1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * kvm guest debug support
4 *
5 * Copyright IBM Corp. 2014
6 *
7 * Author(s): David Hildenbrand <dahi@linux.vnet.ibm.com>
8 */
9 #include <linux/kvm_host.h>
10 #include <linux/errno.h>
11 #include "kvm-s390.h"
12 #include "gaccess.h"
13
14 /*
15 * Extends the address range given by *start and *stop to include the address
16 * range starting with estart and the length len. Takes care of overflowing
17 * intervals and tries to minimize the overall interval size.
18 */
extend_address_range(u64 * start,u64 * stop,u64 estart,int len)19 static void extend_address_range(u64 *start, u64 *stop, u64 estart, int len)
20 {
21 u64 estop;
22
23 if (len > 0)
24 len--;
25 else
26 len = 0;
27
28 estop = estart + len;
29
30 /* 0-0 range represents "not set" */
31 if ((*start == 0) && (*stop == 0)) {
32 *start = estart;
33 *stop = estop;
34 } else if (*start <= *stop) {
35 /* increase the existing range */
36 if (estart < *start)
37 *start = estart;
38 if (estop > *stop)
39 *stop = estop;
40 } else {
41 /* "overflowing" interval, whereby *stop > *start */
42 if (estart <= *stop) {
43 if (estop > *stop)
44 *stop = estop;
45 } else if (estop > *start) {
46 if (estart < *start)
47 *start = estart;
48 }
49 /* minimize the range */
50 else if ((estop - *stop) < (*start - estart))
51 *stop = estop;
52 else
53 *start = estart;
54 }
55 }
56
57 #define MAX_INST_SIZE 6
58
enable_all_hw_bp(struct kvm_vcpu * vcpu)59 static void enable_all_hw_bp(struct kvm_vcpu *vcpu)
60 {
61 unsigned long start, len;
62 u64 *cr9 = &vcpu->arch.sie_block->gcr[9];
63 u64 *cr10 = &vcpu->arch.sie_block->gcr[10];
64 u64 *cr11 = &vcpu->arch.sie_block->gcr[11];
65 int i;
66
67 if (vcpu->arch.guestdbg.nr_hw_bp <= 0 ||
68 vcpu->arch.guestdbg.hw_bp_info == NULL)
69 return;
70
71 /*
72 * If the guest is not interested in branching events, we can safely
73 * limit them to the PER address range.
74 */
75 if (!(*cr9 & PER_EVENT_BRANCH))
76 *cr9 |= PER_CONTROL_BRANCH_ADDRESS;
77 *cr9 |= PER_EVENT_IFETCH | PER_EVENT_BRANCH;
78
79 for (i = 0; i < vcpu->arch.guestdbg.nr_hw_bp; i++) {
80 start = vcpu->arch.guestdbg.hw_bp_info[i].addr;
81 len = vcpu->arch.guestdbg.hw_bp_info[i].len;
82
83 /*
84 * The instruction in front of the desired bp has to
85 * report instruction-fetching events
86 */
87 if (start < MAX_INST_SIZE) {
88 len += start;
89 start = 0;
90 } else {
91 start -= MAX_INST_SIZE;
92 len += MAX_INST_SIZE;
93 }
94
95 extend_address_range(cr10, cr11, start, len);
96 }
97 }
98
enable_all_hw_wp(struct kvm_vcpu * vcpu)99 static void enable_all_hw_wp(struct kvm_vcpu *vcpu)
100 {
101 unsigned long start, len;
102 u64 *cr9 = &vcpu->arch.sie_block->gcr[9];
103 u64 *cr10 = &vcpu->arch.sie_block->gcr[10];
104 u64 *cr11 = &vcpu->arch.sie_block->gcr[11];
105 int i;
106
