Re: [edk2-devel] [RFC] MemoryProtectionLib for Dynamic Memory Guard Settings

["Taylor Beebe" <t@taylorbeebe.com>]

Note: I'll be accepting feedback on this until Friday after which I will 
submit a patch series.

On 7/22/2021 5:32 PM, Taylor Beebe via groups.io wrote:
> Current memory protection settings rely on FixedAtBuild PCD values 
> (minus PcdSetNxForStack). Because of this, the memory protection 
> configuration interface is fixed in nature. Cases arise in which memory 
> protections might need to be adjusted between boots (if platform design 
> allows) to avoid disabling a system. For example, platforms might choose 
> to allow the user to control their protection policies such as allow 
> execution of critical 3rd party software that might violate memory 
> protections.
> 
> This RFC seeks your feedback regarding introducing an interface that 
> allows dynamic configuration of memory protection settings.
> 
> I would like to propose two options:
> 1. Describing the memory protection setting configuration in a HOB that 
> is produced by the platform.
> 2. Introducing a library class (e.g. MemoryProtectionLib) that allows 
> abstraction of the memory protection setting configuration data source.
> 
> In addition, I would like to know if the memory protection FixedAtBuild 
> PCDs currently in MdeModulePkg can be removed so we can move the 
> configuration interface entirely to an option above.
> 
> In any case, I would like the settings to be visible to environments 
> such as Standalone MM where dynamic PCDs are not accessible.
> 
> I am seeking your feedback on this proposal in preparation for sending 
> an edk2 patch series.
> 

-- 
Taylor Beebe
Software Engineer @ Microsoft