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A comment on Looking Glass: Run a Windows VM on Linux in a window with native performance. Parent comment

Re:Looking Glass: Run a Windows VM on Linux in a window with... by imhoguy on Sunday July 18, 2021 @03:10AM (#27871248)
Wouldn't be it possible to let Linux/Xorg give up GPU for a time Windows is used? Which could still let me access it via VNC from Windows. My native platform is Xubuntu on AMD Renoir laptop.
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Re:Looking Glass: Run a Windows VM on Linux in a window with... by guilhas on Sunday July 18, 2021 @05:01AM (#27871632)
That is already possible without the Looking Glass. Just regular libvirt GPU passthrough.

I would say the use case here would be a machine that does not have a monitor connected, for example some Bitcoin mining server in the attic. With Looking Glass the game screen can get streamed to a ultrabook in your living room, with the server GPU performance

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Re:Looking Glass: Run a Windows VM on Linux in a window with... by pizza234 on Sunday July 18, 2021 @04:35AM (#27871560)
It's technically possible, but not stable. On my system, it's not stable, so I prefer to have two cards, but YMMV.
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Re:Looking Glass: Run a Windows VM on Linux in a window with... by genewitch on Sunday July 18, 2021 @03:43AM (#27871370)
If this uses vfio then no, the host never sees the GPU, it's blind to it from boot.
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Re:Looking Glass: Run a Windows VM on Linux in a window with... by fulafel on Sunday July 18, 2021 @03:55AM (#27871434)
What is stopping GPU hot plugging from working?

There was this recent improvement at least: https://phoronix.com/scan.php?page=news_item&px=Linux-5.14-A...

edit: seems there are some howtos - eg https://github.com/joeknock90/Single-GPU-Passthrough

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Re:Looking Glass: Run a Windows VM on Linux in a window with... by pizza234 on Sunday July 18, 2021 @07:55AM (#27872199)
Two reasons (in the context of a standard desktop user, not headless server):

1. Desktop environment, which uses the video card; this is not a big deal, since one can terminate the session

2. video drivers correctly and fully releasing the card; this is possible, but in my opinion, not stable.

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Re:Looking Glass: Run a Windows VM on Linux in a window with... by throwaway2048 on Sunday July 18, 2021 @03:55AM (#27871433)
Not really a problem, you can unbind the VFIO driver
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Re:Looking Glass: Run a Windows VM on Linux in a window with... by genewitch on Sunday July 18, 2021 @02:52PM (#27875414)
> linux /vmlinuz-5.10.27-gentoo root=/dev/nvme0n1p2 ro amd_iommu=on iommu=pt pcie_acs_override=downstream,multifunction pci-stub.ids=10de:1b82,10de:10f0

the host never sees the card.

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Re:Looking Glass: Run a Windows VM on Linux in a window with... by throwaway2048 on Sunday July 18, 2021 @07:48PM (#27877786)
thats using the pci-stub driver, not VFIO
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