arch/arm64/kvm/vgic/vgic-debug.c - third_party/linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2016 Linaro
  * Author: Christoffer Dall <christoffer.dall@linaro.org>
  */

 #include <linux/cpu.h>
 #include <linux/debugfs.h>
 #include <linux/interrupt.h>
 #include <linux/kvm_host.h>
 #include <linux/seq_file.h>
 #include <kvm/arm_vgic.h>
 #include <asm/kvm_mmu.h>
 #include "vgic.h"

 /*
  * Structure to control looping through the entire vgic state.  We start at
  * zero for each field and move upwards.  So, if dist_id is 0 we print the
  * distributor info.  When dist_id is 1, we have already printed it and move
  * on.
  *
  * When vcpu_id < nr_cpus we print the vcpu info until vcpu_id == nr_cpus and
  * so on.
  */
 struct vgic_state_iter {
 	int nr_cpus;
 	int nr_spis;
 	int dist_id;
 	int vcpu_id;
 	unsigned long intid;
 };

 static void iter_next(struct kvm *kvm, struct vgic_state_iter *iter)
 {
 	struct vgic_dist *dist = &kvm->arch.vgic;

 	if (iter->dist_id == 0) {
 		iter->dist_id++;
 		return;
 	}

 	/*
 	 * Let the xarray drive the iterator after the last SPI, as the iterator
 	 * has exhausted the sequentially-allocated INTID space.
 	 */
 	if (iter->intid >= (iter->nr_spis + VGIC_NR_PRIVATE_IRQS - 1)) {
 		if (iter->intid == VGIC_LPI_MAX_INTID + 1)
 			return;

 		rcu_read_lock();
 		if (!xa_find_after(&dist->lpi_xa, &iter->intid,
 				   VGIC_LPI_MAX_INTID, XA_PRESENT))
 			iter->intid = VGIC_LPI_MAX_INTID + 1;
 		rcu_read_unlock();
 		return;
 	}

 	iter->intid++;
 	if (iter->intid == VGIC_NR_PRIVATE_IRQS &&
 	    ++iter->vcpu_id < iter->nr_cpus)
 		iter->intid = 0;
 }

 static int vgic_count_lpis(struct kvm *kvm)
 {
 	struct vgic_dist *dist = &kvm->arch.vgic;
 	struct vgic_irq *irq;
 	unsigned long intid;
 	int nr_lpis = 0;

 	rcu_read_lock();
 	xa_for_each(&dist->lpi_xa, intid, irq)
 		nr_lpis++;
 	rcu_read_unlock();

 	return nr_lpis;
 }

 static void iter_init(struct kvm *kvm, struct vgic_state_iter *iter,
 		      loff_t pos)
 {
 	int nr_cpus = atomic_read(&kvm->online_vcpus);

 	memset(iter, 0, sizeof(*iter));

 	iter->nr_cpus = nr_cpus;
 	iter->nr_spis = kvm->arch.vgic.nr_spis;

 	/* Fast forward to the right position if needed */
 	while (pos--)
 		iter_next(kvm, iter);
 }

 static bool end_of_vgic(struct vgic_state_iter *iter)
 {
 	return iter->dist_id > 0 &&
 		iter->vcpu_id == iter->nr_cpus &&
 		iter->intid >= (iter->nr_spis + VGIC_NR_PRIVATE_IRQS) &&
 		iter->intid > VGIC_LPI_MAX_INTID;
 }

 static void *vgic_debug_start(struct seq_file *s, loff_t *pos)
 {
 	struct kvm *kvm = s->private;
 	struct vgic_state_iter *iter;

 	iter = kmalloc_obj(*iter);
 	if (!iter)
 		return ERR_PTR(-ENOMEM);

 	iter_init(kvm, iter, *pos);

 	if (end_of_vgic(iter)) {
 		kfree(iter);
 		iter = NULL;
 	}

 	return iter;
 }

 static void *vgic_debug_next(struct seq_file *s, void *v, loff_t *pos)
 {
 	struct kvm *kvm = s->private;
 	struct vgic_state_iter *iter = v;

