Dell NativeEdge: USB video device passthrough fails until USB controller passthrough is enabled

• USB video adapter is detected in the guest intermittently or not at all; display output or video capture does not function. 
• On Windows 10/11 IoT guests, driver installation may complete but the virtual machine (VM) fails to use the device; sometimes Windows 10 IoT boot may stall after driver installation.

• By default, only individual USB ports were exposed for passthrough.
• For Fresco Logic USB video adapters and similar devices, the USB host controller must be passed through to the VM for stable device enumeration and operation because it requires a high throughput that is above what Quick Emulator (QEMU) supports (limit for 5 Gbps) for USB passthrough.
• Without controller passthrough, devices can appear but fail to function reliably. 

Short-term workaround:

NativeEdge engineering has produced a dedicated hotfix on the NativeEdge 3.2.0.0 release. To request the hotfix, engage Dell support. 

This hotfix enforces the exposure of USB host controller for passthrough.

Long-term solution:

The permanent solution is implemented in the NativeEdge 4.1.0.0 release.

The required step post upgrade to 4.1.0.0 to enable controller passthrough:

• Set the advanced hypervisor parameter on the target virtual machine to enable controller passthrough:

hw.enable.usb.controller: true

• Apply during VM deployment or edit the VM and add the parameter; the VM shuts down and restarts to apply the change. Reinstallation is not required.

 Notes, limitations, and assumptions

• When controller passthrough is active, individual USB ports may still appear under Peripherals and look selectable; mutual exclusion between the controller and the agent does not enforce ports. Devices attach to the VM that has controller passthrough enabled. 
• Once a USB PCI controller is passed through to one VM, other VMs cannot use it concurrently. Plan workload placement accordingly.