107 if (vcpu->arch.guestdbg.nr_hw_wp <= 0 ||
108 vcpu->arch.guestdbg.hw_wp_info == NULL)
109 return;
110
111 /* if host uses storage alternation for special address
112 * spaces, enable all events and give all to the guest */
113 if (*cr9 & PER_EVENT_STORE && *cr9 & PER_CONTROL_ALTERATION) {
114 *cr9 &= ~PER_CONTROL_ALTERATION;
115 *cr10 = 0;
116 *cr11 = -1UL;
117 } else {
118 *cr9 &= ~PER_CONTROL_ALTERATION;
119 *cr9 |= PER_EVENT_STORE;
120
121 for (i = 0; i < vcpu->arch.guestdbg.nr_hw_wp; i++) {
122 start = vcpu->arch.guestdbg.hw_wp_info[i].addr;
123 len = vcpu->arch.guestdbg.hw_wp_info[i].len;
124
125 extend_address_range(cr10, cr11, start, len);
126 }
127 }
128 }
129
kvm_s390_backup_guest_per_regs(struct kvm_vcpu * vcpu)130 void kvm_s390_backup_guest_per_regs(struct kvm_vcpu *vcpu)
131 {
132 vcpu->arch.guestdbg.cr0 = vcpu->arch.sie_block->gcr[0];
133 vcpu->arch.guestdbg.cr9 = vcpu->arch.sie_block->gcr[9];
134 vcpu->arch.guestdbg.cr10 = vcpu->arch.sie_block->gcr[10];
135 vcpu->arch.guestdbg.cr11 = vcpu->arch.sie_block->gcr[11];
136 }
137
kvm_s390_restore_guest_per_regs(struct kvm_vcpu * vcpu)138 void kvm_s390_restore_guest_per_regs(struct kvm_vcpu *vcpu)
139 {
140 vcpu->arch.sie_block->gcr[0] = vcpu->arch.guestdbg.cr0;
141 vcpu->arch.sie_block->gcr[9] = vcpu->arch.guestdbg.cr9;
142 vcpu->arch.sie_block->gcr[10] = vcpu->arch.guestdbg.cr10;
143 vcpu->arch.sie_block->gcr[11] = vcpu->arch.guestdbg.cr11;
144 }
145
kvm_s390_patch_guest_per_regs(struct kvm_vcpu * vcpu)146 void kvm_s390_patch_guest_per_regs(struct kvm_vcpu *vcpu)
147 {
148 /*
149 * TODO: if guest psw has per enabled, otherwise 0s!
150 * This reduces the amount of reported events.
151 * Need to intercept all psw changes!
152 */
153
154 if (guestdbg_sstep_enabled(vcpu)) {
155 /* disable timer (clock-comparator) interrupts */
156 vcpu->arch.sie_block->gcr[0] &= ~CR0_CLOCK_COMPARATOR_SUBMASK;
157 vcpu->arch.sie_block->gcr[9] |= PER_EVENT_IFETCH;
158 vcpu->arch.sie_block->gcr[10] = 0;
159 vcpu->arch.sie_block->gcr[11] = -1UL;
160 }
161
162 if (guestdbg_hw_bp_enabled(vcpu)) {
163 enable_all_hw_bp(vcpu);
164 enable_all_hw_wp(vcpu);
165 }
166
167 /* TODO: Instruction-fetching-nullification not allowed for now */
168 if (vcpu->arch.sie_block->gcr[9] & PER_EVENT_NULLIFICATION)
169 vcpu->arch.sie_block->gcr[9] &= ~PER_EVENT_NULLIFICATION;
170 }
171
172 #define MAX_WP_SIZE 100
173
__import_wp_info(struct kvm_vcpu * vcpu,struct kvm_hw_breakpoint * bp_data,struct kvm_hw_wp_info_arch * wp_info)174 static int __import_wp_info(struct kvm_vcpu *vcpu,
175 struct kvm_hw_breakpoint *bp_data,
176 struct kvm_hw_wp_info_arch *wp_info)
177 {
178 int ret = 0;
179 wp_info->len = bp_data->len;
180 wp_info->addr = bp_data->addr;
181 wp_info->phys_addr = bp_data->phys_addr;
182 wp_info->old_data = NULL;
183
184 if (wp_info->len < 0 || wp_info->len > MAX_WP_SIZE)
