1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * s390 kvm PCI passthrough support
4 *
5 * Copyright IBM Corp. 2022
6 *
7 * Author(s): Matthew Rosato <mjrosato@linux.ibm.com>
8 */
9
10 #include <linux/kvm_host.h>
11 #include <linux/pci.h>
12 #include <asm/pci.h>
13 #include <asm/pci_insn.h>
14 #include <asm/pci_io.h>
15 #include <asm/sclp.h>
16 #include "pci.h"
17 #include "kvm-s390.h"
18
19 struct zpci_aift *aift;
20
__set_irq_noiib(u16 ctl,u8 isc)21 static inline int __set_irq_noiib(u16 ctl, u8 isc)
22 {
23 union zpci_sic_iib iib = {{0}};
24
25 return zpci_set_irq_ctrl(ctl, isc, &iib);
26 }
27
kvm_s390_pci_aen_exit(void)28 void kvm_s390_pci_aen_exit(void)
29 {
30 unsigned long flags;
31 struct kvm_zdev **gait_kzdev;
32
33 lockdep_assert_held(&aift->aift_lock);
34
35 /*
36 * Contents of the aipb remain registered for the life of the host
37 * kernel, the information preserved in zpci_aipb and zpci_aif_sbv
38 * in case we insert the KVM module again later. Clear the AIFT
39 * information and free anything not registered with underlying
40 * firmware.
41 */
42 spin_lock_irqsave(&aift->gait_lock, flags);
43 gait_kzdev = aift->kzdev;
44 aift->gait = NULL;
45 aift->sbv = NULL;
46 aift->kzdev = NULL;
47 spin_unlock_irqrestore(&aift->gait_lock, flags);
48
49 kfree(gait_kzdev);
50 }
51
zpci_setup_aipb(u8 nisc)52 static int zpci_setup_aipb(u8 nisc)
53 {
54 struct page *page;
55 int size, rc;
56
57 zpci_aipb = kzalloc_obj(union zpci_sic_iib);
58 if (!zpci_aipb)
59 return -ENOMEM;
60
61 aift->sbv = airq_iv_create(ZPCI_NR_DEVICES, AIRQ_IV_ALLOC, NULL);
62 if (!aift->sbv) {
63 rc = -ENOMEM;
64 goto free_aipb;
65 }
66 zpci_aif_sbv = aift->sbv;
67 size = get_order(PAGE_ALIGN(ZPCI_NR_DEVICES *
68 sizeof(struct zpci_gaite)));
69 page = alloc_pages(GFP_KERNEL | __GFP_ZERO, size);
70 if (!page) {
71 rc = -ENOMEM;
72 goto free_sbv;
73 }
74 aift->gait = (struct zpci_gaite *)page_to_virt(page);
75
76 zpci_aipb->aipb.faisb = virt_to_phys(aift->sbv->vector);
77 zpci_aipb->aipb.gait = virt_to_phys(aift->gait);
78 zpci_aipb->aipb.afi = nisc;
79 zpci_aipb->aipb.faal = ZPCI_NR_DEVICES;
80
81 /* Setup Adapter Event Notification Interpretation */
82 if (zpci_set_irq_ctrl(SIC_SET_AENI_CONTROLS, 0, zpci_aipb)) {
83 rc = -EIO;
84 goto free_gait;
85 }
86
87 return 0;
88
89 free_gait:
90 free_pages((unsigned long)aift->gait, size);
91 free_sbv:
92 airq_iv_release(aift->sbv);
93 zpci_aif_sbv = NULL;
94 free_aipb:
95 kfree(zpci_aipb);
96 zpci_aipb = NULL;
97
98 return rc;
99 }
100
zpci_reset_aipb(u8 nisc)101 static int zpci_reset_aipb(u8 nisc)
102 {
103 /*
104 * AEN registration can only happen once per system boot. If
105 * an aipb already exists then AEN was already registered and
106 * we can reuse the aipb contents. This can only happen if
107 * the KVM module was removed and re-inserted. However, we must
108 * ensure that the same forwarding ISC is used as this is assigned
109 * during KVM module load.
