xref: /linux/arch/powerpc/kernel/kvm.c (revision 856e7c4b619af622d56b3b454f7bec32a170ac99)
1 /*
2  * Copyright (C) 2010 SUSE Linux Products GmbH. All rights reserved.
3  * Copyright 2010-2011 Freescale Semiconductor, Inc.
4  *
5  * Authors:
6  *     Alexander Graf <agraf@suse.de>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License, version 2, as
10  * published by the Free Software Foundation.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
20  */
21 
22 #include <linux/kvm_host.h>
23 #include <linux/init.h>
24 #include <linux/export.h>
25 #include <linux/kvm_para.h>
26 #include <linux/slab.h>
27 #include <linux/of.h>
28 #include <linux/pagemap.h>
29 
30 #include <asm/reg.h>
31 #include <asm/sections.h>
32 #include <asm/cacheflush.h>
33 #include <asm/disassemble.h>
34 #include <asm/ppc-opcode.h>
35 #include <asm/epapr_hcalls.h>
36 
37 #define KVM_MAGIC_PAGE		(-4096L)
38 #define magic_var(x) KVM_MAGIC_PAGE + offsetof(struct kvm_vcpu_arch_shared, x)
39 
40 #define KVM_INST_LWZ		0x80000000
41 #define KVM_INST_STW		0x90000000
42 #define KVM_INST_LD		0xe8000000
43 #define KVM_INST_STD		0xf8000000
44 #define KVM_INST_NOP		0x60000000
45 #define KVM_INST_B		0x48000000
46 #define KVM_INST_B_MASK		0x03ffffff
47 #define KVM_INST_B_MAX		0x01ffffff
48 #define KVM_INST_LI		0x38000000
49 
50 #define KVM_MASK_RT		0x03e00000
51 #define KVM_RT_30		0x03c00000
52 #define KVM_MASK_RB		0x0000f800
53 #define KVM_INST_MFMSR		0x7c0000a6
54 
55 #define SPR_FROM		0
56 #define SPR_TO			0x100
57 
58 #define KVM_INST_SPR(sprn, moveto) (0x7c0002a6 | \
59 				    (((sprn) & 0x1f) << 16) | \
60 				    (((sprn) & 0x3e0) << 6) | \
61 				    (moveto))
62 
63 #define KVM_INST_MFSPR(sprn)	KVM_INST_SPR(sprn, SPR_FROM)
64 #define KVM_INST_MTSPR(sprn)	KVM_INST_SPR(sprn, SPR_TO)
65 
66 #define KVM_INST_TLBSYNC	0x7c00046c
67 #define KVM_INST_MTMSRD_L0	0x7c000164
68 #define KVM_INST_MTMSRD_L1	0x7c010164
69 #define KVM_INST_MTMSR		0x7c000124
70 
71 #define KVM_INST_WRTEE		0x7c000106
72 #define KVM_INST_WRTEEI_0	0x7c000146
73 #define KVM_INST_WRTEEI_1	0x7c008146
74 
75 #define KVM_INST_MTSRIN		0x7c0001e4
76 
77 static bool kvm_patching_worked = true;
78 char kvm_tmp[1024 * 1024];
79 static int kvm_tmp_index;
80 
81 static inline void kvm_patch_ins(u32 *inst, u32 new_inst)
82 {
83 	*inst = new_inst;
84 	flush_icache_range((ulong)inst, (ulong)inst + 4);
85 }
86 
87 static void kvm_patch_ins_ll(u32 *inst, long addr, u32 rt)
88 {
89 #ifdef CONFIG_64BIT
90 	kvm_patch_ins(inst, KVM_INST_LD | rt | (addr & 0x0000fffc));
91 #else
92 	kvm_patch_ins(inst, KVM_INST_LWZ | rt | (addr & 0x0000fffc));
93 #endif
94 }
95 
96 static void kvm_patch_ins_ld(u32 *inst, long addr, u32 rt)
97 {
98 #ifdef CONFIG_64BIT
99 	kvm_patch_ins(inst, KVM_INST_LD | rt | (addr & 0x0000fffc));
100 #else
101 	kvm_patch_ins(inst, KVM_INST_LWZ | rt | ((addr + 4) & 0x0000fffc));
102 #endif
103 }
104 
105 static void kvm_patch_ins_lwz(u32 *inst, long addr, u32 rt)
106 {
107 	kvm_patch_ins(inst, KVM_INST_LWZ | rt | (addr & 0x0000ffff));
