summaryrefslogtreecommitdiff
path: root/arch/powerpc/kvm/emulate.c
blob: de9a340d22ed248286a903a1e61d329a3c3d596b (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
/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2, as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 * Copyright IBM Corp. 2007
 * Copyright 2011 Freescale Semiconductor, Inc.
 *
 * Authors: Hollis Blanchard <hollisb@us.ibm.com>
 */

#include <linux/jiffies.h>
#include <linux/hrtimer.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/kvm_host.h>
#include <linux/clockchips.h>

#include <asm/reg.h>
#include <asm/time.h>
#include <asm/byteorder.h>
#include <asm/kvm_ppc.h>
#include <asm/disassemble.h>
#include <asm/ppc-opcode.h>
#include "timing.h"
#include "trace.h"

void kvmppc_emulate_dec(struct kvm_vcpu *vcpu)
{
	unsigned long dec_nsec;
	unsigned long long dec_time;

	pr_debug("mtDEC: %x\n", vcpu->arch.dec);
	hrtimer_try_to_cancel(&vcpu->arch.dec_timer);

#ifdef CONFIG_PPC_BOOK3S
	/* mtdec lowers the interrupt line when positive. */
	kvmppc_core_dequeue_dec(vcpu);

	/* POWER4+ triggers a dec interrupt if the value is < 0 */
	if (vcpu->arch.dec & 0x80000000) {
		kvmppc_core_queue_dec(vcpu);
		return;
	}
#endif

#ifdef CONFIG_BOOKE
	/* On BOOKE, DEC = 0 is as good as decrementer not enabled */
	if (vcpu->arch.dec == 0)
		return;
#endif

	/*
	 * The decrementer ticks at the same rate as the timebase, so
	 * that's how we convert the guest DEC value to the number of
	 * host ticks.
	 */

	dec_time = vcpu->arch.dec;
	/*
	 * Guest timebase ticks at the same frequency as host decrementer.
	 * So use the host decrementer calculations for decrementer emulation.
	 */
	dec_time = dec_time << decrementer_clockevent.shift;
	do_div(dec_time, decrementer_clockevent.mult);
	dec_nsec = do_div(dec_time, NSEC_PER_SEC);
	hrtimer_start(&vcpu->arch.dec_timer,
		ktime_set(dec_time, dec_nsec), HRTIMER_MODE_REL);
	vcpu->arch.dec_jiffies = get_tb();
}

u32 kvmppc_get_dec(struct kvm_vcpu *vcpu, u64 tb)
{
	u64 jd = tb - vcpu->arch.dec_jiffies;

#ifdef CONFIG_BOOKE
	if (vcpu->arch.dec < jd)
		return 0;
#endif

	return vcpu->arch.dec - jd;
}

static int kvmppc_emulate_mtspr(struct kvm_vcpu *vcpu, int sprn, int rs)
{
	enum emulation_result emulated = EMULATE_DONE;
	ulong spr_val = kvmppc_get_gpr(vcpu, rs);

	switch (sprn) {
	case SPRN_SRR0:
		vcpu->arch.shared->srr0 = spr_val;
		break;
	case SPRN_SRR1:
		vcpu->arch.shared->srr1 = spr_val;
		break;

	/* XXX We need to context-switch the timebase for
	 * watchdog and FIT. */
	case SPRN_TBWL: break;
	case SPRN_TBWU: break;

	case SPRN_DEC:
		vcpu->arch.dec = spr_val;
		kvmppc_emulate_dec(vcpu);
		break;

	case SPRN_SPRG0:
		vcpu->arch.shared->sprg0 = spr_val;
		break;
	case SPRN_SPRG1:
		vcpu->arch.shared->sprg1 = spr_val;
		break;
	case SPRN_SPRG2:
		vcpu->arch.shared->sprg2 = spr_val;
		break;
	case SPRN_SPRG3:
		vcpu->arch.shared->sprg3 = spr_val;
		break;

	/* PIR can legally be written, but we ignore it */
	case SPRN_PIR: break;

	default:
		emulated = kvmppc_ops->emulate_mtspr(vcpu, sprn,
						     spr_val);
		if (emulated == EMULATE_FAIL)
			printk(KERN_INFO "mtspr: unknown spr "
				"0x%x\n", sprn);
		break;
	}

	kvmppc_set_exit_type(vcpu, EMULATED_MTSPR_EXITS);

	return emulated;
}

static int kvmppc_emulate_mfspr(struct kvm_vcpu *vcpu, int sprn, int rt)
{
	enum emulation_result emulated = EMULATE_DONE;
	ulong spr_val = 0;

	switch (sprn) {
	case SPRN_SRR0:
		spr_val = vcpu->arch.shared->srr0;
		break;
	case SPRN_SRR1:
		spr_val = vcpu->arch.shared->srr1;
		break;
	case SPRN_PVR:
		spr_val = vcpu->arch.pvr;
		break;
	case SPRN_PIR:
		spr_val = vcpu->vcpu_id;
		break;

