1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Adjunct processor matrix VFIO device driver callbacks.
4  *
5  * Copyright IBM Corp. 2018
6  *
7  * Author(s): Tony Krowiak <akrowiak@linux.ibm.com>
8  *	      Halil Pasic <pasic@linux.ibm.com>
9  *	      Pierre Morel <pmorel@linux.ibm.com>
10  */
11 #include <linux/string.h>
12 #include <linux/vfio.h>
13 #include <linux/device.h>
14 #include <linux/list.h>
15 #include <linux/ctype.h>
16 #include <linux/bitops.h>
17 #include <linux/kvm_host.h>
18 #include <linux/module.h>
19 #include <asm/kvm.h>
20 #include <asm/zcrypt.h>
21 
22 #include "vfio_ap_private.h"
23 
24 #define VFIO_AP_MDEV_TYPE_HWVIRT "passthrough"
25 #define VFIO_AP_MDEV_NAME_HWVIRT "VFIO AP Passthrough Device"
26 
27 static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev);
28 static struct vfio_ap_queue *vfio_ap_find_queue(int apqn);
29 
30 static int match_apqn(struct device *dev, const void *data)
31 {
32 	struct vfio_ap_queue *q = dev_get_drvdata(dev);
33 
34 	return (q->apqn == *(int *)(data)) ? 1 : 0;
35 }
36 
37 /**
38  * vfio_ap_get_queue: Retrieve a queue with a specific APQN from a list
39  * @matrix_mdev: the associated mediated matrix
40  * @apqn: The queue APQN
41  *
42  * Retrieve a queue with a specific APQN from the list of the
43  * devices of the vfio_ap_drv.
44  * Verify that the APID and the APQI are set in the matrix.
45  *
46  * Returns the pointer to the associated vfio_ap_queue
47  */
48 static struct vfio_ap_queue *vfio_ap_get_queue(
49 					struct ap_matrix_mdev *matrix_mdev,
50 					int apqn)
51 {
52 	struct vfio_ap_queue *q;
53 
54 	if (!test_bit_inv(AP_QID_CARD(apqn), matrix_mdev->matrix.apm))
55 		return NULL;
56 	if (!test_bit_inv(AP_QID_QUEUE(apqn), matrix_mdev->matrix.aqm))
57 		return NULL;
58 
59 	q = vfio_ap_find_queue(apqn);
60 	if (q)
61 		q->matrix_mdev = matrix_mdev;
62 
63 	return q;
64 }
65 
66 /**
67  * vfio_ap_wait_for_irqclear
68  * @apqn: The AP Queue number
69  *
70  * Checks the IRQ bit for the status of this APQN using ap_tapq.
71  * Returns if the ap_tapq function succeeded and the bit is clear.
72  * Returns if ap_tapq function failed with invalid, deconfigured or
73  * checkstopped AP.
74  * Otherwise retries up to 5 times after waiting 20ms.
75  *
76  */
77 static void vfio_ap_wait_for_irqclear(int apqn)
78 {
79 	struct ap_queue_status status;
80 	int retry = 5;
81 
82 	do {
83 		status = ap_tapq(apqn, NULL);
84 		switch (status.response_code) {
85 		case AP_RESPONSE_NORMAL:
86 		case AP_RESPONSE_RESET_IN_PROGRESS:
87 			if (!status.irq_enabled)
88 				return;
89 			fallthrough;
90 		case AP_RESPONSE_BUSY:
91 			msleep(20);
92 			break;
93 		case AP_RESPONSE_Q_NOT_AVAIL:
94 		case AP_RESPONSE_DECONFIGURED:
95 		case AP_RESPONSE_CHECKSTOPPED:
96 		default:
97 			WARN_ONCE(1, "%s: tapq rc %02x: %04x\n", __func__,
98 				  status.response_code, apqn);
99 			return;
100 		}
101 	} while (--retry);
102 
103 	WARN_ONCE(1, "%s: tapq rc %02x: %04x could not clear IR bit\n",
104 		  __func__, status.response_code, apqn);
105 }
106 
107 /**
108  * vfio_ap_free_aqic_resources
109  * @q: The vfio_ap_queue
110  *
111  * Unregisters the ISC in the GIB when the saved ISC not invalid.
112  * Unpin the guest's page holding the NIB when it exist.
113  * Reset the saved_pfn and saved_isc to invalid values.
114  *
115  */
116 static void vfio_ap_free_aqic_resources(struct vfio_ap_queue *q)
117 {
118 	if (!q)
119 		return;
120 	if (q->saved_isc != VFIO_AP_ISC_INVALID &&
121 	    !WARN_ON(!(q->matrix_mdev && q->matrix_mdev->kvm))) {
122 		kvm_s390_gisc_unregister(q->matrix_mdev->kvm, q->saved_isc);
123 		q->saved_isc = VFIO_AP_ISC_INVALID;
124 	}
125 	if (q->saved_pfn && !WARN_ON(!q->matrix_mdev)) {
126 		vfio_unpin_pages(mdev_dev(q->matrix_mdev->mdev),
127 				 &q->saved_pfn, 1);
128 		q->saved_pfn = 0;
129 	}
130 }
131 
132 /**
133  * vfio_ap_irq_disable
134  * @q: The vfio_ap_queue
135  *
136  * Uses ap_aqic to disable the interruption and in case of success, reset
137  * in progress or IRQ disable command already proceeded: calls
138  * vfio_ap_wait_for_irqclear() to check for the IRQ bit to be clear
139  * and calls vfio_ap_free_aqic_resources() to free the resources associated
140  * with the AP interrupt handling.
141  *
142  * In the case the AP is busy, or a reset is in progress,
143  * retries after 20ms, up to 5 times.
144  *
145  * Returns if ap_aqic function failed with invalid, deconfigured or
146  * checkstopped AP.