185 return -EINVAL;
186
187 wp_info->old_data = kmalloc(bp_data->len, GFP_KERNEL);
188 if (!wp_info->old_data)
189 return -ENOMEM;
190 /* try to backup the original value */
191 ret = read_guest_abs(vcpu, wp_info->phys_addr, wp_info->old_data,
192 wp_info->len);
193 if (ret) {
194 kfree(wp_info->old_data);
195 wp_info->old_data = NULL;
196 }
197
198 return ret;
199 }
200
201 #define MAX_BP_COUNT 50
202
kvm_s390_import_bp_data(struct kvm_vcpu * vcpu,struct kvm_guest_debug * dbg)203 int kvm_s390_import_bp_data(struct kvm_vcpu *vcpu,
204 struct kvm_guest_debug *dbg)
205 {
206 int ret = 0, nr_wp = 0, nr_bp = 0, i;
207 struct kvm_hw_breakpoint *bp_data = NULL;
208 struct kvm_hw_wp_info_arch *wp_info = NULL;
209 struct kvm_hw_bp_info_arch *bp_info = NULL;
210
211 if (dbg->arch.nr_hw_bp <= 0 || !dbg->arch.hw_bp)
212 return 0;
213 else if (dbg->arch.nr_hw_bp > MAX_BP_COUNT)
214 return -EINVAL;
215
216 bp_data = memdup_user(dbg->arch.hw_bp,
217 sizeof(*bp_data) * dbg->arch.nr_hw_bp);
218 if (IS_ERR(bp_data))
219 return PTR_ERR(bp_data);
220
221 for (i = 0; i < dbg->arch.nr_hw_bp; i++) {
222 switch (bp_data[i].type) {
223 case KVM_HW_WP_WRITE:
224 nr_wp++;
225 break;
226 case KVM_HW_BP:
227 nr_bp++;
228 break;
229 default:
230 break;
231 }
232 }
233
234 if (nr_wp > 0) {
235 wp_info = kmalloc_array(nr_wp,
236 sizeof(*wp_info),
237 GFP_KERNEL);
238 if (!wp_info) {
239 ret = -ENOMEM;
240 goto error;
241 }
242 }
243 if (nr_bp > 0) {
244 bp_info = kmalloc_array(nr_bp,
245 sizeof(*bp_info),
246 GFP_KERNEL);
247 if (!bp_info) {
248 ret = -ENOMEM;
249 goto error;
250 }
251 }
252
253 for (nr_wp = 0, nr_bp = 0, i = 0; i < dbg->arch.nr_hw_bp; i++) {
254 switch (bp_data[i].type) {
255 case KVM_HW_WP_WRITE:
256 ret = __import_wp_info(vcpu, &bp_data[i],
257 &wp_info[nr_wp]);
258 if (ret)
259 goto error;
260 nr_wp++;
261 break;
262 case KVM_HW_BP:
263 bp_info[nr_bp].len = bp_data[i].len;
264 bp_info[nr_bp].addr = bp_data[i].addr;
265 nr_bp++;
266 break;
267 }
268 }
269
270 vcpu->arch.guestdbg.nr_hw_bp = nr_bp;
271 vcpu->arch.guestdbg.hw_bp_info = bp_info;
272 vcpu->arch.guestdbg.nr_hw_wp = nr_wp;
273 vcpu->arch.guestdbg.hw_wp_info = wp_info;
274 return 0;
275 error:
276 kfree(bp_data);
277 kfree(wp_info);
278 kfree(bp_info);
279 return ret;
280 }
281
kvm_s390_clear_bp_data(struct kvm_vcpu * vcpu)282 void kvm_s390_clear_bp_data(struct kvm_vcpu *vcpu)
283 {
284 int i;
285 struct kvm_hw_wp_info_arch *hw_wp_info = NULL;
286
287 for (i = 0; i < vcpu->arch.guestdbg.nr_hw_wp; i++) {
288 hw_wp_info = &vcpu->arch.guestdbg.hw_wp_info[i];
289 kfree(hw_wp_info->old_data);
290 hw_wp_info->old_data = NULL;
291 }
292 kfree(vcpu->arch.guestdbg.hw_wp_info);
293 vcpu->arch.guestdbg.hw_wp_info = NULL;
294
295 kfree(vcpu->arch.guestdbg.hw_bp_info);
296 vcpu->arch.guestdbg.hw_bp_info = NULL;
297
