Is Looking Glass Necessary? KVM/VFIO
ฝัง
- เผยแพร่เมื่อ 7 ก.พ. 2025
- Have you ever played a game in a SPICE virtual display? (its terrible)
Full test footage here: • [VFIO Benchmarks] Look...
Tutorials for how to set something like this up
• Beginner VFIO Tutorial
• Install Looking Glass ...
you can find my other creative endeavors at:
blandmanstudios...
blandmanstudios...
/ blandmanstudios
/ blandmanstudios
![[tutorial] The Ultimate Linux Laptop for Gaming - feat. KVM and VFIO](http://i.ytimg.com/vi/m8xj2Py8KPc/mqdefault.jpg)
Thank you so much for actually benchmarking this. Spice + passthrough is now something I will consider for non-latency sensitive work.
Nice! Glad it's helpful!
There's a obs plugging now I think where can directly pipe output into obs
Thanks for your videos these helped me a lot
@@alone-vf4vy glad to hear it! Thanks for the comment!
It would be interesting to see a comparison to native windows as well.
Native Windows benchmarking is always going to be higher than VFIO passthrough, so it's not needed.
Is the stuttering in the Halo gameplay on Looking Glass just issues with the recording?
The stutters still make the game look unplayable to me.
I'm not 100% sure this still applies, but when I used Looking Glass a few years ago I found through trial and error that you should keep the VM away from the first physical core, use CPU pinning and use the `isolcpus=` Linux kernel argument to isolate the threads you'll run the VM on. In my case I had the VM on threads 2 through 5, so I used `isolcpus=2-5`. This made the Linux scheduler not schedule work on the threads and remap as many interrupts as possible to go through other cores, which is perfect for real time processes like a gaming VM.
Note that you can still run things on those isolated threads from Linux but you'll have to manually tell the scheduler to use those treads (usually with the `taskset` command, in my case I would use something like `taskset 0xFF firefox`).
I'd love to know your opinion about VGPU and ability to use one GPU for multiple VMs ?
My current opinion is that it would be awesome
I'd really like to split a GPU between guest and host or split multiple guests
I think NVIDIA's expensive commercial grade GPUs have the option to do it. I haven't tried any of the consumer grade options like vgpu_unlock
Good comparison.
Thanks!
Really want to start using NixOS on my desktop computer, but i really needed to run zbrush and other 3d software packages. Will try replicating your setup on a laptop, if it works, then will switch to linux at last. Dual booting is not for me, but vm with gpu should be the best option!
I watched a video on how to install Lookingglass and it looked so daunting I would just rather pay $10.00 / mth for parsec that takes 5 mins to setup.
I hate TH-cam so much, I have tried to reply several times now with some extra information that might be of use to you but YT just deletes anything I post that might contain a link. Hit me up in Discord and i'd be happy to provide it there.
I'd love to join a server about virt-manager related talks too! Is there an official server already?
@@Cameronsplaze I did post a link to it but TH-cam just deleted it again. There are two communities here, VFIO and Looking Glass. Based on your comment you'd more likely want the VFIO discord, which a quick search turns up as the first result :)
@@gnif Yep, just found it. Thanks for the info!
What if we skip both of them? Connect the display directly to the GPU, would we regain all the lost performance?
Also, something that I'm thinking of, would we be able to put 2 monitors side by side one connected to passthroughed GPU and one running the linux host and move the mouse between them?
Another wonderfull video, great content, until the end of the year I'll built another desktop and come back to linux.
Thanks! That'll be an exciting time of year :)
has anyone had any luck running fortnite inside a windows VM like this? or is that one of those games that detects that its running in a vm? i would really love to get rid of my dual boot setup because theres been a few windows updates the last year or 2 that have caused me major headaches. i like playing fortnite too though but dual booting is starting to be too much effort just for 1 game
I'm now looking at the option of buying server EATX motherboard with dual CPUs with QEMU version 4 x86-64 ABI compatibility levels like Skylake-Server-v4. I'm looking at the possibility to dedicate one of the CPUs for virtualization only, use PCI passthrough for GPU, use SSD passthrough to access raw physical disk (I don't plan to use snapshots). That way you can use Windows 10 for gaming and work without dual-boot, but you still CAN dual-boot when necessary (for solving problems like anti-cheat software or other software that locks when virtualization is detected).
Also, I would stress on making Windows 10 custom installation ISO that already includes VFIO drivers and debloated to minimum.