147  */
148 static struct ap_queue_status vfio_ap_irq_disable(struct vfio_ap_queue *q)
149 {
150 	struct ap_qirq_ctrl aqic_gisa = {};
151 	struct ap_queue_status status;
152 	int retries = 5;
153 
154 	do {
155 		status = ap_aqic(q->apqn, aqic_gisa, NULL);
156 		switch (status.response_code) {
157 		case AP_RESPONSE_OTHERWISE_CHANGED:
158 		case AP_RESPONSE_NORMAL:
159 			vfio_ap_wait_for_irqclear(q->apqn);
160 			goto end_free;
161 		case AP_RESPONSE_RESET_IN_PROGRESS:
162 		case AP_RESPONSE_BUSY:
163 			msleep(20);
164 			break;
165 		case AP_RESPONSE_Q_NOT_AVAIL:
166 		case AP_RESPONSE_DECONFIGURED:
167 		case AP_RESPONSE_CHECKSTOPPED:
168 		case AP_RESPONSE_INVALID_ADDRESS:
169 		default:
170 			/* All cases in default means AP not operational */
171 			WARN_ONCE(1, "%s: ap_aqic status %d\n", __func__,
172 				  status.response_code);
173 			goto end_free;
174 		}
175 	} while (retries--);
176 
177 	WARN_ONCE(1, "%s: ap_aqic status %d\n", __func__,
178 		  status.response_code);
179 end_free:
180 	vfio_ap_free_aqic_resources(q);
181 	q->matrix_mdev = NULL;
182 	return status;
183 }
184 
185 /**
186  * vfio_ap_setirq: Enable Interruption for a APQN
187  *
188  * @dev: the device associated with the ap_queue
189  * @q:	 the vfio_ap_queue holding AQIC parameters
190  *
191  * Pin the NIB saved in *q
192  * Register the guest ISC to GIB interface and retrieve the
193  * host ISC to issue the host side PQAP/AQIC
194  *
195  * Response.status may be set to AP_RESPONSE_INVALID_ADDRESS in case the
196  * vfio_pin_pages failed.
197  *
198  * Otherwise return the ap_queue_status returned by the ap_aqic(),
199  * all retry handling will be done by the guest.
200  */
201 static struct ap_queue_status vfio_ap_irq_enable(struct vfio_ap_queue *q,
202 						 int isc,
203 						 unsigned long nib)
204 {
205 	struct ap_qirq_ctrl aqic_gisa = {};
206 	struct ap_queue_status status = {};
207 	struct kvm_s390_gisa *gisa;
208 	struct kvm *kvm;
209 	unsigned long h_nib, g_pfn, h_pfn;
210 	int ret;
211 
212 	g_pfn = nib >> PAGE_SHIFT;
213 	ret = vfio_pin_pages(mdev_dev(q->matrix_mdev->mdev), &g_pfn, 1,
214 			     IOMMU_READ | IOMMU_WRITE, &h_pfn);
215 	switch (ret) {
216 	case 1:
217 		break;
218 	default:
219 		status.response_code = AP_RESPONSE_INVALID_ADDRESS;
220 		return status;
221 	}
222 
223 	kvm = q->matrix_mdev->kvm;
224 	gisa = kvm->arch.gisa_int.origin;
225 
226 	h_nib = (h_pfn << PAGE_SHIFT) | (nib & ~PAGE_MASK);
227 	aqic_gisa.gisc = isc;
228 	aqic_gisa.isc = kvm_s390_gisc_register(kvm, isc);
229 	aqic_gisa.ir = 1;
230 	aqic_gisa.gisa = (uint64_t)gisa >> 4;
231 
232 	status = ap_aqic(q->apqn, aqic_gisa, (void *)h_nib);
233 	switch (status.response_code) {
234 	case AP_RESPONSE_NORMAL:
235 		/* See if we did clear older IRQ configuration */
236 		vfio_ap_free_aqic_resources(q);
237 		q->saved_pfn = g_pfn;
238 		q->saved_isc = isc;
239 		break;
240 	case AP_RESPONSE_OTHERWISE_CHANGED:
241 		/* We could not modify IRQ setings: clear new configuration */
242 		vfio_unpin_pages(mdev_dev(q->matrix_mdev->mdev), &g_pfn, 1);
243 		kvm_s390_gisc_unregister(kvm, isc);
244 		break;
245 	default:
246 		pr_warn("%s: apqn %04x: response: %02x\n", __func__, q->apqn,
247 			status.response_code);
248 		vfio_ap_irq_disable(q);
249 		break;
250 	}
251 
252 	return status;
253 }
254 
255 /**
256  * handle_pqap: PQAP instruction callback
257  *
258  * @vcpu: The vcpu on which we received the PQAP instruction
259  *
260  * Get the general register contents to initialize internal variables.
261  * REG[0]: APQN
262  * REG[1]: IR and ISC
263  * REG[2]: NIB
264  *
265  * Response.status may be set to following Response Code:
266  * - AP_RESPONSE_Q_NOT_AVAIL: if the queue is not available
267  * - AP_RESPONSE_DECONFIGURED: if the queue is not configured
268  * - AP_RESPONSE_NORMAL (0) : in case of successs
269  *   Check vfio_ap_setirq() and vfio_ap_clrirq() for other possible RC.
270  * We take the matrix_dev lock to ensure serialization on queues and
271  * mediated device access.
272  *
273  * Return 0 if we could handle the request inside KVM.
274  * otherwise, returns -EOPNOTSUPP to let QEMU handle the fault.
