From patchwork Thu Sep 6 11:30:48 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Wang, Wei W" X-Patchwork-Id: 10590499 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A4140921 for ; Thu, 6 Sep 2018 12:02:11 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8CE452A766 for ; Thu, 6 Sep 2018 12:02:11 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7F3E62A77D; Thu, 6 Sep 2018 12:02:11 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 299372A766 for ; Thu, 6 Sep 2018 12:02:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727427AbeIFQgQ (ORCPT ); Thu, 6 Sep 2018 12:36:16 -0400 Received: from mga18.intel.com ([134.134.136.126]:62802 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726436AbeIFQgQ (ORCPT ); Thu, 6 Sep 2018 12:36:16 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 06 Sep 2018 05:00:49 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,338,1531810800"; d="scan'208";a="71046709" Received: from devel-ww.sh.intel.com ([10.239.48.110]) by orsmga008.jf.intel.com with ESMTP; 06 Sep 2018 05:00:47 -0700 From: Wei Wang To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, pbonzini@redhat.com, ak@linux.intel.com Cc: kan.liang@intel.com, peterz@infradead.org, mingo@redhat.com, rkrcmar@redhat.com, like.xu@intel.com, wei.w.wang@intel.com Subject: [PATCH v2 0/8] Guest LBR Enabling Date: Thu, 6 Sep 2018 19:30:48 +0800 Message-Id: <1536233456-12173-1-git-send-email-wei.w.wang@intel.com> X-Mailer: git-send-email 2.7.4 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Last Branch Recording (LBR) is a performance monitor unit (PMU) feature on Intel CPUs that captures branch related info. This patch series enables this feature to KVM guests. Here is a conclusion of the fundamental methods that we use: 1) the LBR feature is enabled per guest via QEMU setting of KVM_CAP_X86_GUEST_LBR; 2) when the guest has the LBR feature, the LBR stack is passed through to the guest for direct accesses; 3) When the guest uses the LBR feature with the user callstack mode, the host will help save/resotre the LBR stack when the vCPU thread is scheduled out/in. Patches 1-5 implements the above 1) and 2), and patches 6-8 implements the above 3). ChangeLog: v1->v2: - add the per guest LBR capability, KVM_CAP_X86_GUEST_LBR; - save/restore the LBR stack conditionally on the vCPU thread context switching, instead of on VMX transitions; - expose MSR_IA32_PERF_CAPABILITIES to the guest. The first version was sent out long time ago, and can be referenced here: https://lkml.org/lkml/2017/9/25/11 , and thanks for lots of the suggestions from Paolo Bonzini and Andi Kleen. Like Xu (2): KVM: PMU: support to save/restore the guest lbr stack on vCPU switching perf/x86/intel/lbr: add the guest_lbr boolean to cpuc Wei Wang (6): perf/x86: add a function to get the lbr stack KVM/x86: KVM_CAP_X86_GUEST_LBR KVM/vmx: Pass through the lbr stack to a guest KVM/x86: expose MSR_IA32_PERF_CAPABILITIES to the guest KVM/x86: enable the guest to access the debugctl msr perf/x86/intel/lbr: guest requesting KVM for lbr stack save/restore arch/x86/events/intel/lbr.c | 54 +++++++++++++++++++++++++-- arch/x86/events/perf_event.h | 1 + arch/x86/include/asm/kvm_host.h | 3 ++ arch/x86/include/asm/perf_event.h | 19 ++++++++++ arch/x86/include/uapi/asm/kvm_para.h | 2 + arch/x86/kvm/cpuid.c | 5 ++- arch/x86/kvm/pmu_intel.c | 71 +++++++++++++++++++++++++++++++++++- arch/x86/kvm/vmx.c | 60 ++++++++++++++++++++++++++++++ arch/x86/kvm/x86.c | 18 +++------ include/uapi/linux/kvm.h | 1 + 10 files changed, 215 insertions(+), 19 deletions(-)