Re: New "IndustryStandard" fw_cfg?

[Dionna Amalie Glaze <dionnaglaze@google.com>]

I think the option should be boolean since it doesn't look like we're
going to need to tune the number very much.
It all boils down to "does the OS affirmatively support unaccepted
memory?" as in, we have no way to negotiate it, but force unaccepted
memory on.
Ovmf can interpret the existence of an opt/ovmf/unaccepted_memory file
to mean that it's allowed to create unaccepted memory entries in the
memory map.
It's then up to the firmware if it will minimize its use of unaccepted
memory or not. It's not Qemu's place to say.


> >    * accept all memory below 4G
> >    * accept all memory
> >
> > Possibly we need:
> >
> >    * accept all memory below 4G
> >    * accept all memory below 4G, plus x GB of high memory.
> >    * accept all memory
> >
> > In any case the config option should be designed in a way that we can
> > add a 'automatic' choice later, i.e. we can have ...
> >
> >    * automatic (default)
> >    * accept all memory below 4G
> >    * accept all memory
> >

I think "false" can mean either accept all memory or "do what you need
to" and negotiate if the memory map boot service can create unaccepted
memory entries. Whichever appears supported.
Then "true" can be "do whatever, including creating unaccepted memory
entries in the memory map".

That seems the simplest way to allow a configuration of this feature.

-- 
-Dionna Glaze, PhD (she/her)