Flavio Villanustre writes “QEMU is an open source CPU and system emulator, similar in many aspects to Bochs and other commercial emulators. Unlike many of them, QEMU can achieve significatively faster emulation speeds through dynamic instruction translation. Dynamic translation means that every time QEMU finds a new set of instructions it translates them to an equivalent set of native instructions for the host processor, runs them and stores them in a cache, in case they need to be reused later.
In recent versions (since version 0.7.0) QEMU can become a virtualizer as well (similar to VMware) when the target CPU (emulated system) is similar to the host CPU (real system), and the host operating system is either Linux or Windows. Virtualization implies running most of the instructions of the guest operating system or application, natively in the host CPU, instead of dynamically translating them at run time. Only privileged instructions (those that can only run in a privileged level for the host CPU) are trapped and converted.”
Link: /flaviostechnotalk.com
