1 files changed, 30 insertions, 0 deletions

diff --git a/arch/arm/kvm/vgic.c b/arch/arm/kvm/vgic.c
index 8f32702108b2..2d5e29f1c28f 100644
--- a/arch/arm/kvm/vgic.c
+++ b/arch/arm/kvm/vgic.c
@@ -71,6 +71,7 @@
 #define ACCESS_WRITE_VALUE      (3 << 1)
 #define ACCESS_WRITE_MASK(x)    ((x) & (3 << 1))
 
+static void vgic_retire_disabled_irqs(struct kvm_vcpu *vcpu);
 static void vgic_update_state(struct kvm *kvm);
 static void vgic_dispatch_sgi(struct kvm_vcpu *vcpu, u32 reg);
 
@@ -353,6 +354,7 @@ static bool handle_mmio_clear_enable_reg(struct kvm_vcpu *vcpu,
         if (mmio->is_write) {
                 if (offset < 4) /* Force SGI enabled */
                         *reg |= 0xffff;
+                vgic_retire_disabled_irqs(vcpu);
                 vgic_update_state(vcpu->kvm);
                 return true;
         }
@@ -804,6 +806,34 @@ static void vgic_update_state(struct kvm *kvm)
         (((lr) & GICH_LR_PHYSID_CPUID) >> GICH_LR_PHYSID_CPUID_SHIFT)
 #define MK_LR_PEND(src, irq)    \
         (GICH_LR_PENDING_BIT | ((src) << GICH_LR_PHYSID_CPUID_SHIFT) | (irq))
+
+/*
+ * An interrupt may have been disabled after being made pending on the
+ * CPU interface (the classic case is a timer running while we're
+ * rebooting the guest - the interrupt would kick as soon as the CPU
+ * interface gets enabled, with deadly consequences).
+ *
+ * The solution is to examine already active LRs, and check the
+ * interrupt is still enabled. If not, just retire it.
+ */
+static void vgic_retire_disabled_irqs(struct kvm_vcpu *vcpu)
+{
+        struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
+        int lr;
+
+        for_each_set_bit(lr, vgic_cpu->lr_used, vgic_cpu->nr_lr) {
+                int irq = vgic_cpu->vgic_lr[lr] & GICH_LR_VIRTUALID;
+
+                if (!vgic_irq_is_enabled(vcpu, irq)) {
+                        vgic_cpu->vgic_irq_lr_map[irq] = LR_EMPTY;
+                        clear_bit(lr, vgic_cpu->lr_used);
+                        vgic_cpu->vgic_lr[lr] &= ~GICH_LR_STATE;
+                        if (vgic_irq_is_active(vcpu, irq))
+                                vgic_irq_clear_active(vcpu, irq);
+                }
+        }
+}
+
 /*
  * Queue an interrupt to a CPU virtual interface. Return true on success,
  * or false if it wasn't possible to queue it.