Re: [PATCH] x86/gen-cpuid: Distinguish default vs max in feature annotations

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 11/05/2020 08:43, Jan Beulich wrote:
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> On 08.05.2020 17:27, Andrew Cooper wrote:
>> @@ -133,9 +134,13 @@ def crunch_numbers(state):
>>      state.hvm_shadow_def = state.pv_def | state.raw['S']
>>      state.hvm_hap_def = state.hvm_shadow_def | state.raw['H']
>>  
>> +    # TODO: Ignore def/max split until the toolstack migration logic is fixed
>>      state.pv_max = state.pv_def
>>      state.hvm_shadow_max = state.hvm_shadow_def
>>      state.hvm_hap_max = state.hvm_hap_def
>> +    # state.pv_max = state.raw['A'] | state.raw['a']
>> +    # state.hvm_shadow_max = state.pv_max | state.raw['S'] | state.raw['s']
>> +    # state.hvm_hap_max = state.hvm_shadow_max | state.raw['H'] | state.raw['h']
> While in comment form it doesn't matter yet, for actually enabling
> this it would seem to me to be more expressive as
>
>     state.pv_max = state.pv_def | state.raw['a']
>     state.hvm_shadow_max = state.hvm_shadow_def | state.pv_max | state.raw['s']
>     state.hvm_hap_max = state.hvm_hap_def | state.hvm_shadow_max | state.raw['h']
>
> Thoughts?

The format/layout of metadata prohibits that from having any kind of
difference.

Furthermore, expressing it this way doesn't require anyone to look at
the *_def derivation to figure out what is going on.

I'm going to commit it in this form, but will tidy it up to be properly
tabulated in a future patch, to make it easier to read.

~Andrew