Merge branch 'drm-radeon-evergreen-accel' into drm-core-next
[pandora-kernel.git] / arch / s390 / kvm / interrupt.c
1 /*
2  * interrupt.c - handling kvm guest interrupts
3  *
4  * Copyright IBM Corp. 2008
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License (version 2 only)
8  * as published by the Free Software Foundation.
9  *
10  *    Author(s): Carsten Otte <cotte@de.ibm.com>
11  */
12
13 #include <linux/interrupt.h>
14 #include <linux/kvm_host.h>
15 #include <linux/hrtimer.h>
16 #include <linux/signal.h>
17 #include <linux/slab.h>
18 #include <asm/asm-offsets.h>
19 #include <asm/uaccess.h>
20 #include "kvm-s390.h"
21 #include "gaccess.h"
22
23 static int psw_extint_disabled(struct kvm_vcpu *vcpu)
24 {
25         return !(vcpu->arch.sie_block->gpsw.mask & PSW_MASK_EXT);
26 }
27
28 static int psw_interrupts_disabled(struct kvm_vcpu *vcpu)
29 {
30         if ((vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PER) ||
31             (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_IO) ||
32             (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_EXT))
33                 return 0;
34         return 1;
35 }
36
37 static int __interrupt_is_deliverable(struct kvm_vcpu *vcpu,
38                                       struct kvm_s390_interrupt_info *inti)
39 {
40         switch (inti->type) {
41         case KVM_S390_INT_EMERGENCY:
42                 if (psw_extint_disabled(vcpu))
43                         return 0;
44                 if (vcpu->arch.sie_block->gcr[0] & 0x4000ul)
45                         return 1;
46                 return 0;
47         case KVM_S390_INT_SERVICE:
48                 if (psw_extint_disabled(vcpu))
49                         return 0;
50                 if (vcpu->arch.sie_block->gcr[0] & 0x200ul)
51                         return 1;
52                 return 0;
53         case KVM_S390_INT_VIRTIO:
54                 if (psw_extint_disabled(vcpu))
55                         return 0;
56                 if (vcpu->arch.sie_block->gcr[0] & 0x200ul)
57                         return 1;
58                 return 0;
59         case KVM_S390_PROGRAM_INT:
60         case KVM_S390_SIGP_STOP:
61         case KVM_S390_SIGP_SET_PREFIX:
62         case KVM_S390_RESTART:
63                 return 1;
64         default:
65                 BUG();
66         }
67         return 0;
68 }
69
70 static void __set_cpu_idle(struct kvm_vcpu *vcpu)
71 {
72         BUG_ON(vcpu->vcpu_id > KVM_MAX_VCPUS - 1);
73         atomic_set_mask(CPUSTAT_WAIT, &vcpu->arch.sie_block->cpuflags);
74         set_bit(vcpu->vcpu_id, vcpu->arch.local_int.float_int->idle_mask);
75 }
76
77 static void __unset_cpu_idle(struct kvm_vcpu *vcpu)
78 {
79         BUG_ON(vcpu->vcpu_id > KVM_MAX_VCPUS - 1);
80         atomic_clear_mask(CPUSTAT_WAIT, &vcpu->arch.sie_block->cpuflags);
81         clear_bit(vcpu->vcpu_id, vcpu->arch.local_int.float_int->idle_mask);
82 }
83
84 static void __reset_intercept_indicators(struct kvm_vcpu *vcpu)
85 {
86         atomic_clear_mask(CPUSTAT_ECALL_PEND |
87                 CPUSTAT_IO_INT | CPUSTAT_EXT_INT | CPUSTAT_STOP_INT,
88                 &vcpu->arch.sie_block->cpuflags);
89         vcpu->arch.sie_block->lctl = 0x0000;
90 }
91
92 static void __set_cpuflag(struct kvm_vcpu *vcpu, u32 flag)
93 {
94         atomic_set_mask(flag, &vcpu->arch.sie_block->cpuflags);
95 }
96
97 static void __set_intercept_indicator(struct kvm_vcpu *vcpu,
98                                       struct kvm_s390_interrupt_info *inti)
99 {
100         switch (inti->type) {
101         case KVM_S390_INT_EMERGENCY:
102         case KVM_S390_INT_SERVICE:
103         case KVM_S390_INT_VIRTIO:
104                 if (psw_extint_disabled(vcpu))
105                         __set_cpuflag(vcpu, CPUSTAT_EXT_INT);
106                 else
107                         vcpu->arch.sie_block->lctl |= LCTL_CR0;
108                 break;
109         case KVM_S390_SIGP_STOP:
110                 __set_cpuflag(vcpu, CPUSTAT_STOP_INT);
111                 break;
112         default:
113                 BUG();
114         }
115 }
116
117 static void __do_deliver_interrupt(struct kvm_vcpu *vcpu,
118                                    struct kvm_s390_interrupt_info *inti)
119 {
120         const unsigned short table[] = { 2, 4, 4, 6 };
121         int rc, exception = 0;
122
123         switch (inti->type) {
124         case KVM_S390_INT_EMERGENCY:
125                 VCPU_EVENT(vcpu, 4, "%s", "interrupt: sigp emerg");
126                 vcpu->stat.deliver_emergency_signal++;
127                 rc = put_guest_u16(vcpu, __LC_EXT_INT_CODE, 0x1201);
128                 if (rc == -EFAULT)
129                         exception = 1;
130
131                 rc = copy_to_guest(vcpu, __LC_EXT_OLD_PSW,
132                          &vcpu->arch.sie_block->gpsw, sizeof(psw_t));
133                 if (rc == -EFAULT)
134                         exception = 1;
135
136                 rc = copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
137                         __LC_EXT_NEW_PSW, sizeof(psw_t));
138                 if (rc == -EFAULT)
139                         exception = 1;
140                 break;
141
142         case KVM_S390_INT_SERVICE:
143                 VCPU_EVENT(vcpu, 4, "interrupt: sclp parm:%x",
144                            inti->ext.ext_params);
145                 vcpu->stat.deliver_service_signal++;
146                 rc = put_guest_u16(vcpu, __LC_EXT_INT_CODE, 0x2401);
147                 if (rc == -EFAULT)
148                         exception = 1;
149
150                 rc = copy_to_guest(vcpu, __LC_EXT_OLD_PSW,
151                          &vcpu->arch.sie_block->gpsw, sizeof(psw_t));
152                 if (rc == -EFAULT)
153                         exception = 1;
154
155                 rc = copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
156                         __LC_EXT_NEW_PSW, sizeof(psw_t));
157                 if (rc == -EFAULT)
158                         exception = 1;
159
160                 rc = put_guest_u32(vcpu, __LC_EXT_PARAMS, inti->ext.ext_params);
161                 if (rc == -EFAULT)
162                         exception = 1;
163                 break;
164
165         case KVM_S390_INT_VIRTIO:
166                 VCPU_EVENT(vcpu, 4, "interrupt: virtio parm:%x,parm64:%llx",
167                            inti->ext.ext_params, inti->ext.ext_params2);
168                 vcpu->stat.deliver_virtio_interrupt++;
169                 rc = put_guest_u16(vcpu, __LC_EXT_INT_CODE, 0x2603);
170                 if (rc == -EFAULT)
171                         exception = 1;
172
173                 rc = put_guest_u16(vcpu, __LC_CPU_ADDRESS, 0x0d00);
174                 if (rc == -EFAULT)
175                         exception = 1;
176
177                 rc = copy_to_guest(vcpu, __LC_EXT_OLD_PSW,
178                          &vcpu->arch.sie_block->gpsw, sizeof(psw_t));
179                 if (rc == -EFAULT)
180                         exception = 1;
181
182                 rc = copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
183                         __LC_EXT_NEW_PSW, sizeof(psw_t));
184                 if (rc == -EFAULT)
185                         exception = 1;
186
187                 rc = put_guest_u32(vcpu, __LC_EXT_PARAMS, inti->ext.ext_params);
188                 if (rc == -EFAULT)
189                         exception = 1;
190
191                 rc = put_guest_u64(vcpu, __LC_EXT_PARAMS2,
192                                    inti->ext.ext_params2);
193                 if (rc == -EFAULT)
194                         exception = 1;
195                 break;
196
197         case KVM_S390_SIGP_STOP:
198                 VCPU_EVENT(vcpu, 4, "%s", "interrupt: cpu stop");
199                 vcpu->stat.deliver_stop_signal++;
200                 __set_intercept_indicator(vcpu, inti);
201                 break;
202
203         case KVM_S390_SIGP_SET_PREFIX:
204                 VCPU_EVENT(vcpu, 4, "interrupt: set prefix to %x",
205                            inti->prefix.address);