275  */
276 static int handle_pqap(struct kvm_vcpu *vcpu)
277 {
278 	uint64_t status;
279 	uint16_t apqn;
280 	struct vfio_ap_queue *q;
281 	struct ap_queue_status qstatus = {
282 			       .response_code = AP_RESPONSE_Q_NOT_AVAIL, };
283 	struct ap_matrix_mdev *matrix_mdev;
284 
285 	/* If we do not use the AIV facility just go to userland */
286 	if (!(vcpu->arch.sie_block->eca & ECA_AIV))
287 		return -EOPNOTSUPP;
288 
289 	apqn = vcpu->run->s.regs.gprs[0] & 0xffff;
290 	mutex_lock(&matrix_dev->lock);
291 
292 	if (!vcpu->kvm->arch.crypto.pqap_hook)
293 		goto out_unlock;
294 	matrix_mdev = container_of(vcpu->kvm->arch.crypto.pqap_hook,
295 				   struct ap_matrix_mdev, pqap_hook);
296 
297 	q = vfio_ap_get_queue(matrix_mdev, apqn);
298 	if (!q)
299 		goto out_unlock;
300 
301 	status = vcpu->run->s.regs.gprs[1];
302 
303 	/* If IR bit(16) is set we enable the interrupt */
304 	if ((status >> (63 - 16)) & 0x01)
305 		qstatus = vfio_ap_irq_enable(q, status & 0x07,
306 					     vcpu->run->s.regs.gprs[2]);
307 	else
308 		qstatus = vfio_ap_irq_disable(q);
309 
310 out_unlock:
311 	memcpy(&vcpu->run->s.regs.gprs[1], &qstatus, sizeof(qstatus));
312 	vcpu->run->s.regs.gprs[1] >>= 32;
313 	mutex_unlock(&matrix_dev->lock);
314 	return 0;
315 }
316 
317 static void vfio_ap_matrix_init(struct ap_config_info *info,
318 				struct ap_matrix *matrix)
319 {
320 	matrix->apm_max = info->apxa ? info->Na : 63;
321 	matrix->aqm_max = info->apxa ? info->Nd : 15;
322 	matrix->adm_max = info->apxa ? info->Nd : 15;
323 }
324 
325 static int vfio_ap_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
326 {
327 	struct ap_matrix_mdev *matrix_mdev;
328 
329 	if ((atomic_dec_if_positive(&matrix_dev->available_instances) < 0))
330 		return -EPERM;
331 
332 	matrix_mdev = kzalloc(sizeof(*matrix_mdev), GFP_KERNEL);
333 	if (!matrix_mdev) {
334 		atomic_inc(&matrix_dev->available_instances);
335 		return -ENOMEM;
336 	}
337 
338 	matrix_mdev->mdev = mdev;
339 	vfio_ap_matrix_init(&matrix_dev->info, &matrix_mdev->matrix);
340 	mdev_set_drvdata(mdev, matrix_mdev);
341 	matrix_mdev->pqap_hook.hook = handle_pqap;
342 	matrix_mdev->pqap_hook.owner = THIS_MODULE;
343 	mutex_lock(&matrix_dev->lock);
344 	list_add(&matrix_mdev->node, &matrix_dev->mdev_list);
345 	mutex_unlock(&matrix_dev->lock);
346 
347 	return 0;
348 }
349 
350 static int vfio_ap_mdev_remove(struct mdev_device *mdev)
351 {
352 	struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
353 
354 	if (matrix_mdev->kvm)
355 		return -EBUSY;
356 
357 	mutex_lock(&matrix_dev->lock);
358 	vfio_ap_mdev_reset_queues(mdev);
359 	list_del(&matrix_mdev->node);
360 	mutex_unlock(&matrix_dev->lock);
361 
362 	kfree(matrix_mdev);
363 	mdev_set_drvdata(mdev, NULL);
364 	atomic_inc(&matrix_dev->available_instances);
365 
366 	return 0;
367 }
368 
369 static ssize_t name_show(struct kobject *kobj, struct device *dev, char *buf)
370 {
371 	return sprintf(buf, "%s\n", VFIO_AP_MDEV_NAME_HWVIRT);
372 }
373 
374 static MDEV_TYPE_ATTR_RO(name);
375 
376 static ssize_t available_instances_show(struct kobject *kobj,
377 					struct device *dev, char *buf)
378 {
379 	return sprintf(buf, "%d\n",
380 		       atomic_read(&matrix_dev->available_instances));
381 }
382 
383 static MDEV_TYPE_ATTR_RO(available_instances);
384 
385 static ssize_t device_api_show(struct kobject *kobj, struct device *dev,
386 			       char *buf)
387 {
388 	return sprintf(buf, "%s\n", VFIO_DEVICE_API_AP_STRING);
389 }
390 
391 static MDEV_TYPE_ATTR_RO(device_api);
392 
393 static struct attribute *vfio_ap_mdev_type_attrs[] = {
394 	&mdev_type_attr_name.attr,
395 	&mdev_type_attr_device_api.attr,
396 	&mdev_type_attr_available_instances.attr,
397 	NULL,
398 };
399 
400 static struct attribute_group vfio_ap_mdev_hwvirt_type_group = {
401 	.name = VFIO_AP_MDEV_TYPE_HWVIRT,
402 	.attrs = vfio_ap_mdev_type_attrs,
403 };
404 
405 static struct attribute_group *vfio_ap_mdev_type_groups[] = {
406 	&vfio_ap_mdev_hwvirt_type_group,
407 	NULL,
408 };
409 
410 struct vfio_ap_queue_reserved {
411 	unsigned long *apid;
412 	unsigned long *apqi;
413 	bool reserved;
414 };
415 
416 /**
417  * vfio_ap_has_queue
418  *
419  * @dev: an AP queue device
420  * @data: a struct vfio_ap_queue_reserved reference
421  *
422  * Flags whether the AP queue device (@dev) has a queue ID containing the APQN,
423  * apid or apqi specified in @data:
424  *
425  * - If @data contains both an apid and apqi value, then @data will be flagged
426  *   as reserved if the APID and APQI fields for the AP queue device matches
427  *
428  * - If @data contains only an apid value, @data will be flagged as
429  *   reserved if the APID field in the AP queue device matches
430  *
431  * - If @data contains only an apqi value, @data will be flagged as
432  *   reserved if the APQI field in the AP queue device matches
433  *
434  * Returns 0 to indicate the input to function succeeded. Returns -EINVAL if
435  * @data does not contain either an apid or apqi.
436  */
437 static int vfio_ap_has_queue(struct device *dev, void *data)
438 {
439 	struct vfio_ap_queue_reserved *qres = data;
440 	struct ap_queue *ap_queue = to_ap_queue(dev);
441 	ap_qid_t qid;
442 	unsigned long id;
443 
444 	if (qres->apid && qres->apqi) {
445 		qid = AP_MKQID(*qres->apid, *qres->apqi);
446 		if (qid == ap_queue->qid)
447 			qres->reserved = true;
448 	} else if (qres->apid && !qres->apqi) {
449 		id = AP_QID_CARD(ap_queue->qid);
450 		if (id == *qres->apid)
451 			qres->reserved = true;
452 	} else if (!qres->apid && qres->apqi) {
453 		id = AP_QID_QUEUE(ap_queue->qid);
454 		if (id == *qres->apqi)
455 			qres->reserved = true;
456 	} else {
457 		return -EINVAL;
458 	}
459 
460 	return 0;
461 }
462 
463 /**
464  * vfio_ap_verify_queue_reserved
465  *
466  * @matrix_dev: a mediated matrix device
467  * @apid: an AP adapter ID
468  * @apqi: an AP queue index
469  *
470  * Verifies that the AP queue with @apid/@apqi is reserved by the VFIO AP device
471  * driver according to the following rules:
472  *
473  * - If both @apid and @apqi are not NULL, then there must be an AP queue
474  *   device bound to the vfio_ap driver with the APQN identified by @apid and
475  *   @apqi
476  *
477  * - If only @apid is not NULL, then there must be an AP queue device bound
478  *   to the vfio_ap driver with an APQN containing @apid
479  *
480  * - If only @apqi is not NULL, then there must be an AP queue device bound
481  *   to the vfio_ap driver with an APQN containing @apqi
482  *
483  * Returns 0 if the AP queue is reserved; otherwise, returns -EADDRNOTAVAIL.
