From patchwork Mon Sep 2 10:40:31 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joao Martins X-Patchwork-Id: 11126345 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 390451399 for ; Mon, 2 Sep 2019 10:43:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0CE6922DBF for ; Mon, 2 Sep 2019 10:43:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="YivH4ogz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730233AbfIBKnR (ORCPT ); Mon, 2 Sep 2019 06:43:17 -0400 Received: from userp2130.oracle.com ([156.151.31.86]:43464 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730013AbfIBKnR (ORCPT ); Mon, 2 Sep 2019 06:43:17 -0400 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x82AdEn1163436; Mon, 2 Sep 2019 10:41:34 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : mime-version : content-type : content-transfer-encoding; s=corp-2019-08-05; bh=w+G+MVA2YN07SA3UzChr+LYUeDR77rQPujOEa86rr/M=; b=YivH4ogzTkrVZ4L/v7Zsi3AicDuo49zoVJeXpXOn2MMKZ7HZvvaH9OnkGas7dbNc7cyj zI2JDeB1COr6kzMc/ePUPo23okASg63RjKXv3uleXjgwuXaJqryOU6rFJlQJgptXS3I1 CHam049rqgEB79plAMDFpvIB9N9/z3G2Nb6MxYDGScqYgi8hczcHBlPOOhd/PnXwkcvO sUU9woMbp+QCtGfftZajX7zo5kttShWsDEWAp4LpTdW2I2jtVZOhm7/KLOD1IU1e0YJE WTFeEGo9AgVxBbJp2V8HFfyiqsfbDEsI0r+SmQar68HvHAePbhi7QQg7wTygHlTtUIv8 ig== Received: from aserp3030.oracle.com (aserp3030.oracle.com [141.146.126.71]) by userp2130.oracle.com with ESMTP id 2us1d7816c-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 02 Sep 2019 10:41:34 +0000 Received: from pps.filterd (aserp3030.oracle.com [127.0.0.1]) by aserp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x82AcAaB014454; Mon, 2 Sep 2019 10:41:34 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by aserp3030.oracle.com with ESMTP id 2urww6ds8y-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 02 Sep 2019 10:41:33 +0000 Received: from abhmp0014.oracle.com (abhmp0014.oracle.com [141.146.116.20]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x82AfTDZ020042; Mon, 2 Sep 2019 10:41:29 GMT Received: from paddy.uk.oracle.com (/10.175.163.45) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 02 Sep 2019 03:41:27 -0700 From: Joao Martins To: kvm@vger.kernel.org Cc: Joao Martins , Marcelo Tosatti , linux-kernel@vger.kernel.org, Paolo Bonzini , =?utf-8?b?UmFkaW0gS3LEjW3DocWZ?= , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , "Rafael J. Wysocki" , Daniel Lezcano , linux-pm@vger.kernel.org, Boris Ostrovsky Subject: [PATCH v3] cpuidle-haltpoll: vcpu hotplug support Date: Mon, 2 Sep 2019 11:40:31 +0100 Message-Id: <20190902104031.9296-1-joao.m.martins@oracle.com> X-Mailer: git-send-email 2.11.0 MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9367 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=3 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1906280000 definitions=main-1909020122 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9367 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=3 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1906280000 definitions=main-1909020122 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org When cpus != maxcpus cpuidle-haltpoll will fail to register all vcpus past the online ones and thus fail to register the idle driver. This is because cpuidle_add_sysfs() will return with -ENODEV as a consequence from get_cpu_device() return no device for a non-existing CPU. Instead switch to cpuidle_register_driver() and manually register each of the present cpus through cpuhp_setup_state() callbacks and future ones that get onlined or offlined. This mimmics similar logic that intel_idle does. Fixes: fa86ee90eb11 ("add cpuidle-haltpoll driver") Signed-off-by: Joao Martins Signed-off-by: Boris Ostrovsky Reviewed-by: Marcelo Tosatti --- v3: * register the teardown callback for correct handling of hotunplug and error cases. In case cpuhp_setup_state calls fails (e.g. in one of the cpus that it invoked the callback) it will then call the teardown of the previously enabled devices; so no need to handle that manually in haltpoll_uninit(). * use the cpuhp_setup_state() returned dyn allocated state when it succeeds. And use that state in haltpoll_unint() to call cpuhp_remove_state() instead of looping online cpus manually. This is because cpuhp_remove_state() invokes the teardown/offline callback. * fix subsystem name to 'cpuidle' instead of 'idle' in cpuhp_setup_state() v2: * move cpus_read_unlock() after unregistering all cpuidle_devices; (Marcello Tosatti) * redundant usage of cpuidle_unregister() when