From patchwork Sun Jun 16 09:33:41 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Tao Xu X-Patchwork-Id: 10997325 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 222541395 for ; Sun, 16 Jun 2019 09:36:41 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1255028735 for ; Sun, 16 Jun 2019 09:36:41 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 063DA287A2; Sun, 16 Jun 2019 09:36:41 +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 E945328735 for ; Sun, 16 Jun 2019 09:36:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725992AbfFPJgT (ORCPT ); Sun, 16 Jun 2019 05:36:19 -0400 Received: from mga12.intel.com ([192.55.52.136]:50557 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725766AbfFPJgT (ORCPT ); Sun, 16 Jun 2019 05:36:19 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 16 Jun 2019 02:36:18 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.63,381,1557212400"; d="scan'208";a="185427960" Received: from tao-optiplex-7060.sh.intel.com ([10.239.13.104]) by fmsmga002.fm.intel.com with ESMTP; 16 Jun 2019 02:36:16 -0700 From: Tao Xu To: pbonzini@redhat.com, rkrcmar@redhat.com, corbet@lwn.net, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com, sean.j.christopherson@intel.com, fenghua.yu@intel.com Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, tao3.xu@intel.com, jingqi.liu@intel.com Subject: [PATCH v3 0/3] x86: Enable user wait instructions Date: Sun, 16 Jun 2019 17:33:41 +0800 Message-Id: <20190616093344.12582-1-tao3.xu@intel.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP UMONITOR, UMWAIT and TPAUSE are a set of user wait instructions. UMONITOR arms address monitoring hardware using an address. A store to an address within the specified address range triggers the monitoring hardware to wake up the processor waiting in umwait. UMWAIT instructs the processor to enter an implementation-dependent optimized state while monitoring a range of addresses. The optimized state may be either a light-weight power/performance optimized state (c0.1 state) or an improved power/performance optimized state (c0.2 state). TPAUSE instructs the processor to enter an implementation-dependent optimized state c0.1 or c0.2 state and wake up when time-stamp counter reaches specified timeout. Availability of the user wait instructions is indicated by the presence of the CPUID feature flag WAITPKG CPUID.0x07.0x0:ECX[5]. The patches enable the umonitor, umwait and tpause features in KVM. Because umwait and tpause can put a (psysical) CPU into a power saving state, by default we dont't expose it in kvm and provide a capability to enable it. Use kvm capability to enable UMONITOR, UMWAIT and TPAUSE when QEMU use "-overcommit cpu-pm=on, a VM can use UMONITOR, UMWAIT and TPAUSE instructions. If the instruction causes a delay, the amount of time delayed is called here the physical delay. The physical delay is first computed by determining the virtual delay (the time to delay relative to the VM’s timestamp counter). Otherwise, UMONITOR, UMWAIT and TPAUSE cause an invalid-opcode exception(#UD). The dependency KVM patch link: https://lkml.org/lkml/2019/5/24/138 The release document ref below link: https://software.intel.com/sites/default/files/\ managed/39/c5/325462-sdm-vol-1-2abcd-3abcd.pdf Changelog: v3: Simplify the patches, expose user wait instructions when the guest has CPUID (Paolo) v2: Separated from the series https://www.mail-archive.com/qemu-devel@nongnu.org/msg549526.html Use kvm capability to enable UMONITOR, UMWAIT and TPAUSE when QEMU use "-overcommit cpu-pm=on" v1: Sent out with MOVDIRI/MOVDIR64B instructions patches Tao Xu (3): KVM: x86: add support for user wait instructions KVM: vmx: Emulate MSR IA32_UMWAIT_CONTROL KVM: vmx: handle vm-exit for UMWAIT and TPAUSE arch/x86/include/asm/vmx.h | 1 + arch/x86/include/uapi/asm/vmx.h | 6 +++- arch/x86/kvm/cpuid.c | 2 +- arch/x86/kvm/vmx/capabilities.h | 6 ++++ arch/x86/kvm/vmx/vmx.c | 56 +++++++++++++++++++++++++++++++++ arch/x86/kvm/vmx/vmx.h | 3 ++ arch/x86/power/umwait.c | 3 +- 7 files changed, 74 insertions(+), 3 deletions(-)