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
__sigp_sense(struct kvm_vcpu * vcpu,struct kvm_vcpu * dst_vcpu,u64 * reg)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
__inject_sigp_emergency(struct kvm_vcpu * vcpu,struct kvm_vcpu * dst_vcpu)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
__sigp_emergency(struct kvm_vcpu * vcpu,struct kvm_vcpu * dst_vcpu)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
__sigp_conditional_emergency(struct kvm_vcpu * vcpu,struct kvm_vcpu * dst_vcpu,u16 asn,u64 * reg)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
__sigp_external_call(struct kvm_vcpu * vcpu,struct kvm_vcpu * dst_vcpu,u64 * reg)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
__sigp_stop(struct kvm_vcpu * vcpu,struct kvm_vcpu * dst_vcpu)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
__sigp_stop_and_store_status(struct kvm_vcpu * vcpu,struct kvm_vcpu * dst_vcpu,u64 * reg)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
__sigp_set_arch(struct kvm_vcpu * vcpu,u32 parameter,u64 * status_reg)151 static int __sigp_set_arch(struct kvm_vcpu *vcpu, u32 parameter,
152 u64 *status_reg)
153 {
154 unsigned int i;
155 struct kvm_vcpu *v;
156 bool all_stopped = true;
157
158 kvm_for_each_vcpu(i, v, vcpu->kvm) {
159 if (v == vcpu)
160 continue;
161 if (!is_vcpu_stopped(v))
162 all_stopped = false;
163 }
164
165 *status_reg &= 0xffffffff00000000UL;
166
167 /* Reject set arch order, with czam we're always in z/Arch mode. */
168 *status_reg |= (all_stopped ? SIGP_STATUS_INVALID_PARAMETER :
169 SIGP_STATUS_INCORRECT_STATE);
170 return SIGP_CC_STATUS_STORED;
171 }
172
__sigp_set_prefix(struct kvm_vcpu * vcpu,struct kvm_vcpu * dst_vcpu,u32 address,u64 * reg)173 static int __sigp_set_prefix(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu,
174 u32 address, u64 *reg)
175 {
176 struct kvm_s390_irq irq = {
177 .type = KVM_S390_SIGP_SET_PREFIX,
178 .u.prefix.address = address & 0x7fffe000u,
179 };
180 int rc;
181
182 /*
183 * Make sure the new value is valid memory. We only need to check the
184 * first page, since address is 8k aligned and memory pieces are always
185 * at least 1MB aligned and have at least a size of 1MB.
186 */
187 if (kvm_is_error_gpa(vcpu->kvm, irq.u.prefix.address)) {
188 *reg &= 0xffffffff00000000UL;
189 *reg |= SIGP_STATUS_INVALID_PARAMETER;
190 return SIGP_CC_STATUS_STORED;
191 }
192
193 rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
194 if (rc == -EBUSY) {
195 *reg &= 0xffffffff00000000UL;
196 *reg |= SIGP_STATUS_INCORRECT_STATE;
197 return SIGP_CC_STATUS_STORED;
198 }
199
200 return rc;
201 }
202
__sigp_store_status_at_addr(struct kvm_vcpu * vcpu,struct kvm_vcpu * dst_vcpu,u32 addr,u64 * reg)203 static int __sigp_store_status_at_addr(struct kvm_vcpu *vcpu,
204 struct kvm_vcpu *dst_vcpu,
205 u32 addr, u64 *reg)
206 {
207 int rc;
208
209 if (!kvm_s390_test_cpuflags(dst_vcpu, CPUSTAT_STOPPED)) {
210 *reg &= 0xffffffff00000000UL;
211 *reg |= SIGP_STATUS_INCORRECT_STATE;
212 return SIGP_CC_STATUS_STORED;
213 }
214
215 addr &= 0x7ffffe00;
216 rc = kvm_s390_store_status_unloaded(dst_vcpu, addr);
217 if (rc == -EFAULT) {
218 *reg &= 0xffffffff00000000UL;
219 *reg |= SIGP_STATUS_INVALID_PARAMETER;