only cpuidle_unregister_driver() suffices; (Marcelo Tosatti) * cpuhp_setup_state() returns a state (> 0) for CPUHP_AP_ONLINE_DYN --- arch/x86/include/asm/cpuidle_haltpoll.h | 4 +- arch/x86/kernel/kvm.c | 18 +++---- drivers/cpuidle/cpuidle-haltpoll.c | 68 +++++++++++++++++++++++-- include/linux/cpuidle_haltpoll.h | 4 +- 4 files changed, 73 insertions(+), 21 deletions(-) diff --git a/arch/x86/include/asm/cpuidle_haltpoll.h b/arch/x86/include/asm/cpuidle_haltpoll.h index ff8607d81526..c8b39c6716ff 100644 --- a/arch/x86/include/asm/cpuidle_haltpoll.h +++ b/arch/x86/include/asm/cpuidle_haltpoll.h @@ -2,7 +2,7 @@ #ifndef _ARCH_HALTPOLL_H #define _ARCH_HALTPOLL_H -void arch_haltpoll_enable(void); -void arch_haltpoll_disable(void); +void arch_haltpoll_enable(unsigned int cpu); +void arch_haltpoll_disable(unsigned int cpu); #endif diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index 8d150e3732d9..a9b6c4e2446d 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -880,32 +880,26 @@ static void kvm_enable_host_haltpoll(void *i) wrmsrl(MSR_KVM_POLL_CONTROL, 1); } -void arch_haltpoll_enable(void) +void arch_haltpoll_enable(unsigned int cpu) { 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"); + pr_err_once("kvm: host does not support poll control\n"); + pr_err_once("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(); + smp_call_function_single(cpu, kvm_disable_host_haltpoll, NULL, 1); } EXPORT_SYMBOL_GPL(arch_haltpoll_enable); -void arch_haltpoll_disable(void) +void arch_haltpoll_disable(unsigned int cpu) { 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(); + smp_call_function_single(cpu, kvm_enable_host_haltpoll, NULL, 1); } EXPORT_SYMBOL_GPL(arch_haltpoll_disable); #endif diff --git a/drivers/cpuidle/cpuidle-haltpoll.c b/drivers/cpuidle/cpuidle-haltpoll.c index 9ac093dcbb01..56d8ab814466 100644 --- a/drivers/cpuidle/cpuidle-haltpoll.c +++ b/drivers/cpuidle/cpuidle-haltpoll.c @@ -11,12 +11,16 @@ */ #include +#include #include #include #include #include #include +static struct cpuidle_device __percpu *haltpoll_cpuidle_devices; +static enum cpuhp_state haltpoll_hp_state; + static int default_enter_idle(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) { @@ -46,6 +50,46 @@ static struct cpuidle_driver haltpoll_driver = { .state_count = 2, }; +static int haltpoll_cpu_online(unsigned int cpu) +{ + struct cpuidle_device *dev; + + dev = per_cpu_ptr(haltpoll_cpuidle_devices, cpu); + if (!dev->registered) { + dev->cpu = cpu; + if (cpuidle_register_device(dev)) { + pr_notice("cpuidle_register_device %d failed!\n", cpu); + return -EIO; + } + arch_haltpoll_enable(cpu); + } + + return 0; +} + +static int haltpoll_cpu_offline(unsigned int cpu) +{ + struct cpuidle_device *dev; + + dev = per_cpu_ptr(haltpoll_cpuidle_devices, cpu); + if (dev->registered) { + arch_haltpoll_disable(cpu); + cpuidle_unregister_device(dev); + } + + return 0; +} + +static void haltpoll_uninit(void) +{ + if (haltpoll_hp_state) + cpuhp_remove_state(haltpoll_hp_state); + cpuidle_unregister_driver(&haltpoll_driver); + + free_percpu(haltpoll_cpuidle_devices); + haltpoll_cpuidle_devices = NULL; +} + static int __init haltpoll_init(void) { int ret; @@ -56,17 +100,31 @@ static int __init haltpoll_init(void) if (!kvm_para_available()) return 0; - ret = cpuidle_register(&haltpoll_driver, NULL); - if (ret == 0) - arch_haltpoll_enable(); + ret = cpuidle_register_driver(drv); + if (ret < 0) + return ret; + + haltpoll_cpuidle_devices = alloc_percpu(struct cpuidle_device); + if (haltpoll_cpuidle_devices == NULL) { + cpuidle_unregister_driver(drv); + return -ENOMEM; + } + + ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "cpuidle/haltpoll:online", + haltpoll_cpu_online, haltpoll_cpu_offline); + if (ret < 0) { + haltpoll_uninit(); + } else { + haltpoll_hp_state = ret; + ret = 0; + } return ret; } static void __exit haltpoll_exit(void) { - arch_haltpoll_disable(); - cpuidle_unregister(&haltpoll_driver); + haltpoll_uninit(); } module_init(haltpoll_init); diff --git a/include/linux/cpuidle_haltpoll.h b/include/linux/cpuidle_haltpoll.h index fe5954c2409e..d50c1e0411a2 100644 --- a/include/linux/cpuidle_haltpoll.h +++ b/include/linux/cpuidle_haltpoll.h @@ -5,11 +5,11 @@ #ifdef CONFIG_ARCH_CPUIDLE_HALTPOLL #include #else -static inline void arch_haltpoll_enable(void) +static inline void arch_haltpoll_enable(unsigned int cpu) { } -static inline void arch_haltpoll_disable(void) +static inline void arch_haltpoll_disable(unsigned int cpu) { } #endif