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1 /*
2  * handling interprocessor communication
3  *
4  * Copyright IBM Corp. 2008, 2013
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License (version 2 only)
8  * as published by the Free Software Foundation.
9  *
10  *    Author(s): Carsten Otte <cotte@de.ibm.com>
11  *               Christian Borntraeger <borntraeger@de.ibm.com>
12  *               Christian Ehrhardt <ehrhardt@de.ibm.com>
13  */
14 
15 #include <linux/kvm.h>
16 #include <linux/kvm_host.h>
17 #include <linux/slab.h>
18 #include <asm/sigp.h>
19 #include "gaccess.h"
20 #include "kvm-s390.h"
21 #include "trace.h"
22 
__sigp_sense(struct kvm_vcpu * vcpu,struct kvm_vcpu * dst_vcpu,u64 * reg)23 static int __sigp_sense(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu,
24 			u64 *reg)
25 {
26 	struct kvm_s390_local_interrupt *li;
27 	int cpuflags;
28 	int rc;
29 	int ext_call_pending;
30 
31 	li = &dst_vcpu->arch.local_int;
32 
33 	cpuflags = atomic_read(li->cpuflags);
34 	ext_call_pending = kvm_s390_ext_call_pending(dst_vcpu);
35 	if (!(cpuflags & CPUSTAT_STOPPED) && !ext_call_pending)
36 		rc = SIGP_CC_ORDER_CODE_ACCEPTED;
37 	else {
38 		*reg &= 0xffffffff00000000UL;
39 		if (ext_call_pending)
40 			*reg |= SIGP_STATUS_EXT_CALL_PENDING;
41 		if (cpuflags & CPUSTAT_STOPPED)
42 			*reg |= SIGP_STATUS_STOPPED;
43 		rc = SIGP_CC_STATUS_STORED;
44 	}
45 
46 	VCPU_EVENT(vcpu, 4, "sensed status of cpu %x rc %x", dst_vcpu->vcpu_id,
47 		   rc);
48 	return rc;
49 }
50 
__inject_sigp_emergency(struct kvm_vcpu * vcpu,struct kvm_vcpu * dst_vcpu)51 static int __inject_sigp_emergency(struct kvm_vcpu *vcpu,
52 				    struct kvm_vcpu *dst_vcpu)
53 {
54 	struct kvm_s390_irq irq = {
55 		.type = KVM_S390_INT_EMERGENCY,
56 		.u.emerg.code = vcpu->vcpu_id,
57 	};
58 	int rc = 0;
59 
60 	rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
61 	if (!rc)
62 		VCPU_EVENT(vcpu, 4, "sent sigp emerg to cpu %x",
63 			   dst_vcpu->vcpu_id);
64 
65 	return rc ? rc : SIGP_CC_ORDER_CODE_ACCEPTED;
66 }
67 
__sigp_emergency(struct kvm_vcpu * vcpu,struct kvm_vcpu * dst_vcpu)68 static int __sigp_emergency(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu)
69 {
70 	return __inject_sigp_emergency(vcpu, dst_vcpu);
71 }
72 
__sigp_conditional_emergency(struct kvm_vcpu * vcpu,struct kvm_vcpu * dst_vcpu,u16 asn,u64 * reg)73 static int __sigp_conditional_emergency(struct kvm_vcpu *vcpu,
74 					struct kvm_vcpu *dst_vcpu,
75 					u16 asn, u64 *reg)
76 {
77 	const u64 psw_int_mask = PSW_MASK_IO | PSW_MASK_EXT;
78 	u16 p_asn, s_asn;
79 	psw_t *psw;
80 	u32 flags;
81 
82 	flags = atomic_read(&dst_vcpu->arch.sie_block->cpuflags);
83 	psw = &dst_vcpu->arch.sie_block->gpsw;
84 	p_asn = dst_vcpu->arch.sie_block->gcr[4] & 0xffff;  /* Primary ASN */
85 	s_asn = dst_vcpu->arch.sie_block->gcr[3] & 0xffff;  /* Secondary ASN */
86 
87 	/* Inject the emergency signal? */
88 	if (!(flags & CPUSTAT_STOPPED)
89 	    || (psw->mask & psw_int_mask) != psw_int_mask
90 	    || ((flags & CPUSTAT_WAIT) && psw->addr != 0)
91 	    || (!(flags & CPUSTAT_WAIT) && (asn == p_asn || asn == s_asn))) {
92 		return __inject_sigp_emergency(vcpu, dst_vcpu);