298 vcpu->arch.guestdbg.nr_hw_wp = 0;
299 vcpu->arch.guestdbg.nr_hw_bp = 0;
300 }
301
in_addr_range(u64 addr,u64 a,u64 b)302 static inline int in_addr_range(u64 addr, u64 a, u64 b)
303 {
304 if (a <= b)
305 return (addr >= a) && (addr <= b);
306 else
307 /* "overflowing" interval */
308 return (addr >= a) || (addr <= b);
309 }
310
311 #define end_of_range(bp_info) (bp_info->addr + bp_info->len - 1)
312
find_hw_bp(struct kvm_vcpu * vcpu,unsigned long addr)313 static struct kvm_hw_bp_info_arch *find_hw_bp(struct kvm_vcpu *vcpu,
314 unsigned long addr)
315 {
316 struct kvm_hw_bp_info_arch *bp_info = vcpu->arch.guestdbg.hw_bp_info;
317 int i;
318
319 if (vcpu->arch.guestdbg.nr_hw_bp == 0)
320 return NULL;
321
322 for (i = 0; i < vcpu->arch.guestdbg.nr_hw_bp; i++) {
323 /* addr is directly the start or in the range of a bp */
324 if (addr == bp_info->addr)
325 goto found;
326 if (bp_info->len > 0 &&
327 in_addr_range(addr, bp_info->addr, end_of_range(bp_info)))
328 goto found;
329
330 bp_info++;
331 }
332
333 return NULL;
334 found:
335 return bp_info;
336 }
337
any_wp_changed(struct kvm_vcpu * vcpu)338 static struct kvm_hw_wp_info_arch *any_wp_changed(struct kvm_vcpu *vcpu)
339 {
340 int i;
341 struct kvm_hw_wp_info_arch *wp_info = NULL;
342 void *temp = NULL;
343
344 if (vcpu->arch.guestdbg.nr_hw_wp == 0)
345 return NULL;
346
347 for (i = 0; i < vcpu->arch.guestdbg.nr_hw_wp; i++) {
348 wp_info = &vcpu->arch.guestdbg.hw_wp_info[i];
349 if (!wp_info || !wp_info->old_data || wp_info->len <= 0)
350 continue;
351
352 temp = kmalloc(wp_info->len, GFP_KERNEL);
353 if (!temp)
354 continue;
355
356 /* refetch the wp data and compare it to the old value */
357 if (!read_guest_abs(vcpu, wp_info->phys_addr, temp,
358 wp_info->len)) {
359 if (memcmp(temp, wp_info->old_data, wp_info->len)) {
360 kfree(temp);
361 return wp_info;
362 }
363 }
364 kfree(temp);
365 temp = NULL;
366 }
367
368 return NULL;
369 }
370
kvm_s390_prepare_debug_exit(struct kvm_vcpu * vcpu)371 void kvm_s390_prepare_debug_exit(struct kvm_vcpu *vcpu)
372 {
373 vcpu->run->exit_reason = KVM_EXIT_DEBUG;
374 vcpu->guest_debug &= ~KVM_GUESTDBG_EXIT_PENDING;
375 }
376
377 #define PER_CODE_MASK (PER_EVENT_MASK >> 24)
378 #define PER_CODE_BRANCH (PER_EVENT_BRANCH >> 24)
379 #define PER_CODE_IFETCH (PER_EVENT_IFETCH >> 24)
380 #define PER_CODE_STORE (PER_EVENT_STORE >> 24)
381 #define PER_CODE_STORE_REAL (PER_EVENT_STORE_REAL >> 24)
382
383 #define per_bp_event(code) \
384 (code & (PER_CODE_IFETCH | PER_CODE_BRANCH))
385 #define per_write_wp_event(code) \
386 (code & (PER_CODE_STORE | PER_CODE_STORE_REAL))
387
debug_exit_required(struct kvm_vcpu * vcpu,u8 perc,unsigned long peraddr)388 static int debug_exit_required(struct kvm_vcpu *vcpu, u8 perc,
389 unsigned long peraddr)
390 {
391 struct kvm_debug_exit_arch *debug_exit = &vcpu->run->debug.arch;
