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=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 ECB9DC0044D for ; Mon, 16 Mar 2020 15:26:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BE0382071C for ; Mon, 16 Mar 2020 15:26:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731835AbgCPP0x (ORCPT ); Mon, 16 Mar 2020 11:26:53 -0400 Received: from mga09.intel.com ([134.134.136.24]:48163 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731822AbgCPP0v (ORCPT ); Mon, 16 Mar 2020 11:26:51 -0400 IronPort-SDR: 5MFZcVF54I6GT2ul4WgPnvt0ASBKxa79KWYSHNW9elC2Kz/8ys0Pog/MX1Eybslo0ENMVQpPDA BFX4TYaf+gXw== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Mar 2020 08:26:51 -0700 IronPort-SDR: BYukCOSEs4by1h0DChVnv0ZZ8vO+P1f+VhQP6gv4v9KBzZ9qkMrmzSs2YMrjm05nfSwp/5neov uezYMQ4cP2zw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,560,1574150400"; d="scan'208";a="290728497" Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.202]) by FMSMGA003.fm.intel.com with ESMTP; 16 Mar 2020 08:26:50 -0700 Date: Mon, 16 Mar 2020 08:26:50 -0700 From: Sean Christopherson To: Vitaly Kuznetsov Cc: Paolo Bonzini , linmiaohe@huawei.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Subject: Re: [PATCH] KVM: X86: correct meaningless kvm_apicv_activated() check Message-ID: <20200316152650.GD24267@linux.intel.com> References: <1584185480-3556-1-git-send-email-pbonzini@redhat.com> <878sk0n1g1.fsf@vitty.brq.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <878sk0n1g1.fsf@vitty.brq.redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Mon, Mar 16, 2020 at 09:33:50AM +0100, Vitaly Kuznetsov wrote: > Paolo Bonzini writes: > > + if ((old == 0) == (new == 0)) > > + return; > > This is a very laconic expression I personally find hard to read :-) > > /* Check if WE actually changed APICv state */ > if ((!old && !new) || (old && new)) > return; > > would be my preference (not strong though, I read yours several times > and now I feel like I understand it just fine :-) Or maybe this to avoid so many equals signs? if (!old == !new) return;