Re: [RFC PATCH] fpga: region: Add support for FPGA region variants

[Xu Yilun]

> If I understood correctly, your main concern is that having to specify
> all region variants at boot time is verbose and limiting. I see your

Yes, that's my concern. We are pursuing a userspace re-programming
interface for long time. I don't want to easily switch to a whitlist
based interface, which is as you said verbose and limiting. The DTO has
vulnerabilities but I'm not convinced yet it can't be secured.

> point. However, I still think that a statically-defined whitelist of
> variants is the most pragmatic approach, as it guarantees the best
> security while matching the actual FPGA design phase, where

I actually still don't understand how static DT can be more secure if it
references global resources. How could people verify a static DT is
correctly describing a blob on disk? And the blob can be changed by
userspace. If no, it still ends up with manipulating global resources
without reason.

> reconfigurable regions are floorplanned and synthesized, naturally
> resulting in a statically-defined set of partial images/bitstreams with
> their corresponding kernel configurations.
> 
> 
> Thanks,
> Marco