Re: [PATCH 04/10] s390/mm: force swiotlb for protected virtualization

Halil Pasic
2019-04-29T13:59:51Z

On Fri, 26 Apr 2019 12:27:11 -0700
Christoph Hellwig <hch@infradead.org> wrote:

> On Fri, Apr 26, 2019 at 08:32:39PM +0200, Halil Pasic wrote:
> > +EXPORT_SYMBOL_GPL(set_memory_encrypted);
>
> > +EXPORT_SYMBOL_GPL(set_memory_decrypted);
>
> > +EXPORT_SYMBOL_GPL(sev_active);
>
> Why do you export these? I know x86 exports those as well, but
> it shoudn't be needed there either.
>

I export these to be in line with the x86 implementation (which
is the original and seems to be the only one at the moment). I assumed
that 'exported or not' is kind of a part of the interface definition.
Honestly, I did not give it too much thought.

For x86 set_memory(en|de)crypted got exported by 95cf9264d5f3 "x86, drm,
fbdev: Do not specify encrypted memory for video mappings" (Tom
Lendacky, 2017-07-17). With CONFIG_FB_VGA16=m seems to be necessary for x84.

If the consensus is don't export: I won't. I'm fine one way or the other.
@Christian, what is your take on this?

Thank you very much!

Regards,
Halil