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

From: Dave Hansen
Date: Thu May 13 2021 - 13:50:20 EST


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?

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