Re: [PATCH 19/26] x86/tdx: Make pages shared in ioremap()
From: Borislav Petkov
Date: Thu Dec 23 2021 - 16:09:40 EST
On Thu, Dec 23, 2021 at 11:56:04PM +0300, Kirill A. Shutemov wrote:
> Except CC_ATTR_MEM_ENCRYPT is true for TDX too, so it will also depend on
> check order. It is fragile.
So the query you wanna do is:
if (memory encryption in use)
use mask;
and the mask you use depends on whether it is SEV or TDX. Right?
If so, you can either do a cc_get_mask() function which gives you either
the SEV or TDX mask or simply do:
if (CC_ATTR_MEM_ENCRYPT) {
if (CC_ATTR_GUEST_TDX)
mask = tdx_shared_mask();
else if (sme_me_mask)
mask = sme_me_mask;
}
Yeah, sme_me_mask has become synonymous with the kernel running as a AMD
confidential guest. I need to think about how to make this cleaner...
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette