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 25E78C606BD for ; Mon, 8 Jul 2019 15:09:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E41C720844 for ; Mon, 8 Jul 2019 15:09:20 +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="NZu7XgmX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732076AbfGHPJT (ORCPT ); Mon, 8 Jul 2019 11:09:19 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:44102 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725872AbfGHPJT (ORCPT ); Mon, 8 Jul 2019 11:09:19 -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=r7UwcFp7s/JselmOZws/SyZ0vs26xyAmDy6K8E/OEck=; b=NZu7XgmXduMWL7HuE6ocOe90f BMM3Il8oUtGCxdBtF2+rzdhGaMFvmDf2jl8ed5+3eNEhpR1tfvB8WgisJRaBdid9hPqLGTZKvBwl5 udA8H/12Sks5lEojNuAQ/kSlq43katr9ZGYkMwgOULPzyq/YD9DyR8Ajv1sRXKKL3H3Oj5C0NdQ1d QPNZmRFEuGV79a6SBgZxuD/VsRvRCDm525CTAk4qOb0/z05HWnkxtSpO48/C6gdAex06Mj4r3QULN KDyH0ThG788ZfDohWaJsybGO/i85j0lYFLNE07SbzOcWPBT9yJw3na4LnyDzaDWzh/imksZWASbuy 1rpx6evrg==; 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 1hkVGR-0001wF-GQ; Mon, 08 Jul 2019 15:09:11 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id B233420976D8C; Mon, 8 Jul 2019 17:09:09 +0200 (CEST) Date: Mon, 8 Jul 2019 17:09:09 +0200 From: Peter Zijlstra To: Wei Wang Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, pbonzini@redhat.com, ak@linux.intel.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 12/12] KVM/VMX/vPMU: support to report GLOBAL_STATUS_LBRS_FROZEN Message-ID: <20190708150909.GP3402@hirez.programming.kicks-ass.net> References: <1562548999-37095-1-git-send-email-wei.w.wang@intel.com> <1562548999-37095-13-git-send-email-wei.w.wang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1562548999-37095-13-git-send-email-wei.w.wang@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 09:23:19AM +0800, Wei Wang wrote: > This patch enables the LBR related features in Arch v4 in advance, > though the current vPMU only has v2 support. Other arch v4 related > support will be enabled later in another series. > > Arch v4 supports streamlined Freeze_LBR_on_PMI. According to the SDM, > the LBR_FRZ bit is set to global status when debugctl.freeze_lbr_on_pmi > has been set and a PMI is generated. The CTR_FRZ bit is set when > debugctl.freeze_perfmon_on_pmi is set and a PMI is generated. (that's still a misnomer; it is: freeze_perfmon_on_overflow) Why? Who uses that v4 crud? It's broken. It looses events between overflow and PMI.