Is it possible to pass through a GPU to a VM, and take advantage of the graphics acceleration the GPU provides, BUT not connect a monitor to the GPU's physical output ports? And instead, have the VM's display output as a window on the host? The same way a typical VM without graphics passthrough would be displayed.

In general, I'm hoping to find a VM solution that satisfies both of the following criteria:

1. Smooth graphics acceleration in the VM, at least for basic things like moving windows and minimizing them
2. Seamless keyboard/mouse/monitor input switching between host and guest, ideally by having the guest display as a window in the host desktop environment.

This is for a new rig I'm planning to build, which will run a linux guest on a linux host. Ideally, I'd be passing through the CPU's integrated GPU to the VM, but if for some reason this works only when passing through a discrete GPU, I'm open to doing a dual-(discrete-)GPU build instead.

My intuition says that the setup I am asking about should work, but I'm getting mixed signals from my online research. I'm looking for confirmation from you knowledgable folks before moving forward with my plans to build the new rig. I can't test this on my current rig because its intel cpu predates iommu/vt-d. Here are the reasons I think this should work:

1. Laptops can switch between iGPU and discrete gpu using their single built-in monitor, which means one of those GPUs is not directly connected to the monitor and is instead passing the signal back to the other GPU, which relays it to the monitor. Similar to how I would want the iGPU to send the signal somewhere other than its physical display port on the motherboard.
2. External GPUs (eGPUs) can output the display data through their pci-e connection and back through the single port on the computer they're plugged into, as opposed to a display they are directly connected to. (example youtube demo)
3. Youtubers demoing GPU passthrough do not appear to switch monitors, but show GPU passthrough working in a window on the host desktop. (example youtube demo)

Relevant details of the rig I'm planning to build: intel cpu with integrated graphics; nvidia 3090 gpu; 4 monitors connected to 3090; linux mint host running kvm/qemu/virt-manager

If this does work, how do I configure whether the iGPU outputs to a monitor connected to it, or to whatever virtual monitor there needs to be that results in it being displayed as a window on the host?

If this does NOT work, what's the next best solution?

Other related bonus questions:

• What is the setup workflow people typically use with gpu passthrough nowadays? Do they manually switch their monitors between graphics cards when switching between host and guest? Do they buy multiple keyboards and mice, or kvm switches? Or do they remote in? Do they use looking-glass, at least for Windows VMs? Or something else?
• If you were building a computer specifically designed for GPU passthrough, what would be your biggest priorities in the build?

Thanks in advance.

Appendix: Other approaches I've considered

• Paravirtualization: spice + virtio driver + opengl checkbox in virt-manager/qemu. This could work since I only need light graphics acceleration on my linux VMs, but according to my research, newer nvidia drivers appear to block it.
• Virtualization: hack to unlock nvidia vGPU (link). The script doesn't support linux kernel versions above 5.10. (Or Ampere cards like the 3090)
• Looking-glass: Only Windows VMs are supported -- Linux VMs still in development
• Spice + qxl: insufficient graphics acceleration, at least on my current system with a 1070 (not sure if it uses the 1070)

hello,

am trying to use looking glass with kvmfr but eveytime i try to install it through dkms i get the below error with trying to load the module

any suggestions ?

modprobe: FATAL: Module kvmfr not found in directory /lib/modules/6.13.1-zen1-1-zen

So I have this setup where I passthrough a partition of an nvme drive as the VM disk

<disk type='block' device='disk'>

<driver name='qemu' type='raw' cache='none' io='native' discard='unmap'/>

<source dev='/dev/nvme1n1p4'/>

<target dev='vda' bus='virtio'/>

<serial>1111</serial>

<address type='pci' domain='0x0000' bus='0x09' slot='0x00' function='0x0'/>

</disk>

Now the problem is that randomly the device keeps changing (between reboots) between being nvme0 and nvme1. Apparently this is expected behavior and you should just use the UUID for identification. However, probably due to the way this partition was created, this is the only partition that doesn't have an UUID. Eg. It's also not visible in /dev/disk/by-uuid

What could I do to ensure the VM always uses the correct partition?

i just started to use Timeshift and saved my host snapshot externally to a ssd and i was trying to do the same in virt-manager but could not find an option to save it externally? i googled it and found some files in var/lib/libvirt/images, can i just copy and paste these files in my external drive, are they the most updated versions?

