Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5973DC433EF for ; Thu, 13 Jan 2022 22:19:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237449AbiAMWT1 (ORCPT ); Thu, 13 Jan 2022 17:19:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58216 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237352AbiAMWT0 (ORCPT ); Thu, 13 Jan 2022 17:19:26 -0500 Received: from mail-pl1-x62b.google.com (mail-pl1-x62b.google.com [IPv6:2607:f8b0:4864:20::62b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5C9C6C061574 for ; Thu, 13 Jan 2022 14:19:26 -0800 (PST) Received: by mail-pl1-x62b.google.com with SMTP id t18so11599889plg.9 for ; Thu, 13 Jan 2022 14:19:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=fsLvM7YnJBN4ooybRpuDhWGMymnq2SHHolVRxp/E+Yw=; b=HQCL9T5Wjp8Cd4nPObAlAtQ1xk0NWb6yw2+tV62YUTcBe5srnRXi9SCY34CBR+3Tx4 QNeVse260Kn1xHbN+tvi64mnPLwVPK/K25Kqv1EeT59TtbFQkeqGHfLOx7dFzEienO// A/+GPCK1BIJOyWsZ7vMBGqar6A26B20UX+rAemPCndm+IQqqWXO3TS59XxNkrhyB+71o huNoRgbL4hNcaQa9Tb0a5jwMNfPIG4mkswjkMi30LraJ6wfRYJ7RVXhJ/EKxaCMeYX0l qlrmty9lvjdgRHBarAFJSwXB4K6FFZJ2NaARYJNYUQ1TWqqErCPyzGbsPUvovZQKUASh rAIQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=fsLvM7YnJBN4ooybRpuDhWGMymnq2SHHolVRxp/E+Yw=; b=RVQpyRADElLpcYVbC1EenGF5w6UfxbBAfrUGHA8Cl5LwYRuBm6wB7jv7LEImRKBK/+ rX6Rd7PkeswBXNSpdETU1uL1WiFyQuDuYhTDkUrmEywigGJd5ZtrkoFVlXCb6dqDSXxp lH9uMPwzG758hHQ0/V/B1Ob7m1cNgEYWZi+TrAkD4NmRCb+xaG2NN/nMqj1yTwg50TO3 Rwcf94j3wO5uoru2J+gC/02WXipCevJ9D1VgMEFTh60IkKLdVWcYVsA9+EiOYYxQcHdT bVTgzpecsvD5DtHWvTB/7ZVJ4RMsToZ/2zoZpdpgPQIUlCOTcVjQn+PAGQFe1OFiZZxH c2Hg== X-Gm-Message-State: AOAM532cw+jyAkoI0PUt9ITdD2HSJM7n6OkJybJPGAjZD3iV7E2gb5/0 ys8NprP1jgINdPdHZdJ/3bO+OQ== X-Google-Smtp-Source: ABdhPJwZj/DNoOH5CoTksMoa0X0ZOwJFcGwdna0ZtODfjPpv+VtxS2/Ymk+PDq5p/1FeD/RU0kPzwg== X-Received: by 2002:a17:902:6bc1:b0:149:7c61:ad31 with SMTP id m1-20020a1709026bc100b001497c61ad31mr6787586plt.93.1642112365720; Thu, 13 Jan 2022 14:19:25 -0800 (PST) Received: from google.com (157.214.185.35.bc.googleusercontent.com. [35.185.214.157]) by smtp.gmail.com with ESMTPSA id l3sm3088784pgs.74.2022.01.13.14.19.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 13 Jan 2022 14:19:24 -0800 (PST) Date: Thu, 13 Jan 2022 22:19:21 +0000 From: Sean Christopherson To: Maxim Levitsky Cc: Chao Gao , Zeng Guang , Tom Lendacky , Paolo Bonzini , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , "kvm@vger.kernel.org" , Dave Hansen , "Luck, Tony" , Kan Liang , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Kim Phillips , Jarkko Sakkinen , Jethro Beekman , "Huang, Kai" , "x86@kernel.org" , "linux-kernel@vger.kernel.org" , "Hu, Robert" Subject: Re: [PATCH v5 7/8] KVM: VMX: Update PID-pointer table entry when APIC ID is changed Message-ID: References: <20211231142849.611-1-guang.zeng@intel.com> <20211231142849.611-8-guang.zeng@intel.com> <640e82f3-489d-60af-1d31-25096bef1a46@amd.com> <4eee5de5-ab76-7094-17aa-adc552032ba0@intel.com> <20220110074523.GA18434@gao-cwp> <1ff69ed503faa4c5df3ad1b5abe8979d570ef2b8.camel@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1ff69ed503faa4c5df3ad1b5abe8979d570ef2b8.camel@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 11, 2022, Maxim Levitsky wrote: > Both Intel and AMD's PRM also state that changing APIC ID is implementation > dependent. > > I vote to forbid changing apic id, at least in the case any APIC acceleration > is used, be that APICv or AVIC. That has my vote as well. For IPIv in particular there's not much concern with backwards compability, i.e. we can tie the behavior to enable_ipiv.