 	++*pos;
 	iter_next(kvm, iter);
 	if (end_of_vgic(iter)) {
 		kfree(iter);
 		iter = NULL;
 	}
 	return iter;
 }

 static void vgic_debug_stop(struct seq_file *s, void *v)
 {
 	struct vgic_state_iter *iter = v;

 	if (IS_ERR_OR_NULL(v))
 		return;

 	kfree(iter);
 }

 static void print_dist_state(struct seq_file *s, struct vgic_dist *dist,
 			     struct vgic_state_iter *iter)
 {
 	bool v3 = dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3;
 	struct kvm *kvm = s->private;

 	seq_printf(s, "Distributor\n");
 	seq_printf(s, "===========\n");
 	seq_printf(s, "vgic_model:\t%s\n", v3 ? "GICv3" : "GICv2");
 	seq_printf(s, "nr_spis:\t%d\n", dist->nr_spis);
 	if (v3)
 		seq_printf(s, "nr_lpis:\t%d\n", vgic_count_lpis(kvm));
 	seq_printf(s, "enabled:\t%d\n", dist->enabled);
 	seq_printf(s, "\n");

 	seq_printf(s, "P=pending_latch, L=line_level, A=active\n");
 	seq_printf(s, "E=enabled, H=hw, C=config (level=1, edge=0)\n");
 	seq_printf(s, "G=group\n");
 }

 static void print_header(struct seq_file *s, struct vgic_irq *irq,
 			 struct kvm_vcpu *vcpu)
 {
 	int id = 0;
 	char *hdr = "SPI ";

 	if (vcpu) {
 		hdr = "VCPU";
 		id = vcpu->vcpu_idx;
 	}

 	seq_printf(s, "\n");
 	seq_printf(s, "%s%2d TYP   ID TGT_ID PLAEHCG     HWID   TARGET SRC PRI VCPU_ID\n", hdr, id);
 	seq_printf(s, "----------------------------------------------------------------\n");
 }

 static void print_irq_state(struct seq_file *s, struct vgic_irq *irq,
 			    struct kvm_vcpu *vcpu)
 {
 	char *type;
 	bool pending;

 	if (irq->intid < VGIC_NR_SGIS)
 		type = "SGI";
 	else if (irq->intid < VGIC_NR_PRIVATE_IRQS)
 		type = "PPI";
 	else if (irq->intid < VGIC_MAX_SPI)
 		type = "SPI";
 	else
 		type = "LPI";

 	if (irq->intid ==0 || irq->intid == VGIC_NR_PRIVATE_IRQS)
 		print_header(s, irq, vcpu);

 	pending = irq->pending_latch;
 	if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
 		int err;

 		err = irq_get_irqchip_state(irq->host_irq,
 					    IRQCHIP_STATE_PENDING,
 					    &pending);
 		WARN_ON_ONCE(err);
 	}

 	seq_printf(s, "       %s %4d "
 		      "    %2d "
 		      "%d%d%d%d%d%d%d "
 		      "%8d "
 		      "%8x "
 		      " %2x "
 		      "%3d "
 		      "     %2d "
 		      "\n",
 			type, irq->intid,
 			(irq->target_vcpu) ? irq->target_vcpu->vcpu_idx : -1,
 			pending,
 			irq->line_level,
 			irq->active,
 			irq->enabled,
 			irq->hw,
 			irq->config == VGIC_CONFIG_LEVEL,
 			irq->group,
 			irq->hwintid,
 			irq->mpidr,
 			irq->source,
 			irq->priority,
 			(irq->vcpu) ? irq->vcpu->vcpu_idx : -1);
 }

 static int vgic_debug_show(struct seq_file *s, void *v)
 {
 	struct kvm *kvm = s->private;
 	struct vgic_state_iter *iter = v;
 	struct vgic_irq *irq;
 	struct kvm_vcpu *vcpu = NULL;
 	unsigned long flags;

 	if (iter->dist_id == 0) {
 		print_dist_state(s, &kvm->arch.vgic, iter);
 		return 0;
 	}

 	if (!kvm->arch.vgic.initialized)
 		return 0;

 	if (iter->vcpu_id < iter->nr_cpus)
 		vcpu = kvm_get_vcpu(kvm, iter->vcpu_id);

 	if (iter->intid < VGIC_NR_PRIVATE_IRQS)
 		irq = vgic_get_vcpu_irq(vcpu, iter->intid);
 	else
 		irq = vgic_get_irq(kvm, iter->intid);

 	if (!irq)
 		return 0;

 	raw_spin_lock_irqsave(&irq->irq_lock, flags);
 	print_irq_state(s, irq, vcpu);
 	raw_spin_unlock_irqrestore(&irq->irq_lock, flags);

 	vgic_put_irq(kvm, irq);
 	return 0;
 }

 static const struct seq_operations vgic_debug_sops = {
 	.start = vgic_debug_start,
 	.next  = vgic_debug_next,
 	.stop  = vgic_debug_stop,
 	.show  = vgic_debug_show
 };

