20G
is size of your image, or hard disk for virtual machinevirtual.img
is the image file
qemu-img create -f qcow2 virtual.img 20G
2G
is RAM for virtual machine
qemu-system-aarch64 -boot d -cdrom isoimage.iso virtual.img -m 2G -enable-kvm -machine q35,accel=kvm
qemu-system-x86_64 -boot d virtual.img -m 2G -enable-kvm -machine q35,accel=kvm -cpu host