I'm facing a strange issue running Xubuntu (tried Ubuntu also, same problem with Unity, but no problem with Metacity) on Xen HVM while connecting to it via XEN's builtin VNC. Some parts of the user interface appear with artifacts:
Most other things, including most programs, menus, the desktop are rendered normally, but the Terminal, the top status bar are rendered with issues. Terminal is practically unusable, so I have to connect by SSH to control the box. Have anyone ever seen something like this?
So far I tried, with no success:
- Disable compositing in XFCE settings
- Use STDVGA driver in Xen instead of Cirrus emulation
- Changing font rendering settings (hinting etc.)
- Connecting using different VNC client, different compression settings
- Changing screen resolution
- Use a VNC server in the OS (not Xen's builtin VNC server)
The problem persists, and from what I tried, only the Terminal, the top bar, and few other things like "Identify monitor" baloon are affected.
UPDATE: Kind of solved it by adding
nomodeset to kernel arguments at boot, now the only thing which is rendered with artifacts is the desktop wallpaper...
UPDATE 2: Since a software VNC server running inside the target OS shows same graphics distortion, it's probably not a video driver issue, though I'm not 100% sure