xref: /linux/arch/s390/kvm/intercept.c (revision 2241f81c91f211b512bd2c3a26a4a74258d0e008)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * in-kernel handling for sie intercepts
4  *
5  * Copyright IBM Corp. 2008, 2020
6  *
7  *    Author(s): Carsten Otte <cotte@de.ibm.com>
8  *               Christian Borntraeger <borntraeger@de.ibm.com>
9  */
10 
11 #include <linux/kvm_host.h>
12 #include <linux/errno.h>
13 #include <linux/pagemap.h>
14 
15 #include <asm/asm-offsets.h>
16 #include <asm/irq.h>
17 #include <asm/sysinfo.h>
18 #include <asm/uv.h>
19 
20 #include "kvm-s390.h"
21 #include "gaccess.h"
22 #include "trace.h"
23 #include "trace-s390.h"
24 
25 u8 kvm_s390_get_ilen(struct kvm_vcpu *vcpu)
26 {
27 	struct kvm_s390_sie_block *sie_block = vcpu->arch.sie_block;
28 	u8 ilen = 0;
29 
30 	switch (vcpu->arch.sie_block->icptcode) {
31 	case ICPT_INST:
32 	case ICPT_INSTPROGI:
33 	case ICPT_OPEREXC:
34 	case ICPT_PARTEXEC:
35 	case ICPT_IOINST:
36 		/* instruction only stored for these icptcodes */
37 		ilen = insn_length(vcpu->arch.sie_block->ipa >> 8);
38 		/* Use the length of the EXECUTE instruction if necessary */
39 		if (sie_block->icptstatus & 1) {
40 			ilen = (sie_block->icptstatus >> 4) & 0x6;
41 			if (!ilen)
42 				ilen = 4;
43 		}
44 		break;
45 	case ICPT_PROGI:
46 		/* bit 1+2 of pgmilc are the ilc, so we directly get ilen */
47 		ilen = vcpu->arch.sie_block->pgmilc & 0x6;
48 		break;
49 	}
50 	return ilen;
51 }
52 
53 static int handle_stop(struct kvm_vcpu *vcpu)
54 {
55 	struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
56 	int rc = 0;
57 	uint8_t flags, stop_pending;
58 
59 	vcpu->stat.exit_stop_request++;
60 
61 	/* delay the stop if any non-stop irq is pending */
62 	if (kvm_s390_vcpu_has_irq(vcpu, 1))
63 		return 0;
64 
65 	/* avoid races with the injection/SIGP STOP code */
66 	spin_lock(&li->lock);
67 	flags = li->irq.stop.flags;
68 	stop_pending = kvm_s390_is_stop_irq_pending(vcpu);
69 	spin_unlock(&li->lock);
70 
71 	trace_kvm_s390_stop_request(stop_pending, flags);
72 	if (!stop_pending)
73 		return 0;
74 
75 	if (flags & KVM_S390_STOP_FLAG_STORE_STATUS) {
76 		rc = kvm_s390_vcpu_store_status(vcpu,
77 						KVM_S390_STORE_STATUS_NOADDR);
78 		if (rc)
79 			return rc;
80 	}
81 
82 	/*
83 	 * no need to check the return value of vcpu_stop as it can only have
84 	 * an error for protvirt, but protvirt means user cpu state
85 	 */
86 	if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm))
87 		kvm_s390_vcpu_stop(vcpu);
88 	return -EOPNOTSUPP;
89 }
90 
91 static int handle_validity(struct kvm_vcpu *vcpu)
92 {
93 	int viwhy = vcpu->arch.sie_block->ipb >> 16;
94 
95 	vcpu->stat.exit_validity++;
96 	trace_kvm_s390_intercept_validity(vcpu, viwhy);
97 	KVM_EVENT(3, "validity intercept 0x%x for pid %u (kvm 0x%pK)", viwhy,
98 		  current->pid, vcpu->kvm);
99 
100 	/* do not warn on invalid runtime instrumentation mode */
