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Running a virtual machine with PCI-e passthrough using IOMMU virtualization (e.g. intel_iommu in linux) is a popular option in gaming while using the Intel inte

by exDM69 10y ago

Running a virtual machine with PCI-e passthrough using IOMMU virtualization (e.g. intel_iommu in linux) is a popular option in gaming while using the Intel integrated for the Linux desktop. I recently saw someone get better benchmark (Futuremark) results with Win10 running in a VM on Linux than native Win10. I haven't tried this personally yet, but I do intend to.

cm3 10y ago
And isn't this something that Nvidia artificially disables in consumer cards while AMD has no such limitation for passthrough?
- wjoe 10y ago
  They have attempted to in the past, but all it takes is one extra switch on KVM to get around any restrictions for passthrough to Nvidia cards. I currently have that setup running myself and it works perfectly.
- matxip 10y ago
  I'm currently passing though a GTX 760. It was apparently a hassle in the past, but the bypasses are basically built in to the tools now. Nvidia is calling the blocking behavior a "bug", but the have no intention to act on it.
  - throwaway2048 10y ago
    It is not a bug. The windows driver contains KVM signatures, aswell as signatures for Hyper V extensions, and if they are enabled the driver fails to run. However if you modify the signatures in KVM and in HyperV devices, everything works fine. This is clear cut NVIDIA malfesence.
    - matxip 10y ago
      That's why I put it in quotes. It's pretty clear the original intent was to push people to get Quattro cards for using in VMs. My impression is that they gave up on the idea for normal users and are trying to play it off while suggesting they aren't going to fuck with people any further.
      - matxip 10y ago
        I should also specifically note that you don't need to manually change the signature anymore. It's built in now.
    - cm3 10y ago
      This should be documented and spread more widely. Nvidia seems to use the same tactics as Intel in market segregation and also some semi-related bullying tactics.
pizza234 10y ago
It's not a stable solution, and there are two problems with this kind of things. The first is that it's pure, unsubstantiated, guesswork. You'll spend countless hours changing obscure undocumented parameters hoping that things will work. I tried, and it's not a fun thing to do, because you don't learn anything substantial. Second, this type of operations have a sky-high level of brag factor. People will tell on their blogs/posts that they succeeded in "making XXX work and that it's stable", but they don't tell you that their computer explodes (so to speak) two minutes after they start XXX. Again, I know because I've worked on similar things, and the patterns are the same. You may be lucky, but if you aren't, it's a lot of time wasted (it always looks like the "final solution" is behind the corner!).
- cm3 10y ago
  The guys from LinusTechTips have used Unraid (a paid KVM+BTRFS based NAS+VM appliance) to do this with a 7 or 8 GPU machine. See 7 gamers one PC on YouTube. It seemed to be simple to set up, once you have configured the BIOS.
  - eumoria 10y ago
    https://www.youtube.com/watch?v=LXOaCkbt4lI https://www.youtube.com/watch?v=LXOaCkbt4lI is the video. It took them a bit of work but stability is possible.
- fpgaminer 10y ago
  Yeah, it can be a bit guessworky, but that's only because it's bleeding edge stuff. The corners are being sanded down and things are getting better rapidly. I've been happy with the amount of work that I've put into my setup versus the results. And my setup is definitely not one that causes my computer to explode. In fact, I've never had my host machine fail. The VM only bugged out once. This is after long sessions of CS:GO, Overwatch, Game of Thrones, StarCraft 2, etc.
- matxip 10y ago
  I was pretty apprehensive about the concept, but hopeful enough to get a new mobo/CPU just to give it a shot. It does definitely seem to good to be true. I went for it, and it actually ended being significantly easier and better performing than I expected. I did have to take a few days and learn a bit about qemu, but I'd expect that much. I will say that older motherboard (perhaps some new ones too) might not have firmware that fully support what's being done here. It's hard to say which, but you can see what people have had success with if you search around (Asus z170a works for me). This is a little light on details but is a good resource for the steps involved: https://wiki.archlinux.org/index.php/PCI_passthrough_via_OVMF https://wiki.archlinux.org/index.php/PCI_passthrough_via_OVM...

