ARM: KVM: VGIC interrupt injection
Plug the interrupt injection code. Interrupts can now be generated
from user space.
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
diff --git a/arch/arm/kvm/vgic.c b/arch/arm/kvm/vgic.c
index 2d5e29f..2e6a585 100644
--- a/arch/arm/kvm/vgic.c
+++ b/arch/arm/kvm/vgic.c
@@ -73,6 +73,7 @@
static void vgic_retire_disabled_irqs(struct kvm_vcpu *vcpu);
static void vgic_update_state(struct kvm *kvm);
+static void vgic_kick_vcpus(struct kvm *kvm);
static void vgic_dispatch_sgi(struct kvm_vcpu *vcpu, u32 reg);
static u32 *vgic_bitmap_get_reg(struct vgic_bitmap *x,
@@ -708,6 +709,9 @@
kvm_prepare_mmio(run, mmio);
kvm_handle_mmio_return(vcpu, run);
+ if (updated_state)
+ vgic_kick_vcpus(vcpu->kvm);
+
return true;
}
@@ -1104,6 +1108,119 @@
return test_bit(vcpu->vcpu_id, &dist->irq_pending_on_cpu);
}
+static void vgic_kick_vcpus(struct kvm *kvm)
+{
+ struct kvm_vcpu *vcpu;
+ int c;
+
+ /*
+ * We've injected an interrupt, time to find out who deserves
+ * a good kick...
+ */
+ kvm_for_each_vcpu(c, vcpu, kvm) {
+ if (kvm_vgic_vcpu_pending_irq(vcpu))
+ kvm_vcpu_kick(vcpu);
+ }
+}
+
+static int vgic_validate_injection(struct kvm_vcpu *vcpu, int irq, int level)
+{
+ int is_edge = vgic_irq_is_edge(vcpu, irq);
+ int state = vgic_dist_irq_is_pending(vcpu, irq);
+
+ /*
+ * Only inject an interrupt if:
+ * - edge triggered and we have a rising edge
+ * - level triggered and we change level
+ */
+ if (is_edge)
+ return level > state;
+ else
+ return level != state;
+}
+
+static bool vgic_update_irq_state(struct kvm *kvm, int cpuid,
+ unsigned int irq_num, bool level)
+{
+ struct vgic_dist *dist = &kvm->arch.vgic;
+ struct kvm_vcpu *vcpu;
+ int is_edge, is_level;
+ int enabled;
+ bool ret = true;
+
+ spin_lock(&dist->lock);
+
+ vcpu = kvm_get_vcpu(kvm, cpuid);
+ is_edge = vgic_irq_is_edge(vcpu, irq_num);
+ is_level = !is_edge;
+
+ if (!vgic_validate_injection(vcpu, irq_num, level)) {
+ ret = false;
+ goto out;
+ }
+
+ if (irq_num >= VGIC_NR_PRIVATE_IRQS) {
+ cpuid = dist->irq_spi_cpu[irq_num - VGIC_NR_PRIVATE_IRQS];
+ vcpu = kvm_get_vcpu(kvm, cpuid);
+ }
+
+ kvm_debug("Inject IRQ%d level %d CPU%d\n", irq_num, level, cpuid);
+
+ if (level)
+ vgic_dist_irq_set(vcpu, irq_num);
+ else
+ vgic_dist_irq_clear(vcpu, irq_num);
+
+ enabled = vgic_irq_is_enabled(vcpu, irq_num);
+
+ if (!enabled) {
+ ret = false;
+ goto out;
+ }
+
+ if (is_level && vgic_irq_is_active(vcpu, irq_num)) {
+ /*
+ * Level interrupt in progress, will be picked up
+ * when EOId.
+ */
+ ret = false;
+ goto out;
+ }
+
+ if (level) {
+ vgic_cpu_irq_set(vcpu, irq_num);
+ set_bit(cpuid, &dist->irq_pending_on_cpu);
+ }
+
+out:
+ spin_unlock(&dist->lock);
+
+ return ret;
+}
+
+/**
+ * kvm_vgic_inject_irq - Inject an IRQ from a device to the vgic
+ * @kvm: The VM structure pointer
+ * @cpuid: The CPU for PPIs
+ * @irq_num: The IRQ number that is assigned to the device
+ * @level: Edge-triggered: true: to trigger the interrupt
+ * false: to ignore the call
+ * Level-sensitive true: activates an interrupt
+ * false: deactivates an interrupt
+ *
+ * The GIC is not concerned with devices being active-LOW or active-HIGH for
+ * level-sensitive interrupts. You can think of the level parameter as 1
+ * being HIGH and 0 being LOW and all devices being active-HIGH.
+ */
+int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int irq_num,
+ bool level)
+{
+ if (vgic_update_irq_state(kvm, cpuid, irq_num, level))
+ vgic_kick_vcpus(kvm);
+
+ return 0;
+}
+
static bool vgic_ioaddr_overlap(struct kvm *kvm)
{
phys_addr_t dist = kvm->arch.vgic.vgic_dist_base;