101 	WARN_ONCE(viwhy != 0x44, "kvm: unhandled validity intercept 0x%x\n",
102 		  viwhy);
103 	return -EINVAL;
104 }
105 
106 static int handle_instruction(struct kvm_vcpu *vcpu)
107 {
108 	vcpu->stat.exit_instruction++;
109 	trace_kvm_s390_intercept_instruction(vcpu,
110 					     vcpu->arch.sie_block->ipa,
111 					     vcpu->arch.sie_block->ipb);
112 
113 	switch (vcpu->arch.sie_block->ipa >> 8) {
114 	case 0x01:
115 		return kvm_s390_handle_01(vcpu);
116 	case 0x82:
117 		return kvm_s390_handle_lpsw(vcpu);
118 	case 0x83:
119 		return kvm_s390_handle_diag(vcpu);
120 	case 0xaa:
121 		return kvm_s390_handle_aa(vcpu);
122 	case 0xae:
123 		return kvm_s390_handle_sigp(vcpu);
124 	case 0xb2:
125 		return kvm_s390_handle_b2(vcpu);
126 	case 0xb6:
127 		return kvm_s390_handle_stctl(vcpu);
128 	case 0xb7:
129 		return kvm_s390_handle_lctl(vcpu);
130 	case 0xb9:
131 		return kvm_s390_handle_b9(vcpu);
132 	case 0xe3:
133 		return kvm_s390_handle_e3(vcpu);
134 	case 0xe5:
135 		return kvm_s390_handle_e5(vcpu);
136 	case 0xeb:
137 		return kvm_s390_handle_eb(vcpu);
138 	default:
139 		return -EOPNOTSUPP;
140 	}
141 }
142 
143 static int inject_prog_on_prog_intercept(struct kvm_vcpu *vcpu)
144 {
145 	struct kvm_s390_pgm_info pgm_info = {
146 		.code = vcpu->arch.sie_block->iprcc,
147 		/* the PSW has already been rewound */
148 		.flags = KVM_S390_PGM_FLAGS_NO_REWIND,
149 	};
150 
151 	switch (vcpu->arch.sie_block->iprcc & ~PGM_PER) {
152 	case PGM_AFX_TRANSLATION:
153 	case PGM_ASX_TRANSLATION:
154 	case PGM_EX_TRANSLATION:
155 	case PGM_LFX_TRANSLATION:
156 	case PGM_LSTE_SEQUENCE:
157 	case PGM_LSX_TRANSLATION:
158 	case PGM_LX_TRANSLATION:
159 	case PGM_PRIMARY_AUTHORITY:
160 	case PGM_SECONDARY_AUTHORITY:
161 	case PGM_SPACE_SWITCH:
162 		pgm_info.trans_exc_code = vcpu->arch.sie_block->tecmc;
163 		break;
164 	case PGM_ALEN_TRANSLATION:
165 	case PGM_ALE_SEQUENCE:
166 	case PGM_ASTE_INSTANCE:
167 	case PGM_ASTE_SEQUENCE:
168 	case PGM_ASTE_VALIDITY:
169 	case PGM_EXTENDED_AUTHORITY:
170 		pgm_info.exc_access_id = vcpu->arch.sie_block->eai;
171 		break;
172 	case PGM_ASCE_TYPE:
173 	case PGM_PAGE_TRANSLATION:
174 	case PGM_REGION_FIRST_TRANS:
175 	case PGM_REGION_SECOND_TRANS:
176 	case PGM_REGION_THIRD_TRANS:
177 	case PGM_SEGMENT_TRANSLATION:
178 		pgm_info.trans_exc_code = vcpu->arch.sie_block->tecmc;
179 		pgm_info.exc_access_id  = vcpu->arch.sie_block->eai;
180 		pgm_info.op_access_id  = vcpu->arch.sie_block->oai;
181 		break;
182 	case PGM_MONITOR:
183 		pgm_info.mon_class_nr = vcpu->arch.sie_block->mcn;
184 		pgm_info.mon_code = vcpu->arch.sie_block->tecmc;
185 		break;
186 	case PGM_VECTOR_PROCESSING:
187 	case PGM_DATA:
188 		pgm_info.data_exc_code = vcpu->arch.sie_block->dxc;
189 		break;
190 	case PGM_PROTECTION:
191 		pgm_info.trans_exc_code = vcpu->arch.sie_block->tecmc;
192 		pgm_info.exc_access_id  = vcpu->arch.sie_block->eai;
193 		break;