by exDM69 10y ago

cm3 10y ago

And isn't this something that Nvidia artificially disables in consumer cards while AMD has no such limitation for passthrough?

wjoe 10y ago
They have attempted to in the past, but all it takes is one extra switch on KVM to get around any restrictions for passthrough to Nvidia cards. I currently have that setup running myself and it works perfectly.
matxip 10y ago
I'm currently passing though a GTX 760. It was apparently a hassle in the past, but the bypasses are basically built in to the tools now. Nvidia is calling the blocking behavior a "bug", but the have no intention to act on it.
- throwaway2048 10y ago
  It is not a bug. The windows driver contains KVM signatures, aswell as signatures for Hyper V extensions, and if they are enabled the driver fails to run. However if you modify the signatures in KVM and in HyperV devices, everything works fine. This is clear cut NVIDIA malfesence.
  - matxip 10y ago
    That's why I put it in quotes. It's pretty clear the original intent was to push people to get Quattro cards for using in VMs. My impression is that they gave up on the idea for normal users and are trying to play it off while suggesting they aren't going to fuck with people any further.
    - matxip 10y ago
      I should also specifically note that you don't need to manually change the signature anymore. It's built in now.
  - cm3 10y ago
    This should be documented and spread more widely. Nvidia seems to use the same tactics as Intel in market segregation and also some semi-related bullying tactics.

pizza234 10y ago

It's not a stable solution, and there are two problems with this kind of things. The first is that it's pure, unsubstantiated, guesswork. You'll spend countless hours changing obscure undocumented parameters hoping that things will work. I tried, and it's not a fun thing to do, because you don't learn anything substantial. Second, this type of operations have a sky-high level of brag factor. People will tell on their blogs/posts that they succeeded in "making XXX work and that it's stable", but they don't tell you that their computer explodes (so to speak) two minutes after they start XXX. Again, I know because I've worked on similar things, and the patterns are the same. You may be lucky, but if you aren't, it's a lot of time wasted (it always looks like the "final solution" is behind the corner!).

cm3 10y ago
The guys from LinusTechTips have used Unraid (a paid KVM+BTRFS based NAS+VM appliance) to do this with a 7 or 8 GPU machine. See 7 gamers one PC on YouTube. It seemed to be simple to set up, once you have configured the BIOS.
- eumoria 10y ago
  https://www.youtube.com/watch?v=LXOaCkbt4lI https://www.youtube.com/watch?v=LXOaCkbt4lI is the video. It took them a bit of work but stability is possible.
fpgaminer 10y ago
Yeah, it can be a bit guessworky, but that's only because it's bleeding edge stuff. The corners are being sanded down and things are getting better rapidly. I've been happy with the amount of work that I've put into my setup versus the results. And my setup is definitely not one that causes my computer to explode. In fact, I've never had my host machine fail. The VM only bugged out once. This is after long sessions of CS:GO, Overwatch, Game of Thrones, StarCraft 2, etc.
matxip 10y ago
I was pretty apprehensive about the concept, but hopeful enough to get a new mobo/CPU just to give it a shot. It does definitely seem to good to be true. I went for it, and it actually ended being significantly easier and better performing than I expected. I did have to take a few days and learn a bit about qemu, but I'd expect that much. I will say that older motherboard (perhaps some new ones too) might not have firmware that fully support what's being done here. It's hard to say which, but you can see what people have had success with if you search around (Asus z170a works for me). This is a little light on details but is a good resource for the steps involved: https://wiki.archlinux.org/index.php/PCI_passthrough_via_OVMF https://wiki.archlinux.org/index.php/PCI_passthrough_via_OVM...