From patchwork Thu Aug 29 15:10:27 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joao Martins X-Patchwork-Id: 11121653 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 8D15A14E5 for ; Thu, 29 Aug 2019 15:13:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 62E7720644 for ; Thu, 29 Aug 2019 15:13:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="QsmxoNNJ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727403AbfH2PNY (ORCPT ); Thu, 29 Aug 2019 11:13:24 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:36522 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727144AbfH2PNY (ORCPT ); Thu, 29 Aug 2019 11:13:24 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x7TF9Ea7185188; Thu, 29 Aug 2019 15:10:39 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=CKit7+Ighkvtwrce/t6NZ2djJ2x69q1/2NpRpmKU0Ns=; b=QsmxoNNJdYXGkfCwBAdxnOds9NtfKOWPhM7yWMYkqJsjLZio52x1F0o1a0MLl6PBSHm+ eW10j8QgmTkIntRVG6Kdnpn6JmDkBu4y8Y05Vx8RJO7ANs8reggGPtY9fOuVF+leYvCp J4X/4VyJm1XgoU/IKSdydUFznlYLmZNkmHVC2blDERn8Ce+P556P48iXFQF4Ypqk1hOJ SUhHqgzh9coxKr30qoXfquUOksXPaEqJP0mwAggdsfczqlb9M+NXXra/cvXDFXINgC6D nKmmtBq+deAGIJW3lwK6zOgGhiChBBBJ9dVs4YLLbKtG5vEjGsG1QB9GKY5q+p3VJtLl 5w== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by aserp2120.oracle.com with ESMTP id 2uph30g0gw-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 29 Aug 2019 15:10:39 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x7TF9TPI137674; Thu, 29 Aug 2019 15:10:38 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userp3030.oracle.com with ESMTP id 2unvu049sd-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 29 Aug 2019 15:10:38 +0000 Received: from abhmp0019.oracle.com (abhmp0019.oracle.com [141.146.116.25]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x7TFAaxG030672; Thu, 29 Aug 2019 15:10:36 GMT Received: from paddy.uk.oracle.com (/10.175.160.184) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 29 Aug 2019 08:10:35 -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 v2] cpuidle-haltpoll: vcpu hotplug support Date: Thu, 29 Aug 2019 16:10:27 +0100 Message-Id: <20190829151027.9930-1-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=9363 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=996 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1906280000 definitions=main-1908290164 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9363 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-1908290164 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@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() callback and future ones that get onlined. 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 --- v2: * move cpus_read_unlock() right 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) on success with CPUHP_AP_ONLINE_DYN thus we set @ret to 0 --- arch/x86/include/asm/cpuidle_haltpoll.h | 4 +- arch/x86/kernel/kvm.c | 18 +++---- drivers/cpuidle/cpuidle-haltpoll.c | 67 +++++++++++++++++++++++-- include/linux/cpuidle_haltpoll.h | 4 +- 4 files changed, 72 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..8baade23f8d0 100644 --- a/drivers/cpuidle/cpuidle-haltpoll.c +++ b/drivers/cpuidle/cpuidle-haltpoll.c @@ -11,12 +11,15 @@ */ #include +#include #include #include #include #include #include +static struct cpuidle_device __percpu *haltpoll_cpuidle_devices; + static int default_enter_idle(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) { @@ -46,6 +49,48 @@ 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 void haltpoll_uninit(void) +{ + unsigned int cpu; + + cpus_read_lock(); + + for_each_online_cpu(cpu) { + struct cpuidle_device *dev = + per_cpu_ptr(haltpoll_cpuidle_devices, cpu); + + if (!dev->registered) + continue; + + arch_haltpoll_disable(cpu); + cpuidle_unregister_device(dev); + } + + cpus_read_unlock(); + + cpuidle_unregister_driver(&haltpoll_driver); + + free_percpu(haltpoll_cpuidle_devices); + haltpoll_cpuidle_devices = NULL; +} + static int __init haltpoll_init(void) { int ret; @@ -56,17 +101,29 @@ 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, "idle/haltpoll:online", + haltpoll_cpu_online, NULL); + if (ret < 0) + haltpoll_uninit(); + else + 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