A couple of problems though: tremendous cost, finding good cooling for 2 CPUs, finding good EATX case and energy consumption (2 server-grade CPUs + 1 or 2 good GPUs will require solid >1000W power supply). Not to mention that ECC RAM is preferred and around 64 GB is needed (32 GB on Windows 10 machine is long-term good solution and using half of RAM is general rule for VM). Also, I would start to think about data backups (like SSD RAID 1) so additional storages are needed. But this could be good long-term investment. That way I could get server-grade Linux machine with good processing power for like multithread compiling, less software trackers, very good level of security and privacy, needed software at fingertips on the terminal and capable dedicated Windows 10 gaming machine when needed, isolated from my work.
Everything you need. Maximum power. Simultaneous access. All in one case.
Woah that could be a pretty cool build! It would almost be like 2 PCs in one case. Sometimes they're both working together for server grade multi-threading. Sometimes they're doing different things so you can have the best of both operating systems
thank you!
Can u make video on build and setting up looking glass plz
It's on my list, I'm glad to know you're interested!
Is there a way to share your xml for the spice VM? I'm curious where the bottleneck is exactly, and if there's a way to reduce that latency in spice. My initial thoughts are:
- Maybe it's not using virtio drivers?
- Or maybe there's a way to have virt-manager listen on a spice socket, instead of over the network card address? Not sure if this is possible yet, but I started researching it my self for something similar.
Or maybe spice is just an expensive protocall, and there's no way around it. Great video! I love these comparisons. This one definitely surprised me.
When using SPICE for video it's compressing the video and streaming it over a network socket, this is where all the latency comes from. There is no way to improve on the latency that SPICE introduces except to use shared memory, which is what Looking Glass is doing.
@@gnif After some research, it's possible to disable compression, and avoid the network stack entirely. It's possible all the latency comes from the shared memory like you mentioned, but I'm curious how close it'd be. You can setup the initial VM with something like `virt-install --connect qemu:///system --noautoconsole --name=TestVM --graphics type=spice,listen=socket,image.compression=off`. It's a small change, so editing the xml should "just work" (TM).
@@Cameronsplaze listen=socket = network stack... also LG does far more then just improve video latency, we have our own ultra low latency lock-less implementation of the SPICE protocol, as well as audio streaming that uses an adaptive resampler to keep sync as close as possible (see: Controlling adaptive resampling - Kokkini Zita). An enormous amount of work has gone into making LG ultra low latency, to the point being faster then the physical GPU output when configured and tuned right (yes, this doesn't seem possible, I would post a link to demo this but YT yeets anything I post with a URL). Also note that LG was written because virt-viewer is useless for gaming, it was the primary motivation for this project.
@@Cameronsplaze Trying to post this anyway as a separate post, so if it gets deleted at least my other post here still:
th-cam.com/video/kX4IOadmVqU/w-d-xo.html
Recorded at 100fps, 1080p @ 60Hz, left monitor is Looking Glass, right monitor is directly connected to the GPU. Each square is on for exactly one frame. Once LG syncs up (takes about 1-2 seconds after launch) you will see it's consistently ahead of the direct output. Both monitors are identical make model and batch, were purchased at the same time. There is the odd frame skip as this is quite an old release now (between B4 & B5, we are almost ready to release B6)
@@gnif Thanks!! The reason I'm curious with all this, is I'm writing something similar to virt-manager, that solves a different use case. I'm getting close to the part where I need to add some sort of "virt-viewer" that has no latency. This is out of scope of this video though, so can I hit you up on the LG Discord sometime? I'm curious how good of a fit LG might be.
Can u make a proxmox video.. will it give the same performance?
I'm interested in proxmox but haven't tried it yet. Hopefully it'll make it onto the video schedule soon. Thanks for the suggestion!
Hi, quite interesting but for so far I couldn't find a way to use spice, I've just linked my GPU and it's working with Steam Link but as soon as I try to use spice I think I end up connecting to the generic graphic card and I can't control anything.
Will try to put a mouse on the VM and try to disable the generic graphic card ...
What about high fps games like csgo? Last time I tried VFIO GPU pass-through all the games were unplayable because the stuttering. It was about 2 years ago. They had high fps, mut really noticeable stutter. And I was connected straight to the gpu with the screen. Did I configure something badly or has this VFIO improved at all?
Did you do CPU pinning? Cause for games like CSGO they're CPU limited, not GPU limited.
Maybe we should synchronize two atomic clock and compare when something in generated in host game server in server farm and when its loaded in local player machine
No! 1000/60=16.6666 ms, not 33.3333 ms
Tl;dw, yes... Oh god, yes
😂 best summary yet
Is the spice server with PCI pass-through? If so, do you have a tutorial on how to set that up?
Please get a capture card. This hurts my brain.