On 07/12/2021, 18:18:40, Laurent Dufour wrote: > On 07/12/2021, 18:07:50, Nathan Lynch wrote: >> Laurent Dufour <lduf...@linux.ibm.com> writes: >>> On 07/12/2021, 15:32:39, Nathan Lynch wrote: >>>> Is there a reasonable fallback for VMs where this parameter doesn't >>>> exist? PowerVM partitions should always have it, but what do we want the >>>> behavior to be on other hypervisors? >>> >>> In that case, there is no value displayed in the /proc/powerpc/lparcfg and >>> the lparstat -i command will fall back to the device tree value. I can't >>> see any valid reason to report the value defined in the device tree >>> here. >> >> Here's a valid reason :-) >> >> lparstat isn't the only possible consumer of the interface, and the >> 'ibm,partition-name' property and the dynamic system parameter clearly >> serve a common purpose. 'ibm,partition-name' is provided by qemu. > > If the hypervisor is not providing this value, this is not the goal of this > interface to fetch it from the device tree. > > Any consumer should be able to fall back on the device tree value, and > there is no added value to do such a trick in the kernel when it can be > done in the user space. > >> In any case, the function should not print an error when the return >> value is -3 (parameter not supported). > > That's a valid requirement.
I sent a v4 which is printing an error message even if the parameter is not supported by the hypervisor. This is unlikely and since this a call to pr_err_once(), it would be printed only once, so not really annoying. I don't think a v5 is required for such a minor message.