110 */
111 if (zpci_aipb->aipb.afi != nisc)
112 return -EINVAL;
113
114 aift->sbv = zpci_aif_sbv;
115 aift->gait = phys_to_virt(zpci_aipb->aipb.gait);
116
117 return 0;
118 }
119
kvm_s390_pci_aen_init(u8 nisc)120 int kvm_s390_pci_aen_init(u8 nisc)
121 {
122 int rc = 0;
123
124 /* If already enabled for AEN, bail out now */
125 if (aift->gait || aift->sbv)
126 return -EPERM;
127
128 mutex_lock(&aift->aift_lock);
129 aift->kzdev = kzalloc_objs(struct kvm_zdev *, ZPCI_NR_DEVICES);
130 if (!aift->kzdev) {
131 rc = -ENOMEM;
132 goto unlock;
133 }
134
135 if (!zpci_aipb)
136 rc = zpci_setup_aipb(nisc);
137 else
138 rc = zpci_reset_aipb(nisc);
139 if (rc)
140 goto free_zdev;
141
142 /* Enable floating IRQs */
143 if (__set_irq_noiib(SIC_IRQ_MODE_SINGLE, nisc)) {
144 rc = -EIO;
145 kvm_s390_pci_aen_exit();
146 }
147
148 goto unlock;
149
150 free_zdev:
151 kfree(aift->kzdev);
152 unlock:
153 mutex_unlock(&aift->aift_lock);
154 return rc;
155 }
156
157 /* Modify PCI: Register floating adapter interruption forwarding */
kvm_zpci_set_airq(struct zpci_dev * zdev)158 static int kvm_zpci_set_airq(struct zpci_dev *zdev)
159 {
160 u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_REG_INT);
161 struct zpci_fib fib = {};
162 u8 status;
163
164 fib.fmt0.isc = zdev->kzdev->fib.fmt0.isc;
165 fib.fmt0.sum = 1; /* enable summary notifications */
166 fib.fmt0.noi = airq_iv_end(zdev->aibv);
167 fib.fmt0.aibv = virt_to_phys(zdev->aibv->vector);
168 fib.fmt0.aibvo = 0;
169 fib.fmt0.aisb = virt_to_phys(aift->sbv->vector) + (zdev->aisb / 64) * 8;
170 fib.fmt0.aisbo = zdev->aisb & 63;
171 fib.gd = zdev->gisa;
172
173 return zpci_mod_fc(req, &fib, &status) ? -EIO : 0;
174 }
175
176 /* Modify PCI: Unregister floating adapter interruption forwarding */
kvm_zpci_clear_airq(struct zpci_dev * zdev)177 static int kvm_zpci_clear_airq(struct zpci_dev *zdev)
178 {
179 u64 req = ZPCI_CREATE_REQ(zdev->fh, 0, ZPCI_MOD_FC_DEREG_INT);
180 struct zpci_fib fib = {};
181 u8 cc, status;
182
183 fib.gd = zdev->gisa;
184
185 cc = zpci_mod_fc(req, &fib, &status);
186 if (cc == 3 || (cc == 1 && status == 24))
187 /* Function already gone or IRQs already deregistered. */
188 cc = 0;
189
190 return cc ? -EIO : 0;
191 }
192
unaccount_mem(unsigned long nr_pages)193 static inline void unaccount_mem(unsigned long nr_pages)
194 {
195 struct user_struct *user = get_uid(current_user());
196
197 if (user)
198 atomic_long_sub(nr_pages, &user->locked_vm);
199 if (current->mm)
200 atomic64_sub(nr_pages, ¤t->mm->pinned_vm);
201 }
202
account_mem(unsigned long nr_pages)203 static inline int account_mem(unsigned long nr_pages)
204 {
205 struct user_struct *user = get_uid(current_user());
206 unsigned long page_limit, cur_pages, new_pages;
207
208 page_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
209
210 cur_pages = atomic_long_read(&user->locked_vm);
211 do {
212 new_pages = cur_pages + nr_pages;
213 if (new_pages > page_limit)
214 return -ENOMEM;
215 } while (!atomic_long_try_cmpxchg(&user->locked_vm, &cur_pages, new_pages));
216
217 atomic64_add(nr_pages, ¤t->mm->pinned_vm);
218
219 return 0;
220 }
221
kvm_s390_pci_aif_enable(struct zpci_dev * zdev,struct zpci_fib * fib,bool assist)222 static int kvm_s390_pci_aif_enable(struct zpci_dev *zdev, struct zpci_fib *fib,
223 bool assist)
224 {
225 struct page *pages[1], *aibv_page, *aisb_page = NULL;
226 unsigned int msi_vecs, idx;
227 struct zpci_gaite *gaite;
228 unsigned long hva, bit;
229 struct kvm *kvm;
230 phys_addr_t gaddr;
231 int rc = 0, gisc, npages, pcount = 0;
