PVE 5 to 6, Win 7 VM time warp

[Luckyj]

Hi all, I did some searching to see if this issue was reported but didn't see anything. I just upgraded from PVE5 to 6, and had a strange issue with a Windows 7 guest VM. The time in the VM was FLYING, like it would advance a minute for each second or so. The console GUI and programs would also run in this warp-speed time. Displaying the clock, the second hand was spinning around like crazy. The only fix I have at the moment is to change the OS type to Other. I also have a Windows 2016 server guest VM, and another Windows 7 guest VM, and they are both running just fine. Any idea what the issue might be?

 

[Alwin]

Some first guesses, different guest config (as the other Win7), missing windows updates, missing virtIO driver updates.

 

[Luckyj]

The trouble VM was configured as machine type q35. Switching back to the default of i440fx resolved the issue. Something still seems wrong though...why is this a problem.

 

[Alwin]

Are you using the newest virtIO drivers on the Windows VM? The q35 is a different chipset.

 

[Luckyj]

I've been using the latest virtio-win iso from https://docs.fedoraproject.org/en-U...indows-virtual-machines-using-virtio-drivers/

I used that for serial, storage, and network interface. No devices showed up in device manager as having an issue, so I'm not sure if there are any other devices that need a driver from the virtio drivers.

 

[Alwin]

It also greatly depends on the update state of the Windows machine. Did the driver versions update, when you updated the virtIO drivers?

 

[Luckyj]

The drivers for the devices mentioned above all show a 4/12/2019 date, which matches the date of the files in the ISO.

 

[Alwin]

I was able to re-create the 'time warp' with the qemu 4.0 q35. Try the following command to set it to the qemu 3.1 q35 chipset.

qm set <vmid> --machine pc-q35-3.1

EDIT: there is also a bug report on redhat.
https://bugzilla.redhat.com/show_bug.cgi?id=1704375

 

[Luckyj]

Awesome, good info! Setting to pc-q35-3.1 does fix the issue for me. Assuming we'll see an update to qemu at some point in the future that should correct the issue.