From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f72.google.com (mail-wm0-f72.google.com [74.125.82.72]) by kanga.kvack.org (Postfix) with ESMTP id 6F2076B0003 for ; Thu, 29 Mar 2018 07:20:42 -0400 (EDT) Received: by mail-wm0-f72.google.com with SMTP id v21so2335047wmh.9 for ; Thu, 29 Mar 2018 04:20:42 -0700 (PDT) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id v21si1189526wmc.150.2018.03.29.04.20.37 for (version=TLS1 cipher=AES128-SHA bits=128/128); Thu, 29 Mar 2018 04:20:37 -0700 (PDT) Date: Thu, 29 Mar 2018 13:20:34 +0200 From: Michal Hocko Subject: Re: [PATCHv2 06/14] mm/page_alloc: Propagate encryption KeyID through page allocator Message-ID: <20180329112034.GE31039@dhcp22.suse.cz> References: <20180328165540.648-1-kirill.shutemov@linux.intel.com> <20180328165540.648-7-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180328165540.648-7-kirill.shutemov@linux.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: "Kirill A. Shutemov" Cc: Ingo Molnar , x86@kernel.org, Thomas Gleixner , "H. Peter Anvin" , Tom Lendacky , Dave Hansen , Kai Huang , linux-kernel@vger.kernel.org, linux-mm@kvack.org On Wed 28-03-18 19:55:32, Kirill A. Shutemov wrote: > Modify several page allocation routines to pass down encryption KeyID to > be used for the allocated page. > > There are two basic use cases: > > - alloc_page_vma() use VMA's KeyID to allocate the page. > > - Page migration and NUMA balancing path use KeyID of original page as > KeyID for newly allocated page. I am sorry but I am out of time to look closer but this just raised my eyebrows. This looks like a no-go. The basic allocator has no business in fancy stuff like a encryption key. If you need something like that then just build a special allocator API on top. This looks like a no-go to me. -- Michal Hocko SUSE Labs