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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 BA36AC47404 for ; Fri, 11 Oct 2019 07:47:53 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8B54A20679 for ; Fri, 11 Oct 2019 07:47:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8B54A20679 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:46726 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iIpeS-0005BV-Id for qemu-devel@archiver.kernel.org; Fri, 11 Oct 2019 03:47:52 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:35344) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iIpY8-0000cG-I9 for qemu-devel@nongnu.org; Fri, 11 Oct 2019 03:41:22 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iIpY6-0003cD-IF for qemu-devel@nongnu.org; Fri, 11 Oct 2019 03:41:20 -0400 Received: from mga11.intel.com ([192.55.52.93]:1925) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iIpY4-0003Wp-IE for qemu-devel@nongnu.org; Fri, 11 Oct 2019 03:41:18 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 11 Oct 2019 00:41:07 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.67,283,1566889200"; d="scan'208";a="194257161" Received: from tao-optiplex-7060.sh.intel.com ([10.239.159.36]) by fmsmga007.fm.intel.com with ESMTP; 11 Oct 2019 00:41:06 -0700 From: Tao Xu To: pbonzini@redhat.com, rth@twiddle.net, ehabkost@redhat.com, mtosatti@redhat.com Subject: [PATCH RESEND v6 0/2] x86: Enable user wait instructions Date: Fri, 11 Oct 2019 15:41:01 +0800 Message-Id: <20191011074103.30393-1-tao3.xu@intel.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 192.55.52.93 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: jingqi.liu@intel.com, tao3.xu@intel.com, qemu-devel@nongnu.org, kvm@vger.kernel.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" 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 release document ref below link: https://software.intel.com/sites/default/files/\ managed/39/c5/325462-sdm-vol-1-2abcd-3abcd.pdf Changelog: v6: Remove CPUID_7_0_ECX_WAITPKG if enable_cpu_pm is not set. (Paolo) Tao Xu (2): x86/cpu: Add support for UMONITOR/UMWAIT/TPAUSE target/i386: Add support for save/load IA32_UMWAIT_CONTROL MSR target/i386/cpu.c | 2 +- target/i386/cpu.h | 3 +++ target/i386/kvm.c | 19 +++++++++++++++++++ target/i386/machine.c | 20 ++++++++++++++++++++ 4 files changed, 43 insertions(+), 1 deletion(-) -- 2.20.1