xref: /openbmc/linux/arch/s390/kvm/intercept.c (revision a8fe58ce)
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 0x10:
58 		vcpu->stat.exit_external_request++;
59 		break;
60 	default:
61 		break; /* nothing */
62 	}
63 	return 0;
64 }
65 
66 static int handle_stop(struct kvm_vcpu *vcpu)
67 {
68 	struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
69 	int rc = 0;
70 	uint8_t flags, stop_pending;
71 
72 	vcpu->stat.exit_stop_request++;
73 
74 	/* delay the stop if any non-stop irq is pending */
75 	if (kvm_s390_vcpu_has_irq(vcpu, 1))
76 		return 0;
77 
78 	/* avoid races with the injection/SIGP STOP code */
79 	spin_lock(&li->lock);
80 	flags = li->irq.stop.flags;
81 	stop_pending = kvm_s390_is_stop_irq_pending(vcpu);
82 	spin_unlock(&li->lock);
83 
84 	trace_kvm_s390_stop_request(stop_pending, flags);
85 	if (!stop_pending)
86 		return 0;
87 
88 	if (flags & KVM_S390_STOP_FLAG_STORE_STATUS) {
89 		rc = kvm_s390_vcpu_store_status(vcpu,
90 						KVM_S390_STORE_STATUS_NOADDR);
91 		if (rc)
92 			return rc;
93 	}
94 
95 	if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm))
96 		kvm_s390_vcpu_stop(vcpu);
97 	return -EOPNOTSUPP;
98 }
99 
100 static int handle_validity(struct kvm_vcpu *vcpu)
101 {
102 	int viwhy = vcpu->arch.sie_block->ipb >> 16;
103 
104 	vcpu->stat.exit_validity++;
105 	trace_kvm_s390_intercept_validity(vcpu, viwhy);
106 	WARN_ONCE(true, "kvm: unhandled validity intercept 0x%x\n", viwhy);
107 	return -EOPNOTSUPP;
108 }
109 
110 static int handle_instruction(struct kvm_vcpu *vcpu)
111 {
112 	intercept_handler_t handler;
113 
114 	vcpu->stat.exit_instruction++;
115 	trace_kvm_s390_intercept_instruction(vcpu,
116 					     vcpu->arch.sie_block->ipa,
117 					     vcpu->arch.sie_block->ipb);
118 	handler = instruction_handlers[vcpu->arch.sie_block->ipa >> 8];
119 	if (handler)
120 		return handler(vcpu);
121 	return -EOPNOTSUPP;
122 }
123 
124 static void __extract_prog_irq(struct kvm_vcpu *vcpu,
125 			       struct kvm_s390_pgm_info *pgm_info)
126 {
127 	memset(pgm_info, 0, sizeof(struct kvm_s390_pgm_info));
128 	pgm_info->code = vcpu->arch.sie_block->iprcc;
129 
130 	switch (vcpu->arch.sie_block->iprcc & ~PGM_PER) {
131 	case PGM_AFX_TRANSLATION:
132 	case PGM_ASX_TRANSLATION:
133 	case PGM_EX_TRANSLATION:
134 	case PGM_LFX_TRANSLATION:
135 	case PGM_LSTE_SEQUENCE:
136 	case PGM_LSX_TRANSLATION:
137 	case PGM_LX_TRANSLATION:
138 	case PGM_PRIMARY_AUTHORITY:
139 	case PGM_SECONDARY_AUTHORITY:
140 	case PGM_SPACE_SWITCH:
141 		pgm_info->trans_exc_code = vcpu->arch.sie_block->tecmc;
142 		break;
143 	case PGM_ALEN_TRANSLATION:
144 	case PGM_ALE_SEQUENCE:
145 	case PGM_ASTE_INSTANCE:
146 	case PGM_ASTE_SEQUENCE:
147 	case PGM_ASTE_VALIDITY:
148 	case PGM_EXTENDED_AUTHORITY:
149 		pgm_info->exc_access_id = vcpu->arch.sie_block->eai;
150 		break;
151 	case PGM_ASCE_TYPE:
152 	case PGM_PAGE_TRANSLATION:
153 	case PGM_REGION_FIRST_TRANS:
154 	case PGM_REGION_SECOND_TRANS:
155 	case PGM_REGION_THIRD_TRANS:
156 	case PGM_SEGMENT_TRANSLATION:
