VirtIO drivers - QEMU FwCfg Device error

[webcraftag]

Hi there,
when I install the latest version of the VirtIO drivers (0.1.229) the device manager of the guest VM (Windows Server 2019) shows an error for the QEMU FwCfg Device: This device cannot start. (Code 10). Bad data.



It happens with all VirtIO versions back to 0.1.225...with version 0.1.221 for example, the error doesn't appear in the device manager but if I open the properties of the QEMU FwCfg devie, it states: No drivers are installed for this device.

Is there a way to fix this issue and get rid of the error even with VirtIO v. 01.229?
I've installed all the VirtIO drivers (except for balloning) and the latest version of the guest agent.
Configuration of guest VM:



Any help is really appreciated!

 

[ComfySofa]

Getting this as well if anyone can help?

 

[tawapah]

I noticed this as well yesterday.

Also, since I changed the storage from ZFS to LVM I have sometimes noticed a rare short lag in Windows, maybe appearing some hours apart and I'm wondering if the driver issue has anything to do with this.

 

[ComfySofa]

I thought ZFS was supposed to be the better filesystem??

 

[tawapah]

I thought ZFS was supposed to be the better filesystem??

It is, but it also writes double as much to the disk. I'm only using a single SSD for the guest so I changed to LVM to make the disk last longer.

The faulty QEMU FwCfg Device driver seems to handle guest-side hardware interfaces so this is why I though it might have something to do with this. https://www.qemu.org/docs/master/specs/fw_cfg.html

 

[foundata]

Same Problem here: "QEMU FwCfg Device", "This device cannot start. (Code 10)", "Bad data." Only visible when showing hidden devices.

System:

• Windows Server 2022 (MS Updated April 2023, SW_DVD9_Win_Server_STD_CORE_2022_2108.20_64Bit_English_DC_STD_MLF_X23-42932.ISO)
• virtio-win-0.1.229
• pc-q35-7.2, OVMF (UEFI)

Did not find a solution but also did not recognize any negative impact yet. The QEMU-Windows-Agent-Service is running and responds without error to "qm agent <id> ping && echo success"

 

[fiona]

Hi,
AFAIU from this thread https://github.com/virtio-win/kvm-guest-drivers-windows/issues/880, this driver is currently just a dummy driver and can't be used to read the values passed in via the -fw_cfg CLI argument. You would need to do that manually with a specialized tool. Are any of you actually using that CLI argument? If not, you could just disable the driver if you want to get rid of the (irrelevant) error.

 

[SlimTom]

...is this issue resolved somehow? What about Proxmox 8 ?

 

[fiona]

Hi,

...is this issue resolved somehow? What about Proxmox 8 ?

do you have an actual issue? Maybe you can just disable the driver if the error message is annoying to you.

 

[SlimTom]

Hi,

do you have an actual issue? Maybe you can just disable the driver if the error message is annoying to you.

I do have random errors on Windows 2022 machine and I am looking into what could be the cause...

 

[fiona]

I do have random errors on Windows 2022 machine and I am looking into what could be the cause...

View attachment 55192

That rather sounds like that exe tried to access invalid memory. Most likely a bug in that program.

 

[foundata]

[...] from this thread https://github.com/virtio-win/kvm-guest-drivers-windows/issues/880, this driver is currently just a dummy driver [...] If not, you could just disable the driver if you want to get rid of the (irrelevant) error.

Thanks for the info. That's correct, the driver is indeed a dummy at the moment an not needed for usual operations in our environment. We disabled it to silence the errors.