linux-kernel - Re: [PATCH v5 06/15] x86/sev: Drop redundant and potentially misleading 'sev

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20210422121618.GC6361@zn.tnic>
Date:   Thu, 22 Apr 2021 14:16:18 +0200
From:   Borislav Petkov <bp@...e.de>
To:     Sean Christopherson <seanjc@...gle.com>
Cc:     Paolo Bonzini <pbonzini@...hat.com>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Andy Lutomirski <luto@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Tom Lendacky <thomas.lendacky@....com>,
        Brijesh Singh <brijesh.singh@....com>
Subject: Re: [PATCH v5 06/15] x86/sev: Drop redundant and potentially
 misleading 'sev_enabled'

On Wed, Apr 21, 2021 at 07:11:16PM -0700, Sean Christopherson wrote:
> Drop the sev_enabled flag and switch its one user over to sev_active().
> sev_enabled was made redundant with the introduction of sev_status in
> commit b57de6cd1639 ("x86/sev-es: Add SEV-ES Feature Detection").
> sev_enabled and sev_active() are guaranteed to be equivalent, as each is
> true iff 'sev_status & MSR_AMD64_SEV_ENABLED' is true, and are only ever
> written in tandem (ignoring compressed boot's version of sev_status).
> 
> Removing sev_enabled avoids confusion over whether it refers to the guest
> or the host, and will also allow KVM to usurp "sev_enabled" for its own
> purposes.
> 
> No functional change intended.
> 
> Reviewed-by: Tom Lendacky <thomas.lendacky@....com>
> Reviewed-by: Brijesh Singh <brijesh.singh@....com>
> Signed-off-by: Sean Christopherson <seanjc@...gle.com>
> ---
>  arch/x86/include/asm/mem_encrypt.h |  1 -
>  arch/x86/mm/mem_encrypt.c          | 12 +++++-------
>  arch/x86/mm/mem_encrypt_identity.c |  1 -
>  3 files changed, 5 insertions(+), 9 deletions(-)

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

Thx.

-- 
Regards/Gruss,
    Boris.

SUSE Software Solutions Germany GmbH, GF: Felix Imendörffer, HRB 36809, AG Nürnberg