vgic-debug.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (C) 2016 Linaro
  4 * Author: Christoffer Dall <christoffer.dall@linaro.org>
  5 */
  6
  7#include <linux/cpu.h>
  8#include <linux/debugfs.h>
  9#include <linux/interrupt.h>
 10#include <linux/kvm_host.h>
 11#include <linux/seq_file.h>
 12#include <kvm/arm_vgic.h>
 13#include <asm/kvm_mmu.h>
 14#include "vgic.h"
 15
 16/*
 17 * Structure to control looping through the entire vgic state.  We start at
 18 * zero for each field and move upwards.  So, if dist_id is 0 we print the
 19 * distributor info.  When dist_id is 1, we have already printed it and move
 20 * on.
 21 *
 22 * When vcpu_id < nr_cpus we print the vcpu info until vcpu_id == nr_cpus and
 23 * so on.
 24 */
 25struct vgic_state_iter {
 26	int nr_cpus;
 27	int nr_spis;
 28	int nr_lpis;
 29	int dist_id;
 30	int vcpu_id;
 31	unsigned long intid;
 32	int lpi_idx;
 33};
 34
 35static void iter_next(struct kvm *kvm, struct vgic_state_iter *iter)
 36{
 37	struct vgic_dist *dist = &kvm->arch.vgic;
 38
 39	if (iter->dist_id == 0) {
 40		iter->dist_id++;
 41		return;
 42	}
 43
 44	/*
 45	 * Let the xarray drive the iterator after the last SPI, as the iterator
 46	 * has exhausted the sequentially-allocated INTID space.
 47	 */
 48	if (iter->intid >= (iter->nr_spis + VGIC_NR_PRIVATE_IRQS - 1) &&
 49	    iter->nr_lpis) {
 50		if (iter->lpi_idx < iter->nr_lpis)
 51			xa_find_after(&dist->lpi_xa, &iter->intid,
 52				      VGIC_LPI_MAX_INTID,
 53				      LPI_XA_MARK_DEBUG_ITER);
 54		iter->lpi_idx++;
 55		return;
 56	}
 57
 58	iter->intid++;
 59	if (iter->intid == VGIC_NR_PRIVATE_IRQS &&
 60	    ++iter->vcpu_id < iter->nr_cpus)
 61		iter->intid = 0;
 62}
 63
 64static int iter_mark_lpis(struct kvm *kvm)
 65{
 66	struct vgic_dist *dist = &kvm->arch.vgic;
 67	unsigned long intid, flags;
 68	struct vgic_irq *irq;
 69	int nr_lpis = 0;
 70
 71	xa_lock_irqsave(&dist->lpi_xa, flags);
 72
 73	xa_for_each(&dist->lpi_xa, intid, irq) {
 74		if (!vgic_try_get_irq_ref(irq))
 75			continue;
 76
 77		__xa_set_mark(&dist->lpi_xa, intid, LPI_XA_MARK_DEBUG_ITER);
 78		nr_lpis++;
 79	}
 80
 81	xa_unlock_irqrestore(&dist->lpi_xa, flags);
 82
 83	return nr_lpis;
 84}
 85
 86static void iter_unmark_lpis(struct kvm *kvm)
 87{
 88	struct vgic_dist *dist = &kvm->arch.vgic;
 89	unsigned long intid, flags;
 90	struct vgic_irq *irq;
 91
 92	xa_for_each_marked(&dist->lpi_xa, intid, irq, LPI_XA_MARK_DEBUG_ITER) {
 93		xa_lock_irqsave(&dist->lpi_xa, flags);
 94		__xa_clear_mark(&dist->lpi_xa, intid, LPI_XA_MARK_DEBUG_ITER);
 95		xa_unlock_irqrestore(&dist->lpi_xa, flags);
 96
 97		/* vgic_put_irq() expects to be called outside of the xa_lock */
 98		vgic_put_irq(kvm, irq);
 99	}
100}
101
102static void iter_init(struct kvm *kvm, struct vgic_state_iter *iter,
103		      loff_t pos)
104{
105	int nr_cpus = atomic_read(&kvm->online_vcpus);
106
107	memset(iter, 0, sizeof(*iter));
108
