QEMU supports the emulation of various architectures, including x86, MIPS64 (up to Release 6), SPARC (sun4m and sun4u), ARM (Integrator/CP and Versatile/PB), SuperH, PowerPC ( PReP and Power Macintosh), ETRAX CRIS, MicroBlaze, and RISC-V.

Guest operating systems do not need patching in order to run inside QEMU. QEMU can save and restore the state of the virtual machine with all programs running. Xen Hosting QEMU is involved only in the emulation of hardware the execution of the guest is done within Xen and is totally hidden from QEMU. It is still involved in the emulation of hardware, but the execution of the guest is done by KVM as requested by QEMU. KVM Hosting Here QEMU deals with the setting up and migration of KVM images. QEMU can boot many guest operating systems, including Linux, Solaris, Microsoft Windows, DOS, and BSD it supports emulating several instruction sets, including x86, MIPS, 32-bit ARMv7, ARMv8, PowerPC, RISC-V, SPARC, ETRAX CRIS and MicroBlaze. It can be used to provide virtual hosting of several virtual computers on a single computer. System emulation In this mode QEMU emulates a full computer system, including peripherals. Fast cross-compilation and cross-debugging are the main targets for user-mode emulation.

System calls are thunked for endianness and for 32/64 bit mismatches. QEMU has multiple operating modes: User-mode emulation In this mode QEMU runs single Linux or Darwin/ macOS programs that were compiled for a different instruction set. Various parts are released under the BSD license, GNU Lesser General Public License (LGPL) or other GPL-compatible licenses. QEMU was written by Fabrice Bellard and is free software, mainly licensed under the GNU General Public License (GPL for short). QEMU can also do emulation for user-level processes, allowing applications compiled for one architecture to run on another. It can interoperate with Kernel-based Virtual Machine (KVM) to run virtual machines at near-native speed. It emulates the machine's processor through dynamic binary translation and provides a set of different hardware and device models for the machine, enabling it to run a variety of guest operating systems. QEMU (Quick Emulator ) is a free and open-source emulator. Linux, Microsoft Windows, macOS and some other UNIX platforms

Qemu virtual machine tutorial