(btw, would me saving my host via timeshift also save my virt-manager settings? since virt-manager itself is saved on my host system?)

I'm planning a new pc build that will be linux based and will sport a pair of nvidia rtx 3060 gpus (12 gb each). Motherboard is likely to be the Asus Pro WS W680-ACE which appears to support everything i need...2x pcie 5 slots running in x8 mode each for the gpus plus a couple of available chipset lanes pcie 3 slots for other things.

I want to normally run both gpus in linux for day to day work plus ai llm usage. But I also want to be able to unbind one gpu and use it in a windows vm for gaming or for other Windows based work.

So far in my research, I've found a lot of posts, articles and videos about how much a pain this scenario is. Ideally I would be able to switch back and forth the vm used gpu as needed without a reboot... this machine is also going to be a home media server so I want to minimize downtime. But if a reboot with grub configuration is the best way, then I can deal with it.

So my question is this: what is the current state of the art for this use case? Anything to watch out for with the hardware selection, any good guides you can recommend?

I found one guide that said don't use the exact same model of gpu because some of the binding stuff cannot differentiate between the two cards. Any truth to that? I want the 3060s because they are relatively inexpensive and I want to prioritize vram for running larger models. And because nvidia is screwing us with the later series.

Also, I am distro agnostic at the moment, so any recommendations?

Thanks!

Sidenote: I've been using Linux off and on since 1993 but I'm mostly a windows/Microsoft/cloud dev and I'm completely new to vfio. I very much appreciate and and all help!

2025-01 Cumulative Update for Windows 10 Version 22H2 for x64-based Systems Status: Installing - 20%

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2025-01 Cumulative Update for Windows 10 Version 22H2 for x64-based Systems Status: Installing - 43%

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2025-01 Cumulative Update for Windows 10 Version 22H2 for x64-based Systems Status: Installing - 44%

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2025-01 Cumulative Update for Windows 10 Version 22H2 for x64-based Systems Status: Installing - 74%

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2025-01 Cumulative Update for Windows 10 Version 22H2 for x64-based Systems Status: Installing - 89%

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Pending restart

I really don't wanna make this a long post.

How do people manage to play the most demanding games on QEMU/KVM?

My VM has the following specs:

• Windows 11;
• i9-14900K 6 P-cores + 4 E-cores pinned as per lstopo and isolated;
• 48 GB RAM (yes, assigned to the VM);
• NVMe passed through as PCI device;
• 4070 Super passed through as PCI device;
• NO huge pages because after days of testing, they didn't improve nor decrease the performance at all;
• NO emulator CPU pins for the same reason as huge pages.

And I get the following results in different programs/games:

All these issues seem to have nothing in common, especially since:

• CPU (checked on host and guest) is never at 100%;
• RAM testing doesn't cause any lag;
• NVMe testing doesn't cause any lag;
• GPU is never at 100% except for CS2.

I have tried vCPU schedulers, and found that, on some games, namely Forspoken, it's kind of better:

On other games it's definitely worse, like AC Unity:

The scheduler rr gave me the exact same results as fifo. Anyways, turning on LatencyMon shows high DPC latencies on some NVIDIA drivers when the issues occur, but searching anywhere gave me literally zero hints on how to even try to solve this.

When watching videos of people showcasing KVM on YouTube, it really seems they have a flawless experience. Is their "good enough" different than mine? Or maybe are certain systems more capable of low latencies than others? OR am I really missing something huge?

I have 3 Drives, one (F) will always keep the same letter, then the other two are D and E, which switch after every boot, was wondering if there was a way to fix this

I have a windows 11 desktop and I want to run a Linux VM with at least some graphical power, is there a way I can pass the Processors iGPU into the linux vm?

Hello,

I successfully configured my linux distribution to use vfio-pci driver for my GPU. But now it won't launch my desktop anymore, only a blackscreen.

I checked my desktop is launching fine if I unplug my GPU, so IGPU is working.