109	iter->nr_cpus = nr_cpus;
110	iter->nr_spis = kvm->arch.vgic.nr_spis;
111	if (kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3)
112		iter->nr_lpis = iter_mark_lpis(kvm);
113
114	/* Fast forward to the right position if needed */
115	while (pos--)
116		iter_next(kvm, iter);
117}
118
119static bool end_of_vgic(struct vgic_state_iter *iter)
120{
121	return iter->dist_id > 0 &&
122		iter->vcpu_id == iter->nr_cpus &&
123		iter->intid >= (iter->nr_spis + VGIC_NR_PRIVATE_IRQS) &&
124		(!iter->nr_lpis || iter->lpi_idx > iter->nr_lpis);
125}
126
127static void *vgic_debug_start(struct seq_file *s, loff_t *pos)
128{
129	struct kvm *kvm = s->private;
130	struct vgic_state_iter *iter;
131
132	mutex_lock(&kvm->arch.config_lock);
133	iter = kvm->arch.vgic.iter;
134	if (iter) {
135		iter = ERR_PTR(-EBUSY);
136		goto out;
137	}
138
139	iter = kmalloc(sizeof(*iter), GFP_KERNEL);
140	if (!iter) {
141		iter = ERR_PTR(-ENOMEM);
142		goto out;
143	}
144
145	iter_init(kvm, iter, *pos);
146	kvm->arch.vgic.iter = iter;
147
148	if (end_of_vgic(iter))
149		iter = NULL;
150out:
151	mutex_unlock(&kvm->arch.config_lock);
152	return iter;
153}
154
155static void *vgic_debug_next(struct seq_file *s, void *v, loff_t *pos)
156{
157	struct kvm *kvm = s->private;
158	struct vgic_state_iter *iter = kvm->arch.vgic.iter;
159
160	++*pos;
161	iter_next(kvm, iter);
162	if (end_of_vgic(iter))
163		iter = NULL;
164	return iter;
165}
166
167static void vgic_debug_stop(struct seq_file *s, void *v)
168{
169	struct kvm *kvm = s->private;
170	struct vgic_state_iter *iter;
171
172	/*
173	 * If the seq file wasn't properly opened, there's nothing to clearn
174	 * up.
175	 */
176	if (IS_ERR(v))
177		return;
178
179	mutex_lock(&kvm->arch.config_lock);
180	iter = kvm->arch.vgic.iter;
181	iter_unmark_lpis(kvm);
182	kfree(iter);
183	kvm->arch.vgic.iter = NULL;
184	mutex_unlock(&kvm->arch.config_lock);
185}
186
187static void print_dist_state(struct seq_file *s, struct vgic_dist *dist,
188			     struct vgic_state_iter *iter)
189{
190	bool v3 = dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3;
191
192	seq_printf(s, "Distributor\n");
193	seq_printf(s, "===========\n");
194	seq_printf(s, "vgic_model:\t%s\n", v3 ? "GICv3" : "GICv2");
195	seq_printf(s, "nr_spis:\t%d\n", dist->nr_spis);
196	if (v3)
197		seq_printf(s, "nr_lpis:\t%d\n", iter->nr_lpis);
198	seq_printf(s, "enabled:\t%d\n", dist->enabled);
199	seq_printf(s, "\n");
200
201	seq_printf(s, "P=pending_latch, L=line_level, A=active\n");
202	seq_printf(s, "E=enabled, H=hw, C=config (level=1, edge=0)\n");
203	seq_printf(s, "G=group\n");
204}
205
206static void print_header(struct seq_file *s, struct vgic_irq *irq,
207			 struct kvm_vcpu *vcpu)
208{
209	int id = 0;
210	char *hdr = "SPI ";
211
212	if (vcpu) {
213		hdr = "VCPU";
214		id = vcpu->vcpu_idx;
215	}
216
217	seq_printf(s, "\n");
218	seq_printf(s, "%s%2d TYP   ID TGT_ID PLAEHCG     HWID   TARGET SRC PRI VCPU_ID\n", hdr, id);
219	seq_printf(s, "----------------------------------------------------------------\n");
220}
221
222static void print_irq_state(struct seq_file *s, struct vgic_irq *irq,
223			    struct kvm_vcpu *vcpu)
224{
225	char *type;
226	bool pending;
227
228	if (irq->intid < VGIC_NR_SGIS)
229		type = "SGI";
230	else if (irq->intid < VGIC_NR_PRIVATE_IRQS)
231		type = "PPI";
232	else if (irq->intid < VGIC_MAX_SPI)
233		type = "SPI";
234	else
235		type = "LPI";
236
237	if (irq->intid ==0 || irq->intid == VGIC_NR_PRIVATE_IRQS)
238		print_header(s, irq, vcpu);
239
240	pending = irq->pending_latch;
241	if (irq->hw && vgic_irq_is_sgi(irq->intid)) {
242		int err;
243
244		err = irq_get_irqchip_state(irq->host_irq,
245					    IRQCHIP_STATE_PENDING,
246					    &pending);
247		WARN_ON_ONCE(err);
248	}
249
250	seq_printf(s, "       %s %4d "
251		      "    %2d "
252		      "%d%d%d%d%d%d%d "
253		      "%8d "
254		      "%8x "
255		      " %2x "
256		      "%3d "
257		      "     %2d "
258		      "\n",
259			type, irq->intid,
260			(irq->target_vcpu) ? irq->target_vcpu->vcpu_idx : -1,
261			pending,
262			irq->line_level,
263			irq->active,
264			irq->enabled,
265			irq->hw,
266			irq->config == VGIC_CONFIG_LEVEL,
267			irq->group,
268			irq->hwintid,
269			irq->mpidr,
270			irq->source,
271			irq->priority,
272			(irq->vcpu) ? irq->vcpu->vcpu_idx : -1);
273}
274
275static int vgic_debug_show(struct seq_file *s, void *v)
276{
277	struct kvm *kvm = s->private;
278	struct vgic_state_iter *iter = v;
279	struct vgic_irq *irq;
280	struct kvm_vcpu *vcpu = NULL;
281	unsigned long flags;
282
283	if (iter->dist_id == 0) {
284		print_dist_state(s, &kvm->arch.vgic, iter);
285		return 0;
286	}
287
288	if (!kvm->arch.vgic.initialized)
289		return 0;
290
291	if (iter->vcpu_id < iter->nr_cpus)
292		vcpu = kvm_get_vcpu(kvm, iter->vcpu_id);
293
294	/*
295	 * Expect this to succeed, as iter_mark_lpis() takes a reference on
296	 * every LPI to be visited.
297	 */
298	if (iter->intid < VGIC_NR_PRIVATE_IRQS)
299		irq = vgic_get_vcpu_irq(vcpu, iter->intid);
300	else
301		irq = vgic_get_irq(kvm, iter->intid);
302	if (WARN_ON_ONCE(!irq))
303		return -EINVAL;
304
305	raw_spin_lock_irqsave(&irq->irq_lock, flags);
306	print_irq_state(s, irq, vcpu);
307	raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
308
309	vgic_put_irq(kvm, irq);
310	return 0;
311}
312
313static const struct seq_operations vgic_debug_sops = {
314	.start = vgic_debug_start,
315	.next  = vgic_debug_next,
316	.stop  = vgic_debug_stop,
317	.show  = vgic_debug_show
318};
319
320DEFINE_SEQ_ATTRIBUTE(vgic_debug);
321
322void vgic_debug_init(struct kvm *kvm)
323{
324	debugfs_create_file("vgic-state", 0444, kvm->debugfs_dentry, kvm,
325			    &vgic_debug_fops);
326}
327
328void vgic_debug_destroy(struct kvm *kvm)
329{
330}
331
332/**
333 * struct vgic_its_iter - Iterator for traversing VGIC ITS device tables.
