summaryrefslogtreecommitdiffstats
path: root/drivers/virt/acrn/ioreq.c
blob: 5ff1c53740c00ba31b49eb1057662d907f6b7c98 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
// SPDX-License-Identifier: GPL-2.0
/*
 * ACRN_HSM: Handle I/O requests
 *
 * Copyright (C) 2020 Intel Corporation. All rights reserved.
 *
 * Authors:
 *	Jason Chen CJ <jason.cj.chen@intel.com>
 *	Fengwei Yin <fengwei.yin@intel.com>
 */

#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kthread.h>
#include <linux/mm.h>
#include <linux/slab.h>

#include <asm/acrn.h>

#include "acrn_drv.h"

static void ioreq_pause(void);
static void ioreq_resume(void);

static void ioreq_dispatcher(struct work_struct *work);
static struct workqueue_struct *ioreq_wq;
static DECLARE_WORK(ioreq_work, ioreq_dispatcher);

static inline bool has_pending_request(struct acrn_ioreq_client *client)
{
	return !bitmap_empty(client->ioreqs_map, ACRN_IO_REQUEST_MAX);
}

static inline bool is_destroying(struct acrn_ioreq_client *client)
{
	return test_bit(ACRN_IOREQ_CLIENT_DESTROYING, &client->flags);
}

static int ioreq_complete_request(struct acrn_vm *vm, u16 vcpu,
				  struct acrn_io_request *acrn_req)
{
	bool polling_mode;
	int ret = 0;

	polling_mode = acrn_req->completion_polling;
	/* Add barrier() to make sure the writes are done before completion */
	smp_store_release(&acrn_req->processed, ACRN_IOREQ_STATE_COMPLETE);

	/*
	 * To fulfill the requirement of real-time in several industry
	 * scenarios, like automotive, ACRN can run under the partition mode,
	 * in which User VMs and Service VM are bound to dedicated CPU cores.
	 * Polling mode of handling the I/O request is introduced to achieve a
	 * faster I/O request handling. In polling mode, the hypervisor polls
	 * I/O request's completion. Once an I/O request is marked as
	 * ACRN_IOREQ_STATE_COMPLETE, hypervisor resumes from the polling point
	 * to continue the I/O request flow. Thus, the completion notification
	 * from HSM of I/O request is not needed.  Please note,
	 * completion_polling needs to be read before the I/O request being
	 * marked as ACRN_IOREQ_STATE_COMPLETE to avoid racing with the
	 * hypervisor.
	 */
	if (!polling_mode) {
		ret = hcall_notify_req_finish(vm->vmid, vcpu);
		if (ret < 0)
			dev_err(acrn_dev.this_device,
				"Notify I/O request finished failed!\n");
	}

	return ret;
}

static int acrn_ioreq_complete_request(struct acrn_ioreq_client *client,
				       u16 vcpu,
				       struct acrn_io_request *acrn_req)
{
	int ret;

	if (vcpu >= client->vm->vcpu_num)
		return -EINVAL;

	clear_bit(vcpu, client->ioreqs_map);
	if (!acrn_req) {
		acrn_req = (struct acrn_io_request *)client->vm->ioreq_buf;
		acrn_req += vcpu;
	}

	ret = ioreq_complete_request(client->vm, vcpu, acrn_req);

	return ret;
}

int acrn_ioreq_request_default_complete(struct acrn_vm *vm, u16 vcpu)
{
	int ret = 0;

	spin_lock_bh(&vm->ioreq_clients_lock);
	if (vm->default_client)
		ret = acrn_ioreq_complete_request(vm->default_client,
						  vcpu, NULL);
	spin_unlock_bh(&vm->ioreq_clients_lock);

	return ret;
}

/**
 * acrn_ioreq_range_add() - Add an iorange monitored by an ioreq client
 * @client:	The ioreq client
 * @type:	Type (ACRN_IOREQ_TYPE_MMIO or ACRN_IOREQ_TYPE_PORTIO)
 * @start:	Start address of iorange
 * @end:	End address of iorange
 *
 * Return: 0 on success, <0 on error
 */
int acrn_ioreq_range_add(struct acrn_ioreq_client *client,
			 u32 type, u64 start, u64 end)
{
	struct acrn_ioreq_range *range;

	if (end < start) {
		dev_err(acrn_dev.this_device,
			"Invalid IO range [0x%llx,0x%llx]\n", start, end);
		return -EINVAL;
	}

	range = kzalloc(sizeof(*range), GFP_KERNEL);
	if (!range)
		return -ENOMEM;

	range->type = type;
	range->start = start;
	range->end = end;

	write_lock_bh(&client->range_lock);
	list_add(&range->list, &client->range_list);
	write_unlock_bh(&client->range_lock);

	return 0;
}

/**
 * acrn_ioreq_range_del() - Del an iorange monitored by an ioreq client
 * @client:	The ioreq client
 * @type:	Type (ACRN_IOREQ_TYPE_MMIO or ACRN_IOREQ_TYPE_PORTIO)
 * @start:	Start address of iorange
 * @end:	End address of iorange
 */
void acrn_ioreq_range_del(struct acrn_ioreq_client *client,
			  u32 type, u64 start, u64 end)
{
	struct acrn_ioreq_range *range;

	write_lock_bh(&client->range_lock);
	list_for_each_entry(range, &client->range_list, list) {
		if (type == range->type &&
		    start == range->start &&
		    end == range->end) {
			list_del(&range->list);
			kfree(range);
			break;
		}
	}
	write_unlock_bh(&client->range_lock);
}

/*
 * ioreq_task() is the execution entity of handler thread of an I/O client.
 * The handler callback of the I/O client is called within the handler thread.
 */
static int ioreq_task(void *data)
{
	struct acrn_ioreq_client *client = data;
	struct acrn_io_request *req;
	unsigned long *ioreqs_map;
	int vcpu, ret;

	/*
	 * Lockless access to ioreqs_map is safe, because
	 * 1) set_bit() and clear_bit() are atomic operations.
	 * 2) I/O requests arrives serialized. The access flow of ioreqs_map is:
	 *	set_bit() - in ioreq_work handler
	 *	Handler callback handles corresponding I/O request
	 *	clear_bit() - in handler thread (include ACRN userspace)
	 *	Mark corresponding I/O request completed
	 *	Loop again if a new I/O request occurs
	 */
	ioreqs_map = client->ioreqs_map;
	while (!kthread_should_stop()) {
		acrn_ioreq_client_wait(client);
		while (has_pending_request(client)) {
			vcpu = find_first_bit(ioreqs_map, client->vm->vcpu_num);
			req = client->vm->ioreq_buf->req_slot + vcpu;
			ret = client->handler(client, req);
			if (ret < 0) {
				dev_err(acrn_dev.this_device,
					"IO handle failure: %d\n", ret);
				break;
			}
			acrn_ioreq_complete_request(client, vcpu, req);
		}
	}

	return 0;
}

/*
 * For the non-default I/O clients, give them chance to complete the current
 * I/O requests if there are any. For the default I/O client, it is safe to
 * clear all pending I/O requests because the clearing request is from ACRN
 * userspace.
 */
void acrn_ioreq_request_clear(struct acrn_vm *vm)
{
	struct acrn_ioreq_client *client;
	bool has_pending = false;
	unsigned long vcpu;
	int retry = 10;

	/*
	 * IO requests of this VM will be completed directly in
	 * acrn_ioreq_dispatch if ACRN_VM_FLAG_CLEARING_IOREQ flag is set.
	 */
	set_bit(ACRN_VM_FLAG_CLEARING_IOREQ, &vm->flags);

	/*
	 * acrn_ioreq_request_clear is only called in VM reset case. Simply
	 * wait 100ms in total for the IO requests' completion.
	 */
	do {
		spin_lock_bh(&vm->ioreq_clients_lock);
		list_for_each_entry(client, &vm->ioreq_clients, list) {
			has_pending = has_pending_request(client);
			if (has_pending)
				break;
		}
		spin_unlock_bh(&vm->ioreq_clients_lock);

		if (has_pending)
			schedule_timeout_interruptible(HZ / 100);
	} while (has_pending && --retry > 0);
	if (retry == 0)
		dev_warn(acrn_dev.this_device,
			 "%s cannot flush pending request!\n", client->name);

	/* Clear all ioreqs belonging to the default client */
	spin_lock_bh(&vm->ioreq_clients_lock);
	client = vm->default_client;
	if (client) {
		vcpu = find_first_bit(client->ioreqs_map, ACRN_IO_REQUEST_MAX);
		while (vcpu < ACRN_IO_REQUEST_MAX) {
			acrn_ioreq_complete_request(client, vcpu, NULL);
			vcpu = find_next_bit(client->ioreqs_map,
					     ACRN_IO_REQUEST_MAX, vcpu + 1);
		}
	}
	spin_unlock_bh(&vm->ioreq_clients_lock);

	/* Clear ACRN_VM_FLAG_CLEARING_IOREQ flag after the clearing */
	clear_bit(ACRN_VM_FLAG_CLEARING_IOREQ, &vm->flags);
}

int acrn_ioreq_client_wait(struct acrn_ioreq_client *client)
{
	if (client->is_default) {
		/*
		 * In the default client, a user space thread waits on the
		 * waitqueue. The is_destroying() check is used to notify user
		 * space the client is going to be destroyed.
		 */
		wait_event_interruptible(client->wq,
					 has_pending_request(client) ||
					 is_destroying(client));
		if (is_destroying(client))
			return -ENODEV;
	} else {
		wait_event_interruptible(client->wq,
					 has_pending_request(client) ||
					 kthread_should_stop());
	}

	return 0;
}

static bool is_cfg_addr(struct acrn_io_request *req)
{
	return ((req->type == ACRN_IOREQ_TYPE_PORTIO) &&
		(req->reqs.pio_request.address == 0xcf8));
}

static bool is_cfg_data(struct acrn_io_request *req)
{
	return ((req->type == ACRN_IOREQ_TYPE_PORTIO) &&
		((req->reqs.pio_request.address >= 0xcfc) &&
		 (req->reqs.pio_request.address < (0xcfc + 4))));
}

/* The low 8-bit of supported pci_reg addr.*/
#define PCI_LOWREG_MASK  0xFC
/* The high 4-bit of supported pci_reg addr */
#define PCI_HIGHREG_MASK 0xF00
/* Max number of supported functions */
#define PCI_FUNCMAX	7
/* Max number of supported slots */
#define PCI_SLOTMAX	31
/* Max number of supported buses */
#define PCI_BUSMAX	255
#define CONF1_ENABLE	0x80000000UL
/*
 * A PCI configuration space access via PIO 0xCF8 and 0xCFC normally has two
 * following steps:
 *   1) writes address into 0xCF8 port
 *   2) accesses data in/from 0xCFC
 * This function combines such paired PCI configuration space I/O requests into
 * one ACRN_IOREQ_TYPE_PCICFG type I/O request and continues the processing.
 */
static bool handle_cf8cfc(struct acrn_vm *vm,
			  struct acrn_io_request *req, u16 vcpu)
{
	int offset, pci_cfg_addr, pci_reg;
	bool is_handled = false;

	if (is_cfg_addr(req)) {
		WARN_ON(req->reqs.pio_request.size != 4);
		if (req->reqs.pio_request.direction == ACRN_IOREQ_DIR_WRITE)
			vm->pci_conf_addr = req->reqs.pio_request.value;
		else
			req->reqs.pio_request.value = vm->pci_conf_addr;
		is_handled = true;
	} else if (is_cfg_data(req)) {
		if (!(vm->pci_conf_addr & CONF1_ENABLE)) {
			if (req->reqs.pio_request.direction ==
					ACRN_IOREQ_DIR_READ)
				req->reqs.pio_request.value = 0xffffffff;
			is_handled = true;
		} else {
			offset = req->reqs.pio_request.address - 0xcfc;

			req->type = ACRN_IOREQ_TYPE_PCICFG;
			pci_cfg_addr = vm->pci_conf_addr;
			req->reqs.pci_request.bus =
					(pci_cfg_addr >> 16) & PCI_BUSMAX;
			req->reqs.pci_request.dev =
					(pci_cfg_addr >> 11) & PCI_SLOTMAX;
			req->reqs.pci_request.func =
					(pci_cfg_addr >> 8) & PCI_FUNCMAX;
			pci_reg = (pci_cfg_addr & PCI_LOWREG_MASK) +
				   ((pci_cfg_addr >> 16) & PCI_HIGHREG_MASK);
			req->reqs.pci_request.reg = pci_reg + offset;
		}
	}

	if (is_handled)
		ioreq_complete_request(vm, vcpu, req);

	return is_handled;
}

static bool in_range(struct acrn_ioreq_range *range,
		     struct acrn_io_request *req)
{
	bool ret = false;

	if (range->type == req->type) {
		switch (req->type) {
		case ACRN_IOREQ_TYPE_MMIO:
			if (req->reqs.mmio_request.address >= range->start &&
			    (req->reqs.mmio_request.address +
			     req->reqs.mmio_request.size - 1) <= range->end)
				ret = true;
			break;
		case ACRN_IOREQ_TYPE_PORTIO:
			if (req->reqs.pio_request.address >= range->start &&
			    (req->reqs.pio_request.address +
			     req->reqs.pio_request.size - 1) <= range->end)
				ret = true;
			break;
		default:
			break;
		}
	}

