From 7d7f7da2f1fcd5b63d3b250a9cb4f7618c1f235d Mon Sep 17 00:00:00 2001 From: Wanpeng Li Date: Mon, 24 Oct 2016 18:23:09 +0800 Subject: [PATCH] KVM: LAPIC: extract start_sw_period() to handle periodic/oneshot mode MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Extract start_sw_period() to handle periodic/oneshot mode, it will be used by later patch. Cc: Paolo Bonzini Cc: Radim Krčmář Cc: Yunhong Jiang Signed-off-by: Wanpeng Li Signed-off-by: Radim Krčmář --- arch/x86/kvm/lapic.c | 89 +++++++++++++++++++++++--------------------- 1 file changed, 47 insertions(+), 42 deletions(-) diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 23b99f305382..dad743e3c1f5 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -1347,6 +1347,50 @@ static void start_sw_tscdeadline(struct kvm_lapic *apic) local_irq_restore(flags); } +static void start_sw_period(struct kvm_lapic *apic) +{ + ktime_t now; + + /* lapic timer in oneshot or periodic mode */ + now = apic->lapic_timer.timer.base->get_time(); + apic->lapic_timer.period = (u64)kvm_lapic_get_reg(apic, APIC_TMICT) + * APIC_BUS_CYCLE_NS * apic->divide_count; + + if (!apic->lapic_timer.period) + return; + /* + * Do not allow the guest to program periodic timers with small + * interval, since the hrtimers are not throttled by the host + * scheduler. + */ + if (apic_lvtt_period(apic)) { + s64 min_period = min_timer_period_us * 1000LL; + + if (apic->lapic_timer.period < min_period) { + pr_info_ratelimited( + "kvm: vcpu %i: requested %lld ns " + "lapic timer period limited to %lld ns\n", + apic->vcpu->vcpu_id, + apic->lapic_timer.period, min_period); + apic->lapic_timer.period = min_period; + } + } + + hrtimer_start(&apic->lapic_timer.timer, + ktime_add_ns(now, apic->lapic_timer.period), + HRTIMER_MODE_ABS_PINNED); + + apic_debug("%s: bus cycle is %" PRId64 "ns, now 0x%016" + PRIx64 ", " + "timer initial count 0x%x, period %lldns, " + "expire @ 0x%016" PRIx64 ".\n", __func__, + APIC_BUS_CYCLE_NS, ktime_to_ns(now), + kvm_lapic_get_reg(apic, APIC_TMICT), + apic->lapic_timer.period, + ktime_to_ns(ktime_add_ns(now, + apic->lapic_timer.period))); +} + bool kvm_lapic_hv_timer_in_use(struct kvm_vcpu *vcpu) { if (!lapic_in_kernel(vcpu)) @@ -1424,50 +1468,11 @@ EXPORT_SYMBOL_GPL(kvm_lapic_switch_to_sw_timer); static void start_apic_timer(struct kvm_lapic *apic) { - ktime_t now; - atomic_set(&apic->lapic_timer.pending, 0); - if (apic_lvtt_period(apic) || apic_lvtt_oneshot(apic)) { - /* lapic timer in oneshot or periodic mode */ - now = apic->lapic_timer.timer.base->get_time(); - apic->lapic_timer.period = (u64)kvm_lapic_get_reg(apic, APIC_TMICT) - * APIC_BUS_CYCLE_NS * apic->divide_count; - - if (!apic->lapic_timer.period) - return; - /* - * Do not allow the guest to program periodic timers with small - * interval, since the hrtimers are not throttled by the host - * scheduler. - */ - if (apic_lvtt_period(apic)) { - s64 min_period = min_timer_period_us * 1000LL; - - if (apic->lapic_timer.period < min_period) { - pr_info_ratelimited( - "kvm: vcpu %i: requested %lld ns " - "lapic timer period limited to %lld ns\n", - apic->vcpu->vcpu_id, - apic->lapic_timer.period, min_period); - apic->lapic_timer.period = min_period; - } - } - - hrtimer_start(&apic->lapic_timer.timer, - ktime_add_ns(now, apic->lapic_timer.period), - HRTIMER_MODE_ABS_PINNED); - - apic_debug("%s: bus cycle is %" PRId64 "ns, now 0x%016" - PRIx64 ", " - "timer initial count 0x%x, period %lldns, " - "expire @ 0x%016" PRIx64 ".\n", __func__, - APIC_BUS_CYCLE_NS, ktime_to_ns(now), - kvm_lapic_get_reg(apic, APIC_TMICT), - apic->lapic_timer.period, - ktime_to_ns(ktime_add_ns(now, - apic->lapic_timer.period))); - } else if (apic_lvtt_tscdeadline(apic)) { + if (apic_lvtt_period(apic) || apic_lvtt_oneshot(apic)) + start_sw_period(apic); + else if (apic_lvtt_tscdeadline(apic)) { if (!(kvm_x86_ops->set_hv_timer && start_hv_tscdeadline(apic))) start_sw_tscdeadline(apic); } -- 2.30.2