484  */
485 static int vfio_ap_verify_queue_reserved(unsigned long *apid,
486 					 unsigned long *apqi)
487 {
488 	int ret;
489 	struct vfio_ap_queue_reserved qres;
490 
491 	qres.apid = apid;
492 	qres.apqi = apqi;
493 	qres.reserved = false;
494 
495 	ret = driver_for_each_device(&matrix_dev->vfio_ap_drv->driver, NULL,
496 				     &qres, vfio_ap_has_queue);
497 	if (ret)
498 		return ret;
499 
500 	if (qres.reserved)
501 		return 0;
502 
503 	return -EADDRNOTAVAIL;
504 }
505 
506 static int
507 vfio_ap_mdev_verify_queues_reserved_for_apid(struct ap_matrix_mdev *matrix_mdev,
508 					     unsigned long apid)
509 {
510 	int ret;
511 	unsigned long apqi;
512 	unsigned long nbits = matrix_mdev->matrix.aqm_max + 1;
513 
514 	if (find_first_bit_inv(matrix_mdev->matrix.aqm, nbits) >= nbits)
515 		return vfio_ap_verify_queue_reserved(&apid, NULL);
516 
517 	for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm, nbits) {
518 		ret = vfio_ap_verify_queue_reserved(&apid, &apqi);
519 		if (ret)
520 			return ret;
521 	}
522 
523 	return 0;
524 }
525 
526 /**
527  * vfio_ap_mdev_verify_no_sharing
528  *
529  * Verifies that the APQNs derived from the cross product of the AP adapter IDs
530  * and AP queue indexes comprising the AP matrix are not configured for another
531  * mediated device. AP queue sharing is not allowed.
532  *
533  * @matrix_mdev: the mediated matrix device
534  *
535  * Returns 0 if the APQNs are not shared, otherwise; returns -EADDRINUSE.
536  */
537 static int vfio_ap_mdev_verify_no_sharing(struct ap_matrix_mdev *matrix_mdev)
538 {
539 	struct ap_matrix_mdev *lstdev;
540 	DECLARE_BITMAP(apm, AP_DEVICES);
541 	DECLARE_BITMAP(aqm, AP_DOMAINS);
542 
543 	list_for_each_entry(lstdev, &matrix_dev->mdev_list, node) {
544 		if (matrix_mdev == lstdev)
545 			continue;
546 
547 		memset(apm, 0, sizeof(apm));
548 		memset(aqm, 0, sizeof(aqm));
549 
550 		/*
551 		 * We work on full longs, as we can only exclude the leftover
552 		 * bits in non-inverse order. The leftover is all zeros.
553 		 */
554 		if (!bitmap_and(apm, matrix_mdev->matrix.apm,
555 				lstdev->matrix.apm, AP_DEVICES))
556 			continue;
557 
558 		if (!bitmap_and(aqm, matrix_mdev->matrix.aqm,
559 				lstdev->matrix.aqm, AP_DOMAINS))
560 			continue;
561 
562 		return -EADDRINUSE;
563 	}
564 
565 	return 0;
566 }
567 
568 /**
569  * assign_adapter_store
570  *
571  * @dev:	the matrix device
572  * @attr:	the mediated matrix device's assign_adapter attribute
573  * @buf:	a buffer containing the AP adapter number (APID) to
574  *		be assigned
575  * @count:	the number of bytes in @buf
576  *
577  * Parses the APID from @buf and sets the corresponding bit in the mediated
578  * matrix device's APM.
579  *
580  * Returns the number of bytes processed if the APID is valid; otherwise,
581  * returns one of the following errors:
582  *
583  *	1. -EINVAL
584  *	   The APID is not a valid number
585  *
586  *	2. -ENODEV
587  *	   The APID exceeds the maximum value configured for the system
588  *
589  *	3. -EADDRNOTAVAIL
590  *	   An APQN derived from the cross product of the APID being assigned
591  *	   and the APQIs previously assigned is not bound to the vfio_ap device
592  *	   driver; or, if no APQIs have yet been assigned, the APID is not
593  *	   contained in an APQN bound to the vfio_ap device driver.
594  *
595  *	4. -EADDRINUSE
596  *	   An APQN derived from the cross product of the APID being assigned
597  *	   and the APQIs previously assigned is being used by another mediated
598  *	   matrix device
599  */
600 static ssize_t assign_adapter_store(struct device *dev,
601 				    struct device_attribute *attr,
602 				    const char *buf, size_t count)
603 {
604 	int ret;
605 	unsigned long apid;
606 	struct mdev_device *mdev = mdev_from_dev(dev);
607 	struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
608 
609 	/* If the guest is running, disallow assignment of adapter */
610 	if (matrix_mdev->kvm)
611 		return -EBUSY;
612 
613 	ret = kstrtoul(buf, 0, &apid);
614 	if (ret)
615 		return ret;
616 
617 	if (apid > matrix_mdev->matrix.apm_max)
618 		return -ENODEV;
619 
620 	/*
621 	 * Set the bit in the AP mask (APM) corresponding to the AP adapter
622 	 * number (APID). The bits in the mask, from most significant to least
623 	 * significant bit, correspond to APIDs 0-255.
624 	 */
625 	mutex_lock(&matrix_dev->lock);
626 
627 	ret = vfio_ap_mdev_verify_queues_reserved_for_apid(matrix_mdev, apid);
628 	if (ret)
629 		goto done;
630 
631 	set_bit_inv(apid, matrix_mdev->matrix.apm);
632 
633 	ret = vfio_ap_mdev_verify_no_sharing(matrix_mdev);
634 	if (ret)
635 		goto share_err;
636 
637 	ret = count;
638 	goto done;
639 
640 share_err:
641 	clear_bit_inv(apid, matrix_mdev->matrix.apm);
642 done:
643 	mutex_unlock(&matrix_dev->lock);
644 
645 	return ret;
646 }
647 static DEVICE_ATTR_WO(assign_adapter);
648 
649 /**
650  * unassign_adapter_store
651  *
652  * @dev:	the matrix device
653  * @attr:	the mediated matrix device's unassign_adapter attribute
654  * @buf:	a buffer containing the adapter number (APID) to be unassigned
655  * @count:	the number of bytes in @buf
656  *
657  * Parses the APID from @buf and clears the corresponding bit in the mediated
658  * matrix device's APM.
