xref: /openbmc/linux/arch/s390/kvm/intercept.c (revision 6a613ac6)
1 /*
2  * in-kernel handling for sie intercepts
3  *
4  * Copyright IBM Corp. 2008, 2014
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  */
13 
14 #include <linux/kvm_host.h>
15 #include <linux/errno.h>
16 #include <linux/pagemap.h>
17 
18 #include <asm/kvm_host.h>
19 #include <asm/asm-offsets.h>
20 #include <asm/irq.h>
21 
22 #include "kvm-s390.h"
23 #include "gaccess.h"
24 #include "trace.h"
25 #include "trace-s390.h"
26 
27 
28 static const intercept_handler_t instruction_handlers[256] = {
29 	[0x01] = kvm_s390_handle_01,
30 	[0x82] = kvm_s390_handle_lpsw,
31 	[0x83] = kvm_s390_handle_diag,
32 	[0xae] = kvm_s390_handle_sigp,
33 	[0xb2] = kvm_s390_handle_b2,
34 	[0xb6] = kvm_s390_handle_stctl,
35 	[0xb7] = kvm_s390_handle_lctl,
36 	[0xb9] = kvm_s390_handle_b9,
37 	[0xe5] = kvm_s390_handle_e5,
38 	[0xeb] = kvm_s390_handle_eb,
39 };
40 
41 void kvm_s390_rewind_psw(struct kvm_vcpu *vcpu, int ilc)
42 {
43 	struct kvm_s390_sie_block *sie_block = vcpu->arch.sie_block;
44 
45 	/* Use the length of the EXECUTE instruction if necessary */
46 	if (sie_block->icptstatus & 1) {
47 		ilc = (sie_block->icptstatus >> 4) & 0x6;
48 		if (!ilc)
49 			ilc = 4;
50 	}
51 	sie_block->gpsw.addr = __rewind_psw(sie_block->gpsw, ilc);
52 }
53 
54 static int handle_noop(struct kvm_vcpu *vcpu)
55 {
56 	switch (vcpu->arch.sie_block->icptcode) {
57 	case 0x0:
58 		vcpu->stat.exit_null++;
59 		break;
60 	case 0x10:
61 		vcpu->stat.exit_external_request++;
62 		break;
63 	default:
64 		break; /* nothing */
65 	}
66 	return 0;
67 }
68 
69 static int handle_stop(struct kvm_vcpu *vcpu)
70 {
71 	struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
72 	int rc = 0;
73 	uint8_t flags, stop_pending;
74 
75 	vcpu->stat.exit_stop_request++;
76 
77 	/* delay the stop if any non-stop irq is pending */
78 	if (kvm_s390_vcpu_has_irq(vcpu, 1))
79 		return 0;
80 
81 	/* avoid races with the injection/SIGP STOP code */
82 	spin_lock(&li->lock);
83 	flags = li->irq.stop.flags;
84 	stop_pending = kvm_s390_is_stop_irq_pending(vcpu);
85 	spin_unlock(&li->lock);
86 
87 	trace_kvm_s390_stop_request(stop_pending, flags);
88 	if (!stop_pending)
89 		return 0;
90 
91 	if (flags & KVM_S390_STOP_FLAG_STORE_STATUS) {
92 		rc = kvm_s390_vcpu_store_status(vcpu,
93 						KVM_S390_STORE_STATUS_NOADDR);
94 		if (rc)
95 			return rc;
96 	}
97 
98 	if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm))
99 		kvm_s390_vcpu_stop(vcpu);
100 	return -EOPNOTSUPP;
101 }
102 
103 static int handle_validity(struct kvm_vcpu *vcpu)
104 {
105 	int viwhy = vcpu->arch.sie_block->ipb >> 16;
106 
107 	vcpu->stat.exit_validity++;
108 	trace_kvm_s390_intercept_validity(vcpu, viwhy);
109 	WARN_ONCE(true, "kvm: unhandled validity intercept 0x%x\n", viwhy);
110 	return -EOPNOTSUPP;
111 }
112 
113 static int handle_instruction(struct kvm_vcpu *vcpu)
114 {
115 	intercept_handler_t handler;
116 
117 	vcpu->stat.exit_instruction++;
118 	trace_kvm_s390_intercept_instruction(vcpu,
119 					     vcpu->arch.sie_block->ipa,
120 					     vcpu->arch.sie_block->ipb);
121 	handler = instruction_handlers[vcpu->arch.sie_block->ipa >> 8];
122 	if (handler)
123 		return handler(vcpu);
124 	return -EOPNOTSUPP;
125 }
126 
127 static void __extract_prog_irq(struct kvm_vcpu *vcpu,
128 			       struct kvm_s390_pgm_info *pgm_info)
129 {
130 	memset(pgm_info, 0, sizeof(struct kvm_s390_pgm_info));
131 	pgm_info->code = vcpu->arch.sie_block->iprcc;
132 
133 	switch (vcpu->arch.sie_block->iprcc & ~PGM_PER) {
134 	case PGM_AFX_TRANSLATION:
135 	case PGM_ASX_TRANSLATION:
136 	case PGM_EX_TRANSLATION:
137 	case PGM_LFX_TRANSLATION:
