Yesterday, kvm maintainers released kvm release 84 featuring mostly bug fixes and another qemu merge. According to the official announcement, kvm-84 is slower when rendering fonts on Windows than kvm-83 for some unknown reason. The qemu merge includes features such as a new virtio-console device, vnc improvements, scsi fixes and a new -vga none option for headless guests.

Below is the official changelog.

Changes from kvm-83:
- merge qemu-svn
- redirect slirp traffic to qemu-char device
- slirp fixes
- qcow2 fixes
- nic link status control
- enable ac97 audio by default
- add virtio-console device
- fix rtc time drift on Windows (-rtc-td-hack option)
- add -vga none option for running headless guests
- better block device error propagation
- fix guests halting when switching desktop workspace
- improved display interfaces
- better logging support
- don't corrupt qcow2 images when out disk space on host
- dma api
- add pci device vendor ID
- vnc improvements
- improve Virtual PC disk format support
- scsi fixes
- multicast filtering for e1000 and virtio-net
- add libkvm wrapper for KVM_SET_CPUID2 interface (Amit Shah)
- fix cpuid for leaves 4, 11, 13 (Amit Shah)
- save ia64 nvam (Yang Zhang)
- compile fixes (Mark McLaughlin, Jan Kiszka)
- generic irq routing
- build fixes against RHEL 5 hosts (Andrea Arcangeli)
- fix build when pc-bios directory is empty (Eduardo Habkost)
- improve host version check (Mark McLaughlin)
- drop obsolete eflags conversion to/from qemu emulator (Jan Kiszka)
- preallocate memory with -mem-path (John Cooper)
- don't register unassigned PCI BARs (Gleb Natapov)
- more hrtimer API compatibility
- fix build on uniprocessor hosts (Jan Kiszka)
- fix build on pre-msi hosts (Jan Kiszka)
- allow stopping vm from vcpu thread (Gleb Natapov)
- fix cpu and pci hotplug (Gleb Natapov)
- ppc updates (Liu Yu)
- fix ia64 fp trap handler (Yang Zhang)
- fix ia64 vtlb handling (Xiantao Zhang)
- enables Windows 2008 on ia64
- support translating ia64 PAL arguments (Xiantao Zhang)
- implement ia64 PAL calls needed by Windows 2008 (Xiantao Zhang)
- map assigned device mmio as uncachable (Sheng Yang)
- fix lapic pending count calculation (Marcelo Tosatti)
- fix s390 printk (Christian Borntraeger)
- fix s390 problem state check (Christian Borntraeger)
- fix s390 SIGP set prefix ioctl (Christian Borntraeger)
- dynamic ia64 cpu count (Jes Sorensen)
- fix lapic build on i386 (Clemens Noss)
- make irq ack notifications use routing table (Marcelo Tosatti)
- FFXSR support (Alexander Graf)
- fix assigned device circular locking dependency (Mark McLaughlin)
- drop unused code from string pio handlers (Jan Kiszka)
- fix kvmclock on hosts with unstable tsc (Gerd Hoffman)
- reenables Fedora 10 guests on those hosts
- enable msi from userspace (Sheng Yang)
- remove duplicated code in EPT handler (Sheng Yang)
- flush volatile msrs on Intel before emulating rdmsr
- fixes cygwin on Windows x64

You can download kvm-84 here.