194 	default:
195 		break;
196 	}
197 
198 	if (vcpu->arch.sie_block->iprcc & PGM_PER) {
199 		pgm_info.per_code = vcpu->arch.sie_block->perc;
200 		pgm_info.per_atmid = vcpu->arch.sie_block->peratmid;
201 		pgm_info.per_address = vcpu->arch.sie_block->peraddr;
202 		pgm_info.per_access_id = vcpu->arch.sie_block->peraid;
203 	}
204 	return kvm_s390_inject_prog_irq(vcpu, &pgm_info);
205 }
206 
207 /*
208  * restore ITDB to program-interruption TDB in guest lowcore
209  * and set TX abort indication if required
210 */
211 static int handle_itdb(struct kvm_vcpu *vcpu)
212 {
213 	struct kvm_s390_itdb *itdb;
214 	int rc;
215 
216 	if (!IS_TE_ENABLED(vcpu) || !IS_ITDB_VALID(vcpu))
217 		return 0;
218 	if (current->thread.per_flags & PER_FLAG_NO_TE)
219 		return 0;
220 	itdb = phys_to_virt(vcpu->arch.sie_block->itdba);
221 	rc = write_guest_lc(vcpu, __LC_PGM_TDB, itdb, sizeof(*itdb));
222 	if (rc)
223 		return rc;
224 	memset(itdb, 0, sizeof(*itdb));
225 
226 	return 0;
227 }
228 
229 #define per_event(vcpu) (vcpu->arch.sie_block->iprcc & PGM_PER)
230 
231 static bool should_handle_per_event(const struct kvm_vcpu *vcpu)
232 {
233 	if (!guestdbg_enabled(vcpu) || !per_event(vcpu))
234 		return false;
235 	if (guestdbg_sstep_enabled(vcpu) &&
236 	    vcpu->arch.sie_block->iprcc != PGM_PER) {
237 		/*
238 		 * __vcpu_run() will exit after delivering the concurrently
239 		 * indicated condition.
240 		 */
241 		return false;
242 	}
243 	return true;
244 }
245 
246 static int handle_prog(struct kvm_vcpu *vcpu)
247 {
248 	psw_t psw;
249 	int rc;
250 
251 	vcpu->stat.exit_program_interruption++;
252 
253 	/*
254 	 * Intercept 8 indicates a loop of specification exceptions
255 	 * for protected guests.
256 	 */
257 	if (kvm_s390_pv_cpu_is_protected(vcpu))
258 		return -EOPNOTSUPP;
259 
260 	if (should_handle_per_event(vcpu)) {
261 		rc = kvm_s390_handle_per_event(vcpu);
262 		if (rc)
263 			return rc;
264 		/* the interrupt might have been filtered out completely */
265 		if (vcpu->arch.sie_block->iprcc == 0)
266 			return 0;
267 	}
268 
269 	trace_kvm_s390_intercept_prog(vcpu, vcpu->arch.sie_block->iprcc);
270 	if (vcpu->arch.sie_block->iprcc == PGM_SPECIFICATION) {
271 		rc = read_guest_lc(vcpu, __LC_PGM_NEW_PSW, &psw, sizeof(psw_t));
272 		if (rc)
273 			return rc;
274 		/* Avoid endless loops of specification exceptions */
275 		if (!is_valid_psw(&psw))
276 			return -EOPNOTSUPP;
277 	}
278 	rc = handle_itdb(vcpu);
279 	if (rc)
280 		return rc;
281 
282 	return inject_prog_on_prog_intercept(vcpu);
283 }
284 
285 /**
286  * handle_external_interrupt - used for external interruption interceptions
287  * @vcpu: virtual cpu
288  *
289  * This interception occurs if:
290  * - the CPUSTAT_EXT_INT bit was already set when the external interrupt
291  *   occurred. In this case, the interrupt needs to be injected manually to
292  *   preserve interrupt priority.
