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=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 30F50C48BE7 for ; Tue, 9 Jul 2019 11:39:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 062FC214AF for ; Tue, 9 Jul 2019 11:39:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="fW+cgoqb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726620AbfGILjs (ORCPT ); Tue, 9 Jul 2019 07:39:48 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:54684 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726030AbfGILjs (ORCPT ); Tue, 9 Jul 2019 07:39:48 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=yvuN7XriVhLzlpcSf3QVaG6soAikaUqnhDyVf0OF2tA=; b=fW+cgoqbOCQZ9QOR2gx285qFI 6mNy/k+o3AyaHPAribt0An3VQWnxKctGKqeBFtjGaXzpR5va4gyoXE+LPkfint+FybWKF5iyciTZW 5KDadFzerjay70s7FFFQfw15w4/R/o9Ee0SnORIL06dKDHeGHm5/YRFe+WY031YltCzVo3XfQsg7R 06ui9ykPLvMsXNtmpT/r6SotqBTaAwWYr6tmoL93tFVG4k7aBB37Qi0ELaEnrXmkIzhgCxdkMNaEN y6e6/cBALtujliPuU8YHuOD6iBUhFnxfw0dXXiTjjlX1zh73FTKXN7+AJySovHA4uPN7JtMQHV5nm GViR98BoQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.92 #3 (Red Hat Linux)) id 1hkoTI-0006c4-49; Tue, 09 Jul 2019 11:39:44 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 2B6F920120CB1; Tue, 9 Jul 2019 13:39:42 +0200 (CEST) Date: Tue, 9 Jul 2019 13:39:42 +0200 From: Peter Zijlstra To: Andi Kleen Cc: Wei Wang , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, pbonzini@redhat.com, kan.liang@intel.com, mingo@redhat.com, rkrcmar@redhat.com, like.xu@intel.com, jannh@google.com, arei.gonglei@huawei.com, jmattson@google.com Subject: Re: [PATCH v7 10/12] KVM/x86/lbr: lazy save the guest lbr stack Message-ID: <20190709113942.GV3402@hirez.programming.kicks-ass.net> References: <1562548999-37095-1-git-send-email-wei.w.wang@intel.com> <1562548999-37095-11-git-send-email-wei.w.wang@intel.com> <20190708145326.GO3402@hirez.programming.kicks-ass.net> <20190708151141.GL31027@tassilo.jf.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190708151141.GL31027@tassilo.jf.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, Jul 08, 2019 at 08:11:41AM -0700, Andi Kleen wrote: > > I don't understand a word of that. > > > > Who cares if the LBR MSRs are touched; the guest expects up-to-date > > values when it does reads them. > > This is for only when the LBRs are disabled in the guest. But your Changelog didn't clearly state that. It was an unreadable mess.