1 files changed, 224 insertions, 0 deletions
diff --git a/arch/arm64/kvm/vgic/vgic-debug.c b/arch/arm64/kvm/vgic/vgic-debug.c
index afb018528bc3..f8425f381de9 100644
--- a/arch/arm64/kvm/vgic/vgic-debug.c
+++ b/arch/arm64/kvm/vgic/vgic-debug.c
@@ -320,3 +320,227 @@ void vgic_debug_init(struct kvm *kvm)
 void vgic_debug_destroy(struct kvm *kvm)
 {
 }
+
+/**
+ * struct vgic_its_iter - Iterator for traversing VGIC ITS device tables.
+ * @dev: Pointer to the current its_device being processed.
+ * @ite: Pointer to the current its_ite within the device being processed.
+ *
+ * This structure is used to maintain the current position during iteration
+ * over the ITS device tables. It holds pointers to both the current device
+ * and the current ITE within that device.
+ */
+struct vgic_its_iter {
+	struct its_device *dev;
+	struct its_ite *ite;
+};
+
+/**
+ * end_of_iter - Checks if the iterator has reached the end.
+ * @iter: The iterator to check.
+ *
+ * When the iterator completed processing the final ITE in the last device
+ * table, it was marked to indicate the end of iteration by setting its
+ * device and ITE pointers to NULL.
+ * This function checks whether the iterator was marked as end.
+ *
+ * Return: True if the iterator is marked as end, false otherwise.
+ */
+static inline bool end_of_iter(struct vgic_its_iter *iter)
+{
+	return !iter->dev && !iter->ite;
+}
+
+/**
+ * vgic_its_iter_next - Advances the iterator to the next entry in the ITS tables.
+ * @its: The VGIC ITS structure.
+ * @iter: The iterator to advance.
+ *
+ * This function moves the iterator to the next ITE within the current device,
+ * or to the first ITE of the next device if the current ITE is the last in
+ * the device. If the current device is the last device, the iterator is set
+ * to indicate the end of iteration.
+ */
+static void vgic_its_iter_next(struct vgic_its *its, struct vgic_its_iter *iter)
+{
+	struct its_device *dev = iter->dev;
+	struct its_ite *ite = iter->ite;
+
+	if (!ite || list_is_last(&ite->ite_list, &dev->itt_head)) {
+		if (list_is_last(&dev->dev_list, &its->device_list)) {
+			dev = NULL;
+			ite = NULL;
+		} else {
+			dev = list_next_entry(dev, dev_list);
+			ite = list_first_entry_or_null(&dev->itt_head,
+						       struct its_ite,
+						       ite_list);
+		}
+	} else {
+		ite = list_next_entry(ite, ite_list);
+	}
+
+	iter->dev = dev;
+	iter->ite = ite;
+}
+
+/**
+ * vgic_its_debug_start - Start function for the seq_file interface.
+ * @s: The seq_file structure.
+ * @pos: The starting position (offset).
+ *
+ * This function initializes the iterator to the beginning of the ITS tables
+ * and advances it to the specified position. It acquires the its_lock mutex
+ * to protect shared data.
+ *
+ * Return: An iterator pointer on success, NULL if no devices are found or
+ *         the end of the list is reached, or ERR_PTR(-ENOMEM) on memory
+ *         allocation failure.
+ */
+static void *vgic_its_debug_start(struct seq_file *s, loff_t *pos)
+{
+	struct vgic_its *its = s->private;
+	struct vgic_its_iter *iter;
+	struct its_device *dev;
+	loff_t offset = *pos;
+
+	mutex_lock(&its->its_lock);
+
+	dev = list_first_entry_or_null(&its->device_list,
+				       struct its_device, dev_list);
+	if (!dev)
+		return NULL;
+
+	iter = kmalloc(sizeof(*iter), GFP_KERNEL);
+	if (!iter)
+		return ERR_PTR(-ENOMEM);
+
+	iter->dev = dev;
+	iter->ite = list_first_entry_or_null(&dev->itt_head,
+					     struct its_ite, ite_list);
+
+	while (!end_of_iter(iter) && offset--)
+		vgic_its_iter_next(its, iter);
+
+	if (end_of_iter(iter)) {
+		kfree(iter);
+		return NULL;
+	}
+
+	return iter;
+}
+
+/**
+ * vgic_its_debug_next - Next function for the seq_file interface.
