aboutsummaryrefslogtreecommitdiff
path: root/arch/s390/kvm/sigp.c
blob: cb747bf6c7982ec460073e44175d620659bb5c80 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
// SPDX-License-Identifier: GPL-2.0
/*
 * handling interprocessor communication
 *
 * Copyright IBM Corp. 2008, 2013
 *
 *    Author(s): Carsten Otte <cotte@de.ibm.com>
 *               Christian Borntraeger <borntraeger@de.ibm.com>
 *               Christian Ehrhardt <ehrhardt@de.ibm.com>
 */

#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <linux/slab.h>
#include <asm/sigp.h>
#include "gaccess.h"
#include "kvm-s390.h"
#include "trace.h"

static int __sigp_sense(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu,
			u64 *reg)
{
	const bool stopped = kvm_s390_test_cpuflags(dst_vcpu, CPUSTAT_STOPPED);
	int rc;
	int ext_call_pending;

	ext_call_pending = kvm_s390_ext_call_pending(dst_vcpu);
	if (!stopped && !ext_call_pending)
		rc = SIGP_CC_ORDER_CODE_ACCEPTED;
	else {
		*reg &= 0xffffffff00000000UL;
		if (ext_call_pending)
			*reg |= SIGP_STATUS_EXT_CALL_PENDING;
		if (stopped)
			*reg |= SIGP_STATUS_STOPPED;
		rc = SIGP_CC_STATUS_STORED;
	}

	VCPU_EVENT(vcpu, 4, "sensed status of cpu %x rc %x", dst_vcpu->vcpu_id,
		   rc);
	return rc;
}

static int __inject_sigp_emergency(struct kvm_vcpu *vcpu,
				    struct kvm_vcpu *dst_vcpu)
{
	struct kvm_s390_irq irq = {
		.type = KVM_S390_INT_EMERGENCY,
		.u.emerg.code = vcpu->vcpu_id,
	};
	int rc = 0;

	rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
	if (!rc)
		VCPU_EVENT(vcpu, 4, "sent sigp emerg to cpu %x",
			   dst_vcpu->vcpu_id);

	return rc ? rc : SIGP_CC_ORDER_CODE_ACCEPTED;
}

static int __sigp_emergency(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu)
{
	return __inject_sigp_emergency(vcpu, dst_vcpu);
}

static int __sigp_conditional_emergency(struct kvm_vcpu *vcpu,
					struct kvm_vcpu *dst_vcpu,
					u16 asn, u64 *reg)
{
	const u64 psw_int_mask = PSW_MASK_IO | PSW_MASK_EXT;
	u16 p_asn, s_asn;
	psw_t *psw;
	bool idle;

	idle = is_vcpu_idle(vcpu);
	psw = &dst_vcpu->arch.sie_block->gpsw;
	p_asn = dst_vcpu->arch.sie_block->gcr[4] & 0xffff;  /* Primary ASN */
	s_asn = dst_vcpu->arch.sie_block->gcr[3] & 0xffff;  /* Secondary ASN */

	/* Inject the emergency signal? */
	if (!is_vcpu_stopped(vcpu)
	    || (psw->mask & psw_int_mask) != psw_int_mask
	    || (idle && psw->addr != 0)
	    || (!idle && (asn == p_asn || asn == s_asn))) {
		return __inject_sigp_emergency(vcpu, dst_vcpu);
	} else {
		*reg &= 0xffffffff00000000UL;
		*reg |= SIGP_STATUS_INCORRECT_STATE;
		return SIGP_CC_STATUS_STORED;
	}
}

static int __sigp_external_call(struct kvm_vcpu *vcpu,
				struct kvm_vcpu *dst_vcpu, u64 *reg)
{
	struct kvm_s390_irq irq = {
		.type = KVM_S390_INT_EXTERNAL_CALL,
		.u.extcall.code = vcpu->vcpu_id,
	};
	int rc;

	rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
	if (rc == -EBUSY) {
		*reg &= 0xffffffff00000000UL;
		*reg |= SIGP_STATUS_EXT_CALL_PENDING;
		return SIGP_CC_STATUS_STORED;
	} else if (rc == 0) {
		VCPU_EVENT(vcpu, 4, "sent sigp ext call to cpu %x",
			   dst_vcpu->vcpu_id);
	}

	return rc ? rc : SIGP_CC_ORDER_CODE_ACCEPTED;
}

static int __sigp_stop(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu)
{
	struct kvm_s390_irq irq = {
		.type = KVM_S390_SIGP_STOP,
	};
	int rc;

	rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
	if (rc == -EBUSY)
		rc = SIGP_CC_BUSY;
	else if (rc == 0)
		VCPU_EVENT(vcpu, 4, "sent sigp stop to cpu %x",
			   dst_vcpu->vcpu_id);

	return rc;
}

static int __sigp_stop_and_store_status(struct kvm_vcpu *vcpu,
					struct kvm_vcpu *dst_vcpu, u64 *reg)
{
	struct kvm_s390_irq irq = {
		.type = KVM_S390_SIGP_STOP,
		.u.stop.flags = KVM_S390_STOP_FLAG_STORE_STATUS,
	};
	int rc;

	rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
	if (rc == -EBUSY)
		rc = SIGP_CC_BUSY;
	else if (rc == 0)
		VCPU_EVENT(vcpu, 4, "sent sigp stop and store status to cpu %x",
			   dst_vcpu->vcpu_id);

	return rc;
}

static int __sigp_set_arch(struct kvm_vcpu *vcpu, u32 parameter,
			   u64 *status_reg)
{
	*status_reg &= 0xffffffff00000000UL;

	/* Reject set arch order, with czam we're always in z/Arch mode. */
	*status_reg |= SIGP_STATUS_INVALID_PARAMETER;
	return SIGP_CC_STATUS_STORED;
}

static int __sigp_set_prefix(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu,
			     u32 address, u64 *reg)
{
	struct kvm_s390_irq irq = {
		.type = KVM_S390_SIGP_SET_PREFIX,
		.u.prefix.address = address & 0x7fffe000u,
	};
	int rc;

	/*
	 * Make sure the new value is valid memory. We only need to check the
	 * first page, since address is 8k aligned and memory pieces are always
	 * at least 1MB aligned and have at least a size of 1MB.
	 */
	if (kvm_is_error_gpa(vcpu->kvm, irq.u.prefix.address)) {
		*reg &= 0xffffffff00000000UL;
		*reg |= SIGP_STATUS_INVALID_PARAMETER;
		return SIGP_CC_STATUS_STORED;
	}

	rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
	if (rc == -EBUSY) {
		*reg &= 0xffffffff00000000UL;
		*reg |= SIGP_STATUS_INCORRECT_STATE;
		return SIGP_CC_STATUS_STORED;
	}

	return rc;
}

static int __sigp_store_status_at_addr(struct kvm_vcpu *vcpu,
				       struct kvm_vcpu *dst_vcpu,
				       u32 addr, u64 *reg)
{
	int rc;

	if (!kvm_s390_test_cpuflags(dst_vcpu, CPUSTAT_STOPPED)) {
		*reg &= 0xffffffff00000000UL;
		*reg |= SIGP_STATUS_INCORRECT_STATE;
		return SIGP_CC_STATUS_STORED;
	}

	addr &= 0x7ffffe00;
	rc = kvm_s390_store_status_unloaded(dst_vcpu, addr);
	if (rc == -EFAULT) {
		*reg &= 0xffffffff00000000UL;
		*reg |= SIGP_STATUS_INVALID_PARAMETER;
		rc = SIGP_CC_STATUS_STORED;
	}
	return rc;
}

static int __sigp_sense_running(struct kvm_vcpu *vcpu,
				struct kvm_vcpu *dst_vcpu, u64 *reg)
{
	int rc;

	if (!test_kvm_facility(vcpu->kvm, 9)) {
		*reg &= 0xffffffff00000000UL;
		*reg |= SIGP_STATUS_INVALID_ORDER;
		return SIGP_CC_STATUS_STORED;
	}

	if (kvm_s390_test_cpuflags(dst_vcpu, CPUSTAT_RUNNING)) {
		/* running */
		rc = SIGP_CC_ORDER_CODE_ACCEPTED;
	} else {
		/* not running */
		*reg &= 0xffffffff00000000UL;
		*reg |= SIGP_STATUS_NOT_RUNNING;
		rc = SIGP_CC_STATUS_STORED;
	}

	VCPU_EVENT(vcpu, 4, "sensed running status of cpu %x rc %x",
		   dst_vcpu->vcpu_id, rc);

	return rc;
}

static int __prepare_sigp_re_start(struct kvm_vcpu *vcpu,
				   struct kvm_vcpu *dst_vcpu, u8 order_code)
{
	struct kvm_s390_local_interrupt *li = &dst_vcpu->arch.local_int;
	/* handle (RE)START in user space */
	int rc = -EOPNOTSUPP;

