qemu-system-x86_64

Emulate x86_64 systems with QEMU

TLDR

Boot ISO image

$ qemu-system-x86_64 -cdrom [image.iso] -boot d

Boot disk image

$ qemu-system-x86_64 -hda [disk.qcow2]

Boot with memory and CPU

$ qemu-system-x86_64 -m [2G] -smp [2] -hda [disk.qcow2]

Boot with KVM acceleration

$ qemu-system-x86_64 -enable-kvm -m [4G] -hda [disk.qcow2]

Boot with network

$ qemu-system-x86_64 -hda [disk.qcow2] -nic user,hostfwd=tcp::2222-:22

SYNOPSIS

qemu-system-x86_64 [options] [diskimage_]

qemu-system-x86_64 is a full-system emulator for the x86_64 architecture. It can run complete operating systems including Linux, Windows, and BSD. With KVM hardware acceleration on Linux, it achieves near-native performance.
QEMU emulates CPU, memory, storage, network, and display devices. It supports multiple disk image formats (qcow2, raw, vmdk), various network configurations, and both graphical and serial console output. It is the backend for higher-level virtualization tools like libvirt, virt-manager, and Proxmox.

PARAMETERS

-m size

RAM size (e.g., 2G, 4096M).

-smp cpus

Number of CPUs.

-hda file

Primary hard disk image.

-cdrom file

CD-ROM image.

-boot order

Boot order (c=disk, d=cdrom).

-enable-kvm

Enable KVM acceleration.

-nic options

Network configuration.

-nographic

Disable graphical output.

-vnc display

Enable VNC server.

-cpu model

CPU model to emulate.

-drive options

Define a drive (file, format, if, media).

-serial device

Redirect serial port.

CAVEATS

KVM requires hardware virtualization support (Intel VT-x/AMD-V) and the kvm kernel module. Without KVM, emulation is significantly slower. High memory and CPU allocation may impact the host system.

HISTORY

QEMU was created by Fabrice Bellard and first released in 2003. KVM hardware acceleration was merged into the Linux kernel in 2007, making QEMU the standard userspace component of Linux virtualization.