93 	} else {
94 		*reg &= 0xffffffff00000000UL;
95 		*reg |= SIGP_STATUS_INCORRECT_STATE;
96 		return SIGP_CC_STATUS_STORED;
97 	}
98 }
99 
__sigp_external_call(struct kvm_vcpu * vcpu,struct kvm_vcpu * dst_vcpu,u64 * reg)100 static int __sigp_external_call(struct kvm_vcpu *vcpu,
101 				struct kvm_vcpu *dst_vcpu, u64 *reg)
102 {
103 	struct kvm_s390_irq irq = {
104 		.type = KVM_S390_INT_EXTERNAL_CALL,
105 		.u.extcall.code = vcpu->vcpu_id,
106 	};
107 	int rc;
108 
109 	rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
110 	if (rc == -EBUSY) {
111 		*reg &= 0xffffffff00000000UL;
112 		*reg |= SIGP_STATUS_EXT_CALL_PENDING;
113 		return SIGP_CC_STATUS_STORED;
114 	} else if (rc == 0) {
115 		VCPU_EVENT(vcpu, 4, "sent sigp ext call to cpu %x",
116 			   dst_vcpu->vcpu_id);
117 	}
118 
119 	return rc ? rc : SIGP_CC_ORDER_CODE_ACCEPTED;
120 }
121 
__sigp_stop(struct kvm_vcpu * vcpu,struct kvm_vcpu * dst_vcpu)122 static int __sigp_stop(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu)
123 {
124 	struct kvm_s390_irq irq = {
125 		.type = KVM_S390_SIGP_STOP,
126 	};
127 	int rc;
128 
129 	rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
130 	if (rc == -EBUSY)
131 		rc = SIGP_CC_BUSY;
132 	else if (rc == 0)
133 		VCPU_EVENT(vcpu, 4, "sent sigp stop to cpu %x",
134 			   dst_vcpu->vcpu_id);
135 
136 	return rc;
137 }
138 
__sigp_stop_and_store_status(struct kvm_vcpu * vcpu,struct kvm_vcpu * dst_vcpu,u64 * reg)139 static int __sigp_stop_and_store_status(struct kvm_vcpu *vcpu,
140 					struct kvm_vcpu *dst_vcpu, u64 *reg)
141 {
142 	struct kvm_s390_irq irq = {
143 		.type = KVM_S390_SIGP_STOP,
144 		.u.stop.flags = KVM_S390_STOP_FLAG_STORE_STATUS,
145 	};
146 	int rc;
147 
148 	rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
149 	if (rc == -EBUSY)
150 		rc = SIGP_CC_BUSY;
151 	else if (rc == 0)
152 		VCPU_EVENT(vcpu, 4, "sent sigp stop and store status to cpu %x",
153 			   dst_vcpu->vcpu_id);
154 
155 	return rc;
156 }
157 
__sigp_set_arch(struct kvm_vcpu * vcpu,u32 parameter)158 static int __sigp_set_arch(struct kvm_vcpu *vcpu, u32 parameter)
159 {
160 	int rc;
161 	unsigned int i;
162 	struct kvm_vcpu *v;
163 
164 	switch (parameter & 0xff) {
165 	case 0:
166 		rc = SIGP_CC_NOT_OPERATIONAL;
167 		break;
168 	case 1:
169 	case 2:
170 		kvm_for_each_vcpu(i, v, vcpu->kvm) {
171 			v->arch.pfault_token = KVM_S390_PFAULT_TOKEN_INVALID;
172 			kvm_clear_async_pf_completion_queue(v);
173 		}
174 
175 		rc = SIGP_CC_ORDER_CODE_ACCEPTED;
176 		break;
177 	default:
178 		rc = -EOPNOTSUPP;
179 	}
180 	return rc;
181 }
182 
__sigp_set_prefix(struct kvm_vcpu * vcpu,struct kvm_vcpu * dst_vcpu,u32 address,u64 * reg)183 static int __sigp_set_prefix(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu,
184 			     u32 address, u64 *reg)
185 {
186 	struct kvm_s390_irq irq = {
187 		.type = KVM_S390_SIGP_SET_PREFIX,
188 		.u.prefix.address = address & 0x7fffe000u,
189 	};
190 	int rc;
191 
192 	/*
193 	 * Make sure the new value is valid memory. We only need to check the
194 	 * first page, since address is 8k aligned and memory pieces are always
195 	 * at least 1MB aligned and have at least a size of 1MB.
196 	 */
197 	if (kvm_is_error_gpa(vcpu->kvm, irq.u.prefix.address)) {
198 		*reg &= 0xffffffff00000000UL;
199 		*reg |= SIGP_STATUS_INVALID_PARAMETER;
200 		return SIGP_CC_STATUS_STORED;
201 	}
202 
203 	rc = kvm_s390_inject_vcpu(dst_vcpu, &irq);
204 	if (rc == -EBUSY) {
205 		*reg &= 0xffffffff00000000UL;
206 		*reg |= SIGP_STATUS_INCORRECT_STATE;
207 		return SIGP_CC_STATUS_STORED;
208 	}
209 
210 	return rc;
211 }
212 
__sigp_store_status_at_addr(struct kvm_vcpu * vcpu,struct kvm_vcpu * dst_vcpu,u32 addr,u64 * reg)213 static int __sigp_store_status_at_addr(struct kvm_vcpu *vcpu,
214 				       struct kvm_vcpu *dst_vcpu,
215 				       u32 addr, u64 *reg)
216 {
217 	int flags;
218 	int rc;
219 
220 	flags = atomic_read(dst_vcpu->arch.local_int.cpuflags);
221 	if (!(flags & CPUSTAT_STOPPED)) {
222 		*reg &= 0xffffffff00000000UL;
223 		*reg |= SIGP_STATUS_INCORRECT_STATE;
224 		return SIGP_CC_STATUS_STORED;
225 	}
226 
227 	addr &= 0x7ffffe00;
228 	rc = kvm_s390_store_status_unloaded(dst_vcpu, addr);
229 	if (rc == -EFAULT) {
230 		*reg &= 0xffffffff00000000UL;
231 		*reg |= SIGP_STATUS_INVALID_PARAMETER;
232 		rc = SIGP_CC_STATUS_STORED;
233 	}
234 	return rc;
235 }
236 
__sigp_sense_running(struct kvm_vcpu * vcpu,struct kvm_vcpu * dst_vcpu,u64 * reg)237 static int __sigp_sense_running(struct kvm_vcpu *vcpu,
238 				struct kvm_vcpu *dst_vcpu, u64 *reg)
239 {
240 	struct kvm_s390_local_interrupt *li;
241 	int rc;
242 
243 	li = &dst_vcpu->arch.local_int;
244 	if (atomic_read(li->cpuflags) & CPUSTAT_RUNNING) {
245 		/* running */
246 		rc = SIGP_CC_ORDER_CODE_ACCEPTED;
247 	} else {
248 		/* not running */
249 		*reg &= 0xffffffff00000000UL;
250 		*reg |= SIGP_STATUS_NOT_RUNNING;
251 		rc = SIGP_CC_STATUS_STORED;
252 	}
253 
254 	VCPU_EVENT(vcpu, 4, "sensed running status of cpu %x rc %x",
255 		   dst_vcpu->vcpu_id, rc);
256 
257 	return rc;
258 }
259 
__prepare_sigp_re_start(struct kvm_vcpu * vcpu,struct kvm_vcpu * dst_vcpu,u8 order_code)260 static int __prepare_sigp_re_start(struct kvm_vcpu *vcpu,
261 				   struct kvm_vcpu *dst_vcpu, u8 order_code)
262 {
263 	struct kvm_s390_local_interrupt *li = &dst_vcpu->arch.local_int;
264 	/* handle (RE)START in user space */
265 	int rc = -EOPNOTSUPP;
266 
267 	/* make sure we don't race with STOP irq injection */
268 	spin_lock(&li->lock);
269 	if (kvm_s390_is_stop_irq_pending(dst_vcpu))
270 		rc = SIGP_CC_BUSY;
271 	spin_unlock(&li->lock);
272 
273 	return rc;
274 }
275 
__prepare_sigp_cpu_reset(struct kvm_vcpu * vcpu,struct kvm_vcpu * dst_vcpu,u8 order_code)276 static int __prepare_sigp_cpu_reset(struct kvm_vcpu *vcpu,
277 				    struct kvm_vcpu *dst_vcpu, u8 order_code)
278 {
279 	/* handle (INITIAL) CPU RESET in user space */
280 	return -EOPNOTSUPP;
281 }
282 
__prepare_sigp_unknown(struct kvm_vcpu * vcpu,struct kvm_vcpu * dst_vcpu)283 static int __prepare_sigp_unknown(struct kvm_vcpu *vcpu,
284 				  struct kvm_vcpu *dst_vcpu)
285 {
286 	/* handle unknown orders in user space */
287 	return -EOPNOTSUPP;
288 }
289 
handle_sigp_dst(struct kvm_vcpu * vcpu,u8 order_code,u16 cpu_addr,u32 parameter,u64 * status_reg)290 static int handle_sigp_dst(struct kvm_vcpu *vcpu, u8 order_code,
291 			   u16 cpu_addr, u32 parameter, u64 *status_reg)
292 {
293 	int rc;
