HARDWARE REQUIREMENTS

For this trickery to work some vaguely modern hardware is required, and even with modern hardware things sometimes go awry. The graphics card used by the host can be anything, even integrated graphics. If you have two discrete GPUs, then you’ll want to be familiar with the key combination for entering the BIOS/UEFI because your machine will almost certainly try and boot from the wrong graphics card. The guest’s graphics card will need to support UEFI (the motherboard needn’t) since we’re booting with OVMF. It’s possible that an updated GPU BIOS is available from the manufacturer (some people have reported success by just asking them), which you can pass to QEMU rather than flashing your graphics card. Generally anything manufactured after 2012 will be fine. Your motherboard must support IOMMU (aka Directed I/O), which may need to be enabled in the BIOS and your CPU must support it too (Intel call this VT-d and AMD call it AMD-Vi; note that these are in addition to the more commonplace VT-x and AMD-V mentioned earlier).

Besides these requirements, you may wish to invest in a KVM switch (nothing to do with the kernel) or an additional keyboard/ mouse/touchpad since (outside of a VNC or SPICE connection) the guest machine won’t have access to host input devices. You can pass through USB devices, but if something goes wrong on the guest they may not be relinquished, which will leave you unable to control the host. If you don’t like swapping cables around then you’ll also want a monitor with multiple inputs (and another video cable), or a second monitor. If you’re using an Nvidia card you may run into the dreaded “error 43”, which can be worked around by tweaking your QEMU set.