xref: /linux/arch/s390/kvm/intercept.c (revision 383d0b050106abecb82f43101cac94fa423af5cd)
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 	int rc = 0;
72 	unsigned int action_bits;
73 
74 	vcpu->stat.exit_stop_request++;
75 	trace_kvm_s390_stop_request(vcpu->arch.local_int.action_bits);
76 
77 	action_bits = vcpu->arch.local_int.action_bits;
78 
79 	if (!(action_bits & ACTION_STOP_ON_STOP))
80 		return 0;
81 
82 	if (action_bits & ACTION_STORE_ON_STOP) {
83 		rc = kvm_s390_vcpu_store_status(vcpu,
84 						KVM_S390_STORE_STATUS_NOADDR);
85 		if (rc)
86 			return rc;
87 	}
88 
89 	if (!kvm_s390_user_cpu_state_ctrl(vcpu->kvm))
90 		kvm_s390_vcpu_stop(vcpu);
91 	return -EOPNOTSUPP;
92 }
93 
94 static int handle_validity(struct kvm_vcpu *vcpu)
95 {
96 	int viwhy = vcpu->arch.sie_block->ipb >> 16;
97 
98 	vcpu->stat.exit_validity++;
99 	trace_kvm_s390_intercept_validity(vcpu, viwhy);
100 	WARN_ONCE(true, "kvm: unhandled validity intercept 0x%x\n", viwhy);
101 	return -EOPNOTSUPP;
102 }
103 
104 static int handle_instruction(struct kvm_vcpu *vcpu)
105 {
106 	intercept_handler_t handler;
107 
108 	vcpu->stat.exit_instruction++;
109 	trace_kvm_s390_intercept_instruction(vcpu,
110 					     vcpu->arch.sie_block->ipa,
111 					     vcpu->arch.sie_block->ipb);
112 	handler = instruction_handlers[vcpu->arch.sie_block->ipa >> 8];
113 	if (handler)
114 		return handler(vcpu);
115 	return -EOPNOTSUPP;
116 }
117 
118 static void __extract_prog_irq(struct kvm_vcpu *vcpu,
119 			       struct kvm_s390_pgm_info *pgm_info)
120 {
121 	memset(pgm_info, 0, sizeof(struct kvm_s390_pgm_info));
122 	pgm_info->code = vcpu->arch.sie_block->iprcc;
123 
124 	switch (vcpu->arch.sie_block->iprcc & ~PGM_PER) {
125 	case PGM_AFX_TRANSLATION:
126 	case PGM_ASX_TRANSLATION:
127 	case PGM_EX_TRANSLATION:
128 	case PGM_LFX_TRANSLATION:
129 	case PGM_LSTE_SEQUENCE:
130 	case PGM_LSX_TRANSLATION:
131 	case PGM_LX_TRANSLATION:
132 	case PGM_PRIMARY_AUTHORITY:
133 	case PGM_SECONDARY_AUTHORITY:
134 	case PGM_SPACE_SWITCH:
135 		pgm_info->trans_exc_code = vcpu->arch.sie_block->tecmc;
136 		break;
137 	case PGM_ALEN_TRANSLATION:
138 	case PGM_ALE_SEQUENCE:
139 	case PGM_ASTE_INSTANCE:
140 	case PGM_ASTE_SEQUENCE:
141 	case PGM_ASTE_VALIDITY:
142 	case PGM_EXTENDED_AUTHORITY:
143 		pgm_info->exc_access_id = vcpu->arch.sie_block->eai;
144 		break;
145 	case PGM_ASCE_TYPE:
146 	case PGM_PAGE_TRANSLATION:
147 	case PGM_REGION_FIRST_TRANS:
148 	case PGM_REGION_SECOND_TRANS:
149 	case PGM_REGION_THIRD_TRANS:
150 	case PGM_SEGMENT_TRANSLATION:
151 		pgm_info->trans_exc_code = vcpu->arch.sie_block->tecmc;
152 		pgm_info->exc_access_id  = vcpu->arch.sie_block->eai;
153 		pgm_info->op_access_id  = vcpu->arch.sie_block->oai;
154 		break;
155 	case PGM_MONITOR:
156 		pgm_info->mon_class_nr = vcpu->arch.sie_block->mcn;
157 		pgm_info->mon_code = vcpu->arch.sie_block->tecmc;
158 		break;
159 	case PGM_DATA:
