Re: SetMemorySpaceAttributes with EFI_MEMORY_XP

[Laszlo Ersek <lersek@redhat.com>]

On 03/20/17 11:32, Michael Zimmermann wrote:
> Hi,
> 
> I didn't test ArmVirtQemuKernel but I'm trying to use some of the code
> for another platform.
> So does this call ever succeed with PcdDxeNxMemoryProtectionPolicy
> being enabled?
> https://github.com/tianocore/edk2/blob/76874be3d411bf8daac051718e20932e0bf97d70/ArmVirtPkg/HighMemDxe/HighMemDxe.c#L95
> Status = gDS->SetMemorySpaceAttributes (CurBase, CurSize, Attributes);
> 
> Neither the memory that was added by this Dxe nor the one added
> automatically by GCD has the EFI_MEMORY_XP capability which causes
> SetMemorySpaceAttributes to return EFI_UNSUPPORTED.

See commit 413edd470932 ("ArmVirtPkg/HighMemDxe: preserve non-exec
permissions on newly added regions", 2017-02-28). EFI_MEMORY_XP is only
requested if EfiConventionalMemory's bit is set in
PcdDxeNxMemoryProtectionPolicy, but then (I think) the DXE_CORE must
have set the same bit in the "supported" bitmask too, when the memory
was added.

Thanks
Laszlo