232
233 /*
234 * Interrupt forwarding is only applicable if the device is already
235 * enabled for interpretation
236 */
237 if (zdev->gisa == 0)
238 return -EINVAL;
239
240 kvm = zdev->kzdev->kvm;
241 msi_vecs = min_t(unsigned int, fib->fmt0.noi, zdev->max_msi);
242
243 /* Get the associated forwarding ISC - if invalid, return the error */
244 gisc = kvm_s390_gisc_register(kvm, fib->fmt0.isc);
245 if (gisc < 0)
246 return gisc;
247
248 /* Replace AIBV address */
249 idx = srcu_read_lock(&kvm->srcu);
250 hva = gfn_to_hva(kvm, gpa_to_gfn((gpa_t)fib->fmt0.aibv));
251 npages = pin_user_pages_fast(hva, 1, FOLL_WRITE | FOLL_LONGTERM, pages);
252 srcu_read_unlock(&kvm->srcu, idx);
253 if (npages < 1) {
254 rc = -EIO;
255 goto out;
256 }
257 aibv_page = pages[0];
258 pcount++;
259 gaddr = page_to_phys(aibv_page) + (fib->fmt0.aibv & ~PAGE_MASK);
260 fib->fmt0.aibv = gaddr;
261
262 /* Pin the guest AISB if one was specified */
263 if (fib->fmt0.sum == 1) {
264 idx = srcu_read_lock(&kvm->srcu);
265 hva = gfn_to_hva(kvm, gpa_to_gfn((gpa_t)fib->fmt0.aisb));
266 npages = pin_user_pages_fast(hva, 1, FOLL_WRITE | FOLL_LONGTERM,
267 pages);
268 srcu_read_unlock(&kvm->srcu, idx);
269 if (npages < 1) {
270 rc = -EIO;
271 goto unpin1;
272 }
273 aisb_page = pages[0];
274 pcount++;
275 }
276
277 /* Account for pinned pages, roll back on failure */
278 if (account_mem(pcount))
279 goto unpin2;
280
281 /* AISB must be allocated before we can fill in GAITE */
282 mutex_lock(&aift->aift_lock);
283 bit = airq_iv_alloc_bit(aift->sbv);
284 if (bit == -1UL)
285 goto unlock;
286 zdev->aisb = bit; /* store the summary bit number */
287 zdev->aibv = airq_iv_create(msi_vecs, AIRQ_IV_DATA |
288 AIRQ_IV_BITLOCK |
289 AIRQ_IV_GUESTVEC,
290 phys_to_virt(fib->fmt0.aibv));
291
292 spin_lock_irq(&aift->gait_lock);
293 gaite = aift->gait + zdev->aisb;
294
295 /* If assist not requested, host will get all alerts */
296 if (assist)
297 gaite->gisa = (u32)virt_to_phys(&kvm->arch.sie_page2->gisa);
298 else
299 gaite->gisa = 0;
300
301 gaite->gisc = fib->fmt0.isc;
302 gaite->count++;
303 gaite->aisbo = fib->fmt0.aisbo;
304 gaite->aisb = virt_to_phys(page_address(aisb_page) + (fib->fmt0.aisb &
305 ~PAGE_MASK));
306 aift->kzdev[zdev->aisb] = zdev->kzdev;
307 spin_unlock_irq(&aift->gait_lock);
308
309 /* Update guest FIB for re-issue */
310 fib->fmt0.aisbo = zdev->aisb & 63;
311 fib->fmt0.aisb = virt_to_phys(aift->sbv->vector) + (zdev->aisb / 64) * 8;
312 fib->fmt0.isc = gisc;
313
314 /* Save some guest fib values in the host for later use */
315 zdev->kzdev->fib.fmt0.isc = fib->fmt0.isc;
316 zdev->kzdev->fib.fmt0.aibv = fib->fmt0.aibv;
317 mutex_unlock(&aift->aift_lock);
318
319 /* Issue the clp to setup the irq now */
320 rc = kvm_zpci_set_airq(zdev);
321 return rc;
322
323 unlock:
324 mutex_unlock(&aift->aift_lock);
325 unpin2:
326 if (fib->fmt0.sum == 1)
327 unpin_user_page(aisb_page);
328 unpin1:
329 unpin_user_page(aibv_page);
330 out:
331 return rc;
332 }
333
kvm_s390_pci_aif_disable(struct zpci_dev * zdev,bool force)334 static int kvm_s390_pci_aif_disable(struct zpci_dev *zdev, bool force)
335 {
336 struct kvm_zdev *kzdev = zdev->kzdev;
337 struct zpci_gaite *gaite;
338 struct page *vpage = NULL, *spage = NULL;
339 int rc, pcount = 0;
340 u8 isc;
341
342 if (zdev->gisa == 0)
343 return -EINVAL;
344
345 mutex_lock(&aift->aift_lock);
346
347 /*
348 * If the clear fails due to an error, leave now unless we know this
349 * device is about to go away (force) -- In that case clear the GAITE
350 * regardless.