293  * - the external new PSW has external interrupts enabled, which will cause an
294  *   interruption loop. We drop to userspace in this case.
295  *
296  * The latter case can be detected by inspecting the external mask bit in the
297  * external new psw.
298  *
299  * Under PV, only the latter case can occur, since interrupt priorities are
300  * handled in the ultravisor.
301  */
302 static int handle_external_interrupt(struct kvm_vcpu *vcpu)
303 {
304 	u16 eic = vcpu->arch.sie_block->eic;
305 	struct kvm_s390_irq irq;
306 	psw_t newpsw;
307 	int rc;
308 
309 	vcpu->stat.exit_external_interrupt++;
310 
311 	if (kvm_s390_pv_cpu_is_protected(vcpu)) {
312 		newpsw = vcpu->arch.sie_block->gpsw;
313 	} else {
314 		rc = read_guest_lc(vcpu, __LC_EXT_NEW_PSW, &newpsw, sizeof(psw_t));
315 		if (rc)
316 			return rc;
317 	}
318 
319 	/*
320 	 * Clock comparator or timer interrupt with external interrupt enabled
321 	 * will cause interrupt loop. Drop to userspace.
322 	 */
323 	if ((eic == EXT_IRQ_CLK_COMP || eic == EXT_IRQ_CPU_TIMER) &&
324 	    (newpsw.mask & PSW_MASK_EXT))
325 		return -EOPNOTSUPP;
326 
327 	switch (eic) {
328 	case EXT_IRQ_CLK_COMP:
329 		irq.type = KVM_S390_INT_CLOCK_COMP;
330 		break;
331 	case EXT_IRQ_CPU_TIMER:
332 		irq.type = KVM_S390_INT_CPU_TIMER;
333 		break;
334 	case EXT_IRQ_EXTERNAL_CALL:
335 		irq.type = KVM_S390_INT_EXTERNAL_CALL;
336 		irq.u.extcall.code = vcpu->arch.sie_block->extcpuaddr;
337 		rc = kvm_s390_inject_vcpu(vcpu, &irq);
338 		/* ignore if another external call is already pending */
339 		if (rc == -EBUSY)
340 			return 0;
341 		return rc;
342 	default:
343 		return -EOPNOTSUPP;
344 	}
345 
346 	return kvm_s390_inject_vcpu(vcpu, &irq);
347 }
348 
349 /**
350  * handle_mvpg_pei - Handle MOVE PAGE partial execution interception.
351  * @vcpu: virtual cpu
352  *
353  * This interception can only happen for guests with DAT disabled and
354  * addresses that are currently not mapped in the host. Thus we try to
355  * set up the mappings for the corresponding user pages here (or throw
356  * addressing exceptions in case of illegal guest addresses).
357  */
358 static int handle_mvpg_pei(struct kvm_vcpu *vcpu)
359 {
360 	unsigned long srcaddr, dstaddr;
361 	int reg1, reg2, rc;
362 
363 	kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);
364 
365 	/* Ensure that the source is paged-in, no actual access -> no key checking */
366 	rc = guest_translate_address_with_key(vcpu, vcpu->run->s.regs.gprs[reg2],
367 					      reg2, &srcaddr, GACC_FETCH, 0);
368 	if (rc)
369 		return kvm_s390_inject_prog_cond(vcpu, rc);
370 	rc = kvm_arch_fault_in_page(vcpu, srcaddr, 0);
371 	if (rc != 0)
372 		return rc;
373 
374 	/* Ensure that the source is paged-in, no actual access -> no key checking */
375 	rc = guest_translate_address_with_key(vcpu, vcpu->run->s.regs.gprs[reg1],
376 					      reg1, &dstaddr, GACC_STORE, 0);
377 	if (rc)
378 		return kvm_s390_inject_prog_cond(vcpu, rc);
379 	rc = kvm_arch_fault_in_page(vcpu, dstaddr, 1);
380 	if (rc != 0)
381 		return rc;
382 
383 	kvm_s390_retry_instr(vcpu);
384 
385 	return 0;
386 }
387 
388 static int handle_partial_execution(struct kvm_vcpu *vcpu)
389 {
390 	vcpu->stat.exit_pei++;
391 
392 	if (vcpu->arch.sie_block->ipa == 0xb254)	/* MVPG */
393 		return handle_mvpg_pei(vcpu);
394 	if (vcpu->arch.sie_block->ipa >> 8 == 0xae)	/* SIGP */
395 		return kvm_s390_handle_sigp_pei(vcpu);
396 
397 	return -EOPNOTSUPP;
398 }
399 
400 /*
401  * Handle the sthyi instruction that provides the guest with system
402  * information, like current CPU resources available at each level of
403  * the machine.