	/* make sure we don't race with STOP irq injection */
	spin_lock(&li->lock);
	if (kvm_s390_is_stop_irq_pending(dst_vcpu))
		rc = SIGP_CC_BUSY;
	spin_unlock(&li->lock);

	return rc;
}

static int __prepare_sigp_cpu_reset(struct kvm_vcpu *vcpu,
				    struct kvm_vcpu *dst_vcpu, u8 order_code)
{
	/* handle (INITIAL) CPU RESET in user space */
	return -EOPNOTSUPP;
}

static int __prepare_sigp_unknown(struct kvm_vcpu *vcpu,
				  struct kvm_vcpu *dst_vcpu)
{
	/* handle unknown orders in user space */
	return -EOPNOTSUPP;
}

static int handle_sigp_dst(struct kvm_vcpu *vcpu, u8 order_code,
			   u16 cpu_addr, u32 parameter, u64 *status_reg)
{
	int rc;
	struct kvm_vcpu *dst_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, cpu_addr);

	if (!dst_vcpu)
		return SIGP_CC_NOT_OPERATIONAL;

	/*
	 * SIGP RESTART, SIGP STOP, and SIGP STOP AND STORE STATUS orders
	 * are processed asynchronously. Until the affected VCPU finishes
	 * its work and calls back into KVM to clear the (RESTART or STOP)
	 * interrupt, we need to return any new non-reset orders "busy".
	 *
	 * This is important because a single VCPU could issue:
	 *  1) SIGP STOP $DESTINATION
	 *  2) SIGP SENSE $DESTINATION
	 *
	 * If the SIGP SENSE would not be rejected as "busy", it could
	 * return an incorrect answer as to whether the VCPU is STOPPED
	 * or OPERATING.
	 */
	if (order_code != SIGP_INITIAL_CPU_RESET &&
	    order_code != SIGP_CPU_RESET) {
		/*
		 * Lockless check. Both SIGP STOP and SIGP (RE)START
		 * properly synchronize everything while processing
		 * their orders, while the guest cannot observe a
		 * difference when issuing other orders from two
		 * different VCPUs.
		 */
		if (kvm_s390_is_stop_irq_pending(dst_vcpu) ||
		    kvm_s390_is_restart_irq_pending(dst_vcpu))
			return SIGP_CC_BUSY;
	}

	switch (order_code) {
	case SIGP_SENSE:
		vcpu->stat.instruction_sigp_sense++;
		rc = __sigp_sense(vcpu, dst_vcpu, status_reg);
		break;
	case SIGP_EXTERNAL_CALL:
		vcpu->stat.instruction_sigp_external_call++;
		rc = __sigp_external_call(vcpu, dst_vcpu, status_reg);
		break;
	case SIGP_EMERGENCY_SIGNAL:
		vcpu->stat.instruction_sigp_emergency++;
		rc = __sigp_emergency(vcpu, dst_vcpu);
		break;
	case SIGP_STOP:
		vcpu->stat.instruction_sigp_stop++;
		rc = __sigp_stop(vcpu, dst_vcpu);
		break;
	case SIGP_STOP_AND_STORE_STATUS:
		vcpu->stat.instruction_sigp_stop_store_status++;
		rc = __sigp_stop_and_store_status(vcpu, dst_vcpu, status_reg);
		break;
	case SIGP_STORE_STATUS_AT_ADDRESS:
		vcpu->stat.instruction_sigp_store_status++;
		rc = __sigp_store_status_at_addr(vcpu, dst_vcpu, parameter,
						 status_reg);
		break;
	case SIGP_SET_PREFIX:
		vcpu->stat.instruction_sigp_prefix++;
		rc = __sigp_set_prefix(vcpu, dst_vcpu, parameter, status_reg);
		break;
	case SIGP_COND_EMERGENCY_SIGNAL:
		vcpu->stat.instruction_sigp_cond_emergency++;
		rc = __sigp_conditional_emergency(vcpu, dst_vcpu, parameter,
						  status_reg);
		break;
	case SIGP_SENSE_RUNNING:
		vcpu->stat.instruction_sigp_sense_running++;
		rc = __sigp_sense_running(vcpu, dst_vcpu, status_reg);
		break;
	case SIGP_START:
		vcpu->stat.instruction_sigp_start++;
		rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code);
		break;
	case SIGP_RESTART:
		vcpu->stat.instruction_sigp_restart++;
		rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code);
		break;
	case SIGP_INITIAL_CPU_RESET:
		vcpu->stat.instruction_sigp_init_cpu_reset++;
		rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code);
		break;
	case SIGP_CPU_RESET:
		vcpu->stat.instruction_sigp_cpu_reset++;
		rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code);
		break;
	default:
		vcpu->stat.instruction_sigp_unknown++;
		rc = __prepare_sigp_unknown(vcpu, dst_vcpu);
	}

