Subject: Re: [PATCH 07/11] treewide: Replace the use of mem_encrypt_active() with prot_guest_has()

From: "Kuppuswamy, Sathyanarayanan" <[email-masked]>
Date: Tue, 10 Aug 2021 11:45:04 -0700

On 7/27/21 3:26 PM, Tom Lendacky wrote:
> diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
> index de01903c3735..cafed6456d45 100644
> --- a/arch/x86/kernel/head64.c
> +++ b/arch/x86/kernel/head64.c
> @@ -19,7 +19,7 @@
>   #include <linux/start_kernel.h>
>   #include <linux/io.h>
>   #include <linux/memblock.h>
> -#include <linux/mem_encrypt.h>
> +#include <linux/protected_guest.h>
>   #include <linux/pgtable.h>
>   
>   #include <asm/processor.h>
> @@ -285,7 +285,7 @@ unsigned long __head __startup_64(unsigned long physaddr,
>   	 * there is no need to zero it after changing the memory encryption
>   	 * attribute.
>   	 */
> -	if (mem_encrypt_active()) {
> +	if (prot_guest_has(PATTR_MEM_ENCRYPT)) {
>   		vaddr = (unsigned long)__start_bss_decrypted;
>   		vaddr_end = (unsigned long)__end_bss_decrypted;

Since this change is specific to AMD, can you replace PATTR_MEM_ENCRYPT with
prot_guest_has(PATTR_SME) || prot_guest_has(PATTR_SEV). It is not used in
TDX.

-- 
Sathyanarayanan Kuppuswamy
Linux Kernel Developer