	return ret;
}

static struct acrn_ioreq_client *find_ioreq_client(struct acrn_vm *vm,
						   struct acrn_io_request *req)
{
	struct acrn_ioreq_client *client, *found = NULL;
	struct acrn_ioreq_range *range;

	lockdep_assert_held(&vm->ioreq_clients_lock);

	list_for_each_entry(client, &vm->ioreq_clients, list) {
		read_lock_bh(&client->range_lock);
		list_for_each_entry(range, &client->range_list, list) {
			if (in_range(range, req)) {
				found = client;
				break;
			}
		}
		read_unlock_bh(&client->range_lock);
		if (found)
			break;
	}
	return found ? found : vm->default_client;
}

/**
 * acrn_ioreq_client_create() - Create an ioreq client
 * @vm:		The VM that this client belongs to
 * @handler:	The ioreq_handler of ioreq client acrn_hsm will create a kernel
 *		thread and call the handler to handle I/O requests.
 * @priv:	Private data for the handler
 * @is_default:	If it is the default client
 * @name:	The name of ioreq client
 *
 * Return: acrn_ioreq_client pointer on success, NULL on error
 */
struct acrn_ioreq_client *acrn_ioreq_client_create(struct acrn_vm *vm,
						   ioreq_handler_t handler,
						   void *priv, bool is_default,
						   const char *name)
{
	struct acrn_ioreq_client *client;

	if (!handler && !is_default) {
		dev_dbg(acrn_dev.this_device,
			"Cannot create non-default client w/o handler!\n");
		return NULL;
	}
	client = kzalloc(sizeof(*client), GFP_KERNEL);
	if (!client)
		return NULL;

	client->handler = handler;
	client->vm = vm;
	client->priv = priv;
	client->is_default = is_default;
	if (name)
		strncpy(client->name, name, sizeof(client->name) - 1);
	rwlock_init(&client->range_lock);
	INIT_LIST_HEAD(&client->range_list);
	init_waitqueue_head(&client->wq);

	if (client->handler) {
		client->thread = kthread_run(ioreq_task, client, "VM%u-%s",
					     client->vm->vmid, client->name);
		if (IS_ERR(client->thread)) {
			kfree(client);
			return NULL;
		}
	}

	spin_lock_bh(&vm->ioreq_clients_lock);
	if (is_default)
		vm->default_client = client;
	else
		list_add(&client->list, &vm->ioreq_clients);
	spin_unlock_bh(&vm->ioreq_clients_lock);

	dev_dbg(acrn_dev.this_device, "Created ioreq client %s.\n", name);
	return client;
}

/**
 * acrn_ioreq_client_destroy() - Destroy an ioreq client
 * @client:	The ioreq client
 */
void acrn_ioreq_client_destroy(struct acrn_ioreq_client *client)
{
	struct acrn_ioreq_range *range, *next;
	struct acrn_vm *vm = client->vm;

	dev_dbg(acrn_dev.this_device,
		"Destroy ioreq client %s.\n", client->name);
	ioreq_pause();
	set_bit(ACRN_IOREQ_CLIENT_DESTROYING, &client->flags);
	if (client->is_default)
		wake_up_interruptible(&client->wq);
	else
		kthread_stop(client->thread);

	spin_lock_bh(&vm->ioreq_clients_lock);
	if (client->is_default)
		vm->default_client = NULL;
	else
		list_del(&client->list);
	spin_unlock_bh(&vm->ioreq_clients_lock);

	write_lock_bh(&client->range_lock);
	list_for_each_entry_safe(range, next, &client->range_list, list) {
		list_del(&range->list);
		kfree(range);
	}
	write_unlock_bh(&client->range_lock);
	kfree(client);

	ioreq_resume();
}

static int acrn_ioreq_dispatch(struct acrn_vm *vm)
{
	struct acrn_ioreq_client *client;
	struct acrn_io_request *req;
	int i;

	for (i = 0; i < vm->vcpu_num; i++) {
		req = vm->ioreq_buf->req_slot + i;