Here is the error (Xorg.log) :

(EE) [drm] Failed to open DRM device for pci:0000:01:00.0: -19

pci:0000:01:00.0 is the GPU I removed in grub

Instead I would like to use : 11:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Granite Ridge [Radeon Graphics] (rev c6)

service display-manager status :
janv. 31 23:02:17 seb-desktop sddm[1166]: Failed to read display number from pipe
janv. 31 23:02:17 seb-desktop sddm[1166]: Display server stopping...

dmesg here : https://pastebin.com/tAr59Eik

Xorg.log here : https://pastebin.com/EQ0X9EaJ

I tried kubuntu 24.04, 24.10 and KDE Neon.

In case it matters my motherboard is Gigabyte B650 Gaming X AX V2

Thank you for your help

A few years ago, I used to have a machine with a GPU reserved for VFIO.

This type of setup had a big downside - the VFIO GPU had no power management support, consuming a significant amount of power even when the virtualization was not running.

What's the status today? I've seen progress on this starting a couple of years ago, but I was wondering if the work has been completed, and GPUs managed by the vfio driver are able to run in low power mode.

I'm interested in informations about both Nvidia and AMD cards!

Thanks :)

Recently created a vm with gpu passthrough through looking glass and it wont regonize my mouse.

Is it possible to get a high refresh rate with multimon configuration on linux guest?

I can run 2 monitors with virtio-gpu-gl only on spice protocol, but refresh rate is awful - about 15-30 fps.

When I run qemu in 1 display configuration I get >60fps on spice display, and about 110-120fps on sdl/gtk display.

Is it possible to run 2 displays on sdl/gtk display or get acceptable refresh rate on spice display?

In Kubernetes you can configure sriov network attachments. This essentially allows you to declare you want a vf allocated and attached from the host to a container.

I want to mirror this workflow, but instead of the bare metal host being the Kubernetes node, a kvm on the host is a node(s)

So I have tried so far to bind the pf to vfio-pci and pass it through to the VM. This seems to work. I then install ofed drivers and proceed to create my vfs. However I can't successfully create them. It returns permission denied when setting the number (using root inside the VM)

I can pre create the vfs on the host and bind to vfio-pci and pass them, but can't seem to manage them from the VM side.

Anyone have thoughts or suggestions on this?

SOLVED : I found a solution, I had to add a Xorg config file to explicitely tell Xorg to use exclusively my iGPU. >!<

So I'm running PopOs 22.04 on a GTX 1650 and AMD integrated graphics and I followed the guide from this thread. However virt-manager is hanging forever when I try to install the VM.
I figured out that it was because of the VFIO script that tries to detach my nvidia GPU:

$ sudo dmesg -w ... \[ 522.362088\] VFIO - User Level meta-driver version: 0.3 \[ 522.371365\] vfio\_pci: add \[10de:2188\[ffffffff:ffffffff\]\] class 0x000000/00000000 \[ 522.371374\] vfio\_pci: add \[10de:1aeb\[ffffffff:ffffffff\]\] class 0x000000/00000000 \[ 522.388201\] NVRM: Attempting to remove device 0000:01:00.0 with non-zero usage count!

Xorg is keeping my graphics card busy (It doesn't even do anything since my iGPU should already do everything ! )

$ nvidia-smi Wed Jan 29 21:35:11 2025        +-----------------------------------------------------------------------------------------+ | NVIDIA-SMI 560.35.03              Driver Version: 560.35.03      CUDA Version: 12.6     | |-----------------------------------------+------------------------+----------------------+ | GPU  Name                 Persistence-M | Bus-Id          Disp.A | Volatile Uncorr. ECC | | Fan  Temp   Perf          Pwr:Usage/Cap |           Memory-Usage | GPU-Util  Compute M. | |                                         |                        |               MIG M. | |=========================================+========================+======================| |   0  NVIDIA GeForce GTX 1650        Off |   00000000:01:00.0 Off |                  N/A | | 23%   27C    P8              8W /   75W |       7MiB /   4096MiB |      0%      Default | |                                         |                        |                  N/A | +-----------------------------------------+------------------------+----------------------+                                                                                           +-----------------------------------------------------------------------------------------+ | Processes:                                                                              | |  GPU   GI   CI        PID   Type   Process name                              GPU Memory | |        ID   ID                                                               Usage      | |=========================================================================================| |    0   N/A  N/A      8289      G   /usr/lib/xorg/Xorg                              4MiB | +-----------------------------------------------------------------------------------------+

Is there a way to prevent Xorg from using my dGPU ? / Forcing Xorg to exclusively use my iGPU ?