+ * @s: The seq_file structure.
+ * @v: The current iterator.
+ * @pos: The current position (offset).
+ *
+ * This function advances the iterator to the next entry and increments the
+ * position.
+ *
+ * Return: An iterator pointer on success, or NULL if the end of the list is
+ *         reached.
+ */
+static void *vgic_its_debug_next(struct seq_file *s, void *v, loff_t *pos)
+{
+	struct vgic_its *its = s->private;
+	struct vgic_its_iter *iter = v;
+
+	++*pos;
+	vgic_its_iter_next(its, iter);
+
+	if (end_of_iter(iter)) {
+		kfree(iter);
+		return NULL;
+	}
+	return iter;
+}
+
+/**
+ * vgic_its_debug_stop - Stop function for the seq_file interface.
+ * @s: The seq_file structure.
+ * @v: The current iterator.
+ *
+ * This function frees the iterator and releases the its_lock mutex.
+ */
+static void vgic_its_debug_stop(struct seq_file *s, void *v)
+{
+	struct vgic_its *its = s->private;
+	struct vgic_its_iter *iter = v;
+
+	if (!IS_ERR_OR_NULL(iter))
+		kfree(iter);
+	mutex_unlock(&its->its_lock);
+}
+
+/**
+ * vgic_its_debug_show - Show function for the seq_file interface.
+ * @s: The seq_file structure.
+ * @v: The current iterator.
+ *
+ * This function formats and prints the ITS table entry information to the
+ * seq_file output.
+ *
+ * Return: 0 on success.
+ */
+static int vgic_its_debug_show(struct seq_file *s, void *v)
+{
+	struct vgic_its_iter *iter = v;
+	struct its_device *dev = iter->dev;
+	struct its_ite *ite = iter->ite;
+
+	if (list_is_first(&ite->ite_list, &dev->itt_head)) {
+		seq_printf(s, "\n");
+		seq_printf(s, "Device ID: 0x%x, Event ID Range: [0 - %llu]\n",
+			   dev->device_id, BIT_ULL(dev->num_eventid_bits) - 1);
+		seq_printf(s, "EVENT_ID    INTID  HWINTID   TARGET   COL_ID HW\n");
+		seq_printf(s, "-----------------------------------------------\n");
+	}
+
+	if (ite && ite->irq && ite->collection) {
+		seq_printf(s, "%8u %8u %8u %8u %8u %2d\n",
+			   ite->event_id, ite->irq->intid, ite->irq->hwintid,
+			   ite->collection->target_addr,
+			   ite->collection->collection_id, ite->irq->hw);
+	}
+
+	return 0;
+}
+
+static const struct seq_operations vgic_its_debug_sops = {
+	.start = vgic_its_debug_start,
+	.next  = vgic_its_debug_next,
+	.stop  = vgic_its_debug_stop,
+	.show  = vgic_its_debug_show
+};
+
+DEFINE_SEQ_ATTRIBUTE(vgic_its_debug);
+
+/**
+ * vgic_its_debug_init - Initializes the debugfs interface for VGIC ITS.
+ * @dev: The KVM device structure.
+ *
+ * This function creates a debugfs file named "vgic-its-state@%its_base"
+ * to expose the ITS table information.
+ *
+ * Return: 0 on success.
+ */
+int vgic_its_debug_init(struct kvm_device *dev)
+{
+	struct vgic_its *its = dev->private;
+	char *name;
+
+	name = kasprintf(GFP_KERNEL, "vgic-its-state@%llx", (u64)its->vgic_its_base);
+	if (!name)
+		return -ENOMEM;
+
+	debugfs_create_file(name, 0444, dev->kvm->debugfs_dentry, its, &vgic_its_debug_fops);
+
+	kfree(name);
+	return 0;
+}
+
+void vgic_its_debug_destroy(struct kvm_device *dev)
+{
+}