Is it possible to forward a second video card to KVM and use one monitor?

Question

KVM

Given:
Computer running Ubuntu
Components - any (preferably a laptop)
Monitor - any, but 1 pc.
Conditions:
As the main system - Ubuntu
In the virtual machine, as needed, Windows7 is launched
. The second video card is forwarded into the virtual machine.
Challenge:
Run resource intensive 3D applications on Windows 7
Be able to instantly switch to and from Ubuntu.
Variants with additional cables, adapters and monitors with multiple video inputs are not suitable.
Wine - not suitable
A slight drop in 3D performance is expected.
What was done:
A Radeon 7870 was successfully forwarded in KVM, but the picture was received only by the video outputs of this video card (on an external monitor).
Thanks in advance for your valuable advice.

Answer 1

Well, you won’t do anything else if you forward the video card - there will be an acceleration from it, but it only gives out a picture for itself. Through VNC some thread will brake. And the option "take this picture with a grabber, wrap it in a computer from a grabber and look into it" I think will not work even more than the second cable to the monitor and switch video outputs;)

Answer 2

You can try looking glass:
https://looking-glass.io/
https://wiki.archlinux.org/title/PCI_passthrough_v...
It works fine with intel gvt-g, but it may not work if it is the main The "display" in the virtual machine is selected from the virtual video adapter with 2d (qxl, qemu vga, ...). Checked by reading logs in %ProgramData%\Looking Glass (host)\