This is a XEN bugfix update fixing lots of bugs
and one security issue.

CVE-2012-0029: Heap-based buffer overflow in the process_tx_desc function in the e1000 emulation (hw/e1000.c) in qemu-kvm 0.12, and possibly other versions, allows guest OS users to cause a denial of service (QEMU crash) and possibly execute arbitrary code via crafted legacy mode packets.