 DEFINE_SEQ_ATTRIBUTE(vgic_debug);

 void vgic_debug_init(struct kvm *kvm)
 {
 	debugfs_create_file("vgic-state", 0444, kvm->debugfs_dentry, kvm,
 			    &vgic_debug_fops);
 }

 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_obj(*iter);
 	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 (!ite)
 		return 0;

 	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->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)
 {
 }
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Copyright (C) 2016 Linaro
	* Author: Christoffer Dall <christoffer.dall@linaro.org>
	*/

	#include <linux/cpu.h>
	#include <linux/debugfs.h>
	#include <linux/interrupt.h>
	#include <linux/kvm_host.h>
	#include <linux/seq_file.h>
	#include <kvm/arm_vgic.h>
	#include <asm/kvm_mmu.h>
	#include "vgic.h"

	/*
	* Structure to control looping through the entire vgic state. We start at
	* zero for each field and move upwards. So, if dist_id is 0 we print the
	* distributor info. When dist_id is 1, we have already printed it and move
	* on.
	*
	* When vcpu_id < nr_cpus we print the vcpu info until vcpu_id == nr_cpus and
	* so on.
	*/
	struct vgic_state_iter {
	int nr_cpus;
	int nr_spis;
	int dist_id;
	int vcpu_id;
	unsigned long intid;
	};

	static void iter_next(struct kvm kvm, struct vgic_state_iter iter)
	{
	struct vgic_dist *dist = &kvm->arch.vgic;

	if (iter->dist_id == 0) {
	iter->dist_id++;
	return;
	}

	/*
	* Let the xarray drive the iterator after the last SPI, as the iterator
	* has exhausted the sequentially-allocated INTID space.
	*/
	if (iter->intid >= (iter->nr_spis + VGIC_NR_PRIVATE_IRQS - 1)) {
	if (iter->intid == VGIC_LPI_MAX_INTID + 1)
	return;

	rcu_read_lock();
	if (!xa_find_after(&dist->lpi_xa, &iter->intid,
	VGIC_LPI_MAX_INTID, XA_PRESENT))
	iter->intid = VGIC_LPI_MAX_INTID + 1;
	rcu_read_unlock();
	return;
	}

	iter->intid++;
	if (iter->intid == VGIC_NR_PRIVATE_IRQS &&
	++iter->vcpu_id < iter->nr_cpus)
	iter->intid = 0;
	}

	static int vgic_count_lpis(struct kvm *kvm)
	{
	struct vgic_dist *dist = &kvm->arch.vgic;
	struct vgic_irq *irq;
	unsigned long intid;
	int nr_lpis = 0;

	rcu_read_lock();
	xa_for_each(&dist->lpi_xa, intid, irq)
	nr_lpis++;
	rcu_read_unlock();

	return nr_lpis;
	}

	static void iter_init(struct kvm kvm, struct vgic_state_iter iter,
	loff_t pos)
	{
	int nr_cpus = atomic_read(&kvm->online_vcpus);

	memset(iter, 0, sizeof(*iter));

	iter->nr_cpus = nr_cpus;
	iter->nr_spis = kvm->arch.vgic.nr_spis;

	/* Fast forward to the right position if needed */
	while (pos--)
	iter_next(kvm, iter);
	}

	static bool end_of_vgic(struct vgic_state_iter *iter)
	{
	return iter->dist_id > 0 &&
	iter->vcpu_id == iter->nr_cpus &&
	iter->intid >= (iter->nr_spis + VGIC_NR_PRIVATE_IRQS) &&
	iter->intid > VGIC_LPI_MAX_INTID;
	}

	static void vgic_debug_start(struct seq_file s, loff_t *pos)
	{
	struct kvm *kvm = s->private;
	struct vgic_state_iter *iter;

	iter = kmalloc_obj(*iter);
	if (!iter)
	return ERR_PTR(-ENOMEM);

	iter_init(kvm, iter, *pos);

	if (end_of_vgic(iter)) {
	kfree(iter);
	iter = NULL;
	}

	return iter;
	}

	static void vgic_debug_next(struct seq_file s, void v, loff_t pos)
	{
	struct kvm *kvm = s->private;
	struct vgic_state_iter *iter = v;

