Overview
Looking Glass displays a Windows virtual machine in a low-latency Linux window. It transfers completed frames through shared memory instead of sending compressed video over a network. The current IDD provides video and direct input through LGMP, while SPICE normally provides audio, clipboard and fallback services.
The names used throughout this guide are:
- Linux host
The physical machine running KVM/QEMU and the Looking Glass Client.
- Windows guest
The Windows virtual machine shown by Looking Glass.
- Looking Glass Client
The Linux application that displays the guest and sends user input. There are currently no distribution packages for it, so it must be built from source before installation.
- Looking Glass Server
The Windows guest application that generates the video feed for the Looking Glass client. There are broadly two implementations of the server: the Looking Glass IDD and the legacy host application.
- Looking Glass IDD
The recommended Windows Indirect Display Driver. It creates a virtual monitor, sends its frames to the client and provides direct keyboard and mouse input. The installer also includes the IDD helper and input driver.
- Legacy Host Application
The older Windows capture application. It captures an existing display rather than creating a virtual one. It is documented for existing B7 workflows, but is no longer recommended for current installations.
- KVMFR and IVSHMEM
The shared-memory path between the Windows guest and Linux host. KVMFR is the recommended Linux kernel module because it permits direct GPU imports where supported.
- LGMP
The protocol used by Looking Glass components over shared memory.
- SPICE
An optional fallback transport for video, input, audio and clipboard services. With the IDD active, Looking Glass normally uses its direct input path and uses SPICE only for services that are enabled and available.
Recommended setup
For a new installation, use:
the current Looking Glass Client on the Linux host;
KVMFR shared memory attached to the Windows guest;
the matching Looking Glass IDD in the Windows guest; and
SPICE only for the fallback or convenience services you need.
Use matching Looking Glass releases for the current client, IDD, and OBS plugin. The shared-memory protocol changes between releases and incompatible components will not connect. Users of the legacy host application must use the complete matching B7 stack described below.
Legacy Host Application
The Host Application is the legacy implementation of the Looking Glass server. The IDD is recommended because it does not require a physical monitor or dummy plug and supports current display, input and scheduling features.
If your workflow specifically requires non-capture mouse input with the Host Application, B7 is the last recommended release. Use the matching B7 client, Host Application and B7 documentation together; do not mix B7 components with current releases.
Download the complete B7 release from https://looking-glass.io/downloads and see the Legacy Host Application section.