1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * handling interprocessor communication
4 *
5 * Copyright IBM Corp. 2008, 2013
6 *
7 * Author(s): Carsten Otte <cotte@de.ibm.com>
8 * Christian Borntraeger <borntraeger@de.ibm.com>
9 * Christian Ehrhardt <ehrhardt@de.ibm.com>
10 */
11
12 #include <linux/kvm.h>
13 #include <linux/kvm_host.h>
14 #include <linux/slab.h>
15 #include <asm/sigp.h>
16 #include "gaccess.h"
17 #include "kvm-s390.h"
18 #include "trace.h"
19
20 static int __sigp_sense(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu,
21 u64 *reg)
22 {
23 const bool stopped = kvm_s390_test_cpuflags(dst_vcpu, CPUSTAT_STOPPED);
24 int rc;
25 int ext_call_pending;
26
27 ext_call_pending = kvm_s390_ext_call_pending(dst_vcpu);
28 if (!stopped && !ext_call_pending)
29 rc = SIGP_CC_ORDER_CODE_ACCEPTED;
30 else {
31 *reg &= 0xffffffff00000000UL;
32 if (ext_call_pending)
33 *reg |= SIGP_STATUS_EXT_CALL_PENDING;
34 if (stopped)
35 *reg |= SIGP_STATUS_STOPPED;
36 rc = SIGP_CC_STATUS_STORED;
37 }
38
39 VCPU_EVENT(vcpu, 4, "sensed status of cpu %x rc %x", dst_vcpu->vcpu_id,
40 rc);
41 return rc;
42 }
43
44 static int __inject_sigp_emergency(struct kvm_vcpu *vcpu,
45 struct kvm_vcpu *dst_vcpu)
46 {
47 struct kvm_s390_irq irq = {
48 .type = KVM_S390_INT_EMERGENCY,
49 .u.emerg.code = vcpu->vcpu_id,
50 };
51 int rc = 0;
52
53 rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
54 if (!rc)
55 VCPU_EVENT(vcpu, 4, "sent sigp emerg to cpu %x",
56 dst_vcpu->vcpu_id);
57
58 return rc ? rc : SIGP_CC_ORDER_CODE_ACCEPTED;
59 }
60
61 static int __sigp_emergency(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu)
62 {
63 return __inject_sigp_emergency(vcpu, dst_vcpu);
64 }
65
66 static int __sigp_conditional_emergency(struct kvm_vcpu *vcpu,
67 struct kvm_vcpu *dst_vcpu,
68 u16 asn, u64 *reg)
69 {
70 const u64 psw_int_mask = PSW_MASK_IO | PSW_MASK_EXT;
71 u16 p_asn, s_asn;
72 psw_t *psw;
73 bool idle;
74
75 idle = is_vcpu_idle(vcpu);
76 psw = &dst_vcpu->arch.sie_block->gpsw;
77 p_asn = dst_vcpu->arch.sie_block->gcr[4] & 0xffff; /* Primary ASN */
78 s_asn = dst_vcpu->arch.sie_block->gcr[3] & 0xffff; /* Secondary ASN */
79
80 /* Inject the emergency signal? */
81 if (!is_vcpu_stopped(vcpu)
82 || (psw->mask & psw_int_mask) != psw_int_mask
83 || (idle && psw->addr != 0)
84 || (!idle && (asn == p_asn || asn == s_asn))) {
85 return __inject_sigp_emergency(vcpu, dst_vcpu);
86 } else {
87 *reg &= 0xffffffff00000000UL;
88 *reg |= SIGP_STATUS_INCORRECT_STATE;
89 return SIGP_CC_STATUS_STORED;
90 }
91 }
92
93 static int __sigp_external_call(struct kvm_vcpu *vcpu,
94 struct kvm_vcpu *dst_vcpu, u64 *reg)
95 {
96 struct kvm_s390_irq irq = {
97 .type = KVM_S390_INT_EXTERNAL_CALL,
98 .u.extcall.code = vcpu->vcpu_id,
99 };
100 int rc;
101
102 rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
103 if (rc == -EBUSY) {
104 *reg &= 0xffffffff00000000UL;
105 *reg |= SIGP_STATUS_EXT_CALL_PENDING;
106 return SIGP_CC_STATUS_STORED;
107 } else if (rc == 0) {
108 VCPU_EVENT(vcpu, 4, "sent sigp ext call to cpu %x",
109 dst_vcpu->vcpu_id);
110 }
111
112 return rc ? rc : SIGP_CC_ORDER_CODE_ACCEPTED;
113 }
114
115 static int __sigp_stop(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu)
116 {
117 struct kvm_s390_irq irq = {
118 .type = KVM_S390_SIGP_STOP,
119 };
120 int rc;
121
122 rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
123 if (rc == -EBUSY)
124 rc = SIGP_CC_BUSY;
125 else if (rc == 0)
126 VCPU_EVENT(vcpu, 4, "sent sigp stop to cpu %x",
127 dst_vcpu->vcpu_id);
128
129 return rc;
130 }
131
132 static int __sigp_stop_and_store_status(struct kvm_vcpu *vcpu,
133 struct kvm_vcpu *dst_vcpu, u64 *reg)
134 {
135 struct kvm_s390_irq irq = {
136 .type = KVM_S390_SIGP_STOP,
137 .u.stop.flags = KVM_S390_STOP_FLAG_STORE_STATUS,
138 };
139 int rc;
140
141 rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
142 if (rc == -EBUSY)
143 rc = SIGP_CC_BUSY;
144 else if (rc == 0)
145 VCPU_EVENT(vcpu, 4, "sent sigp stop and store status to cpu %x",
146 dst_vcpu->vcpu_id);
147
148 return rc;
149 }
150
151 static int __sigp_set_arch(struct kvm_vcpu *vcpu, u32 parameter,
152 u64 *status_reg)
153 {
154 *status_reg &= 0xffffffff00000000UL;
155
156 /* Reject set arch order, with czam we're always in z/Arch mode. */
157 *status_reg |= SIGP_STATUS_INVALID_PARAMETER;
158 return SIGP_CC_STATUS_STORED;
159 }
160
161 static int __sigp_set_prefix(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu,
162 u32 address, u64 *reg)
163 {
164 struct kvm_s390_irq irq = {
165 .type = KVM_S390_SIGP_SET_PREFIX,
166 .u.prefix.address = address & 0x7fffe000u,
167 };
168 int rc;
169
170 /*
171 * Make sure the new value is valid memory. We only need to check the
172 * first page, since address is 8k aligned and memory pieces are always
173 * at least 1MB aligned and have at least a size of 1MB.
174 */
175 if (!kvm_is_gpa_in_memslot(vcpu->kvm, irq.u.prefix.address)) {
176 *reg &= 0xffffffff00000000UL;
177 *reg |= SIGP_STATUS_INVALID_PARAMETER;
178 return SIGP_CC_STATUS_STORED;
179 }
180
181 rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
182 if (rc == -EBUSY) {
183 *reg &= 0xffffffff00000000UL;
184 *reg |= SIGP_STATUS_INCORRECT_STATE;
185 return SIGP_CC_STATUS_STORED;
186 }
187
188 return rc;
189 }
190
191 static int __sigp_store_status_at_addr(struct kvm_vcpu *vcpu,
192 struct kvm_vcpu *dst_vcpu,
193 u32 addr, u64 *reg)
194 {
195 int rc;
196
197 if (!kvm_s390_test_cpuflags(dst_vcpu, CPUSTAT_STOPPED)) {
198 *reg &= 0xffffffff00000000UL;
199 *reg |= SIGP_STATUS_INCORRECT_STATE;
200 return SIGP_CC_STATUS_STORED;
201 }
202
203 addr &= 0x7ffffe00;
204 rc = kvm_s390_store_status_unloaded(dst_vcpu, addr);
205 if (rc == -EFAULT) {
206 *reg &= 0xffffffff00000000UL;
207 *reg |= SIGP_STATUS_INVALID_PARAMETER;
208 rc = SIGP_CC_STATUS_STORED;
209 }
210 return rc;
211 }
212
213 static int __sigp_sense_running(struct kvm_vcpu *vcpu,
214 struct kvm_vcpu *dst_vcpu, u64 *reg)
215 {
216 int rc;
217
218 if (!test_kvm_facility(vcpu->kvm, 9)) {
219 *reg &= 0xffffffff00000000UL;
220 *reg |= SIGP_STATUS_INVALID_ORDER;
221 return SIGP_CC_STATUS_STORED;
222 }
223
224 if (kvm_s390_test_cpuflags(dst_vcpu, CPUSTAT_RUNNING)) {
225 /* running */
226 rc = SIGP_CC_ORDER_CODE_ACCEPTED;
227 } else {
228 /* not running */
229 *reg &= 0xffffffff00000000UL;
230 *reg |= SIGP_STATUS_NOT_RUNNING;
231 rc = SIGP_CC_STATUS_STORED;
232 }
233
234 VCPU_EVENT(vcpu, 4, "sensed running status of cpu %x rc %x",
235 dst_vcpu->vcpu_id, rc);
236
237 return rc;
238 }
239
240 static int __prepare_sigp_re_start(struct kvm_vcpu *vcpu,
241 struct kvm_vcpu *dst_vcpu, u8 order_code)
242 {
243 struct kvm_s390_local_interrupt *li = &dst_vcpu->arch.local_int;
244 /* handle (RE)START in user space */
245 int rc = -EOPNOTSUPP;
246
247 /* make sure we don't race with STOP irq injection */
248 spin_lock(&li->lock);
249 if (kvm_s390_is_stop_irq_pending(dst_vcpu))
250 rc = SIGP_CC_BUSY;
251 spin_unlock(&li->lock);
252
253 return rc;
254 }
255
256 static int __prepare_sigp_cpu_reset(struct kvm_vcpu *vcpu,
257 struct kvm_vcpu *dst_vcpu, u8 order_code)
258 {
259 /* handle (INITIAL) CPU RESET in user space */
260 return -EOPNOTSUPP;
261 }
262
263 static int __prepare_sigp_unknown(struct kvm_vcpu *vcpu,
264 struct kvm_vcpu *dst_vcpu)
265 {
266 /* handle unknown orders in user space */
267 return -EOPNOTSUPP;
268 }
269
270 static int handle_sigp_dst(struct kvm_vcpu *vcpu, u8 order_code,
271 u16 cpu_addr, u32 parameter, u64 *status_reg)
272 {
273 int rc;
274 struct kvm_vcpu *dst_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, cpu_addr);
275
276 if (!dst_vcpu)
277 return SIGP_CC_NOT_OPERATIONAL;
278
279 /*
280 * SIGP RESTART, SIGP STOP, and SIGP STOP AND STORE STATUS orders
281 * are processed asynchronously. Until the affected VCPU finishes
282 * its work and calls back into KVM to clear the (RESTART or STOP)
283 * interrupt, we need to return any new non-reset orders "busy".
284 *
285 * This is important because a single VCPU could issue:
286 * 1) SIGP STOP $DESTINATION
287 * 2) SIGP SENSE $DESTINATION
288 *
289 * If the SIGP SENSE would not be rejected as "busy", it could
290 * return an incorrect answer as to whether the VCPU is STOPPED
291 * or OPERATING.
292 */
293 if (order_code != SIGP_INITIAL_CPU_RESET &&
294 order_code != SIGP_CPU_RESET) {
295 /*
296 * Lockless check. Both SIGP STOP and SIGP (RE)START
297 * properly synchronize everything while processing
298 * their orders, while the guest cannot observe a
299 * difference when issuing other orders from two
300 * different VCPUs.