392 struct kvm_hw_wp_info_arch *wp_info = NULL;
393 struct kvm_hw_bp_info_arch *bp_info = NULL;
394 unsigned long addr = vcpu->arch.sie_block->gpsw.addr;
395
396 if (guestdbg_hw_bp_enabled(vcpu)) {
397 if (per_write_wp_event(perc) &&
398 vcpu->arch.guestdbg.nr_hw_wp > 0) {
399 wp_info = any_wp_changed(vcpu);
400 if (wp_info) {
401 debug_exit->addr = wp_info->addr;
402 debug_exit->type = KVM_HW_WP_WRITE;
403 goto exit_required;
404 }
405 }
406 if (per_bp_event(perc) &&
407 vcpu->arch.guestdbg.nr_hw_bp > 0) {
408 bp_info = find_hw_bp(vcpu, addr);
409 /* remove duplicate events if PC==PER address */
410 if (bp_info && (addr != peraddr)) {
411 debug_exit->addr = addr;
412 debug_exit->type = KVM_HW_BP;
413 vcpu->arch.guestdbg.last_bp = addr;
414 goto exit_required;
415 }
416 /* breakpoint missed */
417 bp_info = find_hw_bp(vcpu, peraddr);
418 if (bp_info && vcpu->arch.guestdbg.last_bp != peraddr) {
419 debug_exit->addr = peraddr;
420 debug_exit->type = KVM_HW_BP;
421 goto exit_required;
422 }
423 }
424 }
425 if (guestdbg_sstep_enabled(vcpu) && per_bp_event(perc)) {
426 debug_exit->addr = addr;
427 debug_exit->type = KVM_SINGLESTEP;
428 goto exit_required;
429 }
430
431 return 0;
432 exit_required:
433 return 1;
434 }
435
per_fetched_addr(struct kvm_vcpu * vcpu,unsigned long * addr)436 static int per_fetched_addr(struct kvm_vcpu *vcpu, unsigned long *addr)
437 {
438 u8 exec_ilen = 0;
439 u16 opcode[3];
440 int rc;
441
442 if (vcpu->arch.sie_block->icptcode == ICPT_PROGI) {
443 /* PER address references the fetched or the execute instr */
444 *addr = vcpu->arch.sie_block->peraddr;
445 /*
446 * Manually detect if we have an EXECUTE instruction. As
447 * instructions are always 2 byte aligned we can read the
448 * first two bytes unconditionally
449 */
450 rc = read_guest_instr(vcpu, *addr, &opcode, 2);
451 if (rc)
452 return rc;
453 if (opcode[0] >> 8 == 0x44)
454 exec_ilen = 4;
455 if ((opcode[0] & 0xff0f) == 0xc600)
456 exec_ilen = 6;
457 } else {
458 /* instr was suppressed, calculate the responsible instr */
459 *addr = __rewind_psw(vcpu->arch.sie_block->gpsw,
460 kvm_s390_get_ilen(vcpu));
461 if (vcpu->arch.sie_block->icptstatus & 0x01) {
462 exec_ilen = (vcpu->arch.sie_block->icptstatus & 0x60) >> 4;
463 if (!exec_ilen)
464 exec_ilen = 4;
465 }
466 }
467
468 if (exec_ilen) {
469 /* read the complete EXECUTE instr to detect the fetched addr */
470 rc = read_guest_instr(vcpu, *addr, &opcode, exec_ilen);
471 if (rc)
472 return rc;
473 if (exec_ilen == 6) {
474 /* EXECUTE RELATIVE LONG - RIL-b format */
475 s32 rl = *((s32 *) (opcode + 1));
476
477 /* rl is a _signed_ 32 bit value specifying halfwords */
478 *addr += (u64)(s64) rl * 2;
479 } else {
480 /* EXECUTE - RX-a format */
481 u32 base = (opcode[1] & 0xf000) >> 12;
482 u32 disp = opcode[1] & 0x0fff;