659  *
660  * Returns the number of bytes processed if the APID is valid; otherwise,
661  * returns one of the following errors:
662  *	-EINVAL if the APID is not a number
663  *	-ENODEV if the APID it exceeds the maximum value configured for the
664  *		system
665  */
666 static ssize_t unassign_adapter_store(struct device *dev,
667 				      struct device_attribute *attr,
668 				      const char *buf, size_t count)
669 {
670 	int ret;
671 	unsigned long apid;
672 	struct mdev_device *mdev = mdev_from_dev(dev);
673 	struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
674 
675 	/* If the guest is running, disallow un-assignment of adapter */
676 	if (matrix_mdev->kvm)
677 		return -EBUSY;
678 
679 	ret = kstrtoul(buf, 0, &apid);
680 	if (ret)
681 		return ret;
682 
683 	if (apid > matrix_mdev->matrix.apm_max)
684 		return -ENODEV;
685 
686 	mutex_lock(&matrix_dev->lock);
687 	clear_bit_inv((unsigned long)apid, matrix_mdev->matrix.apm);
688 	mutex_unlock(&matrix_dev->lock);
689 
690 	return count;
691 }
692 static DEVICE_ATTR_WO(unassign_adapter);
693 
694 static int
695 vfio_ap_mdev_verify_queues_reserved_for_apqi(struct ap_matrix_mdev *matrix_mdev,
696 					     unsigned long apqi)
697 {
698 	int ret;
699 	unsigned long apid;
700 	unsigned long nbits = matrix_mdev->matrix.apm_max + 1;
701 
702 	if (find_first_bit_inv(matrix_mdev->matrix.apm, nbits) >= nbits)
703 		return vfio_ap_verify_queue_reserved(NULL, &apqi);
704 
705 	for_each_set_bit_inv(apid, matrix_mdev->matrix.apm, nbits) {
706 		ret = vfio_ap_verify_queue_reserved(&apid, &apqi);
707 		if (ret)
708 			return ret;
709 	}
710 
711 	return 0;
712 }
713 
714 /**
715  * assign_domain_store
716  *
717  * @dev:	the matrix device
718  * @attr:	the mediated matrix device's assign_domain attribute
719  * @buf:	a buffer containing the AP queue index (APQI) of the domain to
720  *		be assigned
721  * @count:	the number of bytes in @buf
722  *
723  * Parses the APQI from @buf and sets the corresponding bit in the mediated
724  * matrix device's AQM.
725  *
726  * Returns the number of bytes processed if the APQI is valid; otherwise returns
727  * one of the following errors:
728  *
729  *	1. -EINVAL
730  *	   The APQI is not a valid number
731  *
732  *	2. -ENODEV
733  *	   The APQI exceeds the maximum value configured for the system
734  *
735  *	3. -EADDRNOTAVAIL
736  *	   An APQN derived from the cross product of the APQI being assigned
737  *	   and the APIDs previously assigned is not bound to the vfio_ap device
738  *	   driver; or, if no APIDs have yet been assigned, the APQI is not
739  *	   contained in an APQN bound to the vfio_ap device driver.
740  *
741  *	4. -EADDRINUSE
742  *	   An APQN derived from the cross product of the APQI being assigned
743  *	   and the APIDs previously assigned is being used by another mediated
744  *	   matrix device
745  */
746 static ssize_t assign_domain_store(struct device *dev,
747 				   struct device_attribute *attr,
748 				   const char *buf, size_t count)
749 {
750 	int ret;
751 	unsigned long apqi;
752 	struct mdev_device *mdev = mdev_from_dev(dev);
753 	struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
754 	unsigned long max_apqi = matrix_mdev->matrix.aqm_max;
755 
756 	/* If the guest is running, disallow assignment of domain */
757 	if (matrix_mdev->kvm)
758 		return -EBUSY;
759 
760 	ret = kstrtoul(buf, 0, &apqi);
761 	if (ret)
762 		return ret;
763 	if (apqi > max_apqi)
764 		return -ENODEV;
765 
766 	mutex_lock(&matrix_dev->lock);
767 
768 	ret = vfio_ap_mdev_verify_queues_reserved_for_apqi(matrix_mdev, apqi);
769 	if (ret)
770 		goto done;
771 
772 	set_bit_inv(apqi, matrix_mdev->matrix.aqm);
773 
774 	ret = vfio_ap_mdev_verify_no_sharing(matrix_mdev);
775 	if (ret)
776 		goto share_err;
777 
778 	ret = count;
779 	goto done;
780 
781 share_err:
782 	clear_bit_inv(apqi, matrix_mdev->matrix.aqm);
783 done:
784 	mutex_unlock(&matrix_dev->lock);
785 
786 	return ret;
787 }
788 static DEVICE_ATTR_WO(assign_domain);
789 
790 
791 /**
792  * unassign_domain_store
793  *
794  * @dev:	the matrix device
795  * @attr:	the mediated matrix device's unassign_domain attribute
796  * @buf:	a buffer containing the AP queue index (APQI) of the domain to
797  *		be unassigned
798  * @count:	the number of bytes in @buf
799  *
800  * Parses the APQI from @buf and clears the corresponding bit in the
801  * mediated matrix device's AQM.
802  *
803  * Returns the number of bytes processed if the APQI is valid; otherwise,
804  * returns one of the following errors:
805  *	-EINVAL if the APQI is not a number
806  *	-ENODEV if the APQI exceeds the maximum value configured for the system
807  */
808 static ssize_t unassign_domain_store(struct device *dev,
809 				     struct device_attribute *attr,
810 				     const char *buf, size_t count)
811 {
812 	int ret;
813 	unsigned long apqi;
814 	struct mdev_device *mdev = mdev_from_dev(dev);
815 	struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
816 
817 	/* If the guest is running, disallow un-assignment of domain */
818 	if (matrix_mdev->kvm)
819 		return -EBUSY;
820 
821 	ret = kstrtoul(buf, 0, &apqi);
822 	if (ret)
823 		return ret;
824 
825 	if (apqi > matrix_mdev->matrix.aqm_max)
826 		return -ENODEV;
827 
828 	mutex_lock(&matrix_dev->lock);
829 	clear_bit_inv((unsigned long)apqi, matrix_mdev->matrix.aqm);
830 	mutex_unlock(&matrix_dev->lock);
831 
832 	return count;
833 }
834 static DEVICE_ATTR_WO(unassign_domain);
835 
836 /**
837  * assign_control_domain_store
838  *
839  * @dev:	the matrix device
840  * @attr:	the mediated matrix device's assign_control_domain attribute
841  * @buf:	a buffer containing the domain ID to be assigned
842  * @count:	the number of bytes in @buf
843  *
844  * Parses the domain ID from @buf and sets the corresponding bit in the mediated
845  * matrix device's ADM.
