Hi Michael, Michal, I got back from vacation. Checking this one.
On 02/20/2018 02:06 PM, Michal Suchánek wrote:
I did it the way I did because otherwise we waste memory on every system on earth just to support a use case that we don't actually intend for anyone to ever use - ie. migrating from a patched machine to an unpatched machine.
If this thread eventually closes in 'ok, so that memory has to be reserved/wasted anyway', that can be done only in pseries, right? It seems not so much memory for this particular platform/hardware.
If you have multiple hosts running some LPMs and want to update them without shutting down the whole thing I suppose it might easily happen that a machine (re)started on a patched host is migrated to unpatched host.
Right, but that should be temporary, I think -- after updating some of the hosts, the LPAR(s) can be migrated back to one of them, where the fallback flush is not required anymore.
I think I'm inclined to leave it the way it is, unless you feel strongly about it Michal?
I think it would be more user friendly to either support the fallback method 100% or remove it and require patched firmware.
I beg to disagree. Since the matter is a security issue, the option of still have some sort of fix that works on unpatched firmware does look good and friendly to users (rather than require 'you _must_ get the firmware update') IMHO. cheers, Mauricio