157 		pgm_info->trans_exc_code = vcpu->arch.sie_block->tecmc;
158 		pgm_info->exc_access_id  = vcpu->arch.sie_block->eai;
159 		pgm_info->op_access_id  = vcpu->arch.sie_block->oai;
160 		break;
161 	case PGM_MONITOR:
162 		pgm_info->mon_class_nr = vcpu->arch.sie_block->mcn;
163 		pgm_info->mon_code = vcpu->arch.sie_block->tecmc;
164 		break;
165 	case PGM_VECTOR_PROCESSING:
166 	case PGM_DATA:
167 		pgm_info->data_exc_code = vcpu->arch.sie_block->dxc;
168 		break;
169 	case PGM_PROTECTION:
170 		pgm_info->trans_exc_code = vcpu->arch.sie_block->tecmc;
171 		pgm_info->exc_access_id  = vcpu->arch.sie_block->eai;
172 		break;
173 	default:
174 		break;
175 	}
176 
177 	if (vcpu->arch.sie_block->iprcc & PGM_PER) {
178 		pgm_info->per_code = vcpu->arch.sie_block->perc;
179 		pgm_info->per_atmid = vcpu->arch.sie_block->peratmid;
180 		pgm_info->per_address = vcpu->arch.sie_block->peraddr;
181 		pgm_info->per_access_id = vcpu->arch.sie_block->peraid;
182 	}
183 }
184 
185 /*
186  * restore ITDB to program-interruption TDB in guest lowcore
187  * and set TX abort indication if required
188 */
189 static int handle_itdb(struct kvm_vcpu *vcpu)
190 {
191 	struct kvm_s390_itdb *itdb;
192 	int rc;
193 
194 	if (!IS_TE_ENABLED(vcpu) || !IS_ITDB_VALID(vcpu))
195 		return 0;
196 	if (current->thread.per_flags & PER_FLAG_NO_TE)
197 		return 0;
198 	itdb = (struct kvm_s390_itdb *)vcpu->arch.sie_block->itdba;
199 	rc = write_guest_lc(vcpu, __LC_PGM_TDB, itdb, sizeof(*itdb));
200 	if (rc)
201 		return rc;
202 	memset(itdb, 0, sizeof(*itdb));
203 
204 	return 0;
205 }
206 
207 #define per_event(vcpu) (vcpu->arch.sie_block->iprcc & PGM_PER)
208 
209 static int handle_prog(struct kvm_vcpu *vcpu)
210 {
211 	struct kvm_s390_pgm_info pgm_info;
212 	psw_t psw;
213 	int rc;
214 
215 	vcpu->stat.exit_program_interruption++;
216 
217 	if (guestdbg_enabled(vcpu) && per_event(vcpu)) {
218 		kvm_s390_handle_per_event(vcpu);
219 		/* the interrupt might have been filtered out completely */
220 		if (vcpu->arch.sie_block->iprcc == 0)
221 			return 0;
222 	}
223 
224 	trace_kvm_s390_intercept_prog(vcpu, vcpu->arch.sie_block->iprcc);
225 	if (vcpu->arch.sie_block->iprcc == PGM_SPECIFICATION) {
226 		rc = read_guest_lc(vcpu, __LC_PGM_NEW_PSW, &psw, sizeof(psw_t));
227 		if (rc)
228 			return rc;
229 		/* Avoid endless loops of specification exceptions */
230 		if (!is_valid_psw(&psw))
231 			return -EOPNOTSUPP;
232 	}
233 	rc = handle_itdb(vcpu);
234 	if (rc)
235 		return rc;
236 
237 	__extract_prog_irq(vcpu, &pgm_info);
238 	return kvm_s390_inject_prog_irq(vcpu, &pgm_info);
239 }
240 
241 /**
242  * handle_external_interrupt - used for external interruption interceptions
243  *
244  * This interception only occurs if the CPUSTAT_EXT_INT bit was set, or if
245  * the new PSW does not have external interrupts disabled. In the first case,
246  * we've got to deliver the interrupt manually, and in the second case, we
247  * drop to userspace to handle the situation there.
248  */
249 static int handle_external_interrupt(struct kvm_vcpu *vcpu)
250 {
251 	u16 eic = vcpu->arch.sie_block->eic;
252 	struct kvm_s390_irq irq;
253 	psw_t newpsw;
254 	int rc;
255 
256 	vcpu->stat.exit_external_interrupt++;
257 
258 	rc = read_guest_lc(vcpu, __LC_EXT_NEW_PSW, &newpsw, sizeof(psw_t));
259 	if (rc)
260 		return rc;
261 	/* We can not handle clock comparator or timer interrupt with bad PSW */
262 	if ((eic == EXT_IRQ_CLK_COMP || eic == EXT_IRQ_CPU_TIMER) &&
263 	    (newpsw.mask & PSW_MASK_EXT))
264 		return -EOPNOTSUPP;
265 
266 	switch (eic) {
267 	case EXT_IRQ_CLK_COMP:
268 		irq.type = KVM_S390_INT_CLOCK_COMP;
269 		break;
270 	case EXT_IRQ_CPU_TIMER:
271 		irq.type = KVM_S390_INT_CPU_TIMER;
272 		break;
273 	case EXT_IRQ_EXTERNAL_CALL:
274 		irq.type = KVM_S390_INT_EXTERNAL_CALL;
275 		irq.u.extcall.code = vcpu->arch.sie_block->extcpuaddr;
276 		rc = kvm_s390_inject_vcpu(vcpu, &irq);
277 		/* ignore if another external call is already pending */
278 		if (rc == -EBUSY)
279 			return 0;
280 		return rc;
281 	default:
282 		return -EOPNOTSUPP;
283 	}
284 
285 	return kvm_s390_inject_vcpu(vcpu, &irq);
286 }
287 
288 /**
289  * Handle MOVE PAGE partial execution interception.
290  *
291  * This interception can only happen for guests with DAT disabled and
292  * addresses that are currently not mapped in the host. Thus we try to
293  * set up the mappings for the corresponding user pages here (or throw
294  * addressing exceptions in case of illegal guest addresses).
295  */
296 static int handle_mvpg_pei(struct kvm_vcpu *vcpu)
297 {
298 	unsigned long srcaddr, dstaddr;
299 	int reg1, reg2, rc;
300 
301 	kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);
302 
303 	/* Make sure that the source is paged-in */
304 	rc = guest_translate_address(vcpu, vcpu->run->s.regs.gprs[reg2],
305 				     reg2, &srcaddr, 0);
306 	if (rc)
307 		return kvm_s390_inject_prog_cond(vcpu, rc);
308 	rc = kvm_arch_fault_in_page(vcpu, srcaddr, 0);
309 	if (rc != 0)
310 		return rc;
311 
312 	/* Make sure that the destination is paged-in */
313 	rc = guest_translate_address(vcpu, vcpu->run->s.regs.gprs[reg1],
314 				     reg1, &dstaddr, 1);
315 	if (rc)
316 		return kvm_s390_inject_prog_cond(vcpu, rc);
317 	rc = kvm_arch_fault_in_page(vcpu, dstaddr, 1);
318 	if (rc != 0)
319 		return rc;
320 
321 	kvm_s390_rewind_psw(vcpu, 4);
322 
323 	return 0;
324 }
325 
326 static int handle_partial_execution(struct kvm_vcpu *vcpu)
327 {
328 	if (vcpu->arch.sie_block->ipa == 0xb254)	/* MVPG */
329 		return handle_mvpg_pei(vcpu);
330 	if (vcpu->arch.sie_block->ipa >> 8 == 0xae)	/* SIGP */
331 		return kvm_s390_handle_sigp_pei(vcpu);
332 
333 	return -EOPNOTSUPP;
334 }
335 
336 int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
337 {
338 	if (kvm_is_ucontrol(vcpu->kvm))
339 		return -EOPNOTSUPP;
340 
341 	switch (vcpu->arch.sie_block->icptcode) {
342 	case 0x10:
343 	case 0x18:
344 		return handle_noop(vcpu);
345 	case 0x04:
346 		return handle_instruction(vcpu);
347 	case 0x08:
348 		return handle_prog(vcpu);
349 	case 0x14:
350 		return handle_external_interrupt(vcpu);
351 	case 0x1c:
352 		return kvm_s390_handle_wait(vcpu);
353 	case 0x20:
354 		return handle_validity(vcpu);
355 	case 0x28:
356 		return handle_stop(vcpu);
357 	case 0x38:
358 		return handle_partial_execution(vcpu);
359 	default:
360 		return -EOPNOTSUPP;
361 	}
362 }
363