linux-kernel - Re: [Patch v3 05/14] x86/mm: Handle decryption/re-encryption of bss

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Date:   Mon, 21 Nov 2022 15:39:11 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     "Michael Kelley (LINUX)" <mikelley@...rosoft.com>
Cc:     Sathyanarayanan Kuppuswamy 
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Subject: Re: [Patch v3 05/14] x86/mm: Handle decryption/re-encryption of
 bss_decrypted consistently

On Fri, Nov 18, 2022 at 02:55:32AM +0000, Michael Kelley (LINUX) wrote:
> But I had not thought about TDX.  In the TDX case, it appears that
> sme_postprocess_startup() will not decrypt the bss_decrypted section.
> The corresponding mem_encrypt_free_decrypted_mem() is a no-op unless
> CONFIG_AMD_MEM_ENCRYPT is set.  But maybe if someone builds a
> kernel image that supports both TDX and AMD encryption, it could break

sme_me_mask better be 0 on a kernel with both built in and running as a
TDX guest.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette