Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932307Ab1BKSV2 (ORCPT ); Fri, 11 Feb 2011 13:21:28 -0500 Received: from mx1.redhat.com ([209.132.183.28]:64064 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932246Ab1BKSVY (ORCPT ); Fri, 11 Feb 2011 13:21:24 -0500 From: Glauber Costa To: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Rik van Riel , Jeremy Fitzhardinge , Peter Zijlstra , Avi Kivity Subject: [PATCH v3 4/6] KVM-GST: KVM Steal time registration Date: Fri, 11 Feb 2011 13:19:22 -0500 Message-Id: <1297448364-14051-5-git-send-email-glommer@redhat.com> In-Reply-To: <1297448364-14051-1-git-send-email-glommer@redhat.com> References: <1297448364-14051-1-git-send-email-glommer@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3862 Lines: 135 Register steal time within KVM. Everytime we sample the steal time information, we update a local variable that tells what was the last time read. We then account the difference. Signed-off-by: Glauber Costa CC: Rik van Riel CC: Jeremy Fitzhardinge CC: Peter Zijlstra CC: Avi Kivity --- arch/x86/kernel/kvm.c | 43 +++++++++++++++++++++++++++++++++++++++++++ arch/x86/kernel/kvmclock.c | 2 ++ 2 files changed, 45 insertions(+), 0 deletions(-) diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index 33c07b0..ea49217 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -58,6 +58,7 @@ struct kvm_para_state { static DEFINE_PER_CPU(struct kvm_para_state, para_state); static DEFINE_PER_CPU(struct kvm_vcpu_pv_apf_data, apf_reason) __aligned(64); +static DEFINE_PER_CPU_SHARED_ALIGNED(struct kvm_steal_time, steal_time); static struct kvm_para_state *kvm_para_state(void) { @@ -483,24 +484,46 @@ static struct notifier_block kvm_pv_reboot_nb = { .notifier_call = kvm_pv_reboot_notify, }; +static int kvm_register_steal_time(void) +{ + int cpu = smp_processor_id(); + int low, high, ret; + struct kvm_steal_time *st = &per_cpu(steal_time, cpu); + + if (!hypervisor_steal_time) + return 0; + + memset(st, 0, sizeof(*st)); + + low = (int)__pa(st) | 1; + high = ((u64)__pa(st) >> 32); + ret = wrmsr_safe(MSR_KVM_STEAL_TIME, low, high); + printk(KERN_INFO "kvm-stealtime: cpu %d, msr %x:%x\n", + cpu, high, low); + return ret; +} + #ifdef CONFIG_SMP static void __init kvm_smp_prepare_boot_cpu(void) { #ifdef CONFIG_KVM_CLOCK WARN_ON(kvm_register_clock("primary cpu clock")); #endif + WARN_ON(kvm_register_steal_time()); kvm_guest_cpu_init(); native_smp_prepare_boot_cpu(); } static void __cpuinit kvm_guest_cpu_online(void *dummy) { + WARN_ON(kvm_register_steal_time()); kvm_guest_cpu_init(); } static void kvm_guest_cpu_offline(void *dummy) { kvm_pv_disable_apf(NULL); + wrmsr(MSR_KVM_STEAL_TIME, 0, 0); apf_task_wake_all(); } @@ -534,6 +557,23 @@ static void __init kvm_apf_trap_init(void) set_intr_gate(14, &async_page_fault); } +static u64 kvm_account_steal_time(int cpu) +{ + u64 steal; + struct kvm_steal_time *src; + int version; + + src = &per_cpu(steal_time, cpu); + do { + version = src->version; + rmb(); + steal = src->steal; + rmb(); + } while ((src->version & 1) || (version != src->version)); + + return steal; +} + void __init kvm_guest_init(void) { int i; @@ -548,6 +588,9 @@ void __init kvm_guest_init(void) if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF)) x86_init.irqs.trap_init = kvm_apf_trap_init; + if (kvm_para_has_feature(KVM_FEATURE_STEAL_TIME)) + hypervisor_steal_time = kvm_account_steal_time; + #ifdef CONFIG_SMP smp_ops.smp_prepare_boot_cpu = kvm_smp_prepare_boot_cpu; register_cpu_notifier(&kvm_cpu_notifier); diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index f98d3ea..dcb6a67 100644 --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -164,6 +164,7 @@ static void __cpuinit kvm_setup_secondary_clock(void) static void kvm_crash_shutdown(struct pt_regs *regs) { native_write_msr(msr_kvm_system_time, 0, 0); + wrmsr(MSR_KVM_STEAL_TIME, 0, 0); native_machine_crash_shutdown(regs); } #endif @@ -171,6 +172,7 @@ static void kvm_crash_shutdown(struct pt_regs *regs) static void kvm_shutdown(void) { native_write_msr(msr_kvm_system_time, 0, 0); + wrmsr(MSR_KVM_STEAL_TIME, 0, 0); native_machine_shutdown(); } -- 1.7.2.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/