I’m not allowed to post links to the documentation and github repo so I had to break the markdown.
I have Looking Glass working great with Windows 10/11 guest VMs to my linux host/hypervisor, but I want to connect linux guests to the same applications.
For the host, I use the same libvirt XML snippet to create the client backing store:
<shmem name="looking-glass"> <model type="ivshmem-plain"/> <size unit="M">32</size> </shmem>
In the guest, I’ve compiled both the [kernel module] (ttps://looking-glass.io/docs/B5.0.1/module/#compiling-loading-manual) and [host binary] (ttps://looking-glass.io/docs/B5.0.1/build/#for-linux-on-linux) according to the instructions.
$ ls -l /dev/kvmfr0 crw-rw----+ 1 user kvm 243, 0 Mar 19 14:56 /dev/kvmfr0 $ lspci -k -s 02:01.0 02:01.0 RAM memory: Red Hat, Inc. Inter-VM shared memory (rev 01) Subsystem: Red Hat, Inc. QEMU Virtual Machine Kernel modules: kvmfr
But when I run the host binary, it does not report that the Capture has Started:
$ ./build/looking-glass-host [I] 4596620845 app.c:520 | app_main | Looking for configuration file at: /home/user/looking-glass-host.ini [I] 4596620888 app.c:522 | app_main | Configuration file loaded [I] 4596620894 app.c:544 | app_main | Looking Glass Host (B5.0.1+) [I] 4596620972 cpuinfo.c:36 | lgDebugCPU | CPU Model: Intel Xeon Processor (Cooperlake) [I] 4596620978 cpuinfo.c:37 | lgDebugCPU | CPU: 4 cores, 8 threads [I] 4596620980 ivshmem.c:128 | ivshmemOpenDev | KVMFR Device : /dev/kvmfr0 [I] 4596621813 app.c:561 | app_main | IVSHMEM Size : 32 MiB [I] 4596621820 app.c:562 | app_main | IVSHMEM Address : 0x7F3876831000 [I] 4596621821 app.c:563 | app_main | Max Pointer Size : 1024 KiB [I] 4596621822 app.c:564 | app_main | KVMFR Version : 14 [I] 4596622837 app.c:625 | app_main | Max Frame Size : 14 MiB [I] 4596622847 app.c:650 | app_main | Trying : XCB [I] 4596623084 xcb.c:107 | xcb_init | Frame Size : 1920 x 1080 [I] 4596623111 xcb.c:125 | xcb_init | Frame Data : 0x7F3876048000 [I] 4596623118 app.c:675 | app_main | Using : XCB [I] 4596623120 app.c:676 | app_main | Capture Method : Asynchronous
(This is the end of the log; the application has not [printed] (ttps://github.com/gnif/LookingGlass/blob/B5.0.1/host/src/app.c#L350)
==== [ Capture Start ] ====)
I ran it though gdb and found that it’s just in an infinite loop at [lgmpHostQueueHasSubs] (ttps://github.com/gnif/LookingGlass/blob/B5.0.1/host/src/app.c#L694-L695).
I’m not familiar with the Looking Glass protocol. How does the host queue get subs?
I’m not sure what else I can do to connect the kernel module in the guest to the IVSHMEM file on the hypervisor. I’m unsure of if I need to install the kernel module on the host as well, but then what’s the point of the IVSHMEM file in libvirt…
On a slightly unrelated note, the [source repository] (ttps://github.com/gnif/LookingGlass/blob/B5.0.1/module/Makefile#L15) has a
make load command that wants to find a
/dev/uio0 device, but my uio module doesn’t make that…?
$ ls -l /dev/uio* ls: cannot access '/dev/uio*': No such file or directory
Thanks in advance,