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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 18FAAC5ACC0 for ; Mon, 16 Mar 2020 15:51:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E554420719 for ; Mon, 16 Mar 2020 15:51:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="VQs1LV8U" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732071AbgCPPvG (ORCPT ); Mon, 16 Mar 2020 11:51:06 -0400 Received: from us-smtp-delivery-74.mimecast.com ([216.205.24.74]:50761 "EHLO us-smtp-delivery-74.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732058AbgCPPvF (ORCPT ); Mon, 16 Mar 2020 11:51:05 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1584373864; 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: in-reply-to:in-reply-to:references:references; bh=fUuCYueA3lMuDwdeZICwCc8xpvqxEIl0C/2eLY4HFss=; b=VQs1LV8UQt4mqJs2Ff+lpyxud4KmVWxiJtLx0tWgWBs0e8TwkrztCWo5qp355ly65f3Y0b XFwX4eSuf8cK9/681YPalr2e8S4QH3/I+auL4VqyKWqqt7IfvL4smi52SJzl4Dy504mBqr TAwCdYxDb1l2m8YiwnawMgX8jFLyHKg= Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-455-mvdqYcp4M3C4gKvHgVLI3w-1; Mon, 16 Mar 2020 11:44:50 -0400 X-MC-Unique: mvdqYcp4M3C4gKvHgVLI3w-1 Received: by mail-wm1-f70.google.com with SMTP id a23so5964409wmm.8 for ; Mon, 16 Mar 2020 08:44:50 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:in-reply-to:references:date :message-id:mime-version; bh=fUuCYueA3lMuDwdeZICwCc8xpvqxEIl0C/2eLY4HFss=; b=ksBRLzaJ7EKmZ3Qtc0V0zY/Pi/7wzfNqt9y/fKih1JAX6QQtblVAhWBD35nLZOBa5c yODL4ur2Mgh2b7uaPGAqh3pxYgBtV9tU515nDwg3/X+NO2fUT7HIT69oUwFN+rCNX3em x75Y7OVVIZlVP8aQaCBLbPY4baCJMs3hZVCpVFOWUvJaaX1IjFjieUoI738hm5nraDe3 1qW3vPlVk1bIFc6Tj9smLPlLZTTmX2HyM8pS52dE+UMyBwAcYSQBJ4a/Q3hoI8RDeZ55 cW6T7LPfsU9IJcy7/WwALnjj6ZyR7KFtvF8/EhPku/ZFYa65QWsRzd0T81rXHq91TOvK IMWA== X-Gm-Message-State: ANhLgQ1U61o/WaNfBh9WIGXHoD3tj872tu8LQfnpP8hnHPZW5jiXhDRj lqIXPXLoPAOcKHML2JzRup6R+o86ql2sbJfAce/35k/+D6cbH+HZHu4u6wu/jejyAaFRUMvDACm oPSwv4rvOsN66 X-Received: by 2002:a1c:e442:: with SMTP id b63mr29201210wmh.174.1584373489103; Mon, 16 Mar 2020 08:44:49 -0700 (PDT) X-Google-Smtp-Source: ADFU+vsm0twtuBMCOFO0oksSJxj4VZxA6HrZ3ItbOIShmzBDz85OEDCbgoiXWzoQkLGleoeOgMTbZA== X-Received: by 2002:a1c:e442:: with SMTP id b63mr29201190wmh.174.1584373488897; Mon, 16 Mar 2020 08:44:48 -0700 (PDT) Received: from vitty.brq.redhat.com (g-server-2.ign.cz. [91.219.240.2]) by smtp.gmail.com with ESMTPSA id 98sm412922wrk.52.2020.03.16.08.44.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 16 Mar 2020 08:44:48 -0700 (PDT) From: Vitaly Kuznetsov To: Sean Christopherson 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 In-Reply-To: <20200316152650.GD24267@linux.intel.com> References: <1584185480-3556-1-git-send-email-pbonzini@redhat.com> <878sk0n1g1.fsf@vitty.brq.redhat.com> <20200316152650.GD24267@linux.intel.com> Date: Mon, 16 Mar 2020 16:44:47 +0100 Message-ID: <87zhcgl2xc.fsf@vitty.brq.redhat.com> MIME-Version: 1.0 Content-Type: text/plain Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Sean Christopherson writes: > 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; > if (!!old == !!new) return; to make it clear we're converting them to 1/0 :-) -- Vitaly