Virtio Keyboard regression

[ChristophSchmidpeter]

Describe the bug
Regression in virt-input driver:

With a current virtio driver the virtio keyboard device does not work any more. The regression has come in some update. (Don't remember which one)

To Reproduce

• Install the virtio setup including the virtinput driver
• Ensure the VM has a virtio keyboard device
• Start the VM and notice that the keyboard does not work in Windows

Expected behavior
Keyboard works

Screenshots
If applicable, add screenshots to help explain your problem.

Host:

• Disto: Arch Linux
• Kernel version: 6.10.0-zen1-2-zen
• QEMU version: 9.1.1
• QEMU command line: (add virtio keyboard)
• libvirt version: 10.9.0
• libvirt XML file

VM:

• Windows version: 11
• Which driver has a problem: virtio-input
• Driver version or commit hash that was used to build the driver

Additional context
Add any other context about the problem here.

[YanVugenfirer]

@ChristophSchmidpeter Do you have IOMMU device in the system? Is virtio-input device configured with ats=on and iommu_platform=on?

[ChristophSchmidpeter]

@YanVugenfirer No, I have no IOMMU device in the VM, and I don't see any ats=on setting in my libvirt xml. Attached is the VM's libvirt XML:
Windows.txt

[leidwang]

Hi @ChristophSchmidpeter Would you please share the driver version?Thanks.

[ybendito]

@ChristophSchmidpeter Under HKLM\Ssystem\CurrentControlSet\Services\VirtioInput\Parameters remove DmaRemappingCompatible value and reboot. Does this help?
If does - this is strange and unexpected effect of #1140

[leidwang]

Hi @ChristophSchmidpeter
I didn't reproduce the issue in my env, could you please provide more info? Such like driver version that you used.You can find the driver version via "Device Manager" -> "Virtio Input Driver" -> "Properties" -> "Driver".

[YanVugenfirer]

Tracker: https://issues.redhat.com/browse/RHEL-68708