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