Re: [RFC v2 26/32] x86/mm: Move force_dma_unencrypted() to common code

[Kuppuswamy, Sathyanarayanan]

On 5/13/21 10:49 AM, Dave Hansen wrote:
> On 5/13/21 9:40 AM, Kuppuswamy, Sathyanarayanan wrote:
> > +#define PROTECTED_GUEST_BITMAP_LEN    128
> > +
> > +/* Protected Guest vendor types */
> > +#define GUEST_TYPE_TDX            (1)
> > +#define GUEST_TYPE_SEV            (2)
> > +
> > +/* Protected Guest features */
> > +#define MEMORY_ENCRYPTION        (20)
>
> I was assuming we'd reuse the X86_FEATURE infrastructure somehow.  Is
> there a good reason not to?

My assumption is, protected guest abstraction can be also used by
non-x86 arch's in future. So I have tried to keep these definitions
in common code.


> That gives us all the compile-time optimization (via
> en/disabled-features.h) and static branches for "free".

--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer