1 files changed, 81 insertions, 36 deletions

diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c
index 4b43e7f..fc8a723 100644
--- a/virt/kvm/arm/pmu.c
+++ b/virt/kvm/arm/pmu.c
@@ -203,6 +203,24 @@ static u64 kvm_pmu_overflow_status(struct kvm_vcpu *vcpu)
 	return reg;
 }
 
+static void kvm_pmu_check_overflow(struct kvm_vcpu *vcpu)
+{
+	struct kvm_pmu *pmu = &vcpu->arch.pmu;
+	bool overflow = !!kvm_pmu_overflow_status(vcpu);
+
+	if (pmu->irq_level == overflow)
+		return;
+
+	pmu->irq_level = overflow;
+
+	if (likely(irqchip_in_kernel(vcpu->kvm))) {
+		int ret = kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id,
+					      pmu->irq_num, overflow,
+					      &vcpu->arch.pmu);
+		WARN_ON(ret);
+	}
+}
+
 /**
  * kvm_pmu_overflow_set - set PMU overflow interrupt
  * @vcpu: The vcpu pointer
@@ -210,37 +228,18 @@ static u64 kvm_pmu_overflow_status(struct kvm_vcpu *vcpu)
  */
 void kvm_pmu_overflow_set(struct kvm_vcpu *vcpu, u64 val)
 {
-	u64 reg;
-
 	if (val == 0)
 		return;
 
 	vcpu_sys_reg(vcpu, PMOVSSET_EL0) |= val;
-	reg = kvm_pmu_overflow_status(vcpu);
-	if (reg != 0)
-		kvm_vcpu_kick(vcpu);
+	kvm_pmu_check_overflow(vcpu);
 }
 
 static void kvm_pmu_update_state(struct kvm_vcpu *vcpu)
 {
-	struct kvm_pmu *pmu = &vcpu->arch.pmu;
-	bool overflow;
-
 	if (!kvm_arm_pmu_v3_ready(vcpu))
 		return;
-
-	overflow = !!kvm_pmu_overflow_status(vcpu);
-	if (pmu->irq_level == overflow)
-		return;
-
-	pmu->irq_level = overflow;
-
-	if (likely(irqchip_in_kernel(vcpu->kvm))) {
-		int ret;
-		ret = kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id,
-					  pmu->irq_num, overflow);
-		WARN_ON(ret);
-	}
+	kvm_pmu_check_overflow(vcpu);
 }
 
 bool kvm_pmu_should_notify_user(struct kvm_vcpu *vcpu)
@@ -451,34 +450,74 @@ bool kvm_arm_support_pmu_v3(void)
 	return (perf_num_counters() > 0);
 }
 
-static int kvm_arm_pmu_v3_init(struct kvm_vcpu *vcpu)
+int kvm_arm_pmu_v3_enable(struct kvm_vcpu *vcpu)
 {
-	if (!kvm_arm_support_pmu_v3())
-		return -ENODEV;
+	if (!vcpu->arch.pmu.created)
+		return 0;
 
 	/*
-	 * We currently require an in-kernel VGIC to use the PMU emulation,
-	 * because we do not support forwarding PMU overflow interrupts to
-	 * userspace yet.
+	 * A valid interrupt configuration for the PMU is either to have a
+	 * properly configured interrupt number and using an in-kernel
+	 * irqchip, or to not have an in-kernel GIC and not set an IRQ.
 	 */
-	if (!irqchip_in_kernel(vcpu->kvm) || !vgic_initialized(vcpu->kvm))
+	if (irqchip_in_kernel(vcpu->kvm)) {
+		int irq = vcpu->arch.pmu.irq_num;
+		if (!kvm_arm_pmu_irq_initialized(vcpu))
+			return -EINVAL;
+
+		/*
+		 * If we are using an in-kernel vgic, at this point we know
+		 * the vgic will be initialized, so we can check the PMU irq
+		 * number against the dimensions of the vgic and make sure
+		 * it's valid.
+		 */
+		if (!irq_is_ppi(irq) && !vgic_valid_spi(vcpu->kvm, irq))
+			return -EINVAL;
+	} else if (kvm_arm_pmu_irq_initialized(vcpu)) {
+		   return -EINVAL;
+	}
+
+	kvm_pmu_vcpu_reset(vcpu);
+	vcpu->arch.pmu.ready = true;
+
+	return 0;
+}
+
+static int kvm_arm_pmu_v3_init(struct kvm_vcpu *vcpu)
+{
+	if (!kvm_arm_support_pmu_v3())
 		return -ENODEV;
 
-	if (!test_bit(KVM_ARM_VCPU_PMU_V3, vcpu->arch.features) ||
-	    !kvm_arm_pmu_irq_initialized(vcpu))
+	if (!test_bit(KVM_ARM_VCPU_PMU_V3, vcpu->arch.features))
 		return -ENXIO;
 
-	if (kvm_arm_pmu_v3_ready(vcpu))
+	if (vcpu->arch.pmu.created)
 		return -EBUSY;
 
-	kvm_pmu_vcpu_reset(vcpu);
-	vcpu->arch.pmu.ready = true;
+	if (irqchip_in_kernel(vcpu->kvm)) {
+		int ret;
+
+		/*
+		 * If using the PMU with an in-kernel virtual GIC
+		 * implementation, we require the GIC to be already
+		 * initialized when initializing the PMU.
+		 */
+		if (!vgic_initialized(vcpu->kvm))
+			return -ENODEV;
+
+		if (!kvm_arm_pmu_irq_initialized(vcpu))
+			return -ENXIO;
 
+		ret = kvm_vgic_set_owner(vcpu, vcpu->arch.pmu.irq_num,
+					 &vcpu->arch.pmu);
+		if (ret)
+			return ret;
+	}
+
+	vcpu->arch.pmu.created = true;
 	return 0;
 }
 
-#define irq_is_ppi(irq) ((irq) >= VGIC_NR_SGIS && (irq) < VGIC_NR_PRIVATE_IRQS)
-
 /*
  * For one VM the interrupt type must be same for each vcpu.
  * As a PPI, the interrupt number is the same for all vcpus,
@@ -512,6 +551,9 @@ int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
 		int __user *uaddr = (int __user *)(long)attr->addr;
 		int irq;
 
+		if (!irqchip_in_kernel(vcpu->kvm))
+			return -EINVAL;
+
 		if (!test_bit(KVM_ARM_VCPU_PMU_V3, vcpu->arch.features))
 			return -ENODEV;
 
@@ -519,7 +561,7 @@ int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
 			return -EFAULT;
 
 		/* The PMU overflow interrupt can be a PPI or a valid SPI. */
-		if (!(irq_is_ppi(irq) || vgic_valid_spi(vcpu->kvm, irq)))
+		if (!(irq_is_ppi(irq) || irq_is_spi(irq)))
 			return -EINVAL;
 
 		if (!pmu_irq_is_valid(vcpu->kvm, irq))
@@ -546,6 +588,9 @@ int kvm_arm_pmu_v3_get_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr)
 		int __user *uaddr = (int __user *)(long)attr->addr;
 		int irq;
 
+		if (!irqchip_in_kernel(vcpu->kvm))
+			return -EINVAL;
+
 		if (!test_bit(KVM_ARM_VCPU_PMU_V3, vcpu->arch.features))
 			return -ENODEV;