qemu(1)

All the examples & notes use qemu-system-x86_64 but in most cases +this can be swapped with the system emulator for other architectures.

Keybindings

Ctrl+Alt+g         release mouse capture from VM
+
+Ctrl+Alt+1         switch to display of VM
+Ctrl+Alt+2         switch to qemu monitor
+

VM config snippet

Following command-line gives a good starting point to assemble a VM:

qemu-system-x86_64                              \
+        -cpu host -enable-kvm -smp 4            \
+        -m 8G                                   \
+        -vga virtio -display sdl,gl=on          \
+        -boot menu=on                           \
+        -cdrom <iso>                            \
+        -hda <disk>                             \
+        -device qemu-xhci,id=xhci               \
+        -device usb-host,bus=xhci.0,vendorid=0x05e1,productid=0x0408,id=capture-card
+

CPU & RAM

-cpu host emulate host CPU in guest VM
-enable-kvm use KVM instead software models (requires KVM on host machine)
-smp <N> number of guest CPUs

+
List available CPUs qemu-system-x86_64 -cpu help.
+

-m 8G size of guest RAM

Graphic & Display

-vga virtio use virtio as 3D video graphic accelerator (requires virgl in guest)
-display sdl,gl=on use sdl window and enable openGL context

Boot Menu

-boot menu=on enables boot menu to select boot device (enter with ESC)

Block devices

-cdrom <iso> attach cdrom drive with iso to a VM
-hda <disk> attach disk drive to a VM
-drive file=<file>,format=qcow2 generic way to configure & attach a drive to a VM

Create a disk with `qemu-img`

To create a qcow2 disk (qemu copy-on-write) of size 10G:

qemu-img create -f qcow2 disk.qcow2 10G
+

The disk does not contain any partitions or a partition table. +We can format the disk from within the guest as following example:

# Create `gpt` partition table.
+sudo parted /dev/sda mktable gpt
+
+# Create two equally sized primary partitions.
+sudo parted /dev/sda mkpart primary 0% 50%
+sudo parted /dev/sda mkpart primary 50% 100%
+
+# Create filesystem on each partition.
+sudo mkfs.ext3 /dev/sda1
+sudo mkfs.ext4 /dev/sda2
+
+lsblk -f /dev/sda
+  NAME   FSTYPE LABEL UUID FSAVAIL FSUSE% MOUNTPOINT
+  sda
+  ├─sda1 ext3         ....
+  └─sda2 ext4         ....
+

USB

Host Controller

-device qemu-xhci,id=xhci add XHCI USB controller to the VM (supports USB 3.0, 2.0, 1.1). id=xhci creates a usb bus named xhci.

USB Device

-device usb-host,bus=xhci.0,vendorid=0x05e1,productid=0x0408 pass-through USB device from host identified by vendorid & productid and attach to usb bus xhci.0 (defined with controller id)

References

+ +

Notes