From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753262Ab1FSJ6O (ORCPT ); Sun, 19 Jun 2011 05:58:14 -0400 Received: from mx1.redhat.com ([209.132.183.28]:49614 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752369Ab1FSJ6M (ORCPT ); Sun, 19 Jun 2011 05:58:12 -0400 Message-ID: <4DFDC821.2090905@redhat.com> Date: Sun, 19 Jun 2011 12:57:53 +0300 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.17) Gecko/20110428 Fedora/3.1.10-1.fc15 Thunderbird/3.1.10 MIME-Version: 1.0 To: Glauber Costa CC: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Rik van Riel , Jeremy Fitzhardinge , Peter Zijlstra , Anthony Liguori , Eric B Munson Subject: Re: [PATCH v2 3/7] KVM-HV: KVM Steal time implementation References: <1308262856-5779-1-git-send-email-glommer@redhat.com> <1308262856-5779-4-git-send-email-glommer@redhat.com> In-Reply-To: <1308262856-5779-4-git-send-email-glommer@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/17/2011 01:20 AM, Glauber Costa wrote: > To implement steal time, we need the hypervisor to pass the guest information > about how much time was spent running other processes outside the VM. > This is per-vcpu, and using the kvmclock structure for that is an abuse > we decided not to make. > > In this patchset, I am introducing a new msr, KVM_MSR_STEAL_TIME, that > holds the memory area address containing information about steal time > > This patch contains the hypervisor part for it. I am keeping it separate from > the headers to facilitate backports to people who wants to backport the kernel > part but not the hypervisor, or the other way around. > > > > +#define KVM_STEAL_ALIGNMENT_BITS 5 > +#define KVM_STEAL_VALID_BITS ((-1ULL<< (KVM_STEAL_ALIGNMENT_BITS + 1))) > +#define KVM_STEAL_RESERVED_MASK (((1<< KVM_STEAL_ALIGNMENT_BITS) - 1 )<< 1) Clumsy, but okay. > +static void record_steal_time(struct kvm_vcpu *vcpu) > +{ > + u64 delta; > + > + if (vcpu->arch.st.stime&& vcpu->arch.st.this_time_out) { 0 is a valid value for stime. > + > + if (unlikely(kvm_read_guest(vcpu->kvm, vcpu->arch.st.stime, > + &vcpu->arch.st.steal, sizeof(struct kvm_steal_time)))) { > + > + vcpu->arch.st.stime = 0; > + return; > + } > + > + delta = (get_kernel_ns() - vcpu->arch.st.this_time_out); > + > + vcpu->arch.st.steal.steal += delta; > + vcpu->arch.st.steal.version += 2; > + > + if (unlikely(kvm_write_guest(vcpu->kvm, vcpu->arch.st.stime, > + &vcpu->arch.st.steal, sizeof(struct kvm_steal_time)))) { > + > + vcpu->arch.st.stime = 0; > + return; > + } > + } > + > +} > + > > @@ -2158,6 +2206,8 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) > kvm_migrate_timers(vcpu); > vcpu->cpu = cpu; > } > + > + record_steal_time(vcpu); > } This records time spent in userspace in the vcpu thread as steal time. Is this what we want? Or just time preempted away? -- error compiling committee.c: too many arguments to function