334 * @dev: Pointer to the current its_device being processed.
335 * @ite: Pointer to the current its_ite within the device being processed.
336 *
337 * This structure is used to maintain the current position during iteration
338 * over the ITS device tables. It holds pointers to both the current device
339 * and the current ITE within that device.
340 */
341struct vgic_its_iter {
342	struct its_device *dev;
343	struct its_ite *ite;
344};
345
346/**
347 * end_of_iter - Checks if the iterator has reached the end.
348 * @iter: The iterator to check.
349 *
350 * When the iterator completed processing the final ITE in the last device
351 * table, it was marked to indicate the end of iteration by setting its
352 * device and ITE pointers to NULL.
353 * This function checks whether the iterator was marked as end.
354 *
355 * Return: True if the iterator is marked as end, false otherwise.
356 */
357static inline bool end_of_iter(struct vgic_its_iter *iter)
358{
359	return !iter->dev && !iter->ite;
360}
361
362/**
363 * vgic_its_iter_next - Advances the iterator to the next entry in the ITS tables.
364 * @its: The VGIC ITS structure.
365 * @iter: The iterator to advance.
366 *
367 * This function moves the iterator to the next ITE within the current device,
368 * or to the first ITE of the next device if the current ITE is the last in
369 * the device. If the current device is the last device, the iterator is set
370 * to indicate the end of iteration.
371 */
372static void vgic_its_iter_next(struct vgic_its *its, struct vgic_its_iter *iter)
373{
374	struct its_device *dev = iter->dev;
375	struct its_ite *ite = iter->ite;
376
377	if (!ite || list_is_last(&ite->ite_list, &dev->itt_head)) {
378		if (list_is_last(&dev->dev_list, &its->device_list)) {
379			dev = NULL;
380			ite = NULL;
381		} else {
382			dev = list_next_entry(dev, dev_list);
383			ite = list_first_entry_or_null(&dev->itt_head,
384						       struct its_ite,
385						       ite_list);
386		}
387	} else {
388		ite = list_next_entry(ite, ite_list);
389	}
390
391	iter->dev = dev;
392	iter->ite = ite;
393}
394
395/**
396 * vgic_its_debug_start - Start function for the seq_file interface.
397 * @s: The seq_file structure.
398 * @pos: The starting position (offset).
399 *
400 * This function initializes the iterator to the beginning of the ITS tables
401 * and advances it to the specified position. It acquires the its_lock mutex
402 * to protect shared data.
403 *
404 * Return: An iterator pointer on success, NULL if no devices are found or
405 *         the end of the list is reached, or ERR_PTR(-ENOMEM) on memory
406 *         allocation failure.
407 */
408static void *vgic_its_debug_start(struct seq_file *s, loff_t *pos)
409{
410	struct vgic_its *its = s->private;
411	struct vgic_its_iter *iter;
412	struct its_device *dev;
413	loff_t offset = *pos;
414
415	mutex_lock(&its->its_lock);
416
417	dev = list_first_entry_or_null(&its->device_list,
418				       struct its_device, dev_list);
419	if (!dev)
420		return NULL;
421
422	iter = kmalloc(sizeof(*iter), GFP_KERNEL);
423	if (!iter)
424		return ERR_PTR(-ENOMEM);
425
426	iter->dev = dev;
427	iter->ite = list_first_entry_or_null(&dev->itt_head,
428					     struct its_ite, ite_list);
429
430	while (!end_of_iter(iter) && offset--)
431		vgic_its_iter_next(its, iter);
432
433	if (end_of_iter(iter)) {
434		kfree(iter);
435		return NULL;
436	}
437
438	return iter;
439}
440
441/**
442 * vgic_its_debug_next - Next function for the seq_file interface.
