3 ms·

Is pass-through good enough on modern hardware where I can just run a windows VM for gaming and then shutdown windows when I'm done? This would be the ideal sce

Is pass-through good enough on modern hardware where I can just run a windows VM for gaming and then shutdown windows when I'm done? This would be the ideal scenario for me. I applaud Valve's efforts with proton, but I think Microsoft will start pushing back. I bet starfield will be very difficult to run well in Linux, for example.

genewitch 3y ago
yes, with vfio. I've had a windows 10 in a VM on my "main desktop" for nearly 3 years now. Gentoo gets two screens and an "ok" GPU, windows gets the beefier GPU and its own screen. I use qemu, there may be other ways to do it. The linux machine can't "see" the other GPU or screen(s). if you want to do this, there are a couple of gotchas. One i'd recommend bearing in mind is not using identical cards. Either two vendors or two different types of cards (like a 1060 and a 1070). This makes it easier to stub the windows card and also write/edit the scripts (which are probably searchable on goog with "vfio-bind"). The second is one that i lost the information about, but if it affects you, it should be possible to dig up the info. Some games get micro-stuttering or stuttering when running with vfio under qemu; the fix can be an application that applies settings on windows or editing the windows registry. All that aside, it works fine. The audio latency is minimal, but if you have a machine with more than 24 PCIe lanes, you can just dedicate an entire USB PCI card to windows, passing that through and plugging all the windows related hardware through that. I think Linus (LTT) mentioned doing something like this, virtualizing even multiple windows machines on a single machine with the threadripper (32-64 lanes) and Epyc (64, 96, or 128 lanes) - having a dedicated USB and GPU for each virtualized desktop. Nice.
- intelVISA 3y ago
  Fwiw the stuttering fix you describe is likely moving from IRQ to MSI, it's common to edit the passed-through PCI device in regedit to use MSI (message signalled interrupts) instead.
  - genewitch 3y ago
    Yes, that's what it was. And i just remember the arch wiki had something about it back when i set it up, but it was[0] incomplete - it fixed most of the issues i had with my setup, but not the MSI (i think) stuff. The site that did have the correct information and possibly even a windows download link was light grey text on a black background, and otherwise a very minimal site. I had it bookmarked on firefox on an old PC, and for some reason firefox loves deleting history/bookmarks that are older than some age. I've never bothered to track it down and it bites me every couple of years when i try to find/remember information just like this. Technology, it's so advanced. [0] it may be more complete now. I probably wouldn't do this again myself; but at the time i had been "selling" this service (qemu/xen virtualization of PCI cards) for linux on linux for over a decade, so it was something i already knew enough about to stumble through - windows on linux.
hot_gril 3y ago
Oh by all means I would just boot into Windows or have a separate PC for video games if I cared about them. Not worth messing with emulation unless you find it fun.
- deelowe 3y ago
  Not emulation, virtualization. That would be easier than emulation or dual booting, if it worked well. Surely virtualization must be getting pretty good given it's ubiquitous use in the cloud. In fact, I was hoping that one day we'd see games distributed in a fully containerized manner so that the OS becomes irrelevant. That's probably just a pipe dream though...

genewitch 3y ago

yes, with vfio. I've had a windows 10 in a VM on my "main desktop" for nearly 3 years now. Gentoo gets two screens and an "ok" GPU, windows gets the beefier GPU and its own screen. I use qemu, there may be other ways to do it. The linux machine can't "see" the other GPU or screen(s). if you want to do this, there are a couple of gotchas. One i'd recommend bearing in mind is not using identical cards. Either two vendors or two different types of cards (like a 1060 and a 1070). This makes it easier to stub the windows card and also write/edit the scripts (which are probably searchable on goog with "vfio-bind"). The second is one that i lost the information about, but if it affects you, it should be possible to dig up the info. Some games get micro-stuttering or stuttering when running with vfio under qemu; the fix can be an application that applies settings on windows or editing the windows registry. All that aside, it works fine. The audio latency is minimal, but if you have a machine with more than 24 PCIe lanes, you can just dedicate an entire USB PCI card to windows, passing that through and plugging all the windows related hardware through that. I think Linus (LTT) mentioned doing something like this, virtualizing even multiple windows machines on a single machine with the threadripper (32-64 lanes) and Epyc (64, 96, or 128 lanes) - having a dedicated USB and GPU for each virtualized desktop. Nice.

intelVISA 3y ago
Fwiw the stuttering fix you describe is likely moving from IRQ to MSI, it's common to edit the passed-through PCI device in regedit to use MSI (message signalled interrupts) instead.
- genewitch 3y ago
  Yes, that's what it was. And i just remember the arch wiki had something about it back when i set it up, but it was[0] incomplete - it fixed most of the issues i had with my setup, but not the MSI (i think) stuff. The site that did have the correct information and possibly even a windows download link was light grey text on a black background, and otherwise a very minimal site. I had it bookmarked on firefox on an old PC, and for some reason firefox loves deleting history/bookmarks that are older than some age. I've never bothered to track it down and it bites me every couple of years when i try to find/remember information just like this. Technology, it's so advanced. [0] it may be more complete now. I probably wouldn't do this again myself; but at the time i had been "selling" this service (qemu/xen virtualization of PCI cards) for linux on linux for over a decade, so it was something i already knew enough about to stumble through - windows on linux.

hot_gril 3y ago

Oh by all means I would just boot into Windows or have a separate PC for video games if I cared about them. Not worth messing with emulation unless you find it fun.

deelowe 3y ago
Not emulation, virtualization. That would be easier than emulation or dual booting, if it worked well. Surely virtualization must be getting pretty good given it's ubiquitous use in the cloud. In fact, I was hoping that one day we'd see games distributed in a fully containerized manner so that the OS becomes irrelevant. That's probably just a pipe dream though...