351 */
352 rc = kvm_zpci_clear_airq(zdev);
353 if (rc && !force)
354 goto out;
355
356 if (zdev->kzdev->fib.fmt0.aibv == 0)
357 goto out;
358 spin_lock_irq(&aift->gait_lock);
359 gaite = aift->gait + zdev->aisb;
360 isc = gaite->gisc;
361 gaite->count--;
362 if (gaite->count == 0) {
363 /* Release guest AIBV and AISB */
364 vpage = phys_to_page(kzdev->fib.fmt0.aibv);
365 if (gaite->aisb != 0)
366 spage = phys_to_page(gaite->aisb);
367 /* Clear the GAIT entry */
368 gaite->aisb = 0;
369 gaite->gisc = 0;
370 gaite->aisbo = 0;
371 gaite->gisa = 0;
372 aift->kzdev[zdev->aisb] = NULL;
373 /* Clear zdev info */
374 airq_iv_free_bit(aift->sbv, zdev->aisb);
375 airq_iv_release(zdev->aibv);
376 zdev->aisb = 0;
377 zdev->aibv = NULL;
378 }
379 spin_unlock_irq(&aift->gait_lock);
380 kvm_s390_gisc_unregister(kzdev->kvm, isc);
381 kzdev->fib.fmt0.isc = 0;
382 kzdev->fib.fmt0.aibv = 0;
383
384 if (vpage) {
385 unpin_user_page(vpage);
386 pcount++;
387 }
388 if (spage) {
389 unpin_user_page(spage);
390 pcount++;
391 }
392 if (pcount > 0)
393 unaccount_mem(pcount);
394 out:
395 mutex_unlock(&aift->aift_lock);
396
397 return rc;
398 }
399
kvm_s390_pci_dev_open(struct zpci_dev * zdev)400 static int kvm_s390_pci_dev_open(struct zpci_dev *zdev)
401 {
402 struct kvm_zdev *kzdev;
403
404 kzdev = kzalloc_obj(struct kvm_zdev);
405 if (!kzdev)
406 return -ENOMEM;
407
408 kzdev->zdev = zdev;
409 zdev->kzdev = kzdev;
410
411 return 0;
412 }
413
kvm_s390_pci_dev_release(struct zpci_dev * zdev)414 static void kvm_s390_pci_dev_release(struct zpci_dev *zdev)
415 {
416 struct kvm_zdev *kzdev;
417
418 kzdev = zdev->kzdev;
419 WARN_ON(kzdev->zdev != zdev);
420 zdev->kzdev = NULL;
421 kfree(kzdev);
422 }
423
424
425 /*
426 * Register device with the specified KVM. If interpretation facilities are
427 * available, enable them and let userspace indicate whether or not they will
428 * be used (specify SHM bit to disable).
429 */
kvm_s390_pci_register_kvm(void * opaque,struct kvm * kvm)430 static int kvm_s390_pci_register_kvm(void *opaque, struct kvm *kvm)
431 {
432 struct zpci_dev *zdev = opaque;
433 int rc;
434
435 if (!zdev)
436 return -EINVAL;
437
438 mutex_lock(&zdev->kzdev_lock);
439
440 if (zdev->kzdev || zdev->gisa != 0 || !kvm) {
441 mutex_unlock(&zdev->kzdev_lock);
442 return -EINVAL;
443 }
444
445 kvm_get_kvm(kvm);
446
447 mutex_lock(&kvm->lock);
448
449 rc = kvm_s390_pci_dev_open(zdev);
450 if (rc)
451 goto err;
452
453 /*
454 * If interpretation facilities aren't available, add the device to
455 * the kzdev list but don't enable for interpretation.