483 u32 index = opcode[0] & 0x000f;
484
485 *addr = base ? vcpu->run->s.regs.gprs[base] : 0;
486 *addr += index ? vcpu->run->s.regs.gprs[index] : 0;
487 *addr += disp;
488 }
489 *addr = kvm_s390_logical_to_effective(vcpu, *addr);
490 }
491 return 0;
492 }
493
494 #define guest_per_enabled(vcpu) \
495 (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PER)
496
kvm_s390_handle_per_ifetch_icpt(struct kvm_vcpu * vcpu)497 int kvm_s390_handle_per_ifetch_icpt(struct kvm_vcpu *vcpu)
498 {
499 const u64 cr10 = vcpu->arch.sie_block->gcr[10];
500 const u64 cr11 = vcpu->arch.sie_block->gcr[11];
501 const u8 ilen = kvm_s390_get_ilen(vcpu);
502 struct kvm_s390_pgm_info pgm_info = {
503 .code = PGM_PER,
504 .per_code = PER_CODE_IFETCH,
505 .per_address = __rewind_psw(vcpu->arch.sie_block->gpsw, ilen),
506 };
507 unsigned long fetched_addr;
508 int rc;
509
510 /*
511 * The PSW points to the next instruction, therefore the intercepted
512 * instruction generated a PER i-fetch event. PER address therefore
513 * points at the previous PSW address (could be an EXECUTE function).
514 */
515 if (!guestdbg_enabled(vcpu))
516 return kvm_s390_inject_prog_irq(vcpu, &pgm_info);
517
518 if (debug_exit_required(vcpu, pgm_info.per_code, pgm_info.per_address))
519 vcpu->guest_debug |= KVM_GUESTDBG_EXIT_PENDING;
520
521 if (!guest_per_enabled(vcpu) ||
522 !(vcpu->arch.sie_block->gcr[9] & PER_EVENT_IFETCH))
523 return 0;
524
525 rc = per_fetched_addr(vcpu, &fetched_addr);
526 if (rc < 0)
527 return rc;
528 if (rc)
529 /* instruction-fetching exceptions */
530 return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
531
532 if (in_addr_range(fetched_addr, cr10, cr11))
533 return kvm_s390_inject_prog_irq(vcpu, &pgm_info);
534 return 0;
535 }
536
filter_guest_per_event(struct kvm_vcpu * vcpu)537 static int filter_guest_per_event(struct kvm_vcpu *vcpu)
538 {
539 const u8 perc = vcpu->arch.sie_block->perc;
540 u64 addr = vcpu->arch.sie_block->gpsw.addr;
541 u64 cr9 = vcpu->arch.sie_block->gcr[9];
542 u64 cr10 = vcpu->arch.sie_block->gcr[10];
543 u64 cr11 = vcpu->arch.sie_block->gcr[11];
544 /* filter all events, demanded by the guest */
545 u8 guest_perc = perc & (cr9 >> 24) & PER_CODE_MASK;
546 unsigned long fetched_addr;
547 int rc;
548
549 if (!guest_per_enabled(vcpu))
550 guest_perc = 0;
551
552 /* filter "successful-branching" events */
553 if (guest_perc & PER_CODE_BRANCH &&
554 cr9 & PER_CONTROL_BRANCH_ADDRESS &&
555 !in_addr_range(addr, cr10, cr11))
556 guest_perc &= ~PER_CODE_BRANCH;
557
558 /* filter "instruction-fetching" events */
559 if (guest_perc & PER_CODE_IFETCH) {
560 rc = per_fetched_addr(vcpu, &fetched_addr);
561 if (rc < 0)
562 return rc;
563 /*
564 * Don't inject an irq on exceptions. This would make handling
565 * on icpt code 8 very complex (as PSW was already rewound).