404  */
405 int handle_sthyi(struct kvm_vcpu *vcpu)
406 {
407 	int reg1, reg2, cc = 0, r = 0;
408 	u64 code, addr, rc = 0;
409 	struct sthyi_sctns *sctns = NULL;
410 
411 	if (!test_kvm_facility(vcpu->kvm, 74))
412 		return kvm_s390_inject_program_int(vcpu, PGM_OPERATION);
413 
414 	kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);
415 	code = vcpu->run->s.regs.gprs[reg1];
416 	addr = vcpu->run->s.regs.gprs[reg2];
417 
418 	vcpu->stat.instruction_sthyi++;
419 	VCPU_EVENT(vcpu, 3, "STHYI: fc: %llu addr: 0x%016llx", code, addr);
420 	trace_kvm_s390_handle_sthyi(vcpu, code, addr);
421 
422 	if (reg1 == reg2 || reg1 & 1 || reg2 & 1)
423 		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
424 
425 	if (code & 0xffff) {
426 		cc = 3;
427 		rc = 4;
428 		goto out;
429 	}
430 
431 	if (!kvm_s390_pv_cpu_is_protected(vcpu) && (addr & ~PAGE_MASK))
432 		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
433 
434 	sctns = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT);
435 	if (!sctns)
436 		return -ENOMEM;
437 
438 	cc = sthyi_fill(sctns, &rc);
439 	if (cc < 0) {
440 		free_page((unsigned long)sctns);
441 		return cc;
442 	}
443 out:
444 	if (!cc) {
445 		if (kvm_s390_pv_cpu_is_protected(vcpu)) {
446 			memcpy(sida_addr(vcpu->arch.sie_block), sctns, PAGE_SIZE);
447 		} else {
448 			r = write_guest(vcpu, addr, reg2, sctns, PAGE_SIZE);
449 			if (r) {
450 				free_page((unsigned long)sctns);
451 				return kvm_s390_inject_prog_cond(vcpu, r);
452 			}
453 		}
454 	}
455 
456 	free_page((unsigned long)sctns);
457 	vcpu->run->s.regs.gprs[reg2 + 1] = rc;
458 	kvm_s390_set_psw_cc(vcpu, cc);
459 	return r;
460 }
461 
462 static int handle_operexc(struct kvm_vcpu *vcpu)
463 {
464 	psw_t oldpsw, newpsw;
465 	int rc;
466 
467 	vcpu->stat.exit_operation_exception++;
468 	trace_kvm_s390_handle_operexc(vcpu, vcpu->arch.sie_block->ipa,
469 				      vcpu->arch.sie_block->ipb);
470 
471 	if (vcpu->arch.sie_block->ipa == 0xb256)
472 		return handle_sthyi(vcpu);
473 
474 	if (vcpu->arch.sie_block->ipa == 0 && vcpu->kvm->arch.user_instr0)
475 		return -EOPNOTSUPP;
476 	rc = read_guest_lc(vcpu, __LC_PGM_NEW_PSW, &newpsw, sizeof(psw_t));
477 	if (rc)
478 		return rc;
479 	/*
480 	 * Avoid endless loops of operation exceptions, if the pgm new
481 	 * PSW will cause a new operation exception.
