We’ve seen that virtualisation (with appropriate hardware support) is much faster than conventional emulation. And we’ve seen that when using paravirtualised VirtIO devices we can speed that up even more. But we can go further. What if, for example, we gave a virtual machine its own physical graphics card?
This technique, known generally as VFIO, has been around for a while. For the particular case of using PCI passthrough with graphics cards, the result is that VMs can run graphically intensive applications to within a hair’s breadth of native speeds. This enables Linux usersto run Windows VMs and play games without taking a performance hit. This is an alternative to , albeit one which is a little tricky to set up and requires that the host machine has (at least) two graphics cards. We covered this in .