i set up a windows 10 vm with qemu/kvm through virt manager with gpu passthrough and im trying to install nvidia drivers for a gtx 550 ti but it doesnt work. i installed it but the gpu doesnt show in task manager and it says code 43 in device manager which afaik is a driver problem. i could install the nvidia drivers fine with no errors.

so i got my vm booting but am trying to pass through my usb controller, i did a virsh gpu_usb in my kvm.conf and the start and stop script but i can't use the mouse an keyboard not sure if it's a me problem

kvm.conf- VIRSH_GPU_VIDEO=pci_0000_2d_00_0

VIRSH_GPU_AUDIO=pci_0000_2d_00_1

VIRSH_GPU_USB=pci_0000_2f_00_3

start script- # debugging

set -x

source "/etc/libvirt/hooks/kvm.conf"

# systemctl stop display-manager

systemctl stop sddm.service

echo 0 > /sys/class/vtconsole/vtcon0/bind

echo 0 > /sys/class/vtconsole/vtcon1/bind

#uncomment the next line if you're getting a black screen

echo efi-framebuffer.0 > /sys/bus/platform/drivers/efi-framebuffer/unbind

sleep 10

modprobe -r amdgpu

virsh nodedev-detach $VIRSH_GPU_VIDEO

virsh nodedev-detach $VIRSH_GPU_AUDIO

virsh nodedev-detach $VIRSH_GPU_USB

sleep 10

modprobe vfio

modprobe vfio_pci

modprobe vfio_iommu_type1

stop script- # Debug

set -x

#reboot

source "/etc/libvirt/hooks/kvm.conf"

modprobe -r vfio

modprobe -r vfio_pci

modprobe -r vfio_iommu_type1

sleep 10

virsh nodedev-reattach $VIRSH_GPU_VIDEO

virsh nodedev-reattach $VIRSH_GPU_AUDIO

virsh nodedev-reattach $VIRSH_GPU_USB

echo 1 > /sys/class/vtconsole/vtcon0/bind

echo 1 > /sys/class/vtconsole/vtcon1/bind

sleep 3

echo "efi-framebuffer.0" > /sys/bus/platform/drivers/efi-framebuffer/bind

modprobe amdgpu

sleep 3

systemctl start sddm.service

I have a reference ASUS Radeon 7900 XT which in the past hasn't worked for passthrough due to a reset bug.

But I've heard the situation might have changed? Can anyone point me in the right direction? I also heard gnif posted instructions or information somewhere in regards to this series of cards but I can't find it.

So, I've got a pretty nice Arch build that I don't feel like throwing away just to install Windows, but I also want to play some kernel ac games (yea, yea, I know, but there's nothing like Battlefield 1 out there for me).

So my question is - If i install Windows as a VM and give it my secondary SSD - could I create a Boot entry in grub or systemd-boot to get into it directly without VFIO?

I'm not new to this and I have a Windows VM with single gpu passthru set up, I just would like to boot Windows directly for kernel ac (unfortunately)

I've successfully followed this guide to get GPU passthrough working, and I'm using Looking Glass with GPU acceleration just fine. My machine has an AMD graphics card that I use for my Linux host, which my main monitor is attached to, and an NVIDIA card that I pass through into the VM as its primary card. Everything works great as long as I keep the Windows VM running.

However, as soon as I stop the Windows VM and the shutdown script runs `nodedev-reattach`, it appears Wayland (or something else in my system) grabs the NVIDIA card for itself. Then, if I try and restart the VM, or just run `nodedev-detach` directly, the card becomes unavailable and Wayland crashes, kicking me to a console screen showing the last thing I saw before I booted into Wayland.

I'd like to be able to use GPU passthrough while the VM is running, but I'd also like to be able to use the card for other purposes, such as LLM inferencing, when the VM isn't running. How can I either prevent my system from grabbing the card as soon as it's available, or force it to give it up again when the VM is starting up?

The title basically explains it all.

Are there any good guides out there?

Is a kernel patch necessary for vGPU passthrough?

Is it even worth doing all the hassle of vGPU passthrough?

Im to a point where my virtual machine detects my igpu but does not display anything. I can however run gpu benchmarks on it on my virtual machine so id assume it works. But whenever i try to run the virtual machine without any virtual displays it gives no signal on my motherboards hdmi port.(Monitor doesnt even get signal on verbose) It just wont display anything from the hdmi.