482 	 * The heuristic checks if the pgm new psw is within 6 bytes before
483 	 * the faulting psw address (with same DAT, AS settings) and the
484 	 * new psw is not a wait psw and the fault was not triggered by
485 	 * problem state.
486 	 */
487 	oldpsw = vcpu->arch.sie_block->gpsw;
488 	if (oldpsw.addr - newpsw.addr <= 6 &&
489 	    !(newpsw.mask & PSW_MASK_WAIT) &&
490 	    !(oldpsw.mask & PSW_MASK_PSTATE) &&
491 	    (newpsw.mask & PSW_MASK_ASC) == (oldpsw.mask & PSW_MASK_ASC) &&
492 	    (newpsw.mask & PSW_MASK_DAT) == (oldpsw.mask & PSW_MASK_DAT))
493 		return -EOPNOTSUPP;
494 
495 	return kvm_s390_inject_program_int(vcpu, PGM_OPERATION);
496 }
497 
498 static int handle_pv_spx(struct kvm_vcpu *vcpu)
499 {
500 	u32 pref = *(u32 *)sida_addr(vcpu->arch.sie_block);
501 
502 	kvm_s390_set_prefix(vcpu, pref);
503 	trace_kvm_s390_handle_prefix(vcpu, 1, pref);
504 	return 0;
505 }
506 
507 static int handle_pv_sclp(struct kvm_vcpu *vcpu)
508 {
509 	struct kvm_s390_float_interrupt *fi = &vcpu->kvm->arch.float_int;
510 
511 	spin_lock(&fi->lock);
512 	/*
513 	 * 2 cases:
514 	 * a: an sccb answering interrupt was already pending or in flight.
515 	 *    As the sccb value is not known we can simply set some value to
516 	 *    trigger delivery of a saved SCCB. UV will then use its saved
517 	 *    copy of the SCCB value.
518 	 * b: an error SCCB interrupt needs to be injected so we also inject
519 	 *    a fake SCCB address. Firmware will use the proper one.
520 	 * This makes sure, that both errors and real sccb returns will only
521 	 * be delivered after a notification intercept (instruction has
522 	 * finished) but not after others.
523 	 */
524 	fi->srv_signal.ext_params |= 0x43000;
525 	set_bit(IRQ_PEND_EXT_SERVICE, &fi->pending_irqs);
526 	clear_bit(IRQ_PEND_EXT_SERVICE, &fi->masked_irqs);
527 	spin_unlock(&fi->lock);
528 	return 0;
529 }
530 
531 static int handle_pv_uvc(struct kvm_vcpu *vcpu)
532 {
533 	struct uv_cb_share *guest_uvcb = sida_addr(vcpu->arch.sie_block);
534 	struct uv_cb_cts uvcb = {
535 		.header.cmd	= UVC_CMD_UNPIN_PAGE_SHARED,
536 		.header.len	= sizeof(uvcb),
537 		.guest_handle	= kvm_s390_pv_get_handle(vcpu->kvm),
538 		.gaddr		= guest_uvcb->paddr,
539 	};
540 	int rc;
541 
542 	if (guest_uvcb->header.cmd != UVC_CMD_REMOVE_SHARED_ACCESS) {
543 		WARN_ONCE(1, "Unexpected notification intercept for UVC 0x%x\n",
544 			  guest_uvcb->header.cmd);
545 		return 0;
546 	}
547 	rc = gmap_make_secure(vcpu->arch.gmap, uvcb.gaddr, &uvcb);
548 	/*
549 	 * If the unpin did not succeed, the guest will exit again for the UVC
550 	 * and we will retry the unpin.
551 	 */
552 	if (rc == -EINVAL)
553 		return 0;
554 	/*
555 	 * If we got -EAGAIN here, we simply return it. It will eventually
556 	 * get propagated all the way to userspace, which should then try
557 	 * again.
