From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752458AbeC2LUj (ORCPT ); Thu, 29 Mar 2018 07:20:39 -0400 Received: from mx2.suse.de ([195.135.220.15]:54273 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751908AbeC2LUi (ORCPT ); Thu, 29 Mar 2018 07:20:38 -0400 Date: Thu, 29 Mar 2018 13:20:34 +0200 From: Michal Hocko 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 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> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.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