements in qemu-img and the snapshot support of qcow2. QEMU's IDE emulation now supports ATA trim, which allows the system to inform storage media of newly available memory areas.