138 	case PGM_LSTE_SEQUENCE:
139 	case PGM_LSX_TRANSLATION:
140 	case PGM_LX_TRANSLATION:
141 	case PGM_PRIMARY_AUTHORITY:
142 	case PGM_SECONDARY_AUTHORITY:
143 	case PGM_SPACE_SWITCH:
144 		pgm_info->trans_exc_code = vcpu->arch.sie_block->tecmc;
145 		break;
146 	case PGM_ALEN_TRANSLATION:
147 	case PGM_ALE_SEQUENCE:
148 	case PGM_ASTE_INSTANCE:
149 	case PGM_ASTE_SEQUENCE:
150 	case PGM_ASTE_VALIDITY:
151 	case PGM_EXTENDED_AUTHORITY:
152 		pgm_info->exc_access_id = vcpu->arch.sie_block->eai;
153 		break;
154 	case PGM_ASCE_TYPE:
155 	case PGM_PAGE_TRANSLATION:
156 	case PGM_REGION_FIRST_TRANS:
157 	case PGM_REGION_SECOND_TRANS:
158 	case PGM_REGION_THIRD_TRANS:
159 	case PGM_SEGMENT_TRANSLATION:
160 		pgm_info->trans_exc_code = vcpu->arch.sie_block->tecmc;
161 		pgm_info->exc_access_id  = vcpu->arch.sie_block->eai;
162 		pgm_info->op_access_id  = vcpu->arch.sie_block->oai;
163 		break;
164 	case PGM_MONITOR:
165 		pgm_info->mon_class_nr = vcpu->arch.sie_block->mcn;
166 		pgm_info->mon_code = vcpu->arch.sie_block->tecmc;
167 		break;
168 	case PGM_VECTOR_PROCESSING:
169 	case PGM_DATA:
170 		pgm_info->data_exc_code = vcpu->arch.sie_block->dxc;
171 		break;
172 	case PGM_PROTECTION:
173 		pgm_info->trans_exc_code = vcpu->arch.sie_block->tecmc;
174 		pgm_info->exc_access_id  = vcpu->arch.sie_block->eai;
175 		break;
176 	default:
177 		break;
178 	}
179 
180 	if (vcpu->arch.sie_block->iprcc & PGM_PER) {
181 		pgm_info->per_code = vcpu->arch.sie_block->perc;
182 		pgm_info->per_atmid = vcpu->arch.sie_block->peratmid;
183 		pgm_info->per_address = vcpu->arch.sie_block->peraddr;
184 		pgm_info->per_access_id = vcpu->arch.sie_block->peraid;
185 	}
186 }
187 
188 /*
189  * restore ITDB to program-interruption TDB in guest lowcore
190  * and set TX abort indication if required
191 */
192 static int handle_itdb(struct kvm_vcpu *vcpu)
193 {
194 	struct kvm_s390_itdb *itdb;
195 	int rc;
196 
197 	if (!IS_TE_ENABLED(vcpu) || !IS_ITDB_VALID(vcpu))
198 		return 0;
199 	if (current->thread.per_flags & PER_FLAG_NO_TE)
200 		return 0;
201 	itdb = (struct kvm_s390_itdb *)vcpu->arch.sie_block->itdba;
202 	rc = write_guest_lc(vcpu, __LC_PGM_TDB, itdb, sizeof(*itdb));
203 	if (rc)
204 		return rc;
205 	memset(itdb, 0, sizeof(*itdb));
206 
207 	return 0;
208 }
209 
210 #define per_event(vcpu) (vcpu->arch.sie_block->iprcc & PGM_PER)
211 
212 static int handle_prog(struct kvm_vcpu *vcpu)
213 {
214 	struct kvm_s390_pgm_info pgm_info;
215 	psw_t psw;
216 	int rc;
217 
218 	vcpu->stat.exit_program_interruption++;
219 
220 	if (guestdbg_enabled(vcpu) && per_event(vcpu)) {
221 		kvm_s390_handle_per_event(vcpu);
222 		/* the interrupt might have been filtered out completely */
223 		if (vcpu->arch.sie_block->iprcc == 0)
224 			return 0;
225 	}
226 
227 	trace_kvm_s390_intercept_prog(vcpu, vcpu->arch.sie_block->iprcc);
228 	if (vcpu->arch.sie_block->iprcc == PGM_SPECIFICATION) {
229 		rc = read_guest_lc(vcpu, __LC_PGM_NEW_PSW, &psw, sizeof(psw_t));
230 		if (rc)
231 			return rc;
232 		/* Avoid endless loops of specification exceptions */
233 		if (!is_valid_psw(&psw))
234 			return -EOPNOTSUPP;
235 	}
236 	rc = handle_itdb(vcpu);
237 	if (rc)
238 		return rc;
239 
240 	__extract_prog_irq(vcpu, &pgm_info);
241 	return kvm_s390_inject_prog_irq(vcpu, &pgm_info);
242 }
243 
244 /**
245  * handle_external_interrupt - used for external interruption interceptions
246  *
247  * This interception only occurs if the CPUSTAT_EXT_INT bit was set, or if
248  * the new PSW does not have external interrupts disabled. In the first case,
249  * we've got to deliver the interrupt manually, and in the second case, we
250  * drop to userspace to handle the situation there.
