linux-kernel - [PATCH v5 4/4] KVM: LAPIC: Don't inject already-expired timer via posted interrupt

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Message-Id: <1561110002-4438-5-git-send-email-wanpengli@tencent.com>
Date:   Fri, 21 Jun 2019 17:40:02 +0800
From:   Wanpeng Li <kernellwp@...il.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     Paolo Bonzini <pbonzini@...hat.com>,
        Radim Krčmář <rkrcmar@...hat.com>,
        Marcelo Tosatti <mtosatti@...hat.com>
Subject: [PATCH v5 4/4] KVM: LAPIC: Don't inject already-expired timer via posted interrupt

From: Wanpeng Li <wanpengli@...cent.com>

already-expired timer interrupt can be injected to guest when vCPU who 
arms the lapic timer re-vmentry, don't posted inject in this case.

Cc: Paolo Bonzini <pbonzini@...hat.com>
Cc: Radim Krčmář <rkrcmar@...hat.com>
Cc: Marcelo Tosatti <mtosatti@...hat.com>
Signed-off-by: Wanpeng Li <wanpengli@...cent.com>
---
 arch/x86/kvm/lapic.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index ae575c0..7cd95ea 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1452,7 +1452,7 @@ static void kvm_apic_inject_pending_timer_irqs(struct kvm_lapic *apic)
 	}
 }
 
-static void apic_timer_expired(struct kvm_lapic *apic)
+static void apic_timer_expired(struct kvm_lapic *apic, bool can_pi_inject)
 {
 	struct kvm_vcpu *vcpu = apic->vcpu;
 	struct swait_queue_head *q = &vcpu->wq;
@@ -1464,7 +1464,7 @@ static void apic_timer_expired(struct kvm_lapic *apic)
 	if (apic_lvtt_tscdeadline(apic) || ktimer->hv_timer_in_use)
 		ktimer->expired_tscdeadline = ktimer->tscdeadline;
 
-	if (posted_interrupt_inject_timer(apic->vcpu)) {
+	if (can_pi_inject && posted_interrupt_inject_timer(apic->vcpu)) {
 		if (apic->lapic_timer.timer_advance_ns)
 			kvm_wait_lapic_expire(vcpu, true);
 		kvm_apic_inject_pending_timer_irqs(apic);
@@ -1607,7 +1607,7 @@ static void start_sw_tscdeadline(struct kvm_lapic *apic)
 		expire = ktime_sub_ns(expire, ktimer->timer_advance_ns);
 		hrtimer_start(&ktimer->timer, expire, HRTIMER_MODE_ABS);
 	} else
-		apic_timer_expired(apic);
+		apic_timer_expired(apic, false);
 
 	local_irq_restore(flags);
 }
@@ -1697,7 +1697,7 @@ static void start_sw_period(struct kvm_lapic *apic)
 
 	if (ktime_after(ktime_get(),
 			apic->lapic_timer.target_expiration)) {
-		apic_timer_expired(apic);
+		apic_timer_expired(apic, false);
 
 		if (apic_lvtt_oneshot(apic))
 			return;
@@ -1759,7 +1759,7 @@ static bool start_hv_timer(struct kvm_lapic *apic)
 		if (atomic_read(&ktimer->pending)) {
 			cancel_hv_timer(apic);
 		} else if (expired) {
-			apic_timer_expired(apic);
+			apic_timer_expired(apic, false);
 			cancel_hv_timer(apic);
 		}
 	}
@@ -1809,7 +1809,7 @@ void kvm_lapic_expired_hv_timer(struct kvm_vcpu *vcpu)
 		goto out;
 	WARN_ON(swait_active(&vcpu->wq));
 	cancel_hv_timer(apic);
-	apic_timer_expired(apic);
+	apic_timer_expired(apic, false);
 
 	if (apic_lvtt_period(apic) && apic->lapic_timer.period) {
 		advance_periodic_target_expiration(apic);
@@ -2312,7 +2312,7 @@ static enum hrtimer_restart apic_timer_fn(struct hrtimer *data)
 	struct kvm_timer *ktimer = container_of(data, struct kvm_timer, timer);
 	struct kvm_lapic *apic = container_of(ktimer, struct kvm_lapic, lapic_timer);
 
-	apic_timer_expired(apic);
+	apic_timer_expired(apic, true);
 
 	if (lapic_is_periodic(apic)) {
 		advance_periodic_target_expiration(apic);
-- 
2.7.4