[PATCH 07/11] treewide: Replace the use of mem_encrypt_active() with prot_guest_has()

[Tom Lendacky]

On 8/12/21 5:07 AM, Kirill A. Shutemov wrote:
> On Wed, Aug 11, 2021 at 10:52:55AM -0500, Tom Lendacky wrote:
>> On 8/11/21 7:19 AM, Kirill A. Shutemov wrote:
>>> On Tue, Aug 10, 2021 at 02:48:54PM -0500, Tom Lendacky wrote:
>>>> On 8/10/21 1:45 PM, Kuppuswamy, Sathyanarayanan wrote:
...
>>> Looking at code agains, now I *think* the reason is accessing a global
>>> variable from __startup_64() inside TDX version of prot_guest_has().
>>>
>>> __startup_64() is special. If you access any global variable you need to
>>> use fixup_pointer(). See comment before __startup_64().
>>>
>>> I'm not sure how you get away with accessing sme_me_mask directly from
>>> there. Any clues? Maybe just a luck and complier generates code just right
>>> for your case, I donno.
>>
>> Hmm... yeah, could be that the compiler is using rip-relative addressing
>> for it because it lives in the .data section?
> 
> I guess. It has to be fixed. It may break with complier upgrade or any
> random change around the code.

I'll look at doing that separate from this series.

> 
> BTW, does it work with clang for you?

I haven't tried with clang, I'll check on that.

Thanks,
Tom

>