On 05/06/2025 02:59, Koralahalli Channabasappa, Smita wrote:
>>
>>
>> To the CXL community,
>>
>> The scenarios mentioned here essentially cover what a correct firmware may 
>> provide. However,
>> I would like to discuss one more scenario that I can simulate with a 
>> modified QEMU:
>> The E820 exposes a SOFT RESERVED region which is the same as a CFMW, but the 
>> HDM decoders are not committed. This means no region will be auto-created 
>> during boot.
>>
>> As an example, after boot, the iomem tree is as follows:
>> 1050000000-304fffffff : CXL Window 0
>>     1050000000-304fffffff : Soft Reserved
>>       <No region>
>>
>> In this case, the SOFT RESERVED resource is not trimmed, so the end-user 
>> cannot create a new region.
>> My question is: Is this scenario a problem? If it is, should we fix it in 
>> this patchset or create a new patch?
>>
> 
> I believe firmware should handle this correctly by ensuring that any exposed 
> SOFT RESERVED ranges correspond to committed HDM decoders and result in 
> region creation.
> 
> That said, I’d be interested in hearing what the rest of the community thinks.


After several days, we still haven't heard other significant opinions. I'm fine 
with keeping the current case coverage.
If the case I described becomes common in the future, we can revisit it then.

Thanks
Zhijian

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