From patchwork Wed Oct 31 22:47:10 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marcelo Tosatti X-Patchwork-Id: 1682081 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id 8CF0740063 for ; Wed, 31 Oct 2012 22:47:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933953Ab2JaWrO (ORCPT ); Wed, 31 Oct 2012 18:47:14 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37471 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932667Ab2JaWrL (ORCPT ); Wed, 31 Oct 2012 18:47:11 -0400 Received: from int-mx12.intmail.prod.int.phx2.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.25]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q9VMkveh011023 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 31 Oct 2012 18:46:57 -0400 Received: from amt.cnet (vpn1-4-132.gru2.redhat.com [10.97.4.132]) by int-mx12.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id q9VMkuE4025237; Wed, 31 Oct 2012 18:46:57 -0400 Received: from amt.cnet (amt.cnet [127.0.0.1]) by amt.cnet (Postfix) with ESMTP id 669AF652296; Wed, 31 Oct 2012 20:46:05 -0200 (BRST) Received: (from marcelo@localhost) by amt.cnet (8.14.5/8.14.5/Submit) id q9VMk58M017093; Wed, 31 Oct 2012 20:46:05 -0200 Message-Id: <20121031224824.471993713@redhat.com> User-Agent: quilt/0.47-1 Date: Wed, 31 Oct 2012 20:47:10 -0200 From: Marcelo Tosatti To: kvm@vger.kernel.org Cc: johnstul@us.ibm.com, jeremy@goop.org, glommer@parallels.com, zamsden@gmail.com, gleb@redhat.com, avi@redhat.com, pbonzini@redhat.com, Marcelo Tosatti Subject: [patch 14/16] KVM: x86: notifier for clocksource changes References: <20121031224656.417434866@redhat.com> Content-Disposition: inline; filename=15-add-kvm-req-pvclock-gtod-update X-Scanned-By: MIMEDefang 2.68 on 10.5.11.25 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Register a notifier for clocksource change event. In case the host switches to clock other than TSC, disable master clock usage. Signed-off-by: Marcelo Tosatti --- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Index: vsyscall/arch/x86/kvm/x86.c =================================================================== --- vsyscall.orig/arch/x86/kvm/x86.c +++ vsyscall/arch/x86/kvm/x86.c @@ -1218,6 +1218,7 @@ static bool kvm_get_time_and_clockread(s return true; } +static atomic_t kvm_guest_has_master_clock = ATOMIC_INIT(0); /* * @@ -1271,6 +1272,8 @@ static void pvclock_update_vm_gtod_copy( ka->use_master_clock = kvm_get_time_and_clockread( &ka->master_kernel_ns, &ka->master_cycle_now); + if (ka->use_master_clock) + atomic_set(&kvm_guest_has_master_clock, 1); vclock_mode = pvclock_gtod_data.clock.vclock_mode; trace_kvm_update_master_clock(ka->use_master_clock, vclock_mode); @@ -5124,6 +5127,44 @@ static void kvm_set_mmio_spte_mask(void) kvm_mmu_set_mmio_spte_mask(mask); } +static void pvclock_gtod_update_fn(struct work_struct *work) +{ + struct kvm *kvm; + struct kvm_vcpu *vcpu; + int i; + + raw_spin_lock(&kvm_lock); + list_for_each_entry(kvm, &vm_list, vm_list) + kvm_for_each_vcpu(i, vcpu, kvm) + set_bit(KVM_REQ_MASTERCLOCK_UPDATE, &vcpu->requests); + atomic_set(&kvm_guest_has_master_clock, 0); + raw_spin_unlock(&kvm_lock); +} + +static DECLARE_WORK(pvclock_gtod_work, pvclock_gtod_update_fn); + +/* + * Notification about pvclock gtod data update. + */ +static int pvclock_gtod_notify(struct notifier_block *nb, unsigned long unused, + void *unused2) +{ + struct pvclock_gtod_data *gtod = &pvclock_gtod_data; + + /* disable master clock if host does not trust, or does not + * use, TSC clocksource + */ + if (gtod->clock.vclock_mode != VCLOCK_TSC && + atomic_read(&kvm_guest_has_master_clock) != 0) + queue_work(system_long_wq, &pvclock_gtod_work); + + return 0; +} + +static struct notifier_block pvclock_gtod_notifier = { + .notifier_call = pvclock_gtod_notify, +}; + int kvm_arch_init(void *opaque) { int r; @@ -5165,6 +5206,8 @@ int kvm_arch_init(void *opaque) host_xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK); kvm_lapic_init(); + pvclock_gtod_register_notifier(&pvclock_gtod_notifier); + return 0; out: @@ -5179,6 +5222,7 @@ void kvm_arch_exit(void) cpufreq_unregister_notifier(&kvmclock_cpufreq_notifier_block, CPUFREQ_TRANSITION_NOTIFIER); unregister_hotcpu_notifier(&kvmclock_cpu_notifier_block); + pvclock_gtod_unregister_notifier(&pvclock_gtod_notifier); kvm_x86_ops = NULL; kvm_mmu_module_exit(); }