Re: [PATCH] x86/tboot: adjust Kconfig default

["Daniel P. Smith" <dpsmith@xxxxxxxxxxxxxxxxxxxx>]

On 3/3/22 07:24, Jan Beulich wrote:
> On 03.03.2022 13:16, Daniel P. Smith wrote:
>>
>> On 3/3/22 07:03, Jan Beulich wrote:
>>> On 03.03.2022 12:50, Daniel P. Smith wrote:
>>>> On 3/3/22 04:49, Jan Beulich wrote:
>>>>> We shouldn't include unsupported code by default, with not even a means
>>>>> for its building to be disabled. Convert the dependency from merely
>>>>> affecting the prompt's visibility to a real one.
>>>>>
>>>>> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
>>>>> ---
>>>>> We could of course go further and make the default also account for
>>>>> DEBUG, as is done elsewhere.
>>>>
>>>> As in you would like to adjust the default based on whether DEBUG is on
>>>> or not? I guess my question is what motivation is there to adjust this
>>>> selection if DEBUG is enabled or disabled?
>>>
>>> This is to have functionality enabled unless overridden in debug builds.
>>
>> Maybe I am misunderstanding you. If I am wanting to debug either TXT or 
>> a configuration with TXT on and I adjust my config to turn on debug, 
>> then I would have to go turn TXT back on. Is that correct? If that is 
>> the correct understanding, honestly that concerns me because if that is 
>> being done for other config options, it would create the situation where 
>> turning on debug to track down an issue would result in a different 
>> configuration than the one I was experiencing the issue.
> 
> In the scenario that you describe (aiui), the default setting wouldn't
> make a difference: If you alter an existing .config by turning on DEBUG,
> the .config's existing TBOOT setting wouldn't change. Defaults matter
> only for items which have no values recorded yet. Plus - I'm suggesting
> to turn the option _on_ by default when DEBUG=y, not off.

Okay, I am following now. Apologies for taking so long. I think that
would be fine as TXT/tboot should be benign if enabled but tboot is not
used to start Xen.

v/r,
dps