Re: [PATCH 19/26] x86/tdx: Make pages shared in ioremap()

[Borislav Petkov]

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