558 	 */
559 	return rc;
560 }
561 
562 static int handle_pv_notification(struct kvm_vcpu *vcpu)
563 {
564 	int ret;
565 
566 	if (vcpu->arch.sie_block->ipa == 0xb210)
567 		return handle_pv_spx(vcpu);
568 	if (vcpu->arch.sie_block->ipa == 0xb220)
569 		return handle_pv_sclp(vcpu);
570 	if (vcpu->arch.sie_block->ipa == 0xb9a4)
571 		return handle_pv_uvc(vcpu);
572 	if (vcpu->arch.sie_block->ipa >> 8 == 0xae) {
573 		/*
574 		 * Besides external call, other SIGP orders also cause a
575 		 * 108 (pv notify) intercept. In contrast to external call,
576 		 * these orders need to be emulated and hence the appropriate
577 		 * place to handle them is in handle_instruction().
578 		 * So first try kvm_s390_handle_sigp_pei() and if that isn't
579 		 * successful, go on with handle_instruction().
580 		 */
581 		ret = kvm_s390_handle_sigp_pei(vcpu);
582 		if (!ret)
583 			return ret;
584 	}
585 
586 	return handle_instruction(vcpu);
587 }
588 
589 static bool should_handle_per_ifetch(const struct kvm_vcpu *vcpu, int rc)
590 {
591 	/* Process PER, also if the instruction is processed in user space. */
592 	if (!(vcpu->arch.sie_block->icptstatus & 0x02))
593 		return false;
594 	if (rc != 0 && rc != -EOPNOTSUPP)
595 		return false;
596 	if (guestdbg_sstep_enabled(vcpu) && vcpu->arch.local_int.pending_irqs)
597 		/* __vcpu_run() will exit after delivering the interrupt. */
598 		return false;
599 	return true;
600 }
601 
602 int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
603 {
604 	int rc, per_rc = 0;
605 
606 	if (kvm_is_ucontrol(vcpu->kvm))
607 		return -EOPNOTSUPP;
608 
609 	switch (vcpu->arch.sie_block->icptcode) {
610 	case ICPT_EXTREQ:
611 		vcpu->stat.exit_external_request++;
612 		return 0;
613 	case ICPT_IOREQ:
614 		vcpu->stat.exit_io_request++;
615 		return 0;
616 	case ICPT_INST:
617 		rc = handle_instruction(vcpu);
618 		break;
619 	case ICPT_PROGI:
620 		return handle_prog(vcpu);
621 	case ICPT_EXTINT:
622 		return handle_external_interrupt(vcpu);
623 	case ICPT_WAIT:
624 		return kvm_s390_handle_wait(vcpu);
625 	case ICPT_VALIDITY:
626 		return handle_validity(vcpu);
627 	case ICPT_STOP:
628 		return handle_stop(vcpu);
629 	case ICPT_OPEREXC:
630 		rc = handle_operexc(vcpu);
631 		break;
632 	case ICPT_PARTEXEC:
633 		rc = handle_partial_execution(vcpu);
634 		break;
635 	case ICPT_KSS:
636 		/* Instruction will be redriven, skip the PER check. */
637 		return kvm_s390_skey_check_enable(vcpu);
638 	case ICPT_MCHKREQ:
639 	case ICPT_INT_ENABLE:
640 		/*
641 		 * PSW bit 13 or a CR (0, 6, 14) changed and we might
642 		 * now be able to deliver interrupts. The pre-run code
643 		 * will take care of this.
644 		 */
645 		rc = 0;
646 		break;
647 	case ICPT_PV_INSTR:
648 		rc = handle_instruction(vcpu);
649 		break;
650 	case ICPT_PV_NOTIFY:
651 		rc = handle_pv_notification(vcpu);
652 		break;
653 	case ICPT_PV_PREF:
654 		rc = 0;
655 		gmap_convert_to_secure(vcpu->arch.gmap,
656 				       kvm_s390_get_prefix(vcpu));
657 		gmap_convert_to_secure(vcpu->arch.gmap,
658 				       kvm_s390_get_prefix(vcpu) + PAGE_SIZE);
659 		break;
660 	default:
661 		return -EOPNOTSUPP;
662 	}
663 
664 	if (should_handle_per_ifetch(vcpu, rc))
665 		per_rc = kvm_s390_handle_per_ifetch_icpt(vcpu);
666 	return per_rc ? per_rc : rc;
667 }
668