Re: [PATCH 3/6] MdePkg/UefiLib: introduce EfiAllocatePeiAccessiblePages routine

["Zeng, Star" <star.zeng@intel.com>]

On 2018/5/23 3:11, Laszlo Ersek wrote:
> On 05/22/18 19:47, Ard Biesheuvel wrote:
> 
>> OK, to summarize:
>> - move the implementation of EfiAllocatePeiAccessiblePages() to
>> DxeServicesLib (and perhaps rename it to something more appropriate
>> for its new home)
>> - only restrict the X64 version to below 4 GB if EfiMemoryTop and
>> EfiFreeMemoryTop are both below 4 GB.

Just checking EfiFreeMemoryTop should be enough as EfiFreeMemoryTop 
means the capable TOP to be allocated.

And seemingly, there is an assumption here that next boot PEI S3 has 
same situation with current boot PEI.


Thanks,
Star
> 
> If this works with pure X64 OVMF (including S3 without SMM), I'd be very
> happy with it.
> 
> Also we should regression test whether IA32X64 OVMF continues working
> (including S3 without SMM, and S3 with SMM).
> 
> I'm glad to help with the testing once patches are posted.
> 
> OVMF installs the permanent PEI RAM in PublishPeiMemory()
> [OvmfPkg/PlatformPei/MemDetect.c]. It keeps things under 4GB, so I think
> this approach should work.
> 
> Thanks Ard & Mike!
> Laszlo
>