Re: [PATCH] X86: __set_clr_pte_enc() miscalculates physical address

[Tom Lendacky]

On 3/18/21 3:26 PM, Isaku Yamahata wrote:
> __set_clr_pte_enc() miscalculates physical address to operate.
> pfn is in unit of PG_LEVEL_4K, not PGL_LEVEL_{2M, 1G}.
> Shift size to get physical address should be PAGE_SHIFT,
> not page_level_shift().
> 
> Fixes: dfaaec9033b8 ("x86: Add support for changing memory encryption attribute in early boot")
> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
> Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>

Reviewed-by: Tom Lendacky <thomas.lendacky@xxxxxxx>

> ---
>  arch/x86/mm/mem_encrypt.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
> index 4b01f7dbaf30..ae78cef79980 100644
> --- a/arch/x86/mm/mem_encrypt.c
> +++ b/arch/x86/mm/mem_encrypt.c
> @@ -262,7 +262,7 @@ static void __init __set_clr_pte_enc(pte_t *kpte, int level, bool enc)
>  	if (pgprot_val(old_prot) == pgprot_val(new_prot))
>  		return;
>  
> -	pa = pfn << page_level_shift(level);
> +	pa = pfn << PAGE_SHIFT;
>  	size = page_level_size(level);
>  
>  	/*
>