KVM is one of several virtualization technologies available for Linux. KVM generally requires hardware support but can run an unmodified OS image but in exchange offers full system virtualization, good performance. Also since KVM is based on a standard Linux kernel the host system uses the standard I/O drivers available for the platform. As there are no MIPS processors on the market featuring the kind of virtualization extensions that would be required to run KVM nor virtualization extensions have been announced by MIPS Techologies or any of its licensees, there is no KVM support available yet.
Kyma claims “We've limited the changes to the Linux guest to less than 10 lines of code and use advanced techniques like run-time binary translation to minimize the number of traps and greatly improve performance.” for their software-only implementation. If their technology holds up to its promise they should deliver performance below but fairly close to that of a hardware-based KVM implementation.
As of 2012-10-31 Kyma has posted a 20 part patch series to add KVM support for MIPS32 processors without hardware virtualization support. A guest kernel is running in user space which means in the lowest 2GB of the address space. As the result the address space for guest applications had to be shrunk so guest kernels now use a 1GB/1GB userspace/kernelspace split.