294 	struct kvm_vcpu *dst_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, cpu_addr);
295 
296 	if (!dst_vcpu)
297 		return SIGP_CC_NOT_OPERATIONAL;
298 
299 	switch (order_code) {
300 	case SIGP_SENSE:
301 		vcpu->stat.instruction_sigp_sense++;
302 		rc = __sigp_sense(vcpu, dst_vcpu, status_reg);
303 		break;
304 	case SIGP_EXTERNAL_CALL:
305 		vcpu->stat.instruction_sigp_external_call++;
306 		rc = __sigp_external_call(vcpu, dst_vcpu, status_reg);
307 		break;
308 	case SIGP_EMERGENCY_SIGNAL:
309 		vcpu->stat.instruction_sigp_emergency++;
310 		rc = __sigp_emergency(vcpu, dst_vcpu);
311 		break;
312 	case SIGP_STOP:
313 		vcpu->stat.instruction_sigp_stop++;
314 		rc = __sigp_stop(vcpu, dst_vcpu);
315 		break;
316 	case SIGP_STOP_AND_STORE_STATUS:
317 		vcpu->stat.instruction_sigp_stop_store_status++;
318 		rc = __sigp_stop_and_store_status(vcpu, dst_vcpu, status_reg);
319 		break;
320 	case SIGP_STORE_STATUS_AT_ADDRESS:
321 		vcpu->stat.instruction_sigp_store_status++;
322 		rc = __sigp_store_status_at_addr(vcpu, dst_vcpu, parameter,
323 						 status_reg);
324 		break;
325 	case SIGP_SET_PREFIX:
326 		vcpu->stat.instruction_sigp_prefix++;
327 		rc = __sigp_set_prefix(vcpu, dst_vcpu, parameter, status_reg);
328 		break;
329 	case SIGP_COND_EMERGENCY_SIGNAL:
330 		vcpu->stat.instruction_sigp_cond_emergency++;
331 		rc = __sigp_conditional_emergency(vcpu, dst_vcpu, parameter,
332 						  status_reg);
333 		break;
334 	case SIGP_SENSE_RUNNING:
335 		vcpu->stat.instruction_sigp_sense_running++;
336 		rc = __sigp_sense_running(vcpu, dst_vcpu, status_reg);
337 		break;
338 	case SIGP_START:
339 		vcpu->stat.instruction_sigp_start++;
340 		rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code);
341 		break;
342 	case SIGP_RESTART:
343 		vcpu->stat.instruction_sigp_restart++;
344 		rc = __prepare_sigp_re_start(vcpu, dst_vcpu, order_code);
345 		break;
346 	case SIGP_INITIAL_CPU_RESET:
347 		vcpu->stat.instruction_sigp_init_cpu_reset++;
348 		rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code);
349 		break;
350 	case SIGP_CPU_RESET:
351 		vcpu->stat.instruction_sigp_cpu_reset++;
352 		rc = __prepare_sigp_cpu_reset(vcpu, dst_vcpu, order_code);
353 		break;
354 	default:
355 		vcpu->stat.instruction_sigp_unknown++;
356 		rc = __prepare_sigp_unknown(vcpu, dst_vcpu);
357 	}
358 
359 	if (rc == -EOPNOTSUPP)
360 		VCPU_EVENT(vcpu, 4,
361 			   "sigp order %u -> cpu %x: handled in user space",
362 			   order_code, dst_vcpu->vcpu_id);
363 
364 	return rc;
365 }
366 
handle_sigp_order_in_user_space(struct kvm_vcpu * vcpu,u8 order_code,u16 cpu_addr)367 static int handle_sigp_order_in_user_space(struct kvm_vcpu *vcpu, u8 order_code,
368 					   u16 cpu_addr)
369 {
370 	if (!vcpu->kvm->arch.user_sigp)
371 		return 0;
372 
373 	switch (order_code) {
374 	case SIGP_SENSE:
375 	case SIGP_EXTERNAL_CALL:
376 	case SIGP_EMERGENCY_SIGNAL:
377 	case SIGP_COND_EMERGENCY_SIGNAL:
378 	case SIGP_SENSE_RUNNING:
379 		return 0;
380 	/* update counters as we're directly dropping to user space */
381 	case SIGP_STOP:
382 		vcpu->stat.instruction_sigp_stop++;
383 		break;
384 	case SIGP_STOP_AND_STORE_STATUS:
385 		vcpu->stat.instruction_sigp_stop_store_status++;
386 		break;
387 	case SIGP_STORE_STATUS_AT_ADDRESS:
