From patchwork Mon Jun 3 22:52:45 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marcelo Tosatti X-Patchwork-Id: 10974067 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 0D6F215E6 for ; Mon, 3 Jun 2019 23:01:26 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EEAF52874A for ; Mon, 3 Jun 2019 23:01:25 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E26DF2875C; Mon, 3 Jun 2019 23:01:25 +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 6E2352875F for ; Mon, 3 Jun 2019 23:01:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726502AbfFCXBW (ORCPT ); Mon, 3 Jun 2019 19:01:22 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40138 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726102AbfFCXBV (ORCPT ); Mon, 3 Jun 2019 19:01:21 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 133EB30821FF; Mon, 3 Jun 2019 23:01:21 +0000 (UTC) Received: from amt.cnet (ovpn-112-8.gru2.redhat.com [10.97.112.8]) by smtp.corp.redhat.com (Postfix) with ESMTP id 598D617154; Mon, 3 Jun 2019 23:01:20 +0000 (UTC) Received: from amt.cnet (localhost [127.0.0.1]) by amt.cnet (Postfix) with ESMTP id 55BB3105165; Mon, 3 Jun 2019 19:54:58 -0300 (BRT) Received: (from marcelo@localhost) by amt.cnet (8.14.7/8.14.7/Submit) id x53MswxR007684; Mon, 3 Jun 2019 19:54:58 -0300 Message-Id: <20190603225254.360289262@amt.cnet> User-Agent: quilt/0.60-1 Date: Mon, 03 Jun 2019 19:52:45 -0300 From: Marcelo Tosatti To: kvm-devel Cc: Paolo Bonzini , =?iso-8859-15?q?Radim_Kr=C4=8Dm=C3?= =?iso-8859-15?q?=A1=C5=99?= , Andrea Arcangeli , "Rafael J. Wysocki" , Peter Zijlstra , Wanpeng Li , Konrad Rzeszutek Wilk , Raslan KarimAllah , Boris Ostrovsky , Ankur Arora , Christian Borntraeger , Marcelo Tosatti Subject: [patch 3/3] cpuidle-haltpoll: disable host side polling when kvm virtualized References: <20190603225242.289109849@amt.cnet> Content-Disposition: inline; filename=03-pollcontrol-guest.patch X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.47]); Mon, 03 Jun 2019 23:01:21 +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 | 40 ++++++++++++++++++++++++++++++++ drivers/cpuidle/cpuidle-haltpoll.c | 9 ++++++- include/linux/cpuidle_haltpoll.h | 16 ++++++++++++ 5 files changed, 79 insertions(+), 1 deletion(-) Index: linux-2.6.git/arch/x86/include/asm/cpuidle_haltpoll.h =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ linux-2.6.git/arch/x86/include/asm/cpuidle_haltpoll.h 2019-06-03 19:38:42.328718617 -0300 @@ -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.git/drivers/cpuidle/cpuidle-haltpoll.c =================================================================== --- linux-2.6.git.orig/drivers/cpuidle/cpuidle-haltpoll.c 2019-06-03 19:38:12.376619124 -0300 +++ linux-2.6.git/drivers/cpuidle/cpuidle-haltpoll.c 2019-06-03 19:38:42.328718617 -0300 @@ -15,6 +15,7 @@ #include #include #include +#include #define CREATE_TRACE_POINTS #include "cpuidle-haltpoll-trace.h" @@ -157,11 +158,17 @@ static int __init haltpoll_init(void) { - return cpuidle_register(&haltpoll_driver, NULL); + int 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.git/include/linux/cpuidle_haltpoll.h =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ linux-2.6.git/include/linux/cpuidle_haltpoll.h 2019-06-03 19:41:57.293366260 -0300 @@ -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.git/arch/x86/Kconfig =================================================================== --- linux-2.6.git.orig/arch/x86/Kconfig 2019-06-03 19:38:12.376619124 -0300 +++ linux-2.6.git/arch/x86/Kconfig 2019-06-03 19:42:34.478489868 -0300 @@ -787,6 +787,7 @@ 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 @@ 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.git/arch/x86/kernel/kvm.c =================================================================== --- linux-2.6.git.orig/arch/x86/kernel/kvm.c 2019-06-03 19:38:12.376619124 -0300 +++ linux-2.6.git/arch/x86/kernel/kvm.c 2019-06-03 19:40:14.359024312 -0300 @@ -853,3 +853,43 @@ } #endif /* CONFIG_PARAVIRT_SPINLOCKS */ + +#ifdef CONFIG_ARCH_CPUIDLE_HALTPOLL + +void kvm_disable_host_haltpoll(void *i) +{ + wrmsrl(MSR_KVM_POLL_CONTROL, 0); +} + +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)) + return; + + preempt_disable(); + /* Enabling 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(); + /* Enabling 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