From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8BC2CC433ED for ; Wed, 12 May 2021 08:50:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 50D94613F8 for ; Wed, 12 May 2021 08:50:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230403AbhELIvw (ORCPT ); Wed, 12 May 2021 04:51:52 -0400 Received: from 8bytes.org ([81.169.241.247]:38848 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230137AbhELIvv (ORCPT ); Wed, 12 May 2021 04:51:51 -0400 Received: by theia.8bytes.org (Postfix, from userid 1000) id D8842F3; Wed, 12 May 2021 10:50:42 +0200 (CEST) Date: Wed, 12 May 2021 10:50:41 +0200 From: 'Joerg Roedel' To: Juergen Gross Cc: David Laight , "x86@kernel.org" , Hyunwook Baek , Joerg Roedel , "stable@vger.kernel.org" , "hpa@zytor.com" , Andy Lutomirski , Dave Hansen , Peter Zijlstra , Jiri Slaby , Dan Williams , Tom Lendacky , Kees Cook , David Rientjes , Cfir Cohen , Erdem Aktas , Masami Hiramatsu , Mike Stunes , Sean Christopherson , Martin Radev , Arvind Sankar , "linux-coco@lists.linux.dev" , "linux-kernel@vger.kernel.org" , "kvm@vger.kernel.org" , "virtualization@lists.linux-foundation.org" Subject: Re: [PATCH 3/6] x86/sev-es: Use __put_user()/__get_user Message-ID: References: <20210512075445.18935-1-joro@8bytes.org> <20210512075445.18935-4-joro@8bytes.org> <0496626f018d4d27a8034a4822170222@AcuMS.aculab.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Wed, May 12, 2021 at 10:16:12AM +0200, Juergen Gross wrote: > You want something like xen_safe_[read|write]_ulong(). >From a first glance I can't see it, what is the difference between the xen_safe_*_ulong() functions and __get_user()/__put_user()? The only difference I can see is that __get/__put_user() support different access sizes, but neither of those disables page-faults by itself, for example. Couldn't these xen-specific functions not also be replaces by __get_user()/__put_user()? Regards, Joerg