kvm Archives - Heiko's Blog

Why Long Tutorials?

Anyone who follows this website will notice that the tutorials are rather long. In these long tutorials I usually give reference specs, explain basic terms or processes, and expand on the how and why.

I wish I could write short, easy, step by step tutorials titled “GPU passthrough made easy” or the “Quick guide to VFIO bliss”. In fact, there are plenty of those out there in the great Internet. Some of the most popular ones are on Youtube, showing you how to get your Windows gaming VM up and running in no time.

Nvidia And The “hidden state”

No more need to hide the hypervisor

Ever since I started to run a Microsoft Windows VM with GPU passthrough, Nvidia graphics drivers would only support their professional Quadro line of graphics cards in a virtual machine. Ten years ago I bit the bullet and bought an outrageously expensive Nvidia Quadro 2000 GPU. Truth be told – it’s been and still is a great GPU and I currently use it for my Linux host. Back then the Quadro was passed through to a Windows 7 VM running on Xen. It worked great.

Passing Through a Nvidia RTX 2070 Super GPU

Tutorial for passing through a Nvidia RTX graphics card to a Windows 10 virtual machine using a modified VBIOS

Last update: September 14, 2021

Starting with the GeForce 1000 series, vfio passthrough of a Nvidia GPU has become a little more complicated. If, when starting the VM, you get a black screen, chances are you need to pass along a VBIOS file to the VM so the GPU can properly initialize.

This post is about passing through a Nvidia RTX 2070 Super GPU or any other modern Nvidia GPU to a Windows 10 guest.

Windows 10 VFIO Passthrough Configuration

I’ve been tweaking my configuration for my needs and it performs very well. As a reference, I’m posting my:

hardware configuration
Linux distro, kernel, etc.
Windows VM configuration (XML)

Creating a Windows 10 kvm VM on the AMD Ryzen 9 3900X using VGA Passthrough

Last updated: January 6, 2022

Introduction

I’ve already written a detailed tutorial on Windows 10 kvm VGA passthrough based on QEMU version 2.11. Years have passed and recent distributions like Ubuntu 20.04, Linux Mint 20, or Manjaro come with QEMU 4.0, 4.2 or 5.1.

A lot has happened since version 2.11. QEMU 4.0 includes numerous changes and improvements such as trim support in the virtio-blk driver, pcie-root-port with PCIe 4.0 support (with Q35-4.0 machine type), as well as improved audio.

Upgrading my PC to an AMD Ryzen 9 3900X System – Benchmarks

It wasn’t easy this time. Don’t get me wrong – the VFIO passthrough part, though challenging in some ways, went quite well. All in all I’m pleased now with the results. Here the Passmark 9.0 benchmark as uploaded onto their database (for more details, click the frame below):

Upgrading my PC to an AMD Ryzen 9 3900X System

Introduction

I’ve been contemplating a PC upgrade for more than a year (see my post here). At first I considered staying with Intel and getting an i9-9900K CPU with integrated GPU on a Z390 motherboard.

Along came the AMD Ryzen 9 3900X that topped the benchmarks, including the Adobe Lightroom and Photoshop benchmarks (to be precise, it ranked #4 in the Adobe Lightroom benchmark, and a narrow #1 in the Adobe Photoshop benchmark). These good news about the AMD Ryzen 3900X were soon followed by reports about BIOS issues and VFIO incompatibility. At the very least, it looked like VGA passthrough was more challenging.

Then I read Bryan Steiner’s GPU passthrough tutorial for the AMD Ryzen 9 3900X and an Ubuntu-based Pop!_OS Linux host. Several users on the VFIO Reddit forum reported successful VFIO VGA passthrough with the AMD Ryzen 9.

Impact of Spectre and Meltdown Protection on Virtual Machine Performance

A year ago I wrote about the 2D graphics performance impact of the Windows 10 (1803) update inside a virtual machine. As it turned out, the performance impact was related to the Spectre vulnerability patch that Microsoft had introduced. However, the same patch had practically no performance impact on a Windows 10 bare-metal installation.

Time has passed and I wanted to see if there has been any progress. Right now I’m running Windows 10 (1903) with Nvidia driver release 431.36. Windows 10 is up-to-date, Nvidia however already offers a newer version (431.60).

GPU Passthrough with Low-End Intel i3-6100 CPU

For some time I wanted to run a kvm virtual machine with GPU passthrough on a low-end Asus H110M-K D3 motherboard with an i3-6100 CPU and an Nvidia GTX 1060 GPU, but never found the time. Now I finally had a chance to give it a try. While the preparations were easy, I ran into a problem when starting the Windows 10 VM:

Jan 22 15:21:24 alon-i3 kernel: [  108.514992] vfio_pin_pages_remote: RLIMIT_MEMLOCK (16777216) exceeded

Continue reading “GPU Passthrough with Low-End Intel i3-6100 CPU”

Blacklisting Graphics Driver

Update September 14, 2021: This is a complete revamp, adding new, more robust methods and dropping outdated ones.

Update November 17, 2022: Kernel 6 seems to break the grub method.

When running a VM with GPU passthrough, that GPU should be bound to the VFIO driver. To make this happen, we need to prevent the regular graphics driver from binding to the passthrough GPU and instead bind the vfio-pci driver.

In the past we used to blacklist the graphics driver. This worked in most cases, but what if you need the graphics driver for another GPU, e.g. the host GPU?