108 }
109 
110 static void kvm_patch_ins_std(u32 *inst, long addr, u32 rt)
111 {
112 #ifdef CONFIG_64BIT
113 	kvm_patch_ins(inst, KVM_INST_STD | rt | (addr & 0x0000fffc));
114 #else
115 	kvm_patch_ins(inst, KVM_INST_STW | rt | ((addr + 4) & 0x0000fffc));
116 #endif
117 }
118 
119 static void kvm_patch_ins_stw(u32 *inst, long addr, u32 rt)
120 {
121 	kvm_patch_ins(inst, KVM_INST_STW | rt | (addr & 0x0000fffc));
122 }
123 
124 static void kvm_patch_ins_nop(u32 *inst)
125 {
126 	kvm_patch_ins(inst, KVM_INST_NOP);
127 }
128 
129 static void kvm_patch_ins_b(u32 *inst, int addr)
130 {
131 #if defined(CONFIG_RELOCATABLE) && defined(CONFIG_PPC_BOOK3S)
132 	/* On relocatable kernels interrupts handlers and our code
133 	   can be in different regions, so we don't patch them */
134 
135 	if ((ulong)inst < (ulong)&__end_interrupts)
136 		return;
137 #endif
138 
139 	kvm_patch_ins(inst, KVM_INST_B | (addr & KVM_INST_B_MASK));
140 }
141 
142 static u32 *kvm_alloc(int len)
143 {
144 	u32 *p;
145 
146 	if ((kvm_tmp_index + len) > ARRAY_SIZE(kvm_tmp)) {
147 		printk(KERN_ERR "KVM: No more space (%d + %d)\n",
148 				kvm_tmp_index, len);
149 		kvm_patching_worked = false;
150 		return NULL;
151 	}
152 
153 	p = (void*)&kvm_tmp[kvm_tmp_index];
154 	kvm_tmp_index += len;
155 
156 	return p;
157 }
158 
159 extern u32 kvm_emulate_mtmsrd_branch_offs;
160 extern u32 kvm_emulate_mtmsrd_reg_offs;
161 extern u32 kvm_emulate_mtmsrd_orig_ins_offs;
162 extern u32 kvm_emulate_mtmsrd_len;
163 extern u32 kvm_emulate_mtmsrd[];
164 
165 static void kvm_patch_ins_mtmsrd(u32 *inst, u32 rt)
166 {
167 	u32 *p;
168 	int distance_start;
169 	int distance_end;
170 	ulong next_inst;
171 
172 	p = kvm_alloc(kvm_emulate_mtmsrd_len * 4);
173 	if (!p)
174 		return;
175 
176 	/* Find out where we are and put everything there */
177 	distance_start = (ulong)p - (ulong)inst;
178 	next_inst = ((ulong)inst + 4);
179 	distance_end = next_inst - (ulong)&p[kvm_emulate_mtmsrd_branch_offs];
180 
181 	/* Make sure we only write valid b instructions */
182 	if (distance_start > KVM_INST_B_MAX) {
183 		kvm_patching_worked = false;
184 		return;
185 	}
186 
187 	/* Modify the chunk to fit the invocation */
188 	memcpy(p, kvm_emulate_mtmsrd, kvm_emulate_mtmsrd_len * 4);
189 	p[kvm_emulate_mtmsrd_branch_offs] |= distance_end & KVM_INST_B_MASK;
190 	switch (get_rt(rt)) {
191 	case 30:
192 		kvm_patch_ins_ll(&p[kvm_emulate_mtmsrd_reg_offs],
193 				 magic_var(scratch2), KVM_RT_30);
194 		break;
195 	case 31:
196 		kvm_patch_ins_ll(&p[kvm_emulate_mtmsrd_reg_offs],
197 				 magic_var(scratch1), KVM_RT_30);
198 		break;
199 	default:
200 		p[kvm_emulate_mtmsrd_reg_offs] |= rt;
201 		break;
202 	}
203 
204 	p[kvm_emulate_mtmsrd_orig_ins_offs] = *inst;
205 	flush_icache_range((ulong)p, (ulong)p + kvm_emulate_mtmsrd_len * 4);
206 
207 	/* Patch the invocation */
208 	kvm_patch_ins_b(inst, distance_start);
209 }
210 
211 extern u32 kvm_emulate_mtmsr_branch_offs;
212 extern u32 kvm_emulate_mtmsr_reg1_offs;
213 extern u32 kvm_emulate_mtmsr_reg2_offs;
214 extern u32 kvm_emulate_mtmsr_orig_ins_offs;
215 extern u32 kvm_emulate_mtmsr_len;
216 extern u32 kvm_emulate_mtmsr[];
217 
218 static void kvm_patch_ins_mtmsr(u32 *inst, u32 rt)
219 {
220 	u32 *p;
221 	int distance_start;
222 	int distance_end;
223 	ulong next_inst;
224 
225 	p = kvm_alloc(kvm_emulate_mtmsr_len * 4);
226 	if (!p)
227 		return;
228 
229 	/* Find out where we are and put everything there */
230 	distance_start = (ulong)p - (ulong)inst;
231 	next_inst = ((ulong)inst + 4);
232 	distance_end = next_inst - (ulong)&p[kvm_emulate_mtmsr_branch_offs];
233 
234 	/* Make sure we only write valid b instructions */
235 	if (distance_start > KVM_INST_B_MAX) {
236 		kvm_patching_worked = false;
237 		return;
238 	}
239 
240 	/* Modify the chunk to fit the invocation */
241 	memcpy(p, kvm_emulate_mtmsr, kvm_emulate_mtmsr_len * 4);
242 	p[kvm_emulate_mtmsr_branch_offs] |= distance_end & KVM_INST_B_MASK;
243 
244 	/* Make clobbered registers work too */
245 	switch (get_rt(rt)) {
246 	case 30:
247 		kvm_patch_ins_ll(&p[kvm_emulate_mtmsr_reg1_offs],
248 				 magic_var(scratch2), KVM_RT_30);
249 		kvm_patch_ins_ll(&p[kvm_emulate_mtmsr_reg2_offs],
250 				 magic_var(scratch2), KVM_RT_30);
251 		break;
252 	case 31:
253 		kvm_patch_ins_ll(&p[kvm_emulate_mtmsr_reg1_offs],
254 				 magic_var(scratch1), KVM_RT_30);
255 		kvm_patch_ins_ll(&p[kvm_emulate_mtmsr_reg2_offs],
256 				 magic_var(scratch1), KVM_RT_30);
257 		break;
258 	default:
259 		p[kvm_emulate_mtmsr_reg1_offs] |= rt;
260 		p[kvm_emulate_mtmsr_reg2_offs] |= rt;
261 		break;
262 	}
263 
264 	p[kvm_emulate_mtmsr_orig_ins_offs] = *inst;
265 	flush_icache_range((ulong)p, (ulong)p + kvm_emulate_mtmsr_len * 4);
266 
267 	/* Patch the invocation */
268 	kvm_patch_ins_b(inst, distance_start);
269 }
270 
271 #ifdef CONFIG_BOOKE
272 
273 extern u32 kvm_emulate_wrtee_branch_offs;
274 extern u32 kvm_emulate_wrtee_reg_offs;
275 extern u32 kvm_emulate_wrtee_orig_ins_offs;
276 extern u32 kvm_emulate_wrtee_len;
277 extern u32 kvm_emulate_wrtee[];
278 
279 static void kvm_patch_ins_wrtee(u32 *inst, u32 rt, int imm_one)
280 {
281 	u32 *p;
282 	int distance_start;
283 	int distance_end;
284 	ulong next_inst;
285 
286 	p = kvm_alloc(kvm_emulate_wrtee_len * 4);
287 	if (!p)
288 		return;
289 
290 	/* Find out where we are and put everything there */
291 	distance_start = (ulong)p - (ulong)inst;
292 	next_inst = ((ulong)inst + 4);
293 	distance_end = next_inst - (ulong)&p[kvm_emulate_wrtee_branch_offs];
294 
295 	/* Make sure we only write valid b instructions */
296 	if (distance_start > KVM_INST_B_MAX) {
297 		kvm_patching_worked = false;
298 		return;
299 	}
300 
301 	/* Modify the chunk to fit the invocation */
302 	memcpy(p, kvm_emulate_wrtee, kvm_emulate_wrtee_len * 4);
303 	p[kvm_emulate_wrtee_branch_offs] |= distance_end & KVM_INST_B_MASK;
304 
305 	if (imm_one) {
306 		p[kvm_emulate_wrtee_reg_offs] =
307 			KVM_INST_LI | __PPC_RT(R30) | MSR_EE;
308 	} else {
309 		/* Make clobbered registers work too */
310 		switch (get_rt(rt)) {
311 		case 30:
312 			kvm_patch_ins_ll(&p[kvm_emulate_wrtee_reg_offs],
313 					 magic_var(scratch2), KVM_RT_30);
314 			break;
315 		case 31:
316 			kvm_patch_ins_ll(&p[kvm_emulate_wrtee_reg_offs],
317 					 magic_var(scratch1), KVM_RT_30);
318 			break;
319 		default:
320 			p[kvm_emulate_wrtee_reg_offs] |= rt;
321 			break;
322 		}
323 	}
324 
325 	p[kvm_emulate_wrtee_orig_ins_offs] = *inst;
326 	flush_icache_range((ulong)p, (ulong)p + kvm_emulate_wrtee_len * 4);
327 
328 	/* Patch the invocation */
329 	kvm_patch_ins_b(inst, distance_start);
330 }
331 
332 extern u32 kvm_emulate_wrteei_0_branch_offs;
333 extern u32 kvm_emulate_wrteei_0_len;
334 extern u32 kvm_emulate_wrteei_0[];
335 
336 static void kvm_patch_ins_wrteei_0(u32 *inst)
337 {
338 	u32 *p;
339 	int distance_start;
340 	int distance_end;
341 	ulong next_inst;
342 
343 	p = kvm_alloc(kvm_emulate_wrteei_0_len * 4);
344 	if (!p)
345 		return;
346 
347 	/* Find out where we are and put everything there */
348 	distance_start = (ulong)p - (ulong)inst;
349 	next_inst = ((ulong)inst + 4);
350 	distance_end = next_inst - (ulong)&p[kvm_emulate_wrteei_0_branch_offs];
351 
352 	/* Make sure we only write valid b instructions */
353 	if (distance_start > KVM_INST_B_MAX) {
354 		kvm_patching_worked = false;
355 		return;
356 	}
357 
358 	memcpy(p, kvm_emulate_wrteei_0, kvm_emulate_wrteei_0_len * 4);
359 	p[kvm_emulate_wrteei_0_branch_offs] |= distance_end & KVM_INST_B_MASK;
360 	flush_icache_range((ulong)p, (ulong)p + kvm_emulate_wrteei_0_len * 4);
361 
362 	/* Patch the invocation */
363 	kvm_patch_ins_b(inst, distance_start);
364 }
365 
366 #endif
367 
368 #ifdef CONFIG_PPC_BOOK3S_32
369 
370 extern u32 kvm_emulate_mtsrin_branch_offs;
371 extern u32 kvm_emulate_mtsrin_reg1_offs;
372 extern u32 kvm_emulate_mtsrin_reg2_offs;
373 extern u32 kvm_emulate_mtsrin_orig_ins_offs;
374 extern u32 kvm_emulate_mtsrin_len;
375 extern u32 kvm_emulate_mtsrin[];
376 
377 static void kvm_patch_ins_mtsrin(u32 *inst, u32 rt, u32 rb)
378 {
379 	u32 *p;
380 	int distance_start;
381 	int distance_end;
382 	ulong next_inst;
383 
384 	p = kvm_alloc(kvm_emulate_mtsrin_len * 4);
385 	if (!p)
386 		return;
387 
388 	/* Find out where we are and put everything there */
389 	distance_start = (ulong)p - (ulong)inst;
390 	next_inst = ((ulong)inst + 4);
391 	distance_end = next_inst - (ulong)&p[kvm_emulate_mtsrin_branch_offs];
392 
393 	/* Make sure we only write valid b instructions */
394 	if (distance_start > KVM_INST_B_MAX) {
395 		kvm_patching_worked = false;
396 		return;
397 	}
398 
399 	/* Modify the chunk to fit the invocation */
400 	memcpy(p, kvm_emulate_mtsrin, kvm_emulate_mtsrin_len * 4);
401 	p[kvm_emulate_mtsrin_branch_offs] |= distance_end & KVM_INST_B_MASK;
402 	p[kvm_emulate_mtsrin_reg1_offs] |= (rb << 10);
403 	p[kvm_emulate_mtsrin_reg2_offs] |= rt;
404 	p[kvm_emulate_mtsrin_orig_ins_offs] = *inst;
405 	flush_icache_range((ulong)p, (ulong)p + kvm_emulate_mtsrin_len * 4);