160 		pgm_info->data_exc_code = vcpu->arch.sie_block->dxc;
161 		break;
162 	case PGM_PROTECTION:
163 		pgm_info->trans_exc_code = vcpu->arch.sie_block->tecmc;
164 		pgm_info->exc_access_id  = vcpu->arch.sie_block->eai;
165 		break;
166 	default:
167 		break;
168 	}
169 
170 	if (vcpu->arch.sie_block->iprcc & PGM_PER) {
171 		pgm_info->per_code = vcpu->arch.sie_block->perc;
172 		pgm_info->per_atmid = vcpu->arch.sie_block->peratmid;
173 		pgm_info->per_address = vcpu->arch.sie_block->peraddr;
174 		pgm_info->per_access_id = vcpu->arch.sie_block->peraid;
175 	}
176 }
177 
178 /*
179  * restore ITDB to program-interruption TDB in guest lowcore
180  * and set TX abort indication if required
181 */
182 static int handle_itdb(struct kvm_vcpu *vcpu)
183 {
184 	struct kvm_s390_itdb *itdb;
185 	int rc;
186 
187 	if (!IS_TE_ENABLED(vcpu) || !IS_ITDB_VALID(vcpu))
188 		return 0;
189 	if (current->thread.per_flags & PER_FLAG_NO_TE)
190 		return 0;
191 	itdb = (struct kvm_s390_itdb *)vcpu->arch.sie_block->itdba;
192 	rc = write_guest_lc(vcpu, __LC_PGM_TDB, itdb, sizeof(*itdb));
193 	if (rc)
194 		return rc;
195 	memset(itdb, 0, sizeof(*itdb));
196 
197 	return 0;
198 }
199 
200 #define per_event(vcpu) (vcpu->arch.sie_block->iprcc & PGM_PER)
201 
202 static int handle_prog(struct kvm_vcpu *vcpu)
203 {
204 	struct kvm_s390_pgm_info pgm_info;
205 	psw_t psw;
206 	int rc;
207 
208 	vcpu->stat.exit_program_interruption++;
209 
210 	if (guestdbg_enabled(vcpu) && per_event(vcpu)) {
211 		kvm_s390_handle_per_event(vcpu);
212 		/* the interrupt might have been filtered out completely */
213 		if (vcpu->arch.sie_block->iprcc == 0)
214 			return 0;
215 	}
216 
217 	trace_kvm_s390_intercept_prog(vcpu, vcpu->arch.sie_block->iprcc);
218 	if (vcpu->arch.sie_block->iprcc == PGM_SPECIFICATION) {
219 		rc = read_guest_lc(vcpu, __LC_PGM_NEW_PSW, &psw, sizeof(psw_t));
220 		if (rc)
221 			return rc;
222 		/* Avoid endless loops of specification exceptions */
223 		if (!is_valid_psw(&psw))
224 			return -EOPNOTSUPP;
225 	}
226 	rc = handle_itdb(vcpu);
227 	if (rc)
228 		return rc;
229 
230 	__extract_prog_irq(vcpu, &pgm_info);
231 	return kvm_s390_inject_prog_irq(vcpu, &pgm_info);
232 }
233 
234 static int handle_instruction_and_prog(struct kvm_vcpu *vcpu)
235 {
236 	int rc, rc2;
237 
238 	vcpu->stat.exit_instr_and_program++;
239 	rc = handle_instruction(vcpu);
240 	rc2 = handle_prog(vcpu);
241 
242 	if (rc == -EOPNOTSUPP)
243 		vcpu->arch.sie_block->icptcode = 0x04;
244 	if (rc)
245 		return rc;
246 	return rc2;
247 }
248 
249 /**
250  * handle_external_interrupt - used for external interruption interceptions
251  *
252  * This interception only occurs if the CPUSTAT_EXT_INT bit was set, or if
253  * the new PSW does not have external interrupts disabled. In the first case,
254  * we've got to deliver the interrupt manually, and in the second case, we
255  * drop to userspace to handle the situation there.