566 */
567 if (rc || !in_addr_range(fetched_addr, cr10, cr11))
568 guest_perc &= ~PER_CODE_IFETCH;
569 }
570
571 /* All other PER events will be given to the guest */
572 /* TODO: Check altered address/address space */
573
574 vcpu->arch.sie_block->perc = guest_perc;
575
576 if (!guest_perc)
577 vcpu->arch.sie_block->iprcc &= ~PGM_PER;
578 return 0;
579 }
580
581 #define pssec(vcpu) (vcpu->arch.sie_block->gcr[1] & _ASCE_SPACE_SWITCH)
582 #define hssec(vcpu) (vcpu->arch.sie_block->gcr[13] & _ASCE_SPACE_SWITCH)
583 #define old_ssec(vcpu) ((vcpu->arch.sie_block->tecmc >> 31) & 0x1)
584 #define old_as_is_home(vcpu) !(vcpu->arch.sie_block->tecmc & 0xffff)
585
kvm_s390_handle_per_event(struct kvm_vcpu * vcpu)586 int kvm_s390_handle_per_event(struct kvm_vcpu *vcpu)
587 {
588 int rc, new_as;
589
590 if (debug_exit_required(vcpu, vcpu->arch.sie_block->perc,
591 vcpu->arch.sie_block->peraddr))
592 vcpu->guest_debug |= KVM_GUESTDBG_EXIT_PENDING;
593
594 rc = filter_guest_per_event(vcpu);
595 if (rc)
596 return rc;
597
598 /*
599 * Only RP, SAC, SACF, PT, PTI, PR, PC instructions can trigger
600 * a space-switch event. PER events enforce space-switch events
601 * for these instructions. So if no PER event for the guest is left,
602 * we might have to filter the space-switch element out, too.
603 */
604 if (vcpu->arch.sie_block->iprcc == PGM_SPACE_SWITCH) {
605 vcpu->arch.sie_block->iprcc = 0;
606 new_as = psw_bits(vcpu->arch.sie_block->gpsw).as;
607
608 /*
609 * If the AS changed from / to home, we had RP, SAC or SACF
610 * instruction. Check primary and home space-switch-event
611 * controls. (theoretically home -> home produced no event)
612 */
613 if (((new_as == PSW_BITS_AS_HOME) ^ old_as_is_home(vcpu)) &&
614 (pssec(vcpu) || hssec(vcpu)))
615 vcpu->arch.sie_block->iprcc = PGM_SPACE_SWITCH;
616
617 /*
618 * PT, PTI, PR, PC instruction operate on primary AS only. Check
619 * if the primary-space-switch-event control was or got set.
620 */
621 if (new_as == PSW_BITS_AS_PRIMARY && !old_as_is_home(vcpu) &&
622 (pssec(vcpu) || old_ssec(vcpu)))
623 vcpu->arch.sie_block->iprcc = PGM_SPACE_SWITCH;
624 }
625 return 0;
626 }
627