	if (rc == -EOPNOTSUPP)
		VCPU_EVENT(vcpu, 4,
			   "sigp order %u -> cpu %x: handled in user space",
			   order_code, dst_vcpu->vcpu_id);

	return rc;
}

static int handle_sigp_order_in_user_space(struct kvm_vcpu *vcpu, u8 order_code,
					   u16 cpu_addr)
{
	if (!vcpu->kvm->arch.user_sigp)
		return 0;

	switch (order_code) {
	case SIGP_SENSE:
	case SIGP_EXTERNAL_CALL:
	case SIGP_EMERGENCY_SIGNAL:
	case SIGP_COND_EMERGENCY_SIGNAL:
	case SIGP_SENSE_RUNNING:
		return 0;
	/* update counters as we're directly dropping to user space */
	case SIGP_STOP:
		vcpu->stat.instruction_sigp_stop++;
		break;
	case SIGP_STOP_AND_STORE_STATUS:
		vcpu->stat.instruction_sigp_stop_store_status++;
		break;
	case SIGP_STORE_STATUS_AT_ADDRESS:
		vcpu->stat.instruction_sigp_store_status++;
		break;
	case SIGP_STORE_ADDITIONAL_STATUS:
		vcpu->stat.instruction_sigp_store_adtl_status++;
		break;
	case SIGP_SET_PREFIX:
		vcpu->stat.instruction_sigp_prefix++;
		break;
	case SIGP_START:
		vcpu->stat.instruction_sigp_start++;
		break;
	case SIGP_RESTART:
		vcpu->stat.instruction_sigp_restart++;
		break;
	case SIGP_INITIAL_CPU_RESET:
		vcpu->stat.instruction_sigp_init_cpu_reset++;
		break;
	case SIGP_CPU_RESET:
		vcpu->stat.instruction_sigp_cpu_reset++;
		break;
	default:
		vcpu->stat.instruction_sigp_unknown++;
	}
	VCPU_EVENT(vcpu, 3, "SIGP: order %u for CPU %d handled in userspace",
		   order_code, cpu_addr);

	return 1;
}

int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu)
{
	int r1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
	int r3 = vcpu->arch.sie_block->ipa & 0x000f;
	u32 parameter;
	u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
	u8 order_code;
	int rc;

	/* sigp in userspace can exit */
	if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
		return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);

	order_code = kvm_s390_get_base_disp_rs(vcpu, NULL);
	if (handle_sigp_order_in_user_space(vcpu, order_code, cpu_addr))
		return -EOPNOTSUPP;

	if (r1 % 2)
		parameter = vcpu->run->s.regs.gprs[r1];
	else
		parameter = vcpu->run->s.regs.gprs[r1 + 1];

	trace_kvm_s390_handle_sigp(vcpu, order_code, cpu_addr, parameter);
	switch (order_code) {
	case SIGP_SET_ARCHITECTURE:
		vcpu->stat.instruction_sigp_arch++;
		rc = __sigp_set_arch(vcpu, parameter,
				     &vcpu->run->s.regs.gprs[r1]);
		break;
	default:
		rc = handle_sigp_dst(vcpu, order_code, cpu_addr,
				     parameter,
				     &vcpu->run->s.regs.gprs[r1]);
	}

	if (rc < 0)
		return rc;

	kvm_s390_set_psw_cc(vcpu, rc);
	return 0;
}

/*
 * Handle SIGP partial execution interception.
 *
 * This interception will occur at the source cpu when a source cpu sends an
 * external call to a target cpu and the target cpu has the WAIT bit set in
 * its cpuflags. Interception will occurr after the interrupt indicator bits at
 * the target cpu have been set. All error cases will lead to instruction
 * interception, therefore nothing is to be checked or prepared.
 */
int kvm_s390_handle_sigp_pei(struct kvm_vcpu *vcpu)
{
	int r3 = vcpu->arch.sie_block->ipa & 0x000f;
	u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
	struct kvm_vcpu *dest_vcpu;
	u8 order_code = kvm_s390_get_base_disp_rs(vcpu, NULL);

	if (order_code == SIGP_EXTERNAL_CALL) {
		trace_kvm_s390_handle_sigp_pei(vcpu, order_code, cpu_addr);

		dest_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, cpu_addr);
		BUG_ON(dest_vcpu == NULL);

		kvm_s390_vcpu_wakeup(dest_vcpu);
		kvm_s390_set_psw_cc(vcpu, SIGP_CC_ORDER_CODE_ACCEPTED);
		return 0;
	}

	return -EOPNOTSUPP;
}