linux-kernel - Re: [RFC, PATCH 19/22] x86/mm: Implement free_encrypt

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: <20180306140932.bdll5vh6qzyydqg4@node.shutemov.name>
Date:   Tue, 6 Mar 2018 17:09:32 +0300
From:   "Kirill A. Shutemov" <kirill@...temov.name>
To:     Dave Hansen <dave.hansen@...el.com>
Cc:     "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
        Ingo Molnar <mingo@...hat.com>, x86@...nel.org,
        Thomas Gleixner <tglx@...utronix.de>,
        "H. Peter Anvin" <hpa@...or.com>,
        Tom Lendacky <thomas.lendacky@....com>,
        Kai Huang <kai.huang@...ux.intel.com>,
        linux-kernel@...r.kernel.org, linux-mm@...ck.org
Subject: Re: [RFC, PATCH 19/22] x86/mm: Implement free_encrypt_page()

On Tue, Mar 06, 2018 at 05:52:44AM -0800, Dave Hansen wrote:
> On 03/06/2018 12:54 AM, Kirill A. Shutemov wrote:
> >> Have you measured how slow this is?
> > No, I have not.
> 
> It would be handy to do this.  I *think* you can do it on normal
> hardware, even if it does not have "real" support for memory encryption.
>  Just don't set the encryption bits in the PTEs but go through all the
> motions of cache flushing.

Yes, allocation/freeing and KeyID interfaces can be tested with MKTME
support in hardware. I did most of my testing this way.

> I think that will help tell us whether this is a really specialized
> thing a la hugetlbfs or whether it's something we really want to support
> as a first-class citizen in the VM.

I will benchmark this. But not right now.

-- 
 Kirill A. Shutemov