From patchwork Fri May 24 07:56:34 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Tao Xu X-Patchwork-Id: 10959253 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 5305814B6 for ; Fri, 24 May 2019 07:59:14 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 445EF287CF for ; Fri, 24 May 2019 07:59:14 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3712C287DA; Fri, 24 May 2019 07:59:14 +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 B56AD287CF for ; Fri, 24 May 2019 07:59:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389231AbfEXH7I (ORCPT ); Fri, 24 May 2019 03:59:08 -0400 Received: from mga17.intel.com ([192.55.52.151]:8668 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388959AbfEXH7I (ORCPT ); Fri, 24 May 2019 03:59:08 -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 fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 24 May 2019 00:59:08 -0700 X-ExtLoop1: 1 Received: from tao-optiplex-7060.sh.intel.com ([10.239.13.104]) by orsmga008.jf.intel.com with ESMTP; 24 May 2019 00:59:03 -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 Cc: x86@kernel.org, kvm@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, tao3.xu@intel.com, jingqi.liu@intel.com Subject: [PATCH v2 0/3] KVM: x86: Enable user wait instructions Date: Fri, 24 May 2019 15:56:34 +0800 Message-Id: <20190524075637.29496-1-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 to kvm and provide a capability to enable it. With this capability enabled, 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 release document ref below link: https://software.intel.com/sites/default/files/\ managed/39/c5/325462-sdm-vol-1-2abcd-3abcd.pdf This patch has a dependency on https://lkml.org/lkml/2019/1/16/909 Changelog: v2: Separated from the series https://lkml.org/lkml/2018/7/10/160 Add provide a capability to enable UMONITOR, UMWAIT and TPAUSE 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 Documentation/virtual/kvm/api.txt | 12 ++++++ arch/x86/include/asm/kvm_host.h | 1 + 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/vmx.c | 62 +++++++++++++++++++++++++++++++ arch/x86/kvm/vmx/vmx.h | 1 + arch/x86/kvm/x86.c | 8 ++++ arch/x86/kvm/x86.h | 5 +++ include/uapi/linux/kvm.h | 1 + 10 files changed, 97 insertions(+), 2 deletions(-)