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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 CA6F7C433DF for ; Thu, 2 Jul 2020 23:24:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A0E0F20760 for ; Thu, 2 Jul 2020 23:24:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=citrix.com header.i=@citrix.com header.b="dSkUvgeH" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726237AbgGBXYN (ORCPT ); Thu, 2 Jul 2020 19:24:13 -0400 Received: from esa4.hc3370-68.iphmx.com ([216.71.155.144]:44850 "EHLO esa4.hc3370-68.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726017AbgGBXYM (ORCPT ); Thu, 2 Jul 2020 19:24:12 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=citrix.com; s=securemail; t=1593732252; h=subject:to:cc:references:from:message-id:date: mime-version:in-reply-to:content-transfer-encoding; bh=DD/40Qz8qZ78c4jky0R8eJwe8SV5DGFlqxwDiyq60pw=; b=dSkUvgeHtKGv8ckYivVY5J7d7/bFXIX60d6R2n8P14Cg/5guSF2fcJIN ayhG79qAW3QIAAHZ46z3oHU0wdFYBLZQwEuIFeeu7/nNwGgFDU1nvzrlu PiXF94l4++psFputDy+FfWtXcocL4FwJMNRallnLRMYV+uJ5qr5v939pE o=; Authentication-Results: esa4.hc3370-68.iphmx.com; dkim=none (message not signed) header.i=none IronPort-SDR: EHdLL4zhLW9bpSAxAYvRa35rsjy9utSWkFNwQ8GKYJ+LgLEnAwpznR4lbdlktDiJaHK1o4M5lZ S9HVefjH7PkelGMqcFH6RJL0JqHfpf9IcxUSI8VAQovcbJluYYMeF1D8rqexJXsykDNol2W6J9 zkUhu+rXVjkd5mxogyU8jPVFs0w0NNcM6Mrh4UdjXGLcHhpaa7BnEGf9ra8xsTjZKldT9NTuNF qTi/2UdOord7K58h1mQXpcGPw8obNGNY7+e1hE0eYiOjt5TnUJpkspi3E+mRNaXVAAtuQJ4Dr7 fRM= X-SBRS: 2.7 X-MesageID: 22346397 X-Ironport-Server: esa4.hc3370-68.iphmx.com X-Remote-IP: 162.221.158.21 X-Policy: $RELAYED X-IronPort-AV: E=Sophos;i="5.75,305,1589256000"; d="scan'208";a="22346397" Subject: Re: [PATCH v2 1/4] x86/xen: remove 32-bit Xen PV guest support To: Boris Ostrovsky , Juergen Gross , , , CC: Stefano Stabellini , Ingo Molnar , Borislav Petkov , Andy Lutomirski , "H. Peter Anvin" , Thomas Gleixner References: <20200701110650.16172-1-jgross@suse.com> <20200701110650.16172-2-jgross@suse.com> <6d0b517a-6c53-61d3-117b-40e33e013037@oracle.com> From: Andrew Cooper Message-ID: <9f8cc440-82f0-d6d8-945d-19c48f69a6b0@citrix.com> Date: Fri, 3 Jul 2020 00:24:06 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <6d0b517a-6c53-61d3-117b-40e33e013037@oracle.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Language: en-GB X-ClientProxiedBy: AMSPEX02CAS02.citrite.net (10.69.22.113) To AMSPEX02CL02.citrite.net (10.69.22.126) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/07/2020 23:59, Boris Ostrovsky wrote: > On 7/1/20 7:06 AM, Juergen Gross wrote: >> >> -#ifdef CONFIG_X86_PAE >> -static void xen_set_pte_atomic(pte_t *ptep, pte_t pte) >> -{ >> - trace_xen_mmu_set_pte_atomic(ptep, pte); >> - __xen_set_pte(ptep, pte); > > Probably not for this series but I wonder whether __xen_set_pte() should > continue to use hypercall now that we are 64-bit only. The hypercall path is a SYSCALL (and SYSRET out). The "writeable" PTE path is a #PF, followed by an x86 instruction emulation, which then reaches the same logic as the hypercall path (and an IRET out). ~Andrew