From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH v2: kvm 4/4] Fix hotplug of CPUs for KVM. Date: Tue, 29 Sep 2009 10:30:23 +0200 Message-ID: <4AC1C59F.6010703@redhat.com> References: <1254197072-889-1-git-send-email-zamsden@redhat.com> <1254197072-889-2-git-send-email-zamsden@redhat.com> <1254197072-889-3-git-send-email-zamsden@redhat.com> <1254197072-889-4-git-send-email-zamsden@redhat.com> <1254197072-889-5-git-send-email-zamsden@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Marcelo Tosatti To: Zachary Amsden Return-path: Received: from mx1.redhat.com ([209.132.183.28]:55353 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752830AbZI2IaJ (ORCPT ); Tue, 29 Sep 2009 04:30:09 -0400 In-Reply-To: <1254197072-889-5-git-send-email-zamsden@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 09/29/2009 06:04 AM, Zachary Amsden wrote: > Both VMX and SVM require per-cpu memory allocation, which is done at module > init time, for only online cpus. > > Backend was not allocating enough structure for all possible CPUs, so > new CPUs coming online could not be hardware enabled. > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index e27b7a9..2cd8bc2 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -1716,9 +1716,6 @@ static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val, > { > int cpu = (long)v; > > - if (!kvm_usage_count) > - return NOTIFY_OK; > - > val&= ~CPU_TASKS_FROZEN; > switch (val) { > case CPU_DYING: > I still don't see how this bit can work. Maybe if we move the notification registration to the point where kvm_usage_count is bumped. -- error compiling committee.c: too many arguments to function