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=-3.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 6D7D9C2D0F8 for ; Wed, 13 May 2020 06:35:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 53EBA206A5 for ; Wed, 13 May 2020 06:35:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729694AbgEMGfa (ORCPT ); Wed, 13 May 2020 02:35:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47216 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725977AbgEMGfa (ORCPT ); Wed, 13 May 2020 02:35:30 -0400 Received: from Galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A157CC061A0C for ; Tue, 12 May 2020 23:35:29 -0700 (PDT) Received: from p5de0bf0b.dip0.t-ipconnect.de ([93.224.191.11] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1jYkyi-0001gu-4c; Wed, 13 May 2020 08:34:52 +0200 Received: by nanos.tec.linutronix.de (Postfix, from userid 1000) id 6ED8D100605; Wed, 13 May 2020 08:34:51 +0200 (CEST) From: Thomas Gleixner To: Steven Rostedt Cc: LKML , x86@kernel.org, "Paul E. McKenney" , Andy Lutomirski , Alexandre Chartre , Frederic Weisbecker , Paolo Bonzini , Sean Christopherson , Masami Hiramatsu , Petr Mladek , Joel Fernandes , Boris Ostrovsky , Juergen Gross , Brian Gerst , Mathieu Desnoyers , Josh Poimboeuf , Will Deacon , Tom Lendacky , Wei Liu , Michael Kelley , Jason Chen CJ , Zhao Yakui , "Peter Zijlstra \(Intel\)" Subject: Re: [patch V5 02/38] x86/entry/64: Use native swapgs in asm_native_load_gs_index() In-Reply-To: <20200512220230.629a230f@oasis.local.home> References: <20200512210059.056244513@linutronix.de> <20200512213809.583980272@linutronix.de> <20200512220230.629a230f@oasis.local.home> Date: Wed, 13 May 2020 08:34:51 +0200 Message-ID: <8736845oms.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Steven Rostedt writes: > On Tue, 12 May 2020 23:01:01 +0200 > Thomas Gleixner wrote: > >> When PARAVIRT_XXL is in use, then load_gs_index() uses >> xen_load_gs_index() and (asm_))native_load_gs_index() is unused. >> >> It's therefore pointless to use the paravirtualized SWAPGS implementation >> in asm_native_load_gs_index(). Switch it to a plain swapgs. >> >> Signed-off-by: Thomas Gleixner >> Cc: Juergen Gross >> --- >> arch/x86/entry/entry_64.S | 6 +++--- >> 1 file changed, 3 insertions(+), 3 deletions(-) >> >> --- a/arch/x86/entry/entry_64.S >> +++ b/arch/x86/entry/entry_64.S >> @@ -1043,11 +1043,11 @@ idtentry simd_coprocessor_error do_simd >> */ >> SYM_FUNC_START(asm_native_load_gs_index) > > Small nit, but I would just call this: asm_load_gs_index. > > The "native" word is usually reserved for functions that are for bare > metal and have a paravirt counterpart. As there is a > native_load_gs_index(), I don't envision a need for a paravirt version > of the asm function. Fair enough.