846  *
847  * Returns the number of bytes processed if the domain ID is valid; otherwise,
848  * returns one of the following errors:
849  *	-EINVAL if the ID is not a number
850  *	-ENODEV if the ID exceeds the maximum value configured for the system
851  */
852 static ssize_t assign_control_domain_store(struct device *dev,
853 					   struct device_attribute *attr,
854 					   const char *buf, size_t count)
855 {
856 	int ret;
857 	unsigned long id;
858 	struct mdev_device *mdev = mdev_from_dev(dev);
859 	struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
860 
861 	/* If the guest is running, disallow assignment of control domain */
862 	if (matrix_mdev->kvm)
863 		return -EBUSY;
864 
865 	ret = kstrtoul(buf, 0, &id);
866 	if (ret)
867 		return ret;
868 
869 	if (id > matrix_mdev->matrix.adm_max)
870 		return -ENODEV;
871 
872 	/* Set the bit in the ADM (bitmask) corresponding to the AP control
873 	 * domain number (id). The bits in the mask, from most significant to
874 	 * least significant, correspond to IDs 0 up to the one less than the
875 	 * number of control domains that can be assigned.
876 	 */
877 	mutex_lock(&matrix_dev->lock);
878 	set_bit_inv(id, matrix_mdev->matrix.adm);
879 	mutex_unlock(&matrix_dev->lock);
880 
881 	return count;
882 }
883 static DEVICE_ATTR_WO(assign_control_domain);
884 
885 /**
886  * unassign_control_domain_store
887  *
888  * @dev:	the matrix device
889  * @attr:	the mediated matrix device's unassign_control_domain attribute
890  * @buf:	a buffer containing the domain ID to be unassigned
891  * @count:	the number of bytes in @buf
892  *
893  * Parses the domain ID from @buf and clears the corresponding bit in the
894  * mediated matrix device's ADM.
895  *
896  * Returns the number of bytes processed if the domain ID is valid; otherwise,
897  * returns one of the following errors:
898  *	-EINVAL if the ID is not a number
899  *	-ENODEV if the ID exceeds the maximum value configured for the system
900  */
901 static ssize_t unassign_control_domain_store(struct device *dev,
902 					     struct device_attribute *attr,
903 					     const char *buf, size_t count)
904 {
905 	int ret;
906 	unsigned long domid;
907 	struct mdev_device *mdev = mdev_from_dev(dev);
908 	struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
909 	unsigned long max_domid =  matrix_mdev->matrix.adm_max;
910 
911 	/* If the guest is running, disallow un-assignment of control domain */
912 	if (matrix_mdev->kvm)
913 		return -EBUSY;
914 
915 	ret = kstrtoul(buf, 0, &domid);
916 	if (ret)
917 		return ret;
918 	if (domid > max_domid)
919 		return -ENODEV;
920 
921 	mutex_lock(&matrix_dev->lock);
922 	clear_bit_inv(domid, matrix_mdev->matrix.adm);
923 	mutex_unlock(&matrix_dev->lock);
924 
925 	return count;
926 }
927 static DEVICE_ATTR_WO(unassign_control_domain);
928 
929 static ssize_t control_domains_show(struct device *dev,
930 				    struct device_attribute *dev_attr,
931 				    char *buf)
932 {
933 	unsigned long id;
934 	int nchars = 0;
935 	int n;
936 	char *bufpos = buf;
937 	struct mdev_device *mdev = mdev_from_dev(dev);
938 	struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
939 	unsigned long max_domid = matrix_mdev->matrix.adm_max;
940 
941 	mutex_lock(&matrix_dev->lock);
942 	for_each_set_bit_inv(id, matrix_mdev->matrix.adm, max_domid + 1) {
943 		n = sprintf(bufpos, "%04lx\n", id);
944 		bufpos += n;
945 		nchars += n;
946 	}
947 	mutex_unlock(&matrix_dev->lock);
948 
949 	return nchars;
950 }
951 static DEVICE_ATTR_RO(control_domains);
952 
953 static ssize_t matrix_show(struct device *dev, struct device_attribute *attr,
954 			   char *buf)
955 {
956 	struct mdev_device *mdev = mdev_from_dev(dev);
957 	struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
958 	char *bufpos = buf;
959 	unsigned long apid;
960 	unsigned long apqi;
961 	unsigned long apid1;
962 	unsigned long apqi1;
963 	unsigned long napm_bits = matrix_mdev->matrix.apm_max + 1;
964 	unsigned long naqm_bits = matrix_mdev->matrix.aqm_max + 1;
965 	int nchars = 0;
966 	int n;
967 
968 	apid1 = find_first_bit_inv(matrix_mdev->matrix.apm, napm_bits);
969 	apqi1 = find_first_bit_inv(matrix_mdev->matrix.aqm, naqm_bits);
970 
971 	mutex_lock(&matrix_dev->lock);
972 
973 	if ((apid1 < napm_bits) && (apqi1 < naqm_bits)) {
974 		for_each_set_bit_inv(apid, matrix_mdev->matrix.apm, napm_bits) {
975 			for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm,
976 					     naqm_bits) {
977 				n = sprintf(bufpos, "%02lx.%04lx\n", apid,
978 					    apqi);
979 				bufpos += n;
980 				nchars += n;
981 			}
982 		}
983 	} else if (apid1 < napm_bits) {
984 		for_each_set_bit_inv(apid, matrix_mdev->matrix.apm, napm_bits) {
985 			n = sprintf(bufpos, "%02lx.\n", apid);
986 			bufpos += n;
987 			nchars += n;
988 		}
989 	} else if (apqi1 < naqm_bits) {
990 		for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm, naqm_bits) {
991 			n = sprintf(bufpos, ".%04lx\n", apqi);
992 			bufpos += n;
993 			nchars += n;
994 		}
995 	}
996 
997 	mutex_unlock(&matrix_dev->lock);
998 
999 	return nchars;
1000 }
1001 static DEVICE_ATTR_RO(matrix);
1002 
1003 static struct attribute *vfio_ap_mdev_attrs[] = {
1004 	&dev_attr_assign_adapter.attr,
1005 	&dev_attr_unassign_adapter.attr,
1006 	&dev_attr_assign_domain.attr,
1007 	&dev_attr_unassign_domain.attr,
1008 	&dev_attr_assign_control_domain.attr,
1009 	&dev_attr_unassign_control_domain.attr,
1010 	&dev_attr_control_domains.attr,
1011 	&dev_attr_matrix.attr,
1012 	NULL,
1013 };
1014 
1015 static struct attribute_group vfio_ap_mdev_attr_group = {
1016 	.attrs = vfio_ap_mdev_attrs
1017 };
1018 
1019 static const struct attribute_group *vfio_ap_mdev_attr_groups[] = {
1020 	&vfio_ap_mdev_attr_group,
1021 	NULL
1022 };
1023 
1024 /**
1025  * vfio_ap_mdev_set_kvm
1026  *
1027  * @matrix_mdev: a mediated matrix device
1028  * @kvm: reference to KVM instance
1029  *
1030  * Verifies no other mediated matrix device has @kvm and sets a reference to
1031  * it in @matrix_mdev->kvm.