406 
407 	/* Patch the invocation */
408 	kvm_patch_ins_b(inst, distance_start);
409 }
410 
411 #endif
412 
413 static void kvm_map_magic_page(void *data)
414 {
415 	u32 *features = data;
416 
417 	ulong in[8] = {0};
418 	ulong out[8];
419 
420 	in[0] = KVM_MAGIC_PAGE;
421 	in[1] = KVM_MAGIC_PAGE | MAGIC_PAGE_FLAG_NOT_MAPPED_NX;
422 
423 	epapr_hypercall(in, out, KVM_HCALL_TOKEN(KVM_HC_PPC_MAP_MAGIC_PAGE));
424 
425 	*features = out[0];
426 }
427 
428 static void kvm_check_ins(u32 *inst, u32 features)
429 {
430 	u32 _inst = *inst;
431 	u32 inst_no_rt = _inst & ~KVM_MASK_RT;
432 	u32 inst_rt = _inst & KVM_MASK_RT;
433 
434 	switch (inst_no_rt) {
435 	/* Loads */
436 	case KVM_INST_MFMSR:
437 		kvm_patch_ins_ld(inst, magic_var(msr), inst_rt);
438 		break;
439 	case KVM_INST_MFSPR(SPRN_SPRG0):
440 		kvm_patch_ins_ld(inst, magic_var(sprg0), inst_rt);
441 		break;
442 	case KVM_INST_MFSPR(SPRN_SPRG1):
443 		kvm_patch_ins_ld(inst, magic_var(sprg1), inst_rt);
444 		break;
445 	case KVM_INST_MFSPR(SPRN_SPRG2):
446 		kvm_patch_ins_ld(inst, magic_var(sprg2), inst_rt);
447 		break;
448 	case KVM_INST_MFSPR(SPRN_SPRG3):
449 		kvm_patch_ins_ld(inst, magic_var(sprg3), inst_rt);
450 		break;
451 	case KVM_INST_MFSPR(SPRN_SRR0):
452 		kvm_patch_ins_ld(inst, magic_var(srr0), inst_rt);
453 		break;
454 	case KVM_INST_MFSPR(SPRN_SRR1):
455 		kvm_patch_ins_ld(inst, magic_var(srr1), inst_rt);
456 		break;
457 #ifdef CONFIG_BOOKE
458 	case KVM_INST_MFSPR(SPRN_DEAR):
459 #else
460 	case KVM_INST_MFSPR(SPRN_DAR):
461 #endif
462 		kvm_patch_ins_ld(inst, magic_var(dar), inst_rt);
463 		break;
464 	case KVM_INST_MFSPR(SPRN_DSISR):
465 		kvm_patch_ins_lwz(inst, magic_var(dsisr), inst_rt);
466 		break;
467 
468 #ifdef CONFIG_PPC_BOOK3E_MMU
469 	case KVM_INST_MFSPR(SPRN_MAS0):
470 		if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
471 			kvm_patch_ins_lwz(inst, magic_var(mas0), inst_rt);
472 		break;
473 	case KVM_INST_MFSPR(SPRN_MAS1):
474 		if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
475 			kvm_patch_ins_lwz(inst, magic_var(mas1), inst_rt);
476 		break;
477 	case KVM_INST_MFSPR(SPRN_MAS2):
478 		if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
479 			kvm_patch_ins_ld(inst, magic_var(mas2), inst_rt);
480 		break;
481 	case KVM_INST_MFSPR(SPRN_MAS3):
482 		if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
483 			kvm_patch_ins_lwz(inst, magic_var(mas7_3) + 4, inst_rt);
484 		break;
485 	case KVM_INST_MFSPR(SPRN_MAS4):
486 		if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
487 			kvm_patch_ins_lwz(inst, magic_var(mas4), inst_rt);
488 		break;
489 	case KVM_INST_MFSPR(SPRN_MAS6):
490 		if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
491 			kvm_patch_ins_lwz(inst, magic_var(mas6), inst_rt);
492 		break;
493 	case KVM_INST_MFSPR(SPRN_MAS7):
494 		if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
495 			kvm_patch_ins_lwz(inst, magic_var(mas7_3), inst_rt);
496 		break;
497 #endif /* CONFIG_PPC_BOOK3E_MMU */
