Right location in sysfs for dlpar file

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

Hi Greg,

So Nathan is working on a patch series to cleanup and improve our
"DLPAR" infrastructure which is basically our hotplug mechanism when
running under the PowerVM (aka pHyp) and KVM hypervisors.

I'll let Nathan give you a bit more details/background and answer
subsequent question you might have as this is really his area of
expertise.

To cut a long story short, we need a sysfs file that allows our
userspace tools to notify the kernel of hotplug events coming from
the management console (which talks to userspace daemons using a
proprietary protocol) to "initiate" the hotplug operations, which in
turn get dispatched internally in the kernel to the right subsystem
(memory, cpu, pci, ...) based on the resource type.

On IRC, Greg suggested /sys/firmware and /sys/hypervisor which both
look like a reasonable option to me, probably better than dlpar...

Cheers,
Ben.