[Bug 1884684] Re: QEMU 5.0: Guest VM hangs/freeze when unplugging USB device

[Thomas Huth]

The QEMU project is currently moving its bug tracking to another system.
For this we need to know which bugs are still valid and which could be
closed already. Thus we are setting older bugs to "Incomplete" now.

If the bug has already been fixed in the latest upstream version of QEMU,
then please close this ticket as "Fix released".

If it is not fixed yet and you think that this bug report here is still
valid, then you have two options:

1) If you already have an account on gitlab.com, please open a new ticket
for this problem in our new tracker here:

    https://gitlab.com/qemu-project/qemu/-/issues

and then close this ticket here on Launchpad (or let it expire auto-
matically after 60 days). Please mention the URL of this bug ticket on
Launchpad in the new ticket on GitLab.

2) If you don't have an account on gitlab.com and don't intend to get
one, but still would like to keep this ticket opened, then please switch
the state back to "New" within the next 60 days (otherwise it will get
closed as "Expired"). We will then eventually migrate the ticket auto-
matically to the new system (but you won't be the reporter of the bug
in the new system and thus won't get notified on changes anymore).

Thank you and sorry for the inconvenience.


** Changed in: qemu
       Status: New => Incomplete

** Tags added: usb

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1884684

Title:
  QEMU 5.0: Guest VM hangs/freeze when unplugging USB device

Status in QEMU:
  Incomplete

Bug description:
  Setup:

  Host: Debian/SID, Kernel 5.6, QEMU 5.0
  Guest: Windows 10 VM with PCI and USB device passthrough.

  Problem: Guest VM suddenly hangs when pulling USB device out from the
  Host.

  Observations:
   - Issue appears to be related to QEMU 5.0
     - It started after an upgrade to QEMU 5.0.
     - Downgrading only QEMU on multiple systems fixes the issue.

   - Issue is very reproducible.
     - Most of the time within a few attempts of pulling/reconnecting the 
device.
     - Issue happens with multiple devices (I did try standard HID devices, a 
webcam and an x-ray sensor).

   - Guest just hangs.
     - Display output remains on last frame shown.
     - Ping to Guest immediately stops working.
     - Logs in the Guest stop logging immediately.

   - Host is fine and thinks the Guest is fine. 
     - Guest continues to show as running in "virsh list".
     - No suspicious entries in the QEMU logs.
     - No suspicious entries in Host syslogs/messages.
     - Host can can kill guest "virsh destroy" and respawn fine.

   - Issue seems widespread.
     - Multiple similar reports from ProxMox users after upgrade to ProxMox 6.2 
for both Windows and Linux guests (First version that uses QEMU 5.0)

  
https://forum.proxmox.com/threads/vm-freezes-when-disconnecting-usb-keyboard-and-mouse.70287/
  https://forum.proxmox.com/threads/usb-drive-crashes-vm.70214/
  
https://forum.proxmox.com/threads/latest-proxmox-usb-disconnects-freeze-kvm.70398/
  
https://forum.proxmox.com/threads/vm-with-gpu-passthrough-freezes-when-turning-off-monitor-after-proxmox-6-2-upgrade.69821/
  
https://forum.proxmox.com/threads/vm-with-gpu-passthrough-freezes-when-turning-off-monitor-after-proxmox-6-2-upgrade.69824/

  I'd be more than happy any debugs that might be helpful.

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1884684/+subscriptions