301 */
302 if (kvm_s390_is_stop_irq_pending(dst_vcpu) ||
303 kvm_s390_is_restart_irq_pending(dst_vcpu))
304 return SIGP_CC_BUSY;
305 }
306
307 switch (order_code) {
308 case SIGP_SENSE:
309 vcpu->stat.instruction_sigp_sense++;
310 rc = __sigp_sense(vcpu, dst_vcpu, status_reg);
311 break;
312 case SIGP_EXTERNAL_CALL:
313 vcpu->stat.instruction_sigp_external_call++;
314 rc = __sigp_external_call(vcpu, dst_vcpu, status_reg);
315 break;
316 case SIGP_EMERGENCY_SIGNAL:
317 vcpu->stat.instruction_sigp_emergency++;
318 rc = __sigp_emergency(vcpu, dst_vcpu);
319 break;
320 case SIGP_STOP:
321 vcpu->stat.instruction_sigp_stop++;
322 rc = __sigp_stop(vcpu, dst_vcpu);
323 break;
324 case SIGP_STOP_AND_STORE_STATUS:
325 vcpu->stat.instruction_sigp_stop_store_status++;
326 rc = __sigp_stop_and_store_status(vcpu, dst_vcpu, status_reg);
327 break;
328 case SIGP_STORE_STATUS_AT_ADDRESS:
329 vcpu->stat.instruction_sigp_store_status++;
330 rc = __sigp_store_status_at_addr(vcpu, dst_vcpu, parameter,
331 status_reg);
332 break;
333 case SIGP_SET_PREFIX:
334 vcpu->stat.instruction_sigp_prefix++;
335 rc = __sigp_set_prefix(vcpu, dst_vcpu, parameter, status_reg);
336 break;
337 case SIGP_COND_EMERGENCY_SIGNAL:
338 vcpu->stat.instruction_sigp_cond_emergency++;
339 rc = __sigp_conditional_emergency(vcpu, dst_vcpu, parameter,
340 status_reg);
341 break;
342 case SIGP_SENSE_RUNNING:
343 vcpu->stat.instruction_sigp_sense_running++;
344 rc = __sigp_sense_running(vcpu, dst_vcpu, status_reg);
345 break;
346 case SIGP_START:
347 vcpu->stat.instruction_sigp_start++;
348 rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code);
349 break;
350 case SIGP_RESTART:
351 vcpu->stat.instruction_sigp_restart++;
352 rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code);
353 break;
354 case SIGP_INITIAL_CPU_RESET:
355 vcpu->stat.instruction_sigp_init_cpu_reset++;
356 rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code);
357 break;
358 case SIGP_CPU_RESET:
359 vcpu->stat.instruction_sigp_cpu_reset++;
360 rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code);
361 break;
362 default:
363 vcpu->stat.instruction_sigp_unknown++;
364 rc = __prepare_sigp_unknown(vcpu, dst_vcpu);
365 }
366
367 if (rc == -EOPNOTSUPP)
368 VCPU_EVENT(vcpu, 4,
369 "sigp order %u -> cpu %x: handled in user space",
370 order_code, dst_vcpu->vcpu_id);
371
372 return rc;
373 }
374
375 static int handle_sigp_order_in_user_space(struct kvm_vcpu *vcpu, u8 order_code,
376 u16 cpu_addr)
377 {
378 if (!vcpu->kvm->arch.user_sigp)
379 return 0;
380
381 switch (order_code) {
382 case SIGP_SENSE:
383 case SIGP_EXTERNAL_CALL:
384 case SIGP_EMERGENCY_SIGNAL:
385 case SIGP_COND_EMERGENCY_SIGNAL:
386 case SIGP_SENSE_RUNNING:
387 return 0;
388 /* update counters as we're directly dropping to user space */
389 case SIGP_STOP:
390 vcpu->stat.instruction_sigp_stop++;
391 break;
392 case SIGP_STOP_AND_STORE_STATUS:
393 vcpu->stat.instruction_sigp_stop_store_status++;
394 break;
395 case SIGP_STORE_STATUS_AT_ADDRESS:
396 vcpu->stat.instruction_sigp_store_status++;
397 break;