220 rc = SIGP_CC_STATUS_STORED;
221 }
222 return rc;
223 }
224
__sigp_sense_running(struct kvm_vcpu * vcpu,struct kvm_vcpu * dst_vcpu,u64 * reg)225 static int __sigp_sense_running(struct kvm_vcpu *vcpu,
226 struct kvm_vcpu *dst_vcpu, u64 *reg)
227 {
228 int rc;
229
230 if (!test_kvm_facility(vcpu->kvm, 9)) {
231 *reg &= 0xffffffff00000000UL;
232 *reg |= SIGP_STATUS_INVALID_ORDER;
233 return SIGP_CC_STATUS_STORED;
234 }
235
236 if (kvm_s390_test_cpuflags(dst_vcpu, CPUSTAT_RUNNING)) {
237 /* running */
238 rc = SIGP_CC_ORDER_CODE_ACCEPTED;
239 } else {
240 /* not running */
241 *reg &= 0xffffffff00000000UL;
242 *reg |= SIGP_STATUS_NOT_RUNNING;
243 rc = SIGP_CC_STATUS_STORED;
244 }
245
246 VCPU_EVENT(vcpu, 4, "sensed running status of cpu %x rc %x",
247 dst_vcpu->vcpu_id, rc);
248
249 return rc;
250 }
251
__prepare_sigp_re_start(struct kvm_vcpu * vcpu,struct kvm_vcpu * dst_vcpu,u8 order_code)252 static int __prepare_sigp_re_start(struct kvm_vcpu *vcpu,
253 struct kvm_vcpu *dst_vcpu, u8 order_code)
254 {
255 struct kvm_s390_local_interrupt *li = &dst_vcpu->arch.local_int;
256 /* handle (RE)START in user space */
257 int rc = -EOPNOTSUPP;
258
259 /* make sure we don't race with STOP irq injection */
260 spin_lock(&li->lock);
261 if (kvm_s390_is_stop_irq_pending(dst_vcpu))
262 rc = SIGP_CC_BUSY;
263 spin_unlock(&li->lock);
264
265 return rc;
266 }
267
__prepare_sigp_cpu_reset(struct kvm_vcpu * vcpu,struct kvm_vcpu * dst_vcpu,u8 order_code)268 static int __prepare_sigp_cpu_reset(struct kvm_vcpu *vcpu,
269 struct kvm_vcpu *dst_vcpu, u8 order_code)
270 {
271 /* handle (INITIAL) CPU RESET in user space */
272 return -EOPNOTSUPP;
273 }
274
__prepare_sigp_unknown(struct kvm_vcpu * vcpu,struct kvm_vcpu * dst_vcpu)275 static int __prepare_sigp_unknown(struct kvm_vcpu *vcpu,
276 struct kvm_vcpu *dst_vcpu)
277 {
278 /* handle unknown orders in user space */
279 return -EOPNOTSUPP;
280 }
281
handle_sigp_dst(struct kvm_vcpu * vcpu,u8 order_code,u16 cpu_addr,u32 parameter,u64 * status_reg)282 static int handle_sigp_dst(struct kvm_vcpu *vcpu, u8 order_code,
283 u16 cpu_addr, u32 parameter, u64 *status_reg)
284 {
285 int rc;
286 struct kvm_vcpu *dst_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, cpu_addr);
287
288 if (!dst_vcpu)
289 return SIGP_CC_NOT_OPERATIONAL;
290
291 /*
292 * SIGP RESTART, SIGP STOP, and SIGP STOP AND STORE STATUS orders
293 * are processed asynchronously. Until the affected VCPU finishes
294 * its work and calls back into KVM to clear the (RESTART or STOP)
295 * interrupt, we need to return any new non-reset orders "busy".
296 *
297 * This is important because a single VCPU could issue:
298 * 1) SIGP STOP $DESTINATION
299 * 2) SIGP SENSE $DESTINATION
300 *
301 * If the SIGP SENSE would not be rejected as "busy", it could
302 * return an incorrect answer as to whether the VCPU is STOPPED
303 * or OPERATING.
304 */
305 if (order_code != SIGP_INITIAL_CPU_RESET &&
306 order_code != SIGP_CPU_RESET) {
307 /*
308 * Lockless check. Both SIGP STOP and SIGP (RE)START
309 * properly synchronize everything while processing
310 * their orders, while the guest cannot observe a
311 * difference when issuing other orders from two
312 * different VCPUs.