256  */
257 static int handle_external_interrupt(struct kvm_vcpu *vcpu)
258 {
259 	u16 eic = vcpu->arch.sie_block->eic;
260 	struct kvm_s390_irq irq;
261 	psw_t newpsw;
262 	int rc;
263 
264 	vcpu->stat.exit_external_interrupt++;
265 
266 	rc = read_guest_lc(vcpu, __LC_EXT_NEW_PSW, &newpsw, sizeof(psw_t));
267 	if (rc)
268 		return rc;
269 	/* We can not handle clock comparator or timer interrupt with bad PSW */
270 	if ((eic == EXT_IRQ_CLK_COMP || eic == EXT_IRQ_CPU_TIMER) &&
271 	    (newpsw.mask & PSW_MASK_EXT))
272 		return -EOPNOTSUPP;
273 
274 	switch (eic) {
275 	case EXT_IRQ_CLK_COMP:
276 		irq.type = KVM_S390_INT_CLOCK_COMP;
277 		break;
278 	case EXT_IRQ_CPU_TIMER:
279 		irq.type = KVM_S390_INT_CPU_TIMER;
280 		break;
281 	case EXT_IRQ_EXTERNAL_CALL:
282 		if (kvm_s390_si_ext_call_pending(vcpu))
283 			return 0;
284 		irq.type = KVM_S390_INT_EXTERNAL_CALL;
285 		irq.u.extcall.code = vcpu->arch.sie_block->extcpuaddr;
286 		break;
287 	default:
288 		return -EOPNOTSUPP;
289 	}
290 
291 	return kvm_s390_inject_vcpu(vcpu, &irq);
292 }
293 
294 /**
295  * Handle MOVE PAGE partial execution interception.
296  *
297  * This interception can only happen for guests with DAT disabled and
298  * addresses that are currently not mapped in the host. Thus we try to
299  * set up the mappings for the corresponding user pages here (or throw
300  * addressing exceptions in case of illegal guest addresses).
301  */
302 static int handle_mvpg_pei(struct kvm_vcpu *vcpu)
303 {
304 	unsigned long srcaddr, dstaddr;
305 	int reg1, reg2, rc;
306 
307 	kvm_s390_get_regs_rre(vcpu, &reg1, &reg2);
308 
309 	/* Make sure that the source is paged-in */
310 	srcaddr = kvm_s390_real_to_abs(vcpu, vcpu->run->s.regs.gprs[reg2]);
311 	if (kvm_is_error_gpa(vcpu->kvm, srcaddr))
312 		return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
313 	rc = kvm_arch_fault_in_page(vcpu, srcaddr, 0);
314 	if (rc != 0)
315 		return rc;
316 
317 	/* Make sure that the destination is paged-in */
318 	dstaddr = kvm_s390_real_to_abs(vcpu, vcpu->run->s.regs.gprs[reg1]);
319 	if (kvm_is_error_gpa(vcpu->kvm, dstaddr))
320 		return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
321 	rc = kvm_arch_fault_in_page(vcpu, dstaddr, 1);
322 	if (rc != 0)
323 		return rc;
324 
325 	kvm_s390_rewind_psw(vcpu, 4);
326 
327 	return 0;
328 }
329 
330 static int handle_partial_execution(struct kvm_vcpu *vcpu)
331 {
332 	if (vcpu->arch.sie_block->ipa == 0xb254)	/* MVPG */
333 		return handle_mvpg_pei(vcpu);
334 	if (vcpu->arch.sie_block->ipa >> 8 == 0xae)	/* SIGP */
335 		return kvm_s390_handle_sigp_pei(vcpu);
336 
337 	return -EOPNOTSUPP;
338 }
339 
340 static const intercept_handler_t intercept_funcs[] = {
341 	[0x00 >> 2] = handle_noop,
342 	[0x04 >> 2] = handle_instruction,
343 	[0x08 >> 2] = handle_prog,
344 	[0x0C >> 2] = handle_instruction_and_prog,
345 	[0x10 >> 2] = handle_noop,
346 	[0x14 >> 2] = handle_external_interrupt,
347 	[0x18 >> 2] = handle_noop,
348 	[0x1C >> 2] = kvm_s390_handle_wait,
349 	[0x20 >> 2] = handle_validity,
350 	[0x28 >> 2] = handle_stop,
351 	[0x38 >> 2] = handle_partial_execution,
352 };
353 
354 int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
355 {
356 	intercept_handler_t func;
357 	u8 code = vcpu->arch.sie_block->icptcode;
358 
359 	if (code & 3 || (code >> 2) >= ARRAY_SIZE(intercept_funcs))
360 		return -EOPNOTSUPP;
361 	func = intercept_funcs[code >> 2];
362 	if (func)
363 		return func(vcpu);
364 	return -EOPNOTSUPP;
365 }
366