	/* Note: mftb and TBRL/TBWL are user-accessible, so
	 * the guest can always access the real TB anyways.
	 * In fact, we probably will never see these traps. */
	case SPRN_TBWL:
		spr_val = get_tb() >> 32;
		break;
	case SPRN_TBWU:
		spr_val = get_tb();
		break;

	case SPRN_SPRG0:
		spr_val = vcpu->arch.shared->sprg0;
		break;
	case SPRN_SPRG1:
		spr_val = vcpu->arch.shared->sprg1;
		break;
	case SPRN_SPRG2:
		spr_val = vcpu->arch.shared->sprg2;
		break;
	case SPRN_SPRG3:
		spr_val = vcpu->arch.shared->sprg3;
		break;
	/* Note: SPRG4-7 are user-readable, so we don't get
	 * a trap. */

	case SPRN_DEC:
		spr_val = kvmppc_get_dec(vcpu, get_tb());
		break;
	default:
		emulated = kvmppc_ops->emulate_mfspr(vcpu, sprn,
						     &spr_val);
		if (unlikely(emulated == EMULATE_FAIL)) {
			printk(KERN_INFO "mfspr: unknown spr "
				"0x%x\n", sprn);
		}
		break;
	}

	if (emulated == EMULATE_DONE)
		kvmppc_set_gpr(vcpu, rt, spr_val);
	kvmppc_set_exit_type(vcpu, EMULATED_MFSPR_EXITS);

	return emulated;
}

/* XXX to do:
 * lhax
 * lhaux
 * lswx
 * lswi
 * stswx
 * stswi
 * lha
 * lhau
 * lmw
 * stmw
 *
 * XXX is_bigendian should depend on MMU mapping or MSR[LE]
 */
/* XXX Should probably auto-generate instruction decoding for a particular core
 * from opcode tables in the future. */
int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
{
	u32 inst = kvmppc_get_last_inst(vcpu);
	int ra = get_ra(inst);
	int rs = get_rs(inst);
	int rt = get_rt(inst);
	int sprn = get_sprn(inst);
	enum emulation_result emulated = EMULATE_DONE;
	int advance = 1;

	/* this default type might be overwritten by subcategories */
	kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);

	pr_debug("Emulating opcode %d / %d\n", get_op(inst), get_xop(inst));

	switch (get_op(inst)) {
	case OP_TRAP:
#ifdef CONFIG_PPC_BOOK3S
	case OP_TRAP_64:
		kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP);
#else
		kvmppc_core_queue_program(vcpu,
					  vcpu->arch.shared->esr | ESR_PTR);
#endif
		advance = 0;
		break;

	case 31:
		switch (get_xop(inst)) {

		case OP_31_XOP_TRAP:
#ifdef CONFIG_64BIT
		case OP_31_XOP_TRAP_64:
#endif
#ifdef CONFIG_PPC_BOOK3S
			kvmppc_core_queue_program(vcpu, SRR1_PROGTRAP);
#else
			kvmppc_core_queue_program(vcpu,
					vcpu->arch.shared->esr | ESR_PTR);
#endif
			advance = 0;
			break;
		case OP_31_XOP_LWZX:
			emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
			break;

		case OP_31_XOP_LBZX:
			emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
			break;

		case OP_31_XOP_LBZUX:
			emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
			kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
			break;

		case OP_31_XOP_STWX:
			emulated = kvmppc_handle_store(run, vcpu,
						       kvmppc_get_gpr(vcpu, rs),
			                               4, 1);
			break;

		case OP_31_XOP_STBX:
			emulated = kvmppc_handle_store(run, vcpu,
						       kvmppc_get_gpr(vcpu, rs),
			                               1, 1);
			break;

		case OP_31_XOP_STBUX:
			emulated = kvmppc_handle_store(run, vcpu,
						       kvmppc_get_gpr(vcpu, rs),
			                               1, 1);
			kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
			break;

		case OP_31_XOP_LHAX:
			emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
			break;

		case OP_31_XOP_LHZX:
			emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
			break;

		case OP_31_XOP_LHZUX:
			emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
			kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
			break;

		case OP_31_XOP_MFSPR:
			emulated = kvmppc_emulate_mfspr(vcpu, sprn, rt);
			break;

		case OP_31_XOP_STHX:
			emulated = kvmppc_handle_store(run, vcpu,
						       kvmppc_get_gpr(vcpu, rs),
			                               2, 1);
			break;