388 		vcpu->stat.instruction_sigp_store_status++;
389 		break;
390 	case SIGP_STORE_ADDITIONAL_STATUS:
391 		vcpu->stat.instruction_sigp_store_adtl_status++;
392 		break;
393 	case SIGP_SET_PREFIX:
394 		vcpu->stat.instruction_sigp_prefix++;
395 		break;
396 	case SIGP_START:
397 		vcpu->stat.instruction_sigp_start++;
398 		break;
399 	case SIGP_RESTART:
400 		vcpu->stat.instruction_sigp_restart++;
401 		break;
402 	case SIGP_INITIAL_CPU_RESET:
403 		vcpu->stat.instruction_sigp_init_cpu_reset++;
404 		break;
405 	case SIGP_CPU_RESET:
406 		vcpu->stat.instruction_sigp_cpu_reset++;
407 		break;
408 	default:
409 		vcpu->stat.instruction_sigp_unknown++;
410 	}
411 	VCPU_EVENT(vcpu, 3, "SIGP: order %u for CPU %d handled in userspace",
412 		   order_code, cpu_addr);
413 
414 	return 1;
415 }
416 
kvm_s390_handle_sigp(struct kvm_vcpu * vcpu)417 int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu)
418 {
419 	int r1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
420 	int r3 = vcpu->arch.sie_block->ipa & 0x000f;
421 	u32 parameter;
422 	u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
423 	u8 order_code;
424 	int rc;
425 
426 	/* sigp in userspace can exit */
427 	if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
428 		return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
429 
430 	order_code = kvm_s390_get_base_disp_rs(vcpu, NULL);
431 	if (handle_sigp_order_in_user_space(vcpu, order_code, cpu_addr))
432 		return -EOPNOTSUPP;
433 
434 	if (r1 % 2)
435 		parameter = vcpu->run->s.regs.gprs[r1];
436 	else
437 		parameter = vcpu->run->s.regs.gprs[r1 + 1];
438 
439 	trace_kvm_s390_handle_sigp(vcpu, order_code, cpu_addr, parameter);
440 	switch (order_code) {
441 	case SIGP_SET_ARCHITECTURE:
442 		vcpu->stat.instruction_sigp_arch++;
443 		rc = __sigp_set_arch(vcpu, parameter);
444 		break;
445 	default:
446 		rc = handle_sigp_dst(vcpu, order_code, cpu_addr,
447 				     parameter,
448 				     &vcpu->run->s.regs.gprs[r1]);
449 	}
450 
451 	if (rc < 0)
452 		return rc;
453 
454 	kvm_s390_set_psw_cc(vcpu, rc);
455 	return 0;
456 }
457 
458 /*
459  * Handle SIGP partial execution interception.
460  *
461  * This interception will occur at the source cpu when a source cpu sends an
462  * external call to a target cpu and the target cpu has the WAIT bit set in
463  * its cpuflags. Interception will occurr after the interrupt indicator bits at
464  * the target cpu have been set. All error cases will lead to instruction
465  * interception, therefore nothing is to be checked or prepared.
466  */
kvm_s390_handle_sigp_pei(struct kvm_vcpu * vcpu)467 int kvm_s390_handle_sigp_pei(struct kvm_vcpu *vcpu)
468 {
469 	int r3 = vcpu->arch.sie_block->ipa & 0x000f;
470 	u16 cpu_addr = vcpu->run->s.regs.gprs[r3];
471 	struct kvm_vcpu *dest_vcpu;
472 	u8 order_code = kvm_s390_get_base_disp_rs(vcpu, NULL);
473 
474 	trace_kvm_s390_handle_sigp_pei(vcpu, order_code, cpu_addr);
475 
476 	if (order_code == SIGP_EXTERNAL_CALL) {
477 		dest_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, cpu_addr);
478 		BUG_ON(dest_vcpu == NULL);
479 
480 		kvm_s390_vcpu_wakeup(dest_vcpu);
481 		kvm_s390_set_psw_cc(vcpu, SIGP_CC_ORDER_CODE_ACCEPTED);
482 		return 0;
483 	}
484 
485 	return -EOPNOTSUPP;
486 }
487