Re: [PATCH v2] hppa: allow max ram size upto 4Gb

[Helge Deller]

On 07.01.20 12:21, Igor Mammedov wrote:
> On Mon, 6 Jan 2020 18:03:49 +0100
>> So, I'd suggest to drop your wrong patch #43.
> As you noted in your first reply, patch is correct.

You probably got me wrong.
Your patch #43 is wrong, and your fixup patch to some degree reverts it back 
again.

In patch #43 you error out and stop, which real hardware wouldn't do.
Real hardware simply ignores the memory which wouldn't be used.

> All it's doing is validating user input versus RAM size
> actually supported by the current code, telling user> current supported limit 
> and enforcing it.

Real hardware would not tell user.

> I agree it's inconvenience for the users since they
> won't be able to specify non-sense values and still
> get board running, but that's clear user error and
> should be corrected on user side and not by QEMU
> magically masking wrong CLI values.

I disagree.
Everything worked as expected before, but with *your* change now people
might need to modify their CLI.
4GB is a valid amount of memory which can be plugged into
the virtual and physical machine.
It's not magic, it's how the architecture works and you changed it.

> Since it could be fixed on user side, I care less
> about user convenience when it comes to correctness
> and unified code.

IMHO, you should care about that the emulation works the same
way as physical machine. Not, how you want to educate end users.

>> If you don't want to drop it, my suggestion for a commit message is:
>>
>> hppa: Revert last wrong patch and give warning if user specified > 4GB RAM
>
> I have to disagree on definition of wrong here,
> in my opinion covering up user errors is wrong especially
> when all users have to do is to adapt their CLI.

See above. Nobody ever needs to adapt anything unless your patches gets applied.

Helge