Messages in this thread | | | Date | Fri, 24 Dec 2021 14:03:00 +0300 | From | "Kirill A. Shutemov" <> | Subject | Re: [PATCH 19/26] x86/tdx: Make pages shared in ioremap() |
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On Thu, Dec 23, 2021 at 10:09:26PM +0100, Borislav Petkov wrote: > 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...
Okay. Meanwhile I leave it this way:
pgprot_t pgprot_cc_encrypted(pgprot_t prot) { if (cc_platform_has(CC_ATTR_MEM_ENCRYPT)) { if (cc_platform_has(CC_ATTR_GUEST_TDX)) return __pgprot(pgprot_val(prot) & ~tdx_shared_mask()); else if (sme_me_mask) return __pgprot(__sme_set(pgprot_val(prot))); else WARN_ON_ONCE(1); }
return prot; } EXPORT_SYMBOL_GPL(pgprot_cc_encrypted);
pgprot_t pgprot_cc_decrypted(pgprot_t prot) { if (cc_platform_has(CC_ATTR_MEM_ENCRYPT)) { if (cc_platform_has(CC_ATTR_GUEST_TDX)) return __pgprot(pgprot_val(prot) | tdx_shared_mask()); else if (sme_me_mask) return __pgprot(__sme_clr(pgprot_val(prot))); else WARN_ON_ONCE(1); }
return prot; } EXPORT_SYMBOL_GPL(pgprot_cc_decrypted);
-- Kirill A. Shutemov
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