Fix Virt-Manager USB Redirect Error After Power Cycle

by Luna Greco 54 views

Hey guys! Ever faced a tech issue that just keeps looping, making you want to pull your hair out? Today, we're diving into a tricky situation with virt-manager where USB auto-redirection fails, and the only escape seems to be forcefully killing the process. Let's break down the problem, understand why it happens, and explore some practical solutions. So, buckle up, and let’s get started!

Understanding the USB Auto-Redirect Issue in Virt-Manager

The core issue revolves around USB auto-redirection within virt-manager, a powerful tool for managing virtual machines. Imagine you have a Windows 10 VM running smoothly, and you decide to add a USB device, say a webcam. Everything works like a charm... until you power-cycle the VM. After the reboot, you're greeted with an onslaught of modal popups, each screaming:

spiceclient-error-quark: Could not auto-redirect
USB Device [291a:3361] at
5-99: error resetting device:
LIBUSB_ERROR_NOT_FOUND (0)

Digging into the details, you find the culprit: "USB redirection error." But here’s the kicker: these popups don't just appear once. They come in rapid succession, leaving you with barely any time to react. And to make matters worse, you have to close them in reverse order, turning a simple task into a frustrating ordeal.

The Frustration is Real

Imagine this: you’re frantically clicking the close button, but new popups keep stacking beneath the current one. The close button doesn’t even have focus, so keyboard shortcuts are out the window. It feels like you're trapped in an endless loop, and the only way out seems to be killing the entire qemu process. This issue isn't new; some users have been battling this for years, highlighting a persistent pain point in the virt-manager experience.

Why Does This Happen?

To really understand the problem, we need to break it down. When you add a USB device to a running VM, virt-manager tries to redirect the device to the VM. This means the VM can directly access the USB device as if it were physically connected. However, when you power-cycle the VM, the redirection process can stumble, especially if the device isn't properly disconnected or if the VM's USB configuration gets out of sync.

The error message LIBUSB_ERROR_NOT_FOUND (0) is a key clue. It suggests that the system can't find the USB device during the auto-redirection attempt. This could be due to various reasons:

  • Device Disconnect: The physical USB device might have been disconnected or become unresponsive during the power cycle.
  • Configuration Mismatch: The VM's USB configuration might not match the actual state of the USB device.
  • Driver Issues: There might be driver-related issues within the VM or on the host system preventing proper USB device recognition.

The Expected Behavior: A User-Friendly Escape

What should happen instead? Users need a clear and easy way out of this mess. Imagine a scenario where virt-manager:

  • Limits Redirection Attempts: Instead of endlessly retrying the redirection, it stops after a few failed attempts.
  • Avoids Popup Overload: Doesn't bombard the user with a new popup for each failed attempt.
  • Offers Clear Options: Provides buttons like Try again and Cancel redirection on the popup.
  • Maintains Control: Allows users to interact with virt-manager even when the dialog is open.

In essence, the goal is to create a more user-friendly experience, preventing the frustrating loop and giving users the tools to resolve the issue gracefully. Modal windows that block all other interactions are a big no-no in this situation.

Diagnosing the Issue: System Information and Context

To effectively tackle this bug, let's look at the system setup where it was encountered. This will help us understand if the bug is limited to certain environments or has a more widespread impact. The system in question runs:

  • Distribution: Opensuse Tumbleweed
  • virt-manager version: 5.0.0-13.1
  • libvirt version: 11.6.0-2.1

These details are crucial because different distributions and versions of software can have varying behaviors and bugs. Knowing the specific environment helps developers narrow down the cause of the problem and devise targeted solutions.

Additional Context: The Devil is in the Details

A key observation made by the user is that the error message within the popup isn't selectable. This means you can't easily copy the error message and paste it into a search engine or a bug report. Instead, you have to manually transcribe it, which is both tedious and error-prone. This highlights a simple but impactful usability issue.

Potential Solutions and Workarounds

Okay, so we know the problem is a persistent pain. What can we do about it? Here are some potential solutions and workarounds:

  1. Preventing Auto-Redirection on Startup:

    • This is a big one. Preventing automatic redirection on startup can completely bypass the popup flood. You might be asking how to do this, so let's break it down. Check your VM settings in virt-manager. There should be an option related to USB device redirection. Look for settings that control automatic connection of USB devices. Disable this, and you'll likely avoid the issue. This ensures that the USB devices are not automatically connected upon VM startup, giving you time to manage them manually.

  2. Manually Redirecting USB Devices:

    • If you disable auto-redirection, you'll need to manually connect your USB devices when the VM is running. This gives you more control and avoids the chaotic auto-redirect loop. After the VM boots, you can go to the