linux-kernel - Re: [PATCH v6 2/5] x86/mm: fix sme_populate

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Message-ID: <20180910113645.GB21815@zn.tnic>
Date:   Mon, 10 Sep 2018 13:36:45 +0200
From:   Borislav Petkov <bp@...e.de>
To:     Brijesh Singh <brijesh.singh@....com>
Cc:     x86@...nel.org, linux-kernel@...r.kernel.org, kvm@...r.kernel.org,
        Tom Lendacky <thomas.lendacky@....com>,
        Thomas Gleixner <tglx@...utronix.de>,
        "H. Peter Anvin" <hpa@...or.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Sean Christopherson <sean.j.christopherson@...el.com>,
        Radim Krčmář <rkrcmar@...hat.com>
Subject: Re: [PATCH v6 2/5] x86/mm: fix sme_populate_pgd() to update page
 flags

On Fri, Sep 07, 2018 at 12:57:27PM -0500, Brijesh Singh wrote:
> Fix sme_populate_pgd() to update page flags if the PMD/PTE entry
> already exists.
> 
> Signed-off-by: Brijesh Singh <brijesh.singh@....com>
> Reviewed-by: Tom Lendacky <thomas.lendacky@....com>
> Cc: Tom Lendacky <thomas.lendacky@....com>
> Cc: kvm@...r.kernel.org
> Cc: Thomas Gleixner <tglx@...utronix.de>
> Cc: Borislav Petkov <bp@...e.de>
> Cc: "H. Peter Anvin" <hpa@...or.com>
> Cc: linux-kernel@...r.kernel.org
> Cc: Paolo Bonzini <pbonzini@...hat.com>
> Cc: Sean Christopherson <sean.j.christopherson@...el.com>
> Cc: kvm@...r.kernel.org
> Cc: "Radim Krčmář" <rkrcmar@...hat.com>
> ---
>  arch/x86/mm/mem_encrypt_identity.c | 6 +-----
>  1 file changed, 1 insertion(+), 5 deletions(-)
> 
> diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c
> index 92265d3..7659e65 100644
> --- a/arch/x86/mm/mem_encrypt_identity.c
> +++ b/arch/x86/mm/mem_encrypt_identity.c
> @@ -154,9 +154,6 @@ static void __init sme_populate_pgd_large(struct sme_populate_pgd_data *ppd)
>  		return;
>  
>  	pmd = pmd_offset(pud, ppd->vaddr);
> -	if (pmd_large(*pmd))
> -		return;
> -
>  	set_pmd(pmd, __pmd(ppd->paddr | ppd->pmd_flags));
>  }
>  
> @@ -182,8 +179,7 @@ static void __init sme_populate_pgd(struct sme_populate_pgd_data *ppd)
>  		return;
>  
>  	pte = pte_offset_map(pmd, ppd->vaddr);
> -	if (pte_none(*pte))
> -		set_pte(pte, __pte(ppd->paddr | ppd->pte_flags));
> +	set_pte(pte, __pte(ppd->paddr | ppd->pte_flags));
>  }
>  
>  static void __init __sme_map_range_pmd(struct sme_populate_pgd_data *ppd)
> -- 

This looks like a bugfix to me and as such should be:

* at the beginning of the series
* contain a Fixes: tag
* contain Cc: <stable@...r.kernel.org>

Right?

With that addressed:

Reviewed-by: Borislav Petkov <bp@...e.de>

-- 
Regards/Gruss,
    Boris.

SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)
--