1032  *
1033  * Return 0 if no other mediated matrix device has a reference to @kvm;
1034  * otherwise, returns an -EPERM.
1035  */
1036 static int vfio_ap_mdev_set_kvm(struct ap_matrix_mdev *matrix_mdev,
1037 				struct kvm *kvm)
1038 {
1039 	struct ap_matrix_mdev *m;
1040 
1041 	list_for_each_entry(m, &matrix_dev->mdev_list, node) {
1042 		if ((m != matrix_mdev) && (m->kvm == kvm))
1043 			return -EPERM;
1044 	}
1045 
1046 	matrix_mdev->kvm = kvm;
1047 	kvm_get_kvm(kvm);
1048 	kvm->arch.crypto.pqap_hook = &matrix_mdev->pqap_hook;
1049 
1050 	return 0;
1051 }
1052 
1053 /*
1054  * vfio_ap_mdev_iommu_notifier: IOMMU notifier callback
1055  *
1056  * @nb: The notifier block
1057  * @action: Action to be taken
1058  * @data: data associated with the request
1059  *
1060  * For an UNMAP request, unpin the guest IOVA (the NIB guest address we
1061  * pinned before). Other requests are ignored.
1062  *
1063  */
1064 static int vfio_ap_mdev_iommu_notifier(struct notifier_block *nb,
1065 				       unsigned long action, void *data)
1066 {
1067 	struct ap_matrix_mdev *matrix_mdev;
1068 
1069 	matrix_mdev = container_of(nb, struct ap_matrix_mdev, iommu_notifier);
1070 
1071 	if (action == VFIO_IOMMU_NOTIFY_DMA_UNMAP) {
1072 		struct vfio_iommu_type1_dma_unmap *unmap = data;
1073 		unsigned long g_pfn = unmap->iova >> PAGE_SHIFT;
1074 
1075 		vfio_unpin_pages(mdev_dev(matrix_mdev->mdev), &g_pfn, 1);
1076 		return NOTIFY_OK;
1077 	}
1078 
1079 	return NOTIFY_DONE;
1080 }
1081 
1082 static void vfio_ap_mdev_unset_kvm(struct ap_matrix_mdev *matrix_mdev)
1083 {
1084 	kvm_arch_crypto_clear_masks(matrix_mdev->kvm);
1085 	matrix_mdev->kvm->arch.crypto.pqap_hook = NULL;
1086 	vfio_ap_mdev_reset_queues(matrix_mdev->mdev);
1087 	kvm_put_kvm(matrix_mdev->kvm);
1088 	matrix_mdev->kvm = NULL;
1089 }
1090 
1091 static int vfio_ap_mdev_group_notifier(struct notifier_block *nb,
1092 				       unsigned long action, void *data)
1093 {
1094 	int ret, notify_rc = NOTIFY_OK;
1095 	struct ap_matrix_mdev *matrix_mdev;
1096 
1097 	if (action != VFIO_GROUP_NOTIFY_SET_KVM)
1098 		return NOTIFY_OK;
1099 
1100 	matrix_mdev = container_of(nb, struct ap_matrix_mdev, group_notifier);
1101 	mutex_lock(&matrix_dev->lock);
1102 
1103 	if (!data) {
1104 		if (matrix_mdev->kvm)
1105 			vfio_ap_mdev_unset_kvm(matrix_mdev);
1106 		goto notify_done;
1107 	}
1108 
1109 	ret = vfio_ap_mdev_set_kvm(matrix_mdev, data);
1110 	if (ret) {
1111 		notify_rc = NOTIFY_DONE;
1112 		goto notify_done;
1113 	}
1114 
1115 	/* If there is no CRYCB pointer, then we can't copy the masks */
1116 	if (!matrix_mdev->kvm->arch.crypto.crycbd) {
1117 		notify_rc = NOTIFY_DONE;
1118 		goto notify_done;
1119 	}
1120 
1121 	kvm_arch_crypto_set_masks(matrix_mdev->kvm, matrix_mdev->matrix.apm,
1122 				  matrix_mdev->matrix.aqm,
1123 				  matrix_mdev->matrix.adm);
1124 
1125 notify_done:
1126 	mutex_unlock(&matrix_dev->lock);
1127 	return notify_rc;
1128 }
1129 
1130 static struct vfio_ap_queue *vfio_ap_find_queue(int apqn)
1131 {
1132 	struct device *dev;
1133 	struct vfio_ap_queue *q = NULL;
1134 
1135 	dev = driver_find_device(&matrix_dev->vfio_ap_drv->driver, NULL,
1136 				 &apqn, match_apqn);
1137 	if (dev) {
1138 		q = dev_get_drvdata(dev);
1139 		put_device(dev);
1140 	}
1141 
1142 	return q;
1143 }
1144 
1145 int vfio_ap_mdev_reset_queue(struct vfio_ap_queue *q,
1146 			     unsigned int retry)
1147 {
1148 	struct ap_queue_status status;
1149 	int ret;
1150 	int retry2 = 2;
1151 
1152 	if (!q)
1153 		return 0;
1154 
1155 retry_zapq:
1156 	status = ap_zapq(q->apqn);
1157 	switch (status.response_code) {
1158 	case AP_RESPONSE_NORMAL:
1159 		ret = 0;
1160 		break;
1161 	case AP_RESPONSE_RESET_IN_PROGRESS:
1162 		if (retry--) {
1163 			msleep(20);
1164 			goto retry_zapq;
1165 		}
1166 		ret = -EBUSY;
1167 		break;
1168 	case AP_RESPONSE_Q_NOT_AVAIL:
1169 	case AP_RESPONSE_DECONFIGURED:
1170 	case AP_RESPONSE_CHECKSTOPPED:
1171 		WARN_ON_ONCE(status.irq_enabled);
1172 		ret = -EBUSY;
1173 		goto free_resources;
1174 	default:
1175 		/* things are really broken, give up */
1176 		WARN(true, "PQAP/ZAPQ completed with invalid rc (%x)\n",
1177 		     status.response_code);
1178 		return -EIO;
1179 	}
1180 
1181 	/* wait for the reset to take effect */
1182 	while (retry2--) {
1183 		if (status.queue_empty && !status.irq_enabled)
1184 			break;
1185 		msleep(20);
1186 		status = ap_tapq(q->apqn, NULL);
1187 	}
1188 	WARN_ON_ONCE(retry2 <= 0);
1189 
1190 free_resources:
1191 	vfio_ap_free_aqic_resources(q);
1192 
1193 	return ret;
1194 }
1195 
1196 static int vfio_ap_mdev_reset_queues(struct mdev_device *mdev)
1197 {
1198 	int ret;
1199 	int rc = 0;
1200 	unsigned long apid, apqi;
1201 	struct vfio_ap_queue *q;
1202 	struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
1203 
1204 	for_each_set_bit_inv(apid, matrix_mdev->matrix.apm,
1205 			     matrix_mdev->matrix.apm_max + 1) {
1206 		for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm,
1207 				     matrix_mdev->matrix.aqm_max + 1) {
1208 			q = vfio_ap_find_queue(AP_MKQID(apid, apqi));
1209 			ret = vfio_ap_mdev_reset_queue(q, 1);
1210 			/*
1211 			 * Regardless whether a queue turns out to be busy, or
1212 			 * is not operational, we need to continue resetting
1213 			 * the remaining queues.
