KVM: arm64: vgic-its: Implement MSI injection in ITS emulation

[cascardo/linux.git] / virt / kvm / arm / vgic / vgic-its.c

diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index 1408c88..d8e8f14 100644 (file)
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -437,6 +437,65 @@ static unsigned long vgic_mmio_read_its_idregs(struct kvm *kvm,
        return 0;
 }
 
+/*
+ * Find the target VCPU and the LPI number for a given devid/eventid pair
+ * and make this IRQ pending, possibly injecting it.
+ * Must be called with the its_lock mutex held.
+ */
+static void vgic_its_trigger_msi(struct kvm *kvm, struct vgic_its *its,
+                                u32 devid, u32 eventid)
+{
+       struct its_itte *itte;
+
+       if (!its->enabled)
+               return;
+
+       itte = find_itte(its, devid, eventid);
+       /* Triggering an unmapped IRQ gets silently dropped. */
+       if (itte && its_is_collection_mapped(itte->collection)) {
+               struct kvm_vcpu *vcpu;
+
+               vcpu = kvm_get_vcpu(kvm, itte->collection->target_addr);
+               if (vcpu && vcpu->arch.vgic_cpu.lpis_enabled) {
+                       spin_lock(&itte->irq->irq_lock);
+                       itte->irq->pending = true;
+                       vgic_queue_irq_unlock(kvm, itte->irq);
+               }
+       }
+}
+
+/*
+ * Queries the KVM IO bus framework to get the ITS pointer from the given
+ * doorbell address.
+ * We then call vgic_its_trigger_msi() with the decoded data.
+ */
+int vgic_its_inject_msi(struct kvm *kvm, struct kvm_msi *msi)
+{
+       u64 address;
+       struct kvm_io_device *kvm_io_dev;
+       struct vgic_io_device *iodev;
+
+       if (!vgic_has_its(kvm))
+               return -ENODEV;
+
+       if (!(msi->flags & KVM_MSI_VALID_DEVID))
+               return -EINVAL;
+
+       address = (u64)msi->address_hi << 32 | msi->address_lo;
+
+       kvm_io_dev = kvm_io_bus_get_dev(kvm, KVM_MMIO_BUS, address);
+       if (!kvm_io_dev)
+               return -ENODEV;
+
+       iodev = container_of(kvm_io_dev, struct vgic_io_device, dev);
+
+       mutex_lock(&iodev->its->its_lock);
+       vgic_its_trigger_msi(kvm, iodev->its, msi->devid, msi->data);
+       mutex_unlock(&iodev->its->its_lock);
+
+       return 0;
+}
+
 /* Requires the its_lock to be held. */
 static void its_free_itte(struct kvm *kvm, struct its_itte *itte)
 {
@@ -896,6 +955,21 @@ static int vgic_its_cmd_handle_movall(struct kvm *kvm, struct vgic_its *its,
        return 0;
 }
 
+/*
+ * The INT command injects the LPI associated with that DevID/EvID pair.
+ * Must be called with the its_lock mutex held.
+ */
+static int vgic_its_cmd_handle_int(struct kvm *kvm, struct vgic_its *its,
+                                  u64 *its_cmd)
+{
+       u32 msi_data = its_cmd_get_id(its_cmd);
+       u64 msi_devid = its_cmd_get_deviceid(its_cmd);
+
+       vgic_its_trigger_msi(kvm, its, msi_devid, msi_data);
+
+       return 0;
+}
+
 /*
  * This function is called with the its_cmd lock held, but the ITS data
  * structure lock dropped.
@@ -932,6 +1006,9 @@ static int vgic_its_handle_command(struct kvm *kvm, struct vgic_its *its,
        case GITS_CMD_MOVALL:
                ret = vgic_its_cmd_handle_movall(kvm, its, its_cmd);
                break;
+       case GITS_CMD_INT:
+               ret = vgic_its_cmd_handle_int(kvm, its, its_cmd);
+               break;
        case GITS_CMD_INV:
                ret = vgic_its_cmd_handle_inv(kvm, its, its_cmd);
                break;