Looking Glass shows Windows VMs with almost no delay
Summary
Looking Glass transfers the framebuffer of a passed-through GPU via shared memory into a Linux window and sends input back. Looking Glass is free software. The project normally requires two graphics devices or suitable alternatives.
Ideas
- VFIO passes a physical GPU exclusively through to the Windows VM.
- A shared memory device transfers image data without network compression.
- The Linux client shows the VM's output like a local window.
- SPICE adds input, clipboard and further integration features.
Insights
- Shared memory can push local virtualisation latency well below network streaming.
- High-performance isolation needs suitable IOMMU groups and hardware planning.
- Seamless use hides a technically complex multi-system architecture.
Facts
- KVM and QEMU form a typical host environment.
Recommendations
- Check IOMMU groups before buying hardware.
- Only reserve CPU cores and hugepages after solid measurements.
References
Links to the original source and the Web Archive open in a new tab.