251  */
252 static int handle_external_interrupt(struct kvm_vcpu *vcpu)
253 {
254 	u16 eic = vcpu->arch.sie_block->eic;
255 	struct kvm_s390_irq irq;
256 	psw_t newpsw;
257 	int rc;
258 
259 	vcpu->stat.exit_external_interrupt++;
260 
261 	rc = read_guest_lc(vcpu, __LC_EXT_NEW_PSW, &newpsw, sizeof(psw_t));
262 	if (rc)
263 		return rc;
264 	/* We can not handle clock comparator or timer interrupt with bad PSW */
265 	if ((eic == EXT_IRQ_CLK_COMP || eic == EXT_IRQ_CPU_TIMER) &&
266 	    (newpsw.mask & PSW_MASK_EXT))
267 		return -EOPNOTSUPP;
268 
269 	switch (eic) {
270 	case EXT_IRQ_CLK_COMP:
271 		irq.type = KVM_S390_INT_CLOCK_COMP;
272 		break;
273 	case EXT_IRQ_CPU_TIMER:
274 		irq.type = KVM_S390_INT_CPU_TIMER;
275 		break;
276 	case EXT_IRQ_EXTERNAL_CALL:
277 		irq.type = KVM_S390_INT_EXTERNAL_CALL;
278 		irq.u.extcall.code = vcpu->arch.sie_block->extcpuaddr;
279 		rc = kvm_s390_inject_vcpu(vcpu, &irq);
280 		/* ignore if another external call is already pending */
281 		if (rc == -EBUSY)
282 			return 0;
283 		return rc;
284 	default:
285 		return -EOPNOTSUPP;
286 	}
287 
288 	return kvm_s390_inject_vcpu(vcpu, &irq);
289 }
290 
291 /**
292  * Handle MOVE PAGE partial execution interception.
293  *
294  * This interception can only happen for guests with DAT disabled and
295  * addresses that are currently not mapped in the host. Thus we try to
296  * set up the mappings for the corresponding user pages here (or throw
297  * addressing exceptions in case of illegal guest addresses).
298  */
299 static int handle_mvpg_pei(struct kvm_vcpu *vcpu)
300 {
301 	unsigned long srcaddr, dstaddr;
302 	int reg1, reg2, rc;
303 
304 	kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);
305 
306 	/* Make sure that the source is paged-in */
307 	rc = guest_translate_address(vcpu, vcpu->run->s.regs.gprs[reg2],
308 				     reg2, &srcaddr, 0);
309 	if (rc)
310 		return kvm_s390_inject_prog_cond(vcpu, rc);
311 	rc = kvm_arch_fault_in_page(vcpu, srcaddr, 0);
312 	if (rc != 0)
313 		return rc;
314 
315 	/* Make sure that the destination is paged-in */
316 	rc = guest_translate_address(vcpu, vcpu->run->s.regs.gprs[reg1],
317 				     reg1, &dstaddr, 1);
318 	if (rc)
319 		return kvm_s390_inject_prog_cond(vcpu, rc);
320 	rc = kvm_arch_fault_in_page(vcpu, dstaddr, 1);
321 	if (rc != 0)
322 		return rc;
323 
324 	kvm_s390_rewind_psw(vcpu, 4);
325 
326 	return 0;
327 }
328 
329 static int handle_partial_execution(struct kvm_vcpu *vcpu)
330 {
331 	if (vcpu->arch.sie_block->ipa == 0xb254)	/* MVPG */
332 		return handle_mvpg_pei(vcpu);
333 	if (vcpu->arch.sie_block->ipa >> 8 == 0xae)	/* SIGP */
334 		return kvm_s390_handle_sigp_pei(vcpu);
335 
336 	return -EOPNOTSUPP;
337 }
338 
339 int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
340 {
341 	switch (vcpu->arch.sie_block->icptcode) {
342 	case 0x00:
343 	case 0x10:
344 	case 0x18:
345 		return handle_noop(vcpu);
346 	case 0x04:
347 		return handle_instruction(vcpu);
348 	case 0x08:
349 		return handle_prog(vcpu);
350 	case 0x14:
351 		return handle_external_interrupt(vcpu);
352 	case 0x1c:
353 		return kvm_s390_handle_wait(vcpu);
354 	case 0x20:
355 		return handle_validity(vcpu);
356 	case 0x28:
357 		return handle_stop(vcpu);
358 	case 0x38:
359 		return handle_partial_execution(vcpu);
360 	default:
361 		return -EOPNOTSUPP;
362 	}
363 }
364