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Subject[PATCH 1/3] KVM: lapic: reorganize start_hv_timer
Date
There are many cases in which the hv timer must be canceled.  Split out
a new function to avoid duplication.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/lapic.c | 40 +++++++++++++++++++++++++++-------------
1 file changed, 27 insertions(+), 13 deletions(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index d24c8742d9b0..b6689dcae1da 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1501,24 +1501,38 @@ static void cancel_hv_timer(struct kvm_lapic *apic)
preempt_enable();
}

-static bool start_hv_timer(struct kvm_lapic *apic)
+static bool __start_hv_timer(struct kvm_lapic *apic)
{
- u64 tscdeadline = apic->lapic_timer.tscdeadline;
+ struct kvm_timer *ktimer = &apic->lapic_timer;
+ int r;

- if ((atomic_read(&apic->lapic_timer.pending) &&
- !apic_lvtt_period(apic)) ||
- kvm_x86_ops->set_hv_timer(apic->vcpu, tscdeadline)) {
- if (apic->lapic_timer.hv_timer_in_use)
- cancel_hv_timer(apic);
- } else {
- apic->lapic_timer.hv_timer_in_use = true;
- hrtimer_cancel(&apic->lapic_timer.timer);
+ if (!apic_lvtt_period(apic) && atomic_read(&ktimer->pending))
+ return false;
+
+ r = kvm_x86_ops->set_hv_timer(apic->vcpu, ktimer->tscdeadline);
+ if (r < 0)
+ return false;
+
+ ktimer->hv_timer_in_use = true;
+ hrtimer_cancel(&ktimer->timer);

- /* In case the sw timer triggered in the window */
- if (atomic_read(&apic->lapic_timer.pending) &&
- !apic_lvtt_period(apic))
+ /*
+ * Also recheck ktimer->pending, in case the sw timer triggered in
+ * the window. For periodic timer, leave the hv timer running for
+ * simplicity, and the deadline will be recomputed on the next vmexit.
+ */
+ if (!apic_lvtt_period(apic) && atomic_read(&ktimer->pending))
+ return false;
+ return true;
+}
+
+static bool start_hv_timer(struct kvm_lapic *apic)
+{
+ if (!__start_hv_timer(apic)) {
+ if (apic->lapic_timer.hv_timer_in_use)
cancel_hv_timer(apic);
}
+
trace_kvm_hv_timer_state(apic->vcpu->vcpu_id,
apic->lapic_timer.hv_timer_in_use);
return apic->lapic_timer.hv_timer_in_use;
--
1.8.3.1

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