456 */
457 if (!kvm_s390_pci_interp_allowed())
458 goto out;
459
460 /*
461 * If this is the first request to use an interpreted device, make the
462 * necessary vcpu changes
463 */
464 if (!kvm->arch.use_zpci_interp)
465 kvm_s390_vcpu_pci_enable_interp(kvm);
466
467 if (zdev_enabled(zdev)) {
468 rc = zpci_disable_device(zdev);
469 if (rc)
470 goto err;
471 }
472
473 /*
474 * Store information about the identity of the kvm guest allowed to
475 * access this device via interpretation to be used by host CLP
476 */
477 zdev->gisa = (u32)virt_to_phys(&kvm->arch.sie_page2->gisa);
478
479 rc = zpci_reenable_device(zdev);
480 if (rc)
481 goto clear_gisa;
482
483 out:
484 zdev->kzdev->kvm = kvm;
485
486 spin_lock(&kvm->arch.kzdev_list_lock);
487 list_add_tail(&zdev->kzdev->entry, &kvm->arch.kzdev_list);
488 spin_unlock(&kvm->arch.kzdev_list_lock);
489
490 mutex_unlock(&kvm->lock);
491 mutex_unlock(&zdev->kzdev_lock);
492 return 0;
493
494 clear_gisa:
495 zdev->gisa = 0;
496 err:
497 if (zdev->kzdev)
498 kvm_s390_pci_dev_release(zdev);
499 mutex_unlock(&kvm->lock);
500 mutex_unlock(&zdev->kzdev_lock);
501 kvm_put_kvm(kvm);
502 return rc;
503 }
504
kvm_s390_pci_unregister_kvm(void * opaque)505 static void kvm_s390_pci_unregister_kvm(void *opaque)
506 {
507 struct zpci_dev *zdev = opaque;
508 struct kvm *kvm;
509
510 if (!zdev)
511 return;
512
513 mutex_lock(&zdev->kzdev_lock);
514
515 if (WARN_ON(!zdev->kzdev)) {
516 mutex_unlock(&zdev->kzdev_lock);
517 return;
518 }
519
520 kvm = zdev->kzdev->kvm;
521 mutex_lock(&kvm->lock);
522
523 /*
524 * A 0 gisa means interpretation was never enabled, just remove the
525 * device from the list.
526 */
527 if (zdev->gisa == 0)
528 goto out;
529
530 /* Forwarding must be turned off before interpretation */
531 if (zdev->kzdev->fib.fmt0.aibv != 0)
532 kvm_s390_pci_aif_disable(zdev, true);
533
534 /* Remove the host CLP guest designation */
535 zdev->gisa = 0;
536
537 if (zdev_enabled(zdev)) {
538 if (zpci_disable_device(zdev))
539 goto out;
540 }
541
542 zpci_reenable_device(zdev);
543
544 out:
545 spin_lock(&kvm->arch.kzdev_list_lock);
546 list_del(&zdev->kzdev->entry);
547 spin_unlock(&kvm->arch.kzdev_list_lock);
548 kvm_s390_pci_dev_release(zdev);
549
550 mutex_unlock(&kvm->lock);
551 mutex_unlock(&zdev->kzdev_lock);
552
553 kvm_put_kvm(kvm);
554 }
555
kvm_s390_pci_init_list(struct kvm * kvm)556 void kvm_s390_pci_init_list(struct kvm *kvm)
557 {
558 spin_lock_init(&kvm->arch.kzdev_list_lock);
559 INIT_LIST_HEAD(&kvm->arch.kzdev_list);
560 }
561
kvm_s390_pci_clear_list(struct kvm * kvm)562 void kvm_s390_pci_clear_list(struct kvm *kvm)
563 {
564 /*
565 * This list should already be empty, either via vfio device closures
566 * or kvm fd cleanup.
