Re: [PATCH] hw/i386: Add unaccepted memory configuration

["Gupta, Pankaj" <pankaj.gupta@amd.com>]

Hi Gerd,

>    Hi,
> 
>> AFAIU 'true' is the behavior you are proposing with your EFI changes?
>> Saying that what's the difference between 'false' & 'default' wrt EFI
>> firmware? Just wondering do we need default?
> 
> true/false will force the one or the other no matter what.
> 
> 'default' allows the firmware to choose depending on various factors,
> for example have cc-specific build variants have a different default
> behavior than the generic builds.
> 
> It also keeps the door open to change default behavior in the future.
> One reasonable approach would be to start with firmware accepting all
> memory by default, wait until support for unaccepted memory has found
> its way into linux distro kernels, then flip the default to pass
> unaccepted memory to the linux kernel.
> 
> In case the uefi boot service spec gets updated to allow negotiating
> unaccepted memory support automatically this can be used easily by
> making that the firmware's default behavior.

Fair. Also, it would be interesting to see the right future combination
of {un/a}cceptable boot vs runtime aceptable memory and also support in 
uefi specs.

o.k to keep placeholder for now but I still see, might have to keep the 
interface extensible, maybe something like bit level negotiations
than true/false/default etc. But for now I don't have any strong opinion 
or ideas and have to catch up from uefi side.

Thank you for explaining.

Best regards,
Pankaj