KVM: arm/arm64: Reset mapped IRQs on VM reset

We currently don't allow resetting mapped IRQs from userspace, because
their state is controlled by the hardware.  But we do need to reset the
state when the VM is reset, so we provide a function for the 'owner' of
the mapped interrupt to reset the interrupt state.

Currently only the timer uses mapped interrupts, so we call this
function from the timer reset logic.

Cc: stable@vger.kernel.org
Fixes: 4c60e360d6df ("KVM: arm/arm64: Provide a get_input_level for the arch timer")
Signed-off-by: Christoffer Dall <cdall@kernel.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

1 files changed, 26 insertions, 0 deletions

diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
index c7c5ef190afa..0001858a2c23 100644
--- a/virt/kvm/arm/vgic/vgic.c
+++ b/virt/kvm/arm/vgic/vgic.c
@@ -495,6 +495,32 @@ int kvm_vgic_map_phys_irq(struct kvm_vcpu *vcpu, unsigned int host_irq,
 	return ret;
 }
 
+/**
+ * kvm_vgic_reset_mapped_irq - Reset a mapped IRQ
+ * @vcpu: The VCPU pointer
+ * @vintid: The INTID of the interrupt
+ *
+ * Reset the active and pending states of a mapped interrupt.  Kernel
+ * subsystems injecting mapped interrupts should reset their interrupt lines
+ * when we are doing a reset of the VM.
+ */
+void kvm_vgic_reset_mapped_irq(struct kvm_vcpu *vcpu, u32 vintid)
+{
+	struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, vintid);
+	unsigned long flags;
+
+	if (!irq->hw)
+		goto out;
+
+	spin_lock_irqsave(&irq->irq_lock, flags);
+	irq->active = false;
+	irq->pending_latch = false;
+	irq->line_level = false;
+	spin_unlock_irqrestore(&irq->irq_lock, flags);
+out:
+	vgic_put_irq(vcpu->kvm, irq);
+}
+
 int kvm_vgic_unmap_phys_irq(struct kvm_vcpu *vcpu, unsigned int vintid)
 {
 	struct vgic_irq *irq;