		/* barrier the read of processed of acrn_io_request */
		if (smp_load_acquire(&req->processed) ==
				     ACRN_IOREQ_STATE_PENDING) {
			/* Complete the IO request directly in clearing stage */
			if (test_bit(ACRN_VM_FLAG_CLEARING_IOREQ, &vm->flags)) {
				ioreq_complete_request(vm, i, req);
				continue;
			}
			if (handle_cf8cfc(vm, req, i))
				continue;

			spin_lock_bh(&vm->ioreq_clients_lock);
			client = find_ioreq_client(vm, req);
			if (!client) {
				dev_err(acrn_dev.this_device,
					"Failed to find ioreq client!\n");
				spin_unlock_bh(&vm->ioreq_clients_lock);
				return -EINVAL;
			}
			if (!client->is_default)
				req->kernel_handled = 1;
			else
				req->kernel_handled = 0;
			/*
			 * Add barrier() to make sure the writes are done
			 * before setting ACRN_IOREQ_STATE_PROCESSING
			 */
			smp_store_release(&req->processed,
					  ACRN_IOREQ_STATE_PROCESSING);
			set_bit(i, client->ioreqs_map);
			wake_up_interruptible(&client->wq);
			spin_unlock_bh(&vm->ioreq_clients_lock);
		}
	}

	return 0;
}

static void ioreq_dispatcher(struct work_struct *work)
{
	struct acrn_vm *vm;

	read_lock(&acrn_vm_list_lock);
	list_for_each_entry(vm, &acrn_vm_list, list) {
		if (!vm->ioreq_buf)
			break;
		acrn_ioreq_dispatch(vm);
	}
	read_unlock(&acrn_vm_list_lock);
}

static void ioreq_intr_handler(void)
{
	queue_work(ioreq_wq, &ioreq_work);
}

static void ioreq_pause(void)
{
	/* Flush and unarm the handler to ensure no I/O requests pending */
	acrn_remove_intr_handler();
	drain_workqueue(ioreq_wq);
}

static void ioreq_resume(void)
{
	/* Schedule after enabling in case other clients miss interrupt */
	acrn_setup_intr_handler(ioreq_intr_handler);
	queue_work(ioreq_wq, &ioreq_work);
}

int acrn_ioreq_intr_setup(void)
{
	acrn_setup_intr_handler(ioreq_intr_handler);
	ioreq_wq = alloc_workqueue("ioreq_wq",
				   WQ_HIGHPRI | WQ_MEM_RECLAIM | WQ_UNBOUND, 1);
	if (!ioreq_wq) {
		dev_err(acrn_dev.this_device, "Failed to alloc workqueue!\n");
		acrn_remove_intr_handler();
		return -ENOMEM;
	}
	return 0;
}

void acrn_ioreq_intr_remove(void)
{
	if (ioreq_wq)
		destroy_workqueue(ioreq_wq);
	acrn_remove_intr_handler();
}

int acrn_ioreq_init(struct acrn_vm *vm, u64 buf_vma)
{
	struct acrn_ioreq_buffer *set_buffer;
	struct page *page;
	int ret;

	if (vm->ioreq_buf)
		return -EEXIST;

	set_buffer = kzalloc(sizeof(*set_buffer), GFP_KERNEL);
	if (!set_buffer)
		return -ENOMEM;

	ret = pin_user_pages_fast(buf_vma, 1,
				  FOLL_WRITE | FOLL_LONGTERM, &page);
	if (unlikely(ret != 1) || !page) {
		dev_err(acrn_dev.this_device, "Failed to pin ioreq page!\n");
		ret = -EFAULT;
		goto free_buf;
	}

	vm->ioreq_buf = page_address(page);
	vm->ioreq_page = page;
	set_buffer->ioreq_buf = page_to_phys(page);
	ret = hcall_set_ioreq_buffer(vm->vmid, virt_to_phys(set_buffer));
	if (ret < 0) {
		dev_err(acrn_dev.this_device, "Failed to init ioreq buffer!\n");
		unpin_user_page(page);
		vm->ioreq_buf = NULL;
		goto free_buf;
	}

	dev_dbg(acrn_dev.this_device,
		"Init ioreq buffer %pK!\n", vm->ioreq_buf);
	ret = 0;
free_buf:
	kfree(set_buffer);
	return ret;
}

void acrn_ioreq_deinit(struct acrn_vm *vm)
{
	struct acrn_ioreq_client *client, *next;

	dev_dbg(acrn_dev.this_device,
		"Deinit ioreq buffer %pK!\n", vm->ioreq_buf);
	/* Destroy all clients belonging to this VM */
	list_for_each_entry_safe(client, next, &vm->ioreq_clients, list)
		acrn_ioreq_client_destroy(client);
	if (vm->default_client)
		acrn_ioreq_client_destroy(vm->default_client);

	if (vm->ioreq_buf && vm->ioreq_page) {
		unpin_user_page(vm->ioreq_page);
		vm->ioreq_buf = NULL;
	}
}