313 */
314 if (kvm_s390_is_stop_irq_pending(dst_vcpu) ||
315 kvm_s390_is_restart_irq_pending(dst_vcpu))
316 return SIGP_CC_BUSY;
317 }
318
319 switch (order_code) {
320 case SIGP_SENSE:
321 vcpu->stat.instruction_sigp_sense++;
322 rc = __sigp_sense(vcpu, dst_vcpu, status_reg);
323 break;
324 case SIGP_EXTERNAL_CALL:
325 vcpu->stat.instruction_sigp_external_call++;
326 rc = __sigp_external_call(vcpu, dst_vcpu, status_reg);
327 break;
328 case SIGP_EMERGENCY_SIGNAL:
329 vcpu->stat.instruction_sigp_emergency++;
330 rc = __sigp_emergency(vcpu, dst_vcpu);
331 break;
332 case SIGP_STOP:
333 vcpu->stat.instruction_sigp_stop++;
334 rc = __sigp_stop(vcpu, dst_vcpu);
335 break;
336 case SIGP_STOP_AND_STORE_STATUS:
337 vcpu->stat.instruction_sigp_stop_store_status++;
338 rc = __sigp_stop_and_store_status(vcpu, dst_vcpu, status_reg);
339 break;
340 case SIGP_STORE_STATUS_AT_ADDRESS:
341 vcpu->stat.instruction_sigp_store_status++;
342 rc = __sigp_store_status_at_addr(vcpu, dst_vcpu, parameter,
343 status_reg);
344 break;
345 case SIGP_SET_PREFIX:
346 vcpu->stat.instruction_sigp_prefix++;
347 rc = __sigp_set_prefix(vcpu, dst_vcpu, parameter, status_reg);
348 break;
349 case SIGP_COND_EMERGENCY_SIGNAL:
350 vcpu->stat.instruction_sigp_cond_emergency++;
351 rc = __sigp_conditional_emergency(vcpu, dst_vcpu, parameter,
352 status_reg);
353 break;
354 case SIGP_SENSE_RUNNING:
355 vcpu->stat.instruction_sigp_sense_running++;
356 rc = __sigp_sense_running(vcpu, dst_vcpu, status_reg);
357 break;
358 case SIGP_START:
359 vcpu->stat.instruction_sigp_start++;
360 rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code);
361 break;
362 case SIGP_RESTART:
363 vcpu->stat.instruction_sigp_restart++;
364 rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code);
365 break;
366 case SIGP_INITIAL_CPU_RESET:
367 vcpu->stat.instruction_sigp_init_cpu_reset++;
368 rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code);
369 break;
370 case SIGP_CPU_RESET:
371 vcpu->stat.instruction_sigp_cpu_reset++;
372 rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code);
373 break;
374 default:
375 vcpu->stat.instruction_sigp_unknown++;
376 rc = __prepare_sigp_unknown(vcpu, dst_vcpu);
377 }
378
379 if (rc == -EOPNOTSUPP)
380 VCPU_EVENT(vcpu, 4,
381 "sigp order %u -> cpu %x: handled in user space",
382 order_code, dst_vcpu->vcpu_id);
383
384 return rc;
385 }
386
handle_sigp_order_in_user_space(struct kvm_vcpu * vcpu,u8 order_code,u16 cpu_addr)387 static int handle_sigp_order_in_user_space(struct kvm_vcpu *vcpu, u8 order_code,
388 u16 cpu_addr)
389 {
390 if (!vcpu->kvm->arch.user_sigp)
391 return 0;
392
393 switch (order_code) {
394 case SIGP_SENSE:
395 case SIGP_EXTERNAL_CALL:
396 case SIGP_EMERGENCY_SIGNAL:
397 case SIGP_COND_EMERGENCY_SIGNAL:
398 case SIGP_SENSE_RUNNING:
399 return 0;
400 /* update counters as we're directly dropping to user space */
401 case SIGP_STOP:
402 vcpu->stat.instruction_sigp_stop++;
403 break;
404 case SIGP_STOP_AND_STORE_STATUS:
405 vcpu->stat.instruction_sigp_stop_store_status++;
406 break;
407 case SIGP_STORE_STATUS_AT_ADDRESS:
408 vcpu->stat.instruction_sigp_store_status++;