		case OP_31_XOP_STHUX:
			emulated = kvmppc_handle_store(run, vcpu,
						       kvmppc_get_gpr(vcpu, rs),
			                               2, 1);
			kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
			break;

		case OP_31_XOP_MTSPR:
			emulated = kvmppc_emulate_mtspr(vcpu, sprn, rs);
			break;

		case OP_31_XOP_DCBST:
		case OP_31_XOP_DCBF:
		case OP_31_XOP_DCBI:
			/* Do nothing. The guest is performing dcbi because
			 * hardware DMA is not snooped by the dcache, but
			 * emulated DMA either goes through the dcache as
			 * normal writes, or the host kernel has handled dcache
			 * coherence. */
			break;

		case OP_31_XOP_LWBRX:
			emulated = kvmppc_handle_load(run, vcpu, rt, 4, 0);
			break;

		case OP_31_XOP_TLBSYNC:
			break;

		case OP_31_XOP_STWBRX:
			emulated = kvmppc_handle_store(run, vcpu,
						       kvmppc_get_gpr(vcpu, rs),
			                               4, 0);
			break;

		case OP_31_XOP_LHBRX:
			emulated = kvmppc_handle_load(run, vcpu, rt, 2, 0);
			break;

		case OP_31_XOP_STHBRX:
			emulated = kvmppc_handle_store(run, vcpu,
						       kvmppc_get_gpr(vcpu, rs),
			                               2, 0);
			break;

		default:
			/* Attempt core-specific emulation below. */
			emulated = EMULATE_FAIL;
		}
		break;

	case OP_LWZ:
		emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
		break;

	/* TBD: Add support for other 64 bit load variants like ldu, ldux, ldx etc. */
	case OP_LD:
		rt = get_rt(inst);
		emulated = kvmppc_handle_load(run, vcpu, rt, 8, 1);
		break;

	case OP_LWZU:
		emulated = kvmppc_handle_load(run, vcpu, rt, 4, 1);
		kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
		break;

	case OP_LBZ:
		emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
		break;

	case OP_LBZU:
		emulated = kvmppc_handle_load(run, vcpu, rt, 1, 1);
		kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
		break;

	case OP_STW:
		emulated = kvmppc_handle_store(run, vcpu,
					       kvmppc_get_gpr(vcpu, rs),
		                               4, 1);
		break;

	/* TBD: Add support for other 64 bit store variants like stdu, stdux, stdx etc. */
	case OP_STD:
		rs = get_rs(inst);
		emulated = kvmppc_handle_store(run, vcpu,
					       kvmppc_get_gpr(vcpu, rs),
		                               8, 1);
		break;

	case OP_STWU:
		emulated = kvmppc_handle_store(run, vcpu,
					       kvmppc_get_gpr(vcpu, rs),
		                               4, 1);
		kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
		break;

	case OP_STB:
		emulated = kvmppc_handle_store(run, vcpu,
					       kvmppc_get_gpr(vcpu, rs),
		                               1, 1);
		break;

	case OP_STBU:
		emulated = kvmppc_handle_store(run, vcpu,
					       kvmppc_get_gpr(vcpu, rs),
		                               1, 1);
		kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
		break;

	case OP_LHZ:
		emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
		break;

	case OP_LHZU:
		emulated = kvmppc_handle_load(run, vcpu, rt, 2, 1);
		kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
		break;

	case OP_LHA:
		emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
		break;

	case OP_LHAU:
		emulated = kvmppc_handle_loads(run, vcpu, rt, 2, 1);
		kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
		break;

	case OP_STH:
		emulated = kvmppc_handle_store(run, vcpu,
					       kvmppc_get_gpr(vcpu, rs),
		                               2, 1);
		break;

	case OP_STHU:
		emulated = kvmppc_handle_store(run, vcpu,
					       kvmppc_get_gpr(vcpu, rs),
		                               2, 1);
		kvmppc_set_gpr(vcpu, ra, vcpu->arch.vaddr_accessed);
		break;

	default:
		emulated = EMULATE_FAIL;
	}

	if (emulated == EMULATE_FAIL) {
		emulated = kvmppc_ops->emulate_op(run, vcpu, inst, &advance);
		if (emulated == EMULATE_AGAIN) {
			advance = 0;
		} else if (emulated == EMULATE_FAIL) {
			advance = 0;
			printk(KERN_ERR "Couldn't emulate instruction 0x%08x "
			       "(op %d xop %d)\n", inst, get_op(inst), get_xop(inst));
			kvmppc_core_queue_program(vcpu, 0);
		}
	}

	trace_kvm_ppc_instr(inst, kvmppc_get_pc(vcpu), emulated);

	/* Advance past emulated instruction. */
	if (advance)
		kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) + 4);

	return emulated;
}
EXPORT_SYMBOL_GPL(kvmppc_emulate_instruction);