Passthrough has been tested on Ubuntu virtual machine(it sends signal).

What ive tested: Every possible boot arg. Dvi port. Checked that whatevergreen and lilu are loaded.

i might have missed something stupid. so there is that also. https://imgur.com/jKblMFQ

A bit of a background: A few months ago, I was trying out gpu-passthrough using bazzite script and for a few days I was getting code 43 error for GPU drivers or something like that, it turns out it was because of having resizable bar on in the bios, disabled it and it worked wonderfully after that. (But I didn't use it since I only had 16gbs of ram and only passed 8) so I waited till I got the opportunity to get another 16gb stick of ram.

Now I don't know whether its true or not but I heard that in some cases resizable bar makes a good difference in gaming performance, anyways there is a way to limit resizable bar "size" that is available on the arch wiki, so I hopped on to arch (tried to do it on bazzite but for some reason didn't work)

I'm starting anew but i'm a bit lost, I want to have a seemless gaming vm that I can somehow bind and unbind my GPU to my Linux host without restarting, and I also want to hide my VM to play destiny 2/anticheat games (I saw that it's possible and I'm open for experiments) But there seems to be so much options and things I'm a bit overwhelmed, so here I am hoping someone here can guide me through this.

My system:

GPU: Rx 5700 xt

CPU: i5 10400 (with igpu)

Ram: 32gb ddr4

Storage: 1tb nvme, 256gb SATA SSD, 1tb HDD

And speaking of storage, which is the best setup/option for storage for vfio, I saw a video made by blandmanstudios about the performance differences between qcow2, raw partitions and just passing in the whole (m.2 I think) drive but I'm not sure which is the better option, should I just use the qcow2 uhh image or what?

I have two monitors available

1: 165hz 1080p which is my main monitor 2: 60hz 1600x900 which is my secondary monitor

But I would rather just use a single monitor with looking glass

Unfortunately in my country I can't find a dummy plug at all for looking glass but correct me if I'm wrong, it's possible to use two ports on the same monitor

How do I proceed? Sorry a bit of a long post I appreciate any of you who read this

thanka to the encoragement from all the questions and head scratching, i have finally figured out what was wrong, while all the solution wasnt the problem it gave me enough momentum to push to figure out what it was

the problem was just a simple 2 lines, vendor ID and hidden state

now i have a functioning Windows VM with single GPU passthrough on a RX7600 to experiment with ^w^

hello everyone, im wondering if i could passthrough my dedicated gpu to a windows vm and have my iGPU take over my host system?

would it be roughly the same steps as if i had two dedicated gpus or different? and would looking glass be feasible or any alternative

thanks

https://www.reddit.com/r/linux/comments/1i2wpb2/amdgpu_virtio_native_context_merged_native_amd/ https://www.phoronix.com/news/AMDGPU-VirtIO-Native-Mesa-25.0

Sources claim this could allow some benchmarks to run at 99% of bare metal speed within VM instances. But what hardware is required for this? And what about drivers in Windows VM instances?

Hello! I got this laptop and I'm using it as a home-server with AlmaLinux 9 server on it. I am trying to fire up a virtual machine with gpu passthrough(using the integrated one).

When I try to fire up the machine with qemu:

virt-install --name windows11 --ram=8192 --vcpus=8 --host-device 00:02.0 --cpu host --hvm --disk path=/home/ISOs/w11vml,size=80 --cdrom /home/ISOs/W1.iso --graphics vnc,port=5901,listen=0.0.0.0,passwd='123456'

I get ERROR unsupported configuration: host doesn't support passthrough of host PCI devices

I've been fallowing this tutorial and I'm stuck at this point. I have VT-D and Virtualisation enabled in BIOS, but some says that I also need the SR-IOV option WHICH I could not find it anywhere in the BIOS. Is it really needed? Should I stop wasting my time searching here and there for tutorials as this system may not support GPU Passthrough?
Any help would be appreciated, ty

Are there any updated verisons of the BIOS/firmware for the reference AMD Radeon 7900 XT? I have one that was branded ASUS.

I'd like to flash it to get rid of the reset bug when passing through to virtual machines, but I can't find any updates for the reference model like I can for third party models.