On Thu, Oct 10, 2019 at 05:57:54PM +0200, Igor Mammedov wrote: > > Then we should consider switching acpi to use fw cfg. > > Or build another interface that can scale. > > Could be an option, it would be a pain to write a driver in AML for fwcfg > access though > (I've looked at possibility to access fwcfg from AML about a year ago and > gave up. > I'm definitely not volunteering for the second attempt and can't even give an > estimate > it it's viable approach). > > But what scaling issue you are talking about, exactly?
Just this: each new thing we add is an ad-hoc data structure with manually maintained backwards compatibility and no built-in discovery. fw cfg has built-in discovery and we've finally managed to handle compatibility reasonably well. PV is already very problematic. Spreading PV code all over the place like this is a very bad idea. For you CPU hotplug is something that you keep in mind first of all, but someone bringing up a new platform already has a steep hill to climb. Adding tons of custom firmware is not helping things. -- MST