From patchwork Sun Jun 16 15:35:23 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Tao Xu X-Patchwork-Id: 10997535 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 1481614B6 for ; Sun, 16 Jun 2019 15:49:04 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0465C28801 for ; Sun, 16 Jun 2019 15:49:04 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id ECEFF2880A; Sun, 16 Jun 2019 15:49:03 +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=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 965F828801 for ; Sun, 16 Jun 2019 15:49:03 +0000 (UTC) Received: from localhost ([::1]:41130 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hcXFH-0000L2-2S for patchwork-qemu-devel@patchwork.kernel.org; Sun, 16 Jun 2019 11:39:03 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:53304) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hcXER-0007Zu-8T for qemu-devel@nongnu.org; Sun, 16 Jun 2019 11:38:12 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hcXEP-0005oE-WC for qemu-devel@nongnu.org; Sun, 16 Jun 2019 11:38:11 -0400 Received: from mga05.intel.com ([192.55.52.43]:22918) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hcXEP-0005Zd-LV for qemu-devel@nongnu.org; Sun, 16 Jun 2019 11:38:09 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 16 Jun 2019 08:38:01 -0700 X-ExtLoop1: 1 Received: from tao-optiplex-7060.sh.intel.com ([10.239.13.104]) by FMSMGA003.fm.intel.com with ESMTP; 16 Jun 2019 08:37:59 -0700 From: Tao Xu To: pbonzini@redhat.com, rth@twiddle.net, ehabkost@redhat.com Date: Sun, 16 Jun 2019 23:35:23 +0800 Message-Id: <20190616153525.27072-1-tao3.xu@intel.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 192.55.52.43 Subject: [Qemu-devel] [PATCH v3 0/2] x86: Enable user wait instructions 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: cohuck@redhat.com, kvm@vger.kernel.org, mst@redhat.com, jingqi.liu@intel.com, tao3.xu@intel.com, mtosatti@redhat.com, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" 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/2019/6/16/50 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 (2): x86/cpu: Add support for UMONITOR/UMWAIT/TPAUSE target/i386: Add support for save/load IA32_UMWAIT_CONTROL MSR target/i386/cpu.c | 3 ++- target/i386/cpu.h | 3 +++ target/i386/kvm.c | 17 +++++++++++++++++ target/i386/machine.c | 20 ++++++++++++++++++++ 4 files changed, 42 insertions(+), 1 deletion(-)