206                 vcpu->stat.deliver_prefix_signal++;
207                 vcpu->arch.sie_block->prefix = inti->prefix.address;
208                 vcpu->arch.sie_block->ihcpu = 0xffff;
209                 break;
210
211         case KVM_S390_RESTART:
212                 VCPU_EVENT(vcpu, 4, "%s", "interrupt: cpu restart");
213                 vcpu->stat.deliver_restart_signal++;
214                 rc = copy_to_guest(vcpu, offsetof(struct _lowcore,
215                   restart_old_psw), &vcpu->arch.sie_block->gpsw, sizeof(psw_t));
216                 if (rc == -EFAULT)
217                         exception = 1;
218
219                 rc = copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
220                         offsetof(struct _lowcore, restart_psw), sizeof(psw_t));
221                 if (rc == -EFAULT)
222                         exception = 1;
223                 break;
224
225         case KVM_S390_PROGRAM_INT:
226                 VCPU_EVENT(vcpu, 4, "interrupt: pgm check code:%x, ilc:%x",
227                            inti->pgm.code,
228                            table[vcpu->arch.sie_block->ipa >> 14]);
229                 vcpu->stat.deliver_program_int++;
230                 rc = put_guest_u16(vcpu, __LC_PGM_INT_CODE, inti->pgm.code);
231                 if (rc == -EFAULT)
232                         exception = 1;
233
234                 rc = put_guest_u16(vcpu, __LC_PGM_ILC,
235                         table[vcpu->arch.sie_block->ipa >> 14]);
236                 if (rc == -EFAULT)
237                         exception = 1;
238
239                 rc = copy_to_guest(vcpu, __LC_PGM_OLD_PSW,
240                          &vcpu->arch.sie_block->gpsw, sizeof(psw_t));
241                 if (rc == -EFAULT)
242                         exception = 1;
243
244                 rc = copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
245                         __LC_PGM_NEW_PSW, sizeof(psw_t));
246                 if (rc == -EFAULT)
247                         exception = 1;
248                 break;
249
250         default:
251                 BUG();
252         }
253         if (exception) {
254                 printk("kvm: The guest lowcore is not mapped during interrupt "
255                         "delivery, killing userspace\n");
256                 do_exit(SIGKILL);
257         }
258 }
259
260 static int __try_deliver_ckc_interrupt(struct kvm_vcpu *vcpu)
261 {
262         int rc, exception = 0;
263
264         if (psw_extint_disabled(vcpu))
265                 return 0;
266         if (!(vcpu->arch.sie_block->gcr[0] & 0x800ul))
267                 return 0;
268         rc = put_guest_u16(vcpu, __LC_EXT_INT_CODE, 0x1004);
269         if (rc == -EFAULT)
270                 exception = 1;
271         rc = copy_to_guest(vcpu, __LC_EXT_OLD_PSW,
272                  &vcpu->arch.sie_block->gpsw, sizeof(psw_t));
273         if (rc == -EFAULT)
274                 exception = 1;
275         rc = copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
276                 __LC_EXT_NEW_PSW, sizeof(psw_t));
277         if (rc == -EFAULT)
278                 exception = 1;
279         if (exception) {
280                 printk("kvm: The guest lowcore is not mapped during interrupt "
281                         "delivery, killing userspace\n");
282                 do_exit(SIGKILL);
283         }
284         return 1;
285 }
286
287 static int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu)
288 {
289         struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
290         struct kvm_s390_float_interrupt *fi = vcpu->arch.local_int.float_int;
291         struct kvm_s390_interrupt_info  *inti;
292         int rc = 0;
293
294         if (atomic_read(&li->active)) {
295                 spin_lock_bh(&li->lock);
296                 list_for_each_entry(inti, &li->list, list)
297                         if (__interrupt_is_deliverable(vcpu, inti)) {
298                                 rc = 1;
299                                 break;
300                         }
301                 spin_unlock_bh(&li->lock);
302         }
303
304         if ((!rc) && atomic_read(&fi->active)) {
305                 spin_lock(&fi->lock);
306                 list_for_each_entry(inti, &fi->list, list)
307                         if (__interrupt_is_deliverable(vcpu, inti)) {
308                                 rc = 1;
309                                 break;
310                         }
311                 spin_unlock(&fi->lock);
312         }
313
314         if ((!rc) && (vcpu->arch.sie_block->ckc <
315                 get_clock() + vcpu->arch.sie_block->epoch)) {
316                 if ((!psw_extint_disabled(vcpu)) &&
317                         (vcpu->arch.sie_block->gcr[0] & 0x800ul))
318                         rc = 1;
319         }
320
321         return rc;
322 }
323
324 int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
325 {
326         return 0;
327 }
328
329 int kvm_s390_handle_wait(struct kvm_vcpu *vcpu)
330 {
331         u64 now, sltime;
332         DECLARE_WAITQUEUE(wait, current);
333
334         vcpu->stat.exit_wait_state++;
335         if (kvm_cpu_has_interrupt(vcpu))
336                 return 0;
337
338         __set_cpu_idle(vcpu);
339         spin_lock_bh(&vcpu->arch.local_int.lock);
340         vcpu->arch.local_int.timer_due = 0;
341         spin_unlock_bh(&vcpu->arch.local_int.lock);
342
343         if (psw_interrupts_disabled(vcpu)) {
344                 VCPU_EVENT(vcpu, 3, "%s", "disabled wait");
345                 __unset_cpu_idle(vcpu);
346                 return -EOPNOTSUPP; /* disabled wait */
347         }
348
349         if (psw_extint_disabled(vcpu) ||
350             (!(vcpu->arch.sie_block->gcr[0] & 0x800ul))) {
351                 VCPU_EVENT(vcpu, 3, "%s", "enabled wait w/o timer");
352                 goto no_timer;
353         }
354
355         now = get_clock() + vcpu->arch.sie_block->epoch;
356         if (vcpu->arch.sie_block->ckc < now) {
357                 __unset_cpu_idle(vcpu);
358                 return 0;
359         }
360
361         sltime = ((vcpu->arch.sie_block->ckc - now)*125)>>9;
362
363         hrtimer_start(&vcpu->arch.ckc_timer, ktime_set (0, sltime) , HRTIMER_MODE_REL);
364         VCPU_EVENT(vcpu, 5, "enabled wait via clock comparator: %llx ns", sltime);
365 no_timer:
366         spin_lock(&vcpu->arch.local_int.float_int->lock);
367         spin_lock_bh(&vcpu->arch.local_int.lock);
368         add_wait_queue(&vcpu->arch.local_int.wq, &wait);
369         while (list_empty(&vcpu->arch.local_int.list) &&
370                 list_empty(&vcpu->arch.local_int.float_int->list) &&
371                 (!vcpu->arch.local_int.timer_due) &&
372                 !signal_pending(current)) {
373                 set_current_state(TASK_INTERRUPTIBLE);
374                 spin_unlock_bh(&vcpu->arch.local_int.lock);
375                 spin_unlock(&vcpu->arch.local_int.float_int->lock);
376                 vcpu_put(vcpu);
377                 schedule();
378                 vcpu_load(vcpu);
379                 spin_lock(&vcpu->arch.local_int.float_int->lock);
380                 spin_lock_bh(&vcpu->arch.local_int.lock);
381         }
382         __unset_cpu_idle(vcpu);
383         __set_current_state(TASK_RUNNING);
384         remove_wait_queue(&vcpu->arch.local_int.wq, &wait);
385         spin_unlock_bh(&vcpu->arch.local_int.lock);
386         spin_unlock(&vcpu->arch.local_int.float_int->lock);
387         hrtimer_try_to_cancel(&vcpu->arch.ckc_timer);
388         return 0;
389 }
390
391 void kvm_s390_tasklet(unsigned long parm)
392 {
393         struct kvm_vcpu *vcpu = (struct kvm_vcpu *) parm;
394
395         spin_lock(&vcpu->arch.local_int.lock);
396         vcpu->arch.local_int.timer_due = 1;
397         if (waitqueue_active(&vcpu->arch.local_int.wq))
398                 wake_up_interruptible(&vcpu->arch.local_int.wq);
399         spin_unlock(&vcpu->arch.local_int.lock);
400 }
401
402 /*
403  * low level hrtimer wake routine. Because this runs in hardirq context
404  * we schedule a tasklet to do the real work.
405  */
406 enum hrtimer_restart kvm_s390_idle_wakeup(struct hrtimer *timer)
407 {
408         struct kvm_vcpu *vcpu;
409
410         vcpu = container_of(timer, struct kvm_vcpu, arch.ckc_timer);
411         tasklet_schedule(&vcpu->arch.tasklet);
412
413         return HRTIMER_NORESTART;
414 }
415
416 void kvm_s390_deliver_pending_interrupts(struct kvm_vcpu *vcpu)
417 {
418         struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
419         struct kvm_s390_float_interrupt *fi = vcpu->arch.local_int.float_int;
420         struct kvm_s390_interrupt_info  *n, *inti = NULL;
421         int deliver;
422
423         __reset_intercept_indicators(vcpu);
424         if (atomic_read(&li->active)) {
425                 do {
426                         deliver = 0;
427                         spin_lock_bh(&li->lock);
428                         list_for_each_entry_safe(inti, n, &li->list, list) {
429                                 if (__interrupt_is_deliverable(vcpu, inti)) {
430                                         list_del(&inti->list);
431                                         deliver = 1;
432                                         break;
433                                 }
434                                 __set_intercept_indicator(vcpu, inti);
435                         }
436                         if (list_empty(&li->list))
437                                 atomic_set(&li->active, 0);
438                         spin_unlock_bh(&li->lock);
439                         if (deliver) {
440                                 __do_deliver_interrupt(vcpu, inti);
441                                 kfree(inti);
442                         }
443                 } while (deliver);
444         }
445
446         if ((vcpu->arch.sie_block->ckc <
447                 get_clock() + vcpu->arch.sie_block->epoch))
448                 __try_deliver_ckc_interrupt(vcpu);
449
450         if (atomic_read(&fi->active)) {
451                 do {
452                         deliver = 0;
453                         spin_lock(&fi->lock);
454                         list_for_each_entry_safe(inti, n, &fi->list, list) {
455                                 if (__interrupt_is_deliverable(vcpu, inti)) {
456                                         list_del(&inti->list);
457                                         deliver = 1;
458                                         break;
459                                 }
460                                 __set_intercept_indicator(vcpu, inti);
461                         }
462                         if (list_empty(&fi->list))
463                                 atomic_set(&fi->active, 0);
464                         spin_unlock(&fi->lock);
465                         if (deliver) {
466                                 __do_deliver_interrupt(vcpu, inti);
467                                 kfree(inti);
468                         }
469                 } while (deliver);
470         }
471 }
472
473 int kvm_s390_inject_program_int(struct kvm_vcpu *vcpu, u16 code)
474 {
475         struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
476         struct kvm_s390_interrupt_info *inti;
477
478         inti = kzalloc(sizeof(*inti), GFP_KERNEL);
479         if (!inti)
480                 return -ENOMEM;
481
482         inti->type = KVM_S390_PROGRAM_INT;
483         inti->pgm.code = code;
484
485         VCPU_EVENT(vcpu, 3, "inject: program check %d (from kernel)", code);
486         spin_lock_bh(&li->lock);
487         list_add(&inti->list, &li->list);
488         atomic_set(&li->active, 1);
489         BUG_ON(waitqueue_active(&li->wq));
490         spin_unlock_bh(&li->lock);
491         return 0;
492 }
493
494 int kvm_s390_inject_vm(struct kvm *kvm,
495                        struct kvm_s390_interrupt *s390int)
496 {
497         struct kvm_s390_local_interrupt *li;
498         struct kvm_s390_float_interrupt *fi;
499         struct kvm_s390_interrupt_info *inti;
500         int sigcpu;
501
502         inti = kzalloc(sizeof(*inti), GFP_KERNEL);
503         if (!inti)
504                 return -ENOMEM;
505
506         switch (s390int->type) {
507         case KVM_S390_INT_VIRTIO:
508                 VM_EVENT(kvm, 5, "inject: virtio parm:%x,parm64:%llx",
509                          s390int->parm, s390int->parm64);
510                 inti->type = s390int->type;
511                 inti->ext.ext_params = s390int->parm;
512                 inti->ext.ext_params2 = s390int->parm64;
513                 break;
514         case KVM_S390_INT_SERVICE:
515                 VM_EVENT(kvm, 5, "inject: sclp parm:%x", s390int->parm);
516                 inti->type = s390int->type;
517                 inti->ext.ext_params = s390int->parm;
518                 break;
519         case KVM_S390_PROGRAM_INT:
520         case KVM_S390_SIGP_STOP:
521         case KVM_S390_INT_EMERGENCY:
522         default:
523                 kfree(inti);
524                 return -EINVAL;
525         }
526
527         mutex_lock(&kvm->lock);
528         fi = &kvm->arch.float_int;
529         spin_lock(&fi->lock);
530         list_add_tail(&inti->list, &fi->list);
531         atomic_set(&fi->active, 1);
532         sigcpu = find_first_bit(fi->idle_mask, KVM_MAX_VCPUS);
533         if (sigcpu == KVM_MAX_VCPUS) {
534                 do {
535                         sigcpu = fi->next_rr_cpu++;
536                         if (sigcpu == KVM_MAX_VCPUS)
537                                 sigcpu = fi->next_rr_cpu = 0;
538                 } while (fi->local_int[sigcpu] == NULL);
539         }
540         li = fi->local_int[sigcpu];
541         spin_lock_bh(&li->lock);
542         atomic_set_mask(CPUSTAT_EXT_INT, li->cpuflags);
543         if (waitqueue_active(&li->wq))
544                 wake_up_interruptible(&li->wq);
545         spin_unlock_bh(&li->lock);
546         spin_unlock(&fi->lock);
547         mutex_unlock(&kvm->lock);
548         return 0;
549 }
550
551 int kvm_s390_inject_vcpu(struct kvm_vcpu *vcpu,
552                          struct kvm_s390_interrupt *s390int)
553 {
554         struct kvm_s390_local_interrupt *li;
555         struct kvm_s390_interrupt_info *inti;
556
557         inti = kzalloc(sizeof(*inti), GFP_KERNEL);
558         if (!inti)
559                 return -ENOMEM;
560
561         switch (s390int->type) {
562         case KVM_S390_PROGRAM_INT:
563                 if (s390int->parm & 0xffff0000) {
564                         kfree(inti);
565                         return -EINVAL;
566                 }
567                 inti->type = s390int->type;
568                 inti->pgm.code = s390int->parm;
569                 VCPU_EVENT(vcpu, 3, "inject: program check %d (from user)",
570                            s390int->parm);
571                 break;
572         case KVM_S390_SIGP_SET_PREFIX:
573                 inti->prefix.address = s390int->parm;
574                 inti->type = s390int->type;
575                 VCPU_EVENT(vcpu, 3, "inject: set prefix to %x (from user)",
576                            s390int->parm);
577                 break;
578         case KVM_S390_SIGP_STOP:
579         case KVM_S390_RESTART:
580         case KVM_S390_INT_EMERGENCY:
581                 VCPU_EVENT(vcpu, 3, "inject: type %x", s390int->type);
582                 inti->type = s390int->type;
583                 break;
584         case KVM_S390_INT_VIRTIO:
585         case KVM_S390_INT_SERVICE:
586         default:
587                 kfree(inti);
588                 return -EINVAL;
589         }
590
591         mutex_lock(&vcpu->kvm->lock);
592         li = &vcpu->arch.local_int;
593         spin_lock_bh(&li->lock);
594         if (inti->type == KVM_S390_PROGRAM_INT)
595                 list_add(&inti->list, &li->list);
596         else
597                 list_add_tail(&inti->list, &li->list);
598         atomic_set(&li->active, 1);
599         if (inti->type == KVM_S390_SIGP_STOP)
600                 li->action_bits |= ACTION_STOP_ON_STOP;
601         atomic_set_mask(CPUSTAT_EXT_INT, li->cpuflags);
602         if (waitqueue_active(&li->wq))
603                 wake_up_interruptible(&vcpu->arch.local_int.wq);
604         spin_unlock_bh(&li->lock);
605         mutex_unlock(&vcpu->kvm->lock);
606         return 0;
607 }