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=-2.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_MUTT autolearn=ham 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 0080DC43219 for ; Mon, 29 Apr 2019 07:36:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BEF9120652 for ; Mon, 29 Apr 2019 07:36:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="baorS2Qb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727506AbfD2Hgd (ORCPT ); Mon, 29 Apr 2019 03:36:33 -0400 Received: from mail.skyhub.de ([5.9.137.197]:34214 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726846AbfD2Hgd (ORCPT ); Mon, 29 Apr 2019 03:36:33 -0400 Received: from zn.tnic (p200300EC2F073600CC908F6B12A96C5F.dip0.t-ipconnect.de [IPv6:2003:ec:2f07:3600:cc90:8f6b:12a9:6c5f]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 6FF101EC0A99; Mon, 29 Apr 2019 09:36:31 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1556523391; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=ecj0aE6gq10rKox5w0C12D0qKcWWyug+xBLPklihyDQ=; b=baorS2QbQlfP18vTtOK0cVWrLq5HKuwlJ3nSCscAr8t9TBRZYApffFMdbzA7Htog2Qfk// xz9T4xLDXMcavQcOCdS9skoBKgNx7Huc/ylacMxvQU5GyJAxdakpWPmnASMO82vOk4Wcyt Et4112kvddtMy0zadeuSMWAOZH3usrk= Date: Mon, 29 Apr 2019 09:36:25 +0200 From: Borislav Petkov To: "Zhao, Yakui" Cc: Ingo Molnar , "linux-kernel@vger.kernel.org" , "x86@kernel.org" , "tglx@linutronix.de" , "Chen, Jason CJ" Subject: Re: [RFC PATCH v5 4/4] x86/acrn: Add hypercall for ACRN guest Message-ID: <20190429073625.GA2324@zn.tnic> References: <1556067260-9128-1-git-send-email-yakui.zhao@intel.com> <1556067260-9128-5-git-send-email-yakui.zhao@intel.com> <20190425070712.GA57256@gmail.com> <6dd021a9-e2c0-ee84-55fd-3e6dfb4bd944@intel.com> <20190425110025.GA16164@zn.tnic> <473d145c-4bfd-4ec8-34c3-8a26a78fe40d@intel.com> <20190427085816.GB12360@zn.tnic> <20190428100309.GA2334@zn.tnic> <4c5ca6d7-ffb1-a5a5-9e46-9057802318e0@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <4c5ca6d7-ffb1-a5a5-9e46-9057802318e0@intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 29, 2019 at 09:24:12AM +0800, Zhao, Yakui wrote: > Yes. "movq" only indicates explicitly that it is 64-bit mov as ACRN guest > only works under 64-bit mode. > I also check the usage of "mov" and "movq" in this scenario. There is no > difference except that the movq is an explicit 64-op. Damn, I'm tired of explaining this: it is explicit only to the code reader. gcc generates the *same* instruction no matter whether it has a "q" suffix or not as long as the destination register is a 64-bit one. If you prefer to have it explicit, sure, use "movq". -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.