From patchwork Mon Jul 1 18:53:15 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marcelo Tosatti X-Patchwork-Id: 11026627 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 4FE1A13A4 for ; Mon, 1 Jul 2019 18:57:34 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4463228749 for ; Mon, 1 Jul 2019 18:57:34 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 384EF2625B; Mon, 1 Jul 2019 18:57:34 +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 B8FEF28749 for ; Mon, 1 Jul 2019 18:57:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726843AbfGAS5c (ORCPT ); Mon, 1 Jul 2019 14:57:32 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60720 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726803AbfGAS5b (ORCPT ); Mon, 1 Jul 2019 14:57:31 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 5509387630; Mon, 1 Jul 2019 18:57:31 +0000 (UTC) Received: from amt.cnet (ovpn-112-3.gru2.redhat.com [10.97.112.3]) by smtp.corp.redhat.com (Postfix) with ESMTP id CE38287CF; Mon, 1 Jul 2019 18:57:30 +0000 (UTC) Received: from amt.cnet (localhost [127.0.0.1]) by amt.cnet (Postfix) with ESMTP id E9743105171; Mon, 1 Jul 2019 15:56:52 -0300 (BRT) Received: (from marcelo@localhost) by amt.cnet (8.14.7/8.14.7/Submit) id x61IuqN4028559; Mon, 1 Jul 2019 15:56:52 -0300 Message-ID: <20190701185528.230754447@asus.localdomain> User-Agent: quilt/0.66 Date: Mon, 01 Jul 2019 15:53:15 -0300 From: Marcelo Tosatti To: kvm@vger.kernel.org, linux-pm@vger.kernel.org Cc: Paolo Bonzini , Radim Krcmar , Andrea Arcangeli , "Rafael J. Wysocki" , Peter Zijlstra , Wanpeng Li , Konrad Rzeszutek Wilk , Raslan KarimAllah , Boris Ostrovsky , Ankur Arora , Christian Borntraeger , Marcelo Tosatti Subject: [patch 5/5] cpuidle-haltpoll: disable host side polling when kvm virtualized References: <20190701185310.540706841@asus.localdomain> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Mon, 01 Jul 2019 18:57:31 +0000 (UTC) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP When performing guest side polling, it is not necessary to also perform host side polling. So disable host side polling, via the new MSR interface, when loading cpuidle-haltpoll driver. Signed-off-by: Marcelo Tosatti --- arch/x86/Kconfig | 7 +++++ arch/x86/include/asm/cpuidle_haltpoll.h | 8 ++++++ arch/x86/kernel/kvm.c | 42 ++++++++++++++++++++++++++++++++ drivers/cpuidle/cpuidle-haltpoll.c | 10 ++++++- include/linux/cpuidle_haltpoll.h | 16 ++++++++++++ 5 files changed, 82 insertions(+), 1 deletion(-) Index: linux-2.6-newcpuidle.git/arch/x86/include/asm/cpuidle_haltpoll.h =================================================================== --- /dev/null +++ linux-2.6-newcpuidle.git/arch/x86/include/asm/cpuidle_haltpoll.h @@ -0,0 +1,8 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ARCH_HALTPOLL_H +#define _ARCH_HALTPOLL_H + +void arch_haltpoll_enable(void); +void arch_haltpoll_disable(void); + +#endif Index: linux-2.6-newcpuidle.git/drivers/cpuidle/cpuidle-haltpoll.c =================================================================== --- linux-2.6-newcpuidle.git.orig/drivers/cpuidle/cpuidle-haltpoll.c +++ linux-2.6-newcpuidle.git/drivers/cpuidle/cpuidle-haltpoll.c @@ -15,6 +15,7 @@ #include #include #include +#include static int default_enter_idle(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) @@ -47,6 +48,7 @@ static struct cpuidle_driver haltpoll_dr static int __init haltpoll_init(void) { + int ret; struct cpuidle_driver *drv = &haltpoll_driver; cpuidle_poll_state_init(drv); @@ -54,11 +56,16 @@ static int __init haltpoll_init(void) if (!kvm_para_available()) return 0; - return cpuidle_register(&haltpoll_driver, NULL); + ret = cpuidle_register(&haltpoll_driver, NULL); + if (ret == 0) + arch_haltpoll_enable(); + + return ret; } static void __exit haltpoll_exit(void) { + arch_haltpoll_disable(); cpuidle_unregister(&haltpoll_driver); } Index: linux-2.6-newcpuidle.git/include/linux/cpuidle_haltpoll.h =================================================================== --- /dev/null +++ linux-2.6-newcpuidle.git/include/linux/cpuidle_haltpoll.h @@ -0,0 +1,16 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _CPUIDLE_HALTPOLL_H +#define _CPUIDLE_HALTPOLL_H + +#ifdef CONFIG_ARCH_CPUIDLE_HALTPOLL +#include +#else +static inline void arch_haltpoll_enable(void) +{ +} + +static inline void arch_haltpoll_disable(void) +{ +} +#endif +#endif Index: linux-2.6-newcpuidle.git/arch/x86/Kconfig =================================================================== --- linux-2.6-newcpuidle.git.orig/arch/x86/Kconfig +++ linux-2.6-newcpuidle.git/arch/x86/Kconfig @@ -787,6 +787,7 @@ config KVM_GUEST bool "KVM Guest support (including kvmclock)" depends on PARAVIRT select PARAVIRT_CLOCK + select ARCH_CPUIDLE_HALTPOLL default y ---help--- This option enables various optimizations for running under the KVM @@ -795,6 +796,12 @@ config KVM_GUEST underlying device model, the host provides the guest with timing infrastructure such as time of day, and system time +config ARCH_CPUIDLE_HALTPOLL + def_bool n + prompt "Disable host haltpoll when loading haltpoll driver" + help + If virtualized under KVM, disable host haltpoll. + config PVH bool "Support for running PVH guests" ---help--- Index: linux-2.6-newcpuidle.git/arch/x86/kernel/kvm.c =================================================================== --- linux-2.6-newcpuidle.git.orig/arch/x86/kernel/kvm.c +++ linux-2.6-newcpuidle.git/arch/x86/kernel/kvm.c @@ -853,3 +853,45 @@ void __init kvm_spinlock_init(void) } #endif /* CONFIG_PARAVIRT_SPINLOCKS */ + +#ifdef CONFIG_ARCH_CPUIDLE_HALTPOLL + +static void kvm_disable_host_haltpoll(void *i) +{ + wrmsrl(MSR_KVM_POLL_CONTROL, 0); +} + +static void kvm_enable_host_haltpoll(void *i) +{ + wrmsrl(MSR_KVM_POLL_CONTROL, 1); +} + +void arch_haltpoll_enable(void) +{ + if (!kvm_para_has_feature(KVM_FEATURE_POLL_CONTROL)) { + printk(KERN_ERR "kvm: host does not support poll control\n"); + printk(KERN_ERR "kvm: host upgrade recommended\n"); + return; + } + + preempt_disable(); + /* Enable guest halt poll disables host halt poll */ + kvm_disable_host_haltpoll(NULL); + smp_call_function(kvm_disable_host_haltpoll, NULL, 1); + preempt_enable(); +} +EXPORT_SYMBOL_GPL(arch_haltpoll_enable); + +void arch_haltpoll_disable(void) +{ + if (!kvm_para_has_feature(KVM_FEATURE_POLL_CONTROL)) + return; + + preempt_disable(); + /* Enable guest halt poll disables host halt poll */ + kvm_enable_host_haltpoll(NULL); + smp_call_function(kvm_enable_host_haltpoll, NULL, 1); + preempt_enable(); +} +EXPORT_SYMBOL_GPL(arch_haltpoll_disable); +#endif