398 case SIGP_STORE_ADDITIONAL_STATUS:
399 vcpu->stat.instruction_sigp_store_adtl_status++;
400 break;
401 case SIGP_SET_PREFIX:
402 vcpu->stat.instruction_sigp_prefix++;
403 break;
404 case SIGP_START:
405 vcpu->stat.instruction_sigp_start++;
406 break;
407 case SIGP_RESTART:
408 vcpu->stat.instruction_sigp_restart++;
409 break;
410 case SIGP_INITIAL_CPU_RESET:
411 vcpu->stat.instruction_sigp_init_cpu_reset++;
412 break;
413 case SIGP_CPU_RESET:
414 vcpu->stat.instruction_sigp_cpu_reset++;
415 break;
416 default:
417 vcpu->stat.instruction_sigp_unknown++;
418 }
419 VCPU_EVENT(vcpu, 3, "SIGP: order %u for CPU %d handled in userspace",
420 order_code, cpu_addr);
421
422 return 1;
423 }
424
425 int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu)
426 {
427 int r1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
428 int r3 = vcpu->arch.sie_block->ipa & 0x000f;
429 u32 parameter;
430 u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
431 u8 order_code;
432 int rc;
433
434 /* sigp in userspace can exit */
435 if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
436 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
437
438 order_code = kvm_s390_get_base_disp_rs(vcpu, NULL);
439 if (handle_sigp_order_in_user_space(vcpu, order_code, cpu_addr))
440 return -EOPNOTSUPP;
441
442 if (r1 % 2)
443 parameter = vcpu->run->s.regs.gprs[r1];
444 else
445 parameter = vcpu->run->s.regs.gprs[r1 + 1];
446
447 trace_kvm_s390_handle_sigp(vcpu, order_code, cpu_addr, parameter);
448 switch (order_code) {
449 case SIGP_SET_ARCHITECTURE:
450 vcpu->stat.instruction_sigp_arch++;
451 rc = __sigp_set_arch(vcpu, parameter,
452 &vcpu->run->s.regs.gprs[r1]);
453 break;
454 default:
455 rc = handle_sigp_dst(vcpu, order_code, cpu_addr,
456 parameter,
457 &vcpu->run->s.regs.gprs[r1]);
458 }
459
460 if (rc < 0)
461 return rc;
462
463 kvm_s390_set_psw_cc(vcpu, rc);
464 return 0;
465 }
466
467 /*
468 * Handle SIGP partial execution interception.
469 *
470 * This interception will occur at the source cpu when a source cpu sends an
471 * external call to a target cpu and the target cpu has the WAIT bit set in
472 * its cpuflags. Interception will occur after the interrupt indicator bits at
473 * the target cpu have been set. All error cases will lead to instruction
474 * interception, therefore nothing is to be checked or prepared.
475 */
476 int kvm_s390_handle_sigp_pei(struct kvm_vcpu *vcpu)
477 {
478 int r3 = vcpu->arch.sie_block->ipa & 0x000f;
479 u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
480 struct kvm_vcpu *dest_vcpu;
481 u8 order_code = kvm_s390_get_base_disp_rs(vcpu, NULL);
482
483 if (order_code == SIGP_EXTERNAL_CALL) {
484 trace_kvm_s390_handle_sigp_pei(vcpu, order_code, cpu_addr);
485
486 dest_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, cpu_addr);
487 BUG_ON(dest_vcpu == NULL);
488
489 kvm_s390_vcpu_wakeup(dest_vcpu);
490 kvm_s390_set_psw_cc(vcpu, SIGP_CC_ORDER_CODE_ACCEPTED);
491 return 0;
492 }
493
494 return -EOPNOTSUPP;
495 }
496
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