In order to assign a peripheral I/O device to a virtual machine, the device needs to be isolated from the host and aspects of the hardware may need to be virtualized for transparency to the guest. Some devices and platforms are better at this than others. Adherence to specifications and creative backdoors through hardware can present challenges to device assignment. In this presentation, Alex Williamson will provide case studies through various examples of troublesome configurations and the workarounds, or quirks, that are sometimes employed to enable them. These quirks are however not without pitfalls and can impose performance, maintenance, functionality, and time-to-market downsides. The goal of this talk is to share some of these common issues, expose the quirks available as workarounds, and discuss how they can be avoided entirely with well-informed hardware design.
Alex Williamson is a Senior Principal Software Engineer with Red Hat, maintainer of VFIO, Linux’s secure userspace driver framework, for both the kernel and QEMU components, and regular contributor to the Linux kernel IOMMU and PCI subsystems. Alex has given previous talks on VFIO... Read More →