Frequently Asked Questions

Submitted by dsjustice on Tue, 12/19/2017 - 00:34


I'm having mouse issues

Mouse integration is not top priority right now.  Consider passing through a hardware mouse.  If you can't or won't...

  • Have you tried hitting Scroll Lock to toggle mouse capture mode?
  • Disable guest mouse acceleration, and/or re-read the "0-READ ME FIRST" document for your host.
  • Yes, sometimes the cursor position doesn't update until you click.  It's a QEMU problem.  See points above.

What is this permission error?

The two common permission errors are ivshmem-server failing with cannot open shm file ivshmem: Permission denied, and the VM refusing to start with a huge dialog full of fail.

  • The ivshmem-server failure is caused by the ivshmem-server process failing to access /dev/shm/ivshmem
    • The device might have been created by a different userid (probably your login id) than you're using to run the ivshmem-server (probably the qemu userid) 
  • The VM won't start with a permission error is caused by the VM process failing to access your socket file, probably /tmp/ivshmem_socket
    • This usually happens when ivshmem-server is run by a different userid (probably your login id) than is running the VM (probably the qemu userid)
  • The best solution varies by distro, but possible solutions include:
    • Run everything, including the VM, as your login user
    • Run ivshmem as your qemu user, eg: sudo -s /bin/bash -u qemu-user ivshmem-server ...
    • Ensure that the qemu user has access to your socket file by setting the file's group attribute.  Run ivshmem-server from a userid in that group!

Is my GPU supported?

Your guest GPU almost certainly supports DXGI.  Use DxDiag to confirm that you have support for WDDM 1.2 or greater.

  • The server-side (guest) probing error "Capture is not possible, unsupported device or driver" indicates NVidia duplication has failed, not that DXGI has failed.
  • You can make the error go away by specifying "-c DXGI"

Why do I need Spice if I don't want a Spice display device?

You don't need Display Spice enabled.  Looking-glass has a Spice client built in to provide some conveniences, but you can disable it with the "-s" argument.

  • Note that without Spice, you will not be sending mouse/keyboard events to the guest.

Where is the host application for Linux?

The "Windows host application"  is actually the display server, which runs in the guest VM.    The only things running in your linux host OS are

  • ivshmem-server
  • looking-glass-client