Problem description
After the driver for a passthrough NVIDIA RTX 2080 is installed on a Windows VM instance, if the operating system uses the GPU as the desktop display device, the virtual display device may no longer output the desktop. The ZStack Cloud VNC console provides graphical access through the virtual display device. When the passthrough GPU takes over desktop display output, the VNC console may be unable to obtain the current desktop image.
This behavior does not indicate that the VM instance has stopped. In the confirmed scenario, the desktop can be displayed and operated normally through Windows Remote Desktop.
Symptoms
- After the NVIDIA RTX 2080 driver is installed on a Windows VM instance and the VM instance restarts, the VNC console cannot display the desktop.
- The VM instance remains in the Running state.
- Network connectivity is normal, and the desktop is available after login through Windows RDP/MSTSC.
- When the passthrough GPU is not used for desktop display output, the VNC console displays normally.
Impact
The VNC console may be unable to display or operate a Windows desktop output by a passthrough GPU. In the confirmed scenario, the VM instance running state, network connectivity, and RDP access are not affected. Validate specific services and GPU workloads in the actual environment.
Workaround
- Before changing the display device or installing the GPU driver, confirm that Windows Remote Desktop is enabled and that the management network, firewall, and login credentials are available.
- To continue using the VNC console, retain the virtual display device as the primary display output for the Windows desktop.
- If the service requires the passthrough GPU to output the desktop, use Windows Remote Desktop or an NVIDIA-supported remote graphics solution. Validate resolution, graphics acceleration, and reconnection capability before production use.
Affected products
- Windows VM instances in ZStack Cloud 4.8.x, 5.4.x, and 5.5.x that use GPU passthrough and meet the following conditions:
- The Guest OS is Windows.
- An NVIDIA RTX 2080 is passed through and its corresponding driver is installed.
- The Windows desktop is output by the passthrough GPU.
Other NVIDIA GPU models, driver versions, and Guest OS combinations are outside the confirmed scope of this article.
Fix status
- Current status: Confirmed; a workaround is available.
- Fixed version: No separate fixed version.
- Related patch/fix package: None. Use RDP or retain the virtual display device as a workaround.