443 * @s: The seq_file structure.
444 * @v: The current iterator.
445 * @pos: The current position (offset).
446 *
447 * This function advances the iterator to the next entry and increments the
448 * position.
449 *
450 * Return: An iterator pointer on success, or NULL if the end of the list is
451 *         reached.
452 */
453static void *vgic_its_debug_next(struct seq_file *s, void *v, loff_t *pos)
454{
455	struct vgic_its *its = s->private;
456	struct vgic_its_iter *iter = v;
457
458	++*pos;
459	vgic_its_iter_next(its, iter);
460
461	if (end_of_iter(iter)) {
462		kfree(iter);
463		return NULL;
464	}
465	return iter;
466}
467
468/**
469 * vgic_its_debug_stop - Stop function for the seq_file interface.
470 * @s: The seq_file structure.
471 * @v: The current iterator.
472 *
473 * This function frees the iterator and releases the its_lock mutex.
474 */
475static void vgic_its_debug_stop(struct seq_file *s, void *v)
476{
477	struct vgic_its *its = s->private;
478	struct vgic_its_iter *iter = v;
479
480	if (!IS_ERR_OR_NULL(iter))
481		kfree(iter);
482	mutex_unlock(&its->its_lock);
483}
484
485/**
486 * vgic_its_debug_show - Show function for the seq_file interface.
487 * @s: The seq_file structure.
488 * @v: The current iterator.
489 *
490 * This function formats and prints the ITS table entry information to the
491 * seq_file output.
492 *
493 * Return: 0 on success.
494 */
495static int vgic_its_debug_show(struct seq_file *s, void *v)
496{
497	struct vgic_its_iter *iter = v;
498	struct its_device *dev = iter->dev;
499	struct its_ite *ite = iter->ite;
500
501	if (!ite)
502		return 0;
503
504	if (list_is_first(&ite->ite_list, &dev->itt_head)) {
505		seq_printf(s, "\n");
506		seq_printf(s, "Device ID: 0x%x, Event ID Range: [0 - %llu]\n",
507			   dev->device_id, BIT_ULL(dev->num_eventid_bits) - 1);
508		seq_printf(s, "EVENT_ID    INTID  HWINTID   TARGET   COL_ID HW\n");
509		seq_printf(s, "-----------------------------------------------\n");
510	}
511
512	if (ite->irq && ite->collection) {
513		seq_printf(s, "%8u %8u %8u %8u %8u %2d\n",
514			   ite->event_id, ite->irq->intid, ite->irq->hwintid,
515			   ite->collection->target_addr,
516			   ite->collection->collection_id, ite->irq->hw);
517	}
518
519	return 0;
520}
521
522static const struct seq_operations vgic_its_debug_sops = {
523	.start = vgic_its_debug_start,
524	.next  = vgic_its_debug_next,
525	.stop  = vgic_its_debug_stop,
526	.show  = vgic_its_debug_show
527};
528
529DEFINE_SEQ_ATTRIBUTE(vgic_its_debug);
530
531/**
532 * vgic_its_debug_init - Initializes the debugfs interface for VGIC ITS.
533 * @dev: The KVM device structure.
534 *
535 * This function creates a debugfs file named "vgic-its-state@%its_base"
536 * to expose the ITS table information.
537 *
538 * Return: 0 on success.
539 */
540int vgic_its_debug_init(struct kvm_device *dev)
541{
542	struct vgic_its *its = dev->private;
543	char *name;
544
545	name = kasprintf(GFP_KERNEL, "vgic-its-state@%llx", (u64)its->vgic_its_base);
546	if (!name)
547		return -ENOMEM;
548
549	debugfs_create_file(name, 0444, dev->kvm->debugfs_dentry, its, &vgic_its_debug_fops);
550
551	kfree(name);
552	return 0;
553}
554
555void vgic_its_debug_destroy(struct kvm_device *dev)
556{
557}