Re: VIO bus not initialized

[Paul Menzel <pmenzel@molgen.mpg.de>]

Dear Michael,


Thank you very much for your response.


Am 15.03.21 um 08:53 schrieb Michael Ellerman:
> Paul Menzel writes:

>> On the POWER8 system IBM S822LC, Linux 5.12-rc2+ logs the errors below.
> 
> That's a bare metal system, you can see that from the line "Using
> PowerNV machine description" in the boot log.
> 
>>       $ dmesg --level=err
>>       [    1.555668] Driver 'hvc_console' was unable to register with bus_type 'vio' because the bus was not initialized.
>>       [    1.558434] Driver 'tpm_ibmvtpm' was unable to register with bus_type 'vio' because the bus was not initialized.
>>       $ grep VIO /boot/config-5.12.0-rc2+
>>       CONFIG_IBMVIO=y
> 
> The "vio" bus is not a real bus, it's a fake bus we use for hypervisor
> provided devices in LPARs (guests).
> 
> So on bare metal machines there is no vio bus, the devices that would
> appear on the vio bus are found via other mechanisms.

Thank you for the explanation. Two questions:

1.  Could a bare metal system be detected, and the VIO “be skipped”?
2.  Should the log level be changed to notice or info then, as it’s an 
expected failure?

[…]


Kind regards,

Paul