Re: [PATCH v2 0/3] x86: Extend LASS support to EFI configurations

[Ard Biesheuvel]

On Tue, 24 Feb 2026, at 19:45, Sohil Mehta wrote:
> Hello x86 Maintainers, Ard,
>
> On 1/20/2026 3:47 PM, Sohil Mehta wrote:
>> Solution
>> --------
>> These patches take LASS out of the path of all EFI boot and runtime
>> service interactions by:
>> 
>>   Patch 1: Deferring LASS enabling until userspace comes up, which
>>   ensures EFI has completed switching to virtual mode and all boot
>>   services memory has been freed [3]. 
>> 
>>   Patch 2: Temporarily disabling LASS every time a runtime service is
>>   executed after boot. Runtime services execute in a special efi_mm
>>   which doesn't have userspace mapped. So, the security implications of
>>   disabling LASS are fairly limited [4].
>> 
>
> The patches now have tested-by tags from Maciej and Tony. Also, the
> patches apply cleanly on v7.0-rc1. I am hoping to get some review
> feedback on the patches before resending another version.
>
> Ard, are you okay with patch 2 that disables LASS during EFI runtime calls?
>

Yeah I think that's fine.