PCIE passthrough GPU - choosing compatible AM5 hardware beforehand

BarriBurt

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G'day all. Finally looking to refresh the old desktop at home.
Target state is a Linux PC, able to host VMs, play games and interact with various hardware items. I might even get it access to work, we'll see, that's just a stretch goal.
I've been trying this with legacy hardware. Plenty of stuff either works via Proton or works natively. Already enough to make me fairly happy - until the GPU died, hence I'm now shopping around. Intend to go AM5+Radeon7k.

Have seen and read about running a Windows VM for gaming titles that refuse to run natively, versus simply dual booting. Apparently there is a hardware limitation to consider - IOMMU groupings, which premium mainboards like ASrock Taichi, Gigabyte Aorus or Asus ROG offer but is often sketchy on anything under $500aud. Who's tried that? If your M/B doesn't feature IOMMU groupings suitable to the task, is there a workaround?

Was hoping the Asrock x670e Steel Lightning would cut it, the price is good, but forum feedback from a user with those was negative last year.
Gigabyte Tough Gaming x670e maybe? Price is fair. Integration with Corsair iCue a bonus. Can either control that with native Linux software or pipe it to a Win VM for iCue. But unsure of IOMMU aspect.
ASRock Taichi is apparently great, but yeesh, the price on those things.
Source: level1techs.com

Now I can keep researching the above and find stuff that should work, but I haven't found anyone saying whether you can switch the GPU from feeding the guest back to feeding the host without restarting. A lot of what I'd play is either Proton supported or native Linux, it's only the odd title that even requires Windows now (what a change right?). And dual boot doesn't require premium anything, but dropping out of Linux to warm up Windows just for a fussy game would be annoying.

If a hypervisor can push the GPU to a VM, and hand it back after, that's a clear advantage and I'd pay more for a mainboard to have that option. Has anyone tried doing that? How'd it go?
 
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Follow up edit, on the ASrock Steel Legend: there's hope! Regarding IOMMU groups at least. Looks like this model may suffice.

Doesn't indicate much hope on the main question above - can you switch the GPU back to the host PC without a computer restart? I'm not holding my breath.
 
Doesn't indicate much hope on the main question above - can you switch the GPU back to the host PC without a computer restart? I'm not holding my breath.
Probably not because there are drivers involved on both the host and the vm that get loaded during boot.
However, due to their size and complexity, GPU drivers do not tend to support dynamic rebinding very well, so you cannot just have some GPU you use on the host be transparently passed to a virtual machine without having both drivers conflict with each other.

Warning: Once you reboot after this procedure, whatever GPU you have configured will no longer be usable on the host until you reverse the manipulation. Make sure the GPU you intend to use on the host is properly configured before doing this - your motherboard should be set to display using the host GPU.
 
F33dm3bits again! You're a help, thanks mate.

Yeah I'm getting that impression. Seems like more of a flex than a practical option.... well, not entirely, it would save someone buying an extra drive to dual boot with. There's that at least.

Well, with Proton development steaming ahead (punny, right? right? I'm a Dad I'm allowed) this novel solution of a PCIE-passthrough VM may be losing relevance in any case.
 
Well, with Proton development steaming ahead (punny, right? right? I'm a Dad I'm allowed) this novel solution of a PCIE-passthrough VM may be losing relevance in any case.
I have been using Linux for quite some time now and I have never used a vm to game on Linux. I use Proton for 99% of my games that I play via Steam and I have several games that I play through Lutris. Although I do have to admit I don't play any of the big mulitplayer games that require kernel level anti-cheat and I wouldn't want to play them either just because of that.
 


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