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Looking glass questions - trying to get it working

Hi All,

I’m running on Fedora 34, have qemu & vfio gpu passthrough working with output to external display and keyboard/mouse. Now I’d like to install Looking Glass and have the following questions:

Is the .exe package that is run and installed on Windows “host”, the one where the PCIe* driver is installed manually by looking for it in the system part of device manager, supposed to create the shared memory file in /dev/shm and will name it “looking-glass”? Or is this something supposed to be created by the Linux host
OS upon reboot?

At first when trying to run ./looking-glass, I got a permission denied error for path /dev/shm/looking-glass , and I had tried manually creating an empty file by that name and also removing it and in both cases I got the permission denied error. When I changed the permissions, I wound up getting an error about could not map to the /dev/shm/looking-glass or something to that effect.

So I recalled that you’re supposed to start the Windows VM before you start Looking Glass, so was thinking that the Windows “host” (VM) is supposed to have the shared memory driver installed and maybe after you do that and reboot, the shared memory file gets created at /dev/shm/looking-glass so that when I run Looking Glass the error will go away.

Am I correct of off the mark?

Also, I followed the Looking-Glass directions but also looked at some other directions online and those have more steps involved… like creating a *.conf file with a command line for 0600 chmod permissions.

So it seems that the Looking-Glass website setup guide is missing some stuff or is it unnecessary?

Thanks!

The guide on the LG website targets a Debian system, it should work for other distributions also but we can’t test all the possible Linux variants and versions out there.

The host executable does not create the /dev/shm/looking-glass file, QEMU does this when it starts provided you added the IVSHMEM device to it and configured it correctly.

It seems you have missed this step, see:

https://looking-glass.io/docs/stable/install/#libvirt-configuration