	++*pos;
	iter_next(kvm, iter);
	if (end_of_vgic(iter)) {
	kfree(iter);
	iter = NULL;
	}
	return iter;
	}

	static void vgic_debug_stop(struct seq_file s, void v)
	{
	struct vgic_state_iter *iter = v;

	if (IS_ERR_OR_NULL(v))
	return;

	kfree(iter);
	}

	static void print_dist_state(struct seq_file s, struct vgic_dist dist,
	struct vgic_state_iter *iter)
	{
	bool v3 = dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3;
	struct kvm *kvm = s->private;

	seq_printf(s, "Distributor\n");
	seq_printf(s, "===========\n");
	seq_printf(s, "vgic_model:\t%s\n", v3 ? "GICv3" : "GICv2");
	seq_printf(s, "nr_spis:\t%d\n", dist->nr_spis);
	if (v3)
	seq_printf(s, "nr_lpis:\t%d\n", vgic_count_lpis(kvm));
	seq_printf(s, "enabled:\t%d\n", dist->enabled);
	seq_printf(s, "\n");

	seq_printf(s, "P=pending_latch, L=line_level, A=active\n");
	seq_printf(s, "E=enabled, H=hw, C=config (level=1, edge=0)\n");
	seq_printf(s, "G=group\n");
	}

	static void print_header(struct seq_file s, struct vgic_irq irq,
	struct kvm_vcpu *vcpu)
	{
	int id = 0;
	char *hdr = "SPI ";

	if (vcpu) {
	hdr = "VCPU";
	id = vcpu->vcpu_idx;
	}

	seq_printf(s, "\n");
	seq_printf(s, "%s%2d TYP ID TGT_ID PLAEHCG HWID TARGET SRC PRI VCPU_ID\n", hdr, id);
	seq_printf(s, "----------------------------------------------------------------\n");
	}

	static void print_irq_state(struct seq_file s, struct vgic_irq irq,
	struct kvm_vcpu *vcpu)
	{
	char *type;
	bool pending;

	if (irq->intid < VGIC_NR_SGIS)
	type = "SGI";
	else if (irq->intid < VGIC_NR_PRIVATE_IRQS)
	type = "PPI";
	else if (irq->intid < VGIC_MAX_SPI)
	type = "SPI";
	else
	type = "LPI";

	if (irq->intid ==0 \|\| irq->intid == VGIC_NR_PRIVATE_IRQS)
	print_header(s, irq, vcpu);

	pending = irq->pending_latch;
	if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
	int err;

	err = irq_get_irqchip_state(irq->host_irq,
	IRQCHIP_STATE_PENDING,
	&pending);
	WARN_ON_ONCE(err);
	}

	seq_printf(s, " %s %4d "
	" %2d "
	"%d%d%d%d%d%d%d "
	"%8d "
	"%8x "
	" %2x "
	"%3d "
	" %2d "
	"\n",
	type, irq->intid,
	(irq->target_vcpu) ? irq->target_vcpu->vcpu_idx : -1,
	pending,
	irq->line_level,
	irq->active,
	irq->enabled,
	irq->hw,
	irq->config == VGIC_CONFIG_LEVEL,
	irq->group,
	irq->hwintid,
	irq->mpidr,
	irq->source,
	irq->priority,
	(irq->vcpu) ? irq->vcpu->vcpu_idx : -1);
	}

	static int vgic_debug_show(struct seq_file s, void v)
	{
	struct kvm *kvm = s->private;
	struct vgic_state_iter *iter = v;
	struct vgic_irq *irq;
	struct kvm_vcpu *vcpu = NULL;
	unsigned long flags;

	if (iter->dist_id == 0) {
	print_dist_state(s, &kvm->arch.vgic, iter);
	return 0;
	}

	if (!kvm->arch.vgic.initialized)
	return 0;

	if (iter->vcpu_id < iter->nr_cpus)
	vcpu = kvm_get_vcpu(kvm, iter->vcpu_id);

	if (iter->intid < VGIC_NR_PRIVATE_IRQS)
	irq = vgic_get_vcpu_irq(vcpu, iter->intid);
	else
	irq = vgic_get_irq(kvm, iter->intid);

	if (!irq)
	return 0;

	raw_spin_lock_irqsave(&irq->irq_lock, flags);
	print_irq_state(s, irq, vcpu);
	raw_spin_unlock_irqrestore(&irq->irq_lock, flags);

	vgic_put_irq(kvm, irq);
	return 0;
	}

	static const struct seq_operations vgic_debug_sops = {
	.start = vgic_debug_start,
	.next = vgic_debug_next,
	.stop = vgic_debug_stop,
	.show = vgic_debug_show
	};

	DEFINE_SEQ_ATTRIBUTE(vgic_debug);

	void vgic_debug_init(struct kvm *kvm)
	{
	debugfs_create_file("vgic-state", 0444, kvm->debugfs_dentry, kvm,
	&vgic_debug_fops);
	}

	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_obj(*iter);
	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 (!ite)
	return 0;

	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->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)
	{
	}