Dovetail on risc-v: Testing strategy, managing efforts for forward porting

Hi Philippe,

I'm currently waiting for a v8 of Tobias' risc-v implementation. A
couple of minor things still need fixing, but overall I would say that
we are looking good - ready for merging - assuming that currently
running tests are successful.

From my point of view there is one issue left, that needs a discussion:
Testing and forward porting in the future.

Up to now I was able to test all architectures using cobalt / x3. That
will change now, as we don't have risc-v support in x3.

I see the following options:

1: Additionally forward port linux-evl in the future, so that we can run
tests against risc-v using x4. Additional effort for me, especially
because we don't have an in-house user for that. Can you estimate how
much time it takes you to forward port linux-evl in comparison to linux-
dovetail?

2: Add risc-v support to x3 as well. To my understanding there were no
plans yet, but it might be worth it to limit forward porting efforts. I
could focus on x3 for testing. This might also help to compare risc-v
against the other architectures.

3: Ignore risc-v during forward porting. Yes, this option exists, but I
don't consider it as a real / valid option.

4: Merge the risc-v support into linux-evl. That would make risc-v
support exclusive to evl, where we could already test it. Would that be
an valid option for the evl side?

Any additional option available, that I missed?

Best regards,
Florian