From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [PATCH 1/3] KVM: cleanup (physical) CPU hotplug Date: Tue, 17 Sep 2013 09:57:09 +0200 Message-ID: <52380B55.5010408@siemens.com> References: <1379340373-5135-1-git-send-email-pbonzini@redhat.com> <1379340373-5135-2-git-send-email-pbonzini@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Cc: linux-kernel@vger.kernel.org, Paul Gortmaker , stable@vger.kernel.org, kvm@vger.kernel.org, gleb@redhat.com To: Paolo Bonzini Return-path: Received: from goliath.siemens.de ([192.35.17.28]:26801 "EHLO goliath.siemens.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751982Ab3IQH5Q (ORCPT ); Tue, 17 Sep 2013 03:57:16 -0400 In-Reply-To: <1379340373-5135-2-git-send-email-pbonzini@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 2013-09-16 16:06, Paolo Bonzini wrote: > Remove the useless argument, and do not do anything if there are no > VMs running at the time of the hotplug. kvm_cpu_hotplug already filters !kvm_usage_count. If we need the check to be under kvm_lock, drop that line as well. If that is not required (machine still halted?), drop the related changes here. Jan > > Cc: stable@vger.kernel.org > Cc: kvm@vger.kernel.org > Cc: gleb@redhat.com > Cc: jan.kiszka@siemens.com > Signed-off-by: Paolo Bonzini > --- > virt/kvm/kvm_main.c | 14 ++++++++------ > 1 file changed, 8 insertions(+), 6 deletions(-) > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index 979bff4..75522b3 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -2681,10 +2681,11 @@ static void hardware_enable_nolock(void *junk) > } > } > > -static void hardware_enable(void *junk) > +static void hardware_enable(void) > { > raw_spin_lock(&kvm_lock); > - hardware_enable_nolock(junk); > + if (kvm_usage_count) > + hardware_enable_nolock(NULL); > raw_spin_unlock(&kvm_lock); > } > > @@ -2698,10 +2699,11 @@ static void hardware_disable_nolock(void *junk) > kvm_arch_hardware_disable(NULL); > } > > -static void hardware_disable(void *junk) > +static void hardware_disable(void) > { > raw_spin_lock(&kvm_lock); > - hardware_disable_nolock(junk); > + if (kvm_usage_count) > + hardware_disable_nolock(NULL); > raw_spin_unlock(&kvm_lock); > } > > @@ -2756,12 +2758,12 @@ static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val, > case CPU_DYING: > printk(KERN_INFO "kvm: disabling virtualization on CPU%d\n", > cpu); > - hardware_disable(NULL); > + hardware_disable(); > break; > case CPU_STARTING: > printk(KERN_INFO "kvm: enabling virtualization on CPU%d\n", > cpu); > - hardware_enable(NULL); > + hardware_enable(); > break; > } > return NOTIFY_OK; > -- Siemens AG, Corporate Technology, CT RTC ITP SES-DE Corporate Competence Center Embedded Linux