From 8d91c1e411f55d7ea91b1183a2e9f8088fb4d5be Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andr=C3=A9=20Fabian=20Silva=20Delgado?=
 <emulatorman@parabola.nu>
Date: Tue, 15 Dec 2015 14:52:16 -0300
Subject: Linux-libre 4.3.2-gnu

---
 virt/kvm/arm/arch_timer.c | 56 +++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 49 insertions(+), 7 deletions(-)

(limited to 'virt/kvm/arm/arch_timer.c')

diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
index 98c95f2fc..b9d3a32cb 100644
--- a/virt/kvm/arm/arch_timer.c
+++ b/virt/kvm/arm/arch_timer.c
@@ -64,10 +64,10 @@ static void kvm_timer_inject_irq(struct kvm_vcpu *vcpu)
 	int ret;
 	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
 
-	timer->cntv_ctl |= ARCH_TIMER_CTRL_IT_MASK;
-	ret = kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id,
-				  timer->irq->irq,
-				  timer->irq->level);
+	kvm_vgic_set_phys_irq_active(timer->map, true);
+	ret = kvm_vgic_inject_mapped_irq(vcpu->kvm, vcpu->vcpu_id,
+					 timer->map,
+					 timer->irq->level);
 	WARN_ON(ret);
 }
 
@@ -117,7 +117,8 @@ bool kvm_timer_should_fire(struct kvm_vcpu *vcpu)
 	cycle_t cval, now;
 
 	if ((timer->cntv_ctl & ARCH_TIMER_CTRL_IT_MASK) ||
-		!(timer->cntv_ctl & ARCH_TIMER_CTRL_ENABLE))
+	    !(timer->cntv_ctl & ARCH_TIMER_CTRL_ENABLE) ||
+	    kvm_vgic_get_phys_irq_active(timer->map))
 		return false;
 
 	cval = timer->cntv_cval;
@@ -136,6 +137,8 @@ bool kvm_timer_should_fire(struct kvm_vcpu *vcpu)
 void kvm_timer_flush_hwstate(struct kvm_vcpu *vcpu)
 {
 	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
+	bool phys_active;
+	int ret;
 
 	/*
 	 * We're about to run this vcpu again, so there is no need to
@@ -150,6 +153,23 @@ void kvm_timer_flush_hwstate(struct kvm_vcpu *vcpu)
 	 */
 	if (kvm_timer_should_fire(vcpu))
 		kvm_timer_inject_irq(vcpu);
+
+	/*
+	 * We keep track of whether the edge-triggered interrupt has been
+	 * signalled to the vgic/guest, and if so, we mask the interrupt and
+	 * the physical distributor to prevent the timer from raising a
+	 * physical interrupt whenever we run a guest, preventing forward
+	 * VCPU progress.
+	 */
+	if (kvm_vgic_get_phys_irq_active(timer->map))
+		phys_active = true;
+	else
+		phys_active = false;
+
+	ret = irq_set_irqchip_state(timer->map->irq,
+				    IRQCHIP_STATE_ACTIVE,
+				    phys_active);
+	WARN_ON(ret);
 }
 
 /**
@@ -184,10 +204,11 @@ void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu)
 	timer_arm(timer, ns);
 }
 
-void kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu,
-			  const struct kvm_irq_level *irq)
+int kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu,
+			 const struct kvm_irq_level *irq)
 {
 	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
+	struct irq_phys_map *map;
 
 	/*
 	 * The vcpu timer irq number cannot be determined in
@@ -196,6 +217,25 @@ void kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu,
 	 * vcpu timer irq number when the vcpu is reset.
 	 */
 	timer->irq = irq;
+
+	/*
+	 * The bits in CNTV_CTL are architecturally reset to UNKNOWN for ARMv8
+	 * and to 0 for ARMv7.  We provide an implementation that always
+	 * resets the timer to be disabled and unmasked and is compliant with
+	 * the ARMv7 architecture.
+	 */
+	timer->cntv_ctl = 0;
+
+	/*
+	 * Tell the VGIC that the virtual interrupt is tied to a
+	 * physical interrupt. We do that once per VCPU.
+	 */
+	map = kvm_vgic_map_phys_irq(vcpu, irq->irq, host_vtimer_irq);
+	if (WARN_ON(IS_ERR(map)))
+		return PTR_ERR(map);
+
+	timer->map = map;
+	return 0;
 }
 
 void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu)
@@ -335,6 +375,8 @@ void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu)
 	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
 
 	timer_disarm(timer);
+	if (timer->map)
+		kvm_vgic_unmap_phys_irq(vcpu, timer->map);
 }
 
 void kvm_timer_enable(struct kvm *kvm)
-- 
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