567 */
568 spin_lock(&kvm->arch.kzdev_list_lock);
569 WARN_ON_ONCE(!list_empty(&kvm->arch.kzdev_list));
570 spin_unlock(&kvm->arch.kzdev_list_lock);
571 }
572
get_zdev_from_kvm_by_fh(struct kvm * kvm,u32 fh)573 static struct zpci_dev *get_zdev_from_kvm_by_fh(struct kvm *kvm, u32 fh)
574 {
575 struct zpci_dev *zdev = NULL;
576 struct kvm_zdev *kzdev;
577
578 spin_lock(&kvm->arch.kzdev_list_lock);
579 list_for_each_entry(kzdev, &kvm->arch.kzdev_list, entry) {
580 if (kzdev->zdev->fh == fh) {
581 zdev = kzdev->zdev;
582 break;
583 }
584 }
585 spin_unlock(&kvm->arch.kzdev_list_lock);
586
587 return zdev;
588 }
589
kvm_s390_pci_zpci_reg_aen(struct zpci_dev * zdev,struct kvm_s390_zpci_op * args)590 static int kvm_s390_pci_zpci_reg_aen(struct zpci_dev *zdev,
591 struct kvm_s390_zpci_op *args)
592 {
593 struct zpci_fib fib = {};
594 bool hostflag;
595
596 fib.fmt0.aibv = args->u.reg_aen.ibv;
597 fib.fmt0.isc = args->u.reg_aen.isc;
598 fib.fmt0.noi = args->u.reg_aen.noi;
599 if (args->u.reg_aen.sb != 0) {
600 fib.fmt0.aisb = args->u.reg_aen.sb;
601 fib.fmt0.aisbo = args->u.reg_aen.sbo;
602 fib.fmt0.sum = 1;
603 } else {
604 fib.fmt0.aisb = 0;
605 fib.fmt0.aisbo = 0;
606 fib.fmt0.sum = 0;
607 }
608
609 hostflag = !(args->u.reg_aen.flags & KVM_S390_ZPCIOP_REGAEN_HOST);
610 return kvm_s390_pci_aif_enable(zdev, &fib, hostflag);
611 }
612
kvm_s390_pci_zpci_op(struct kvm * kvm,struct kvm_s390_zpci_op * args)613 int kvm_s390_pci_zpci_op(struct kvm *kvm, struct kvm_s390_zpci_op *args)
614 {
615 struct kvm_zdev *kzdev;
616 struct zpci_dev *zdev;
617 int r;
618
619 zdev = get_zdev_from_kvm_by_fh(kvm, args->fh);
620 if (!zdev)
621 return -ENODEV;
622
623 mutex_lock(&zdev->kzdev_lock);
624 mutex_lock(&kvm->lock);
625
626 kzdev = zdev->kzdev;
627 if (!kzdev) {
628 r = -ENODEV;
629 goto out;
630 }
631 if (kzdev->kvm != kvm) {
632 r = -EPERM;
633 goto out;
634 }
635
636 switch (args->op) {
637 case KVM_S390_ZPCIOP_REG_AEN:
638 /* Fail on unknown flags */
639 if (args->u.reg_aen.flags & ~KVM_S390_ZPCIOP_REGAEN_HOST) {
640 r = -EINVAL;
641 break;
642 }
643 r = kvm_s390_pci_zpci_reg_aen(zdev, args);
644 break;
645 case KVM_S390_ZPCIOP_DEREG_AEN:
646 r = kvm_s390_pci_aif_disable(zdev, false);
647 break;
648 default:
649 r = -EINVAL;
650 }
651
652 out:
653 mutex_unlock(&kvm->lock);
654 mutex_unlock(&zdev->kzdev_lock);
655 return r;
656 }
657
kvm_s390_pci_init(void)658 int __init kvm_s390_pci_init(void)
659 {
660 zpci_kvm_hook.kvm_register = kvm_s390_pci_register_kvm;
661 zpci_kvm_hook.kvm_unregister = kvm_s390_pci_unregister_kvm;
662
663 if (!kvm_s390_pci_interp_allowed())
664 return 0;
665
666 aift = kzalloc_obj(struct zpci_aift);
667 if (!aift)
668 return -ENOMEM;
669
670 spin_lock_init(&aift->gait_lock);
671 mutex_init(&aift->aift_lock);
672
673 return 0;
674 }
675
kvm_s390_pci_exit(void)676 void kvm_s390_pci_exit(void)
677 {
678 zpci_kvm_hook.kvm_register = NULL;
679 zpci_kvm_hook.kvm_unregister = NULL;
680
681 if (!kvm_s390_pci_interp_allowed())
682 return;
683
684 mutex_destroy(&aift->aift_lock);
685
686 kfree(aift);
687 }
688