409 break;
410 case SIGP_STORE_ADDITIONAL_STATUS:
411 vcpu->stat.instruction_sigp_store_adtl_status++;
412 break;
413 case SIGP_SET_PREFIX:
414 vcpu->stat.instruction_sigp_prefix++;
415 break;
416 case SIGP_START:
417 vcpu->stat.instruction_sigp_start++;
418 break;
419 case SIGP_RESTART:
420 vcpu->stat.instruction_sigp_restart++;
421 break;
422 case SIGP_INITIAL_CPU_RESET:
423 vcpu->stat.instruction_sigp_init_cpu_reset++;
424 break;
425 case SIGP_CPU_RESET:
426 vcpu->stat.instruction_sigp_cpu_reset++;
427 break;
428 default:
429 vcpu->stat.instruction_sigp_unknown++;
430 }
431 VCPU_EVENT(vcpu, 3, "SIGP: order %u for CPU %d handled in userspace",
432 order_code, cpu_addr);
433
434 return 1;
435 }
436
kvm_s390_handle_sigp(struct kvm_vcpu * vcpu)437 int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu)
438 {
439 int r1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
440 int r3 = vcpu->arch.sie_block->ipa & 0x000f;
441 u32 parameter;
442 u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
443 u8 order_code;
444 int rc;
445
446 /* sigp in userspace can exit */
447 if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
448 return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
449
450 order_code = kvm_s390_get_base_disp_rs(vcpu, NULL);
451 if (handle_sigp_order_in_user_space(vcpu, order_code, cpu_addr))
452 return -EOPNOTSUPP;
453
454 if (r1 % 2)
455 parameter = vcpu->run->s.regs.gprs[r1];
456 else
457 parameter = vcpu->run->s.regs.gprs[r1 + 1];
458
459 trace_kvm_s390_handle_sigp(vcpu, order_code, cpu_addr, parameter);
460 switch (order_code) {
461 case SIGP_SET_ARCHITECTURE:
462 vcpu->stat.instruction_sigp_arch++;
463 rc = __sigp_set_arch(vcpu, parameter,
464 &vcpu->run->s.regs.gprs[r1]);
465 break;
466 default:
467 rc = handle_sigp_dst(vcpu, order_code, cpu_addr,
468 parameter,
469 &vcpu->run->s.regs.gprs[r1]);
470 }
471
472 if (rc < 0)
473 return rc;
474
475 kvm_s390_set_psw_cc(vcpu, rc);
476 return 0;
477 }
478
479 /*
480 * Handle SIGP partial execution interception.
481 *
482 * This interception will occur at the source cpu when a source cpu sends an
483 * external call to a target cpu and the target cpu has the WAIT bit set in
484 * its cpuflags. Interception will occurr after the interrupt indicator bits at
485 * the target cpu have been set. All error cases will lead to instruction
486 * interception, therefore nothing is to be checked or prepared.
487 */
kvm_s390_handle_sigp_pei(struct kvm_vcpu * vcpu)488 int kvm_s390_handle_sigp_pei(struct kvm_vcpu *vcpu)
489 {
490 int r3 = vcpu->arch.sie_block->ipa & 0x000f;
491 u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
492 struct kvm_vcpu *dest_vcpu;
493 u8 order_code = kvm_s390_get_base_disp_rs(vcpu, NULL);
494
495 if (order_code == SIGP_EXTERNAL_CALL) {
496 trace_kvm_s390_handle_sigp_pei(vcpu, order_code, cpu_addr);
497
498 dest_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, cpu_addr);
499 BUG_ON(dest_vcpu == NULL);
500
501 kvm_s390_vcpu_wakeup(dest_vcpu);
502 kvm_s390_set_psw_cc(vcpu, SIGP_CC_ORDER_CODE_ACCEPTED);
503 return 0;
504 }
505
506 return -EOPNOTSUPP;
507 }
508