1214 			 */
1215 			if (ret)
1216 				rc = ret;
1217 		}
1218 	}
1219 
1220 	return rc;
1221 }
1222 
1223 static int vfio_ap_mdev_open(struct mdev_device *mdev)
1224 {
1225 	struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
1226 	unsigned long events;
1227 	int ret;
1228 
1229 
1230 	if (!try_module_get(THIS_MODULE))
1231 		return -ENODEV;
1232 
1233 	matrix_mdev->group_notifier.notifier_call = vfio_ap_mdev_group_notifier;
1234 	events = VFIO_GROUP_NOTIFY_SET_KVM;
1235 
1236 	ret = vfio_register_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY,
1237 				     &events, &matrix_mdev->group_notifier);
1238 	if (ret) {
1239 		module_put(THIS_MODULE);
1240 		return ret;
1241 	}
1242 
1243 	matrix_mdev->iommu_notifier.notifier_call = vfio_ap_mdev_iommu_notifier;
1244 	events = VFIO_IOMMU_NOTIFY_DMA_UNMAP;
1245 	ret = vfio_register_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
1246 				     &events, &matrix_mdev->iommu_notifier);
1247 	if (!ret)
1248 		return ret;
1249 
1250 	vfio_unregister_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY,
1251 				 &matrix_mdev->group_notifier);
1252 	module_put(THIS_MODULE);
1253 	return ret;
1254 }
1255 
1256 static void vfio_ap_mdev_release(struct mdev_device *mdev)
1257 {
1258 	struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
1259 
1260 	mutex_lock(&matrix_dev->lock);
1261 	if (matrix_mdev->kvm)
1262 		vfio_ap_mdev_unset_kvm(matrix_mdev);
1263 	mutex_unlock(&matrix_dev->lock);
1264 
1265 	vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
1266 				 &matrix_mdev->iommu_notifier);
1267 	vfio_unregister_notifier(mdev_dev(mdev), VFIO_GROUP_NOTIFY,
1268 				 &matrix_mdev->group_notifier);
1269 	module_put(THIS_MODULE);
1270 }
1271 
1272 static int vfio_ap_mdev_get_device_info(unsigned long arg)
1273 {
1274 	unsigned long minsz;
1275 	struct vfio_device_info info;
1276 
1277 	minsz = offsetofend(struct vfio_device_info, num_irqs);
1278 
1279 	if (copy_from_user(&info, (void __user *)arg, minsz))
1280 		return -EFAULT;
1281 
1282 	if (info.argsz < minsz)
1283 		return -EINVAL;
1284 
1285 	info.flags = VFIO_DEVICE_FLAGS_AP | VFIO_DEVICE_FLAGS_RESET;
1286 	info.num_regions = 0;
1287 	info.num_irqs = 0;
1288 
1289 	return copy_to_user((void __user *)arg, &info, minsz);
1290 }
1291 
1292 static ssize_t vfio_ap_mdev_ioctl(struct mdev_device *mdev,
1293 				    unsigned int cmd, unsigned long arg)
1294 {
1295 	int ret;
1296 
1297 	mutex_lock(&matrix_dev->lock);
1298 	switch (cmd) {
1299 	case VFIO_DEVICE_GET_INFO:
1300 		ret = vfio_ap_mdev_get_device_info(arg);
1301 		break;
1302 	case VFIO_DEVICE_RESET:
1303 		ret = vfio_ap_mdev_reset_queues(mdev);
1304 		break;
1305 	default:
1306 		ret = -EOPNOTSUPP;
1307 		break;
1308 	}
1309 	mutex_unlock(&matrix_dev->lock);
1310 
1311 	return ret;
1312 }
1313 
1314 static const struct mdev_parent_ops vfio_ap_matrix_ops = {
1315 	.owner			= THIS_MODULE,
1316 	.supported_type_groups	= vfio_ap_mdev_type_groups,
1317 	.mdev_attr_groups	= vfio_ap_mdev_attr_groups,
1318 	.create			= vfio_ap_mdev_create,
1319 	.remove			= vfio_ap_mdev_remove,
1320 	.open			= vfio_ap_mdev_open,
1321 	.release		= vfio_ap_mdev_release,
1322 	.ioctl			= vfio_ap_mdev_ioctl,
1323 };
1324 
1325 int vfio_ap_mdev_register(void)
1326 {
1327 	atomic_set(&matrix_dev->available_instances, MAX_ZDEV_ENTRIES_EXT);
1328 
1329 	return mdev_register_device(&matrix_dev->device, &vfio_ap_matrix_ops);
1330 }
1331 
1332 void vfio_ap_mdev_unregister(void)
1333 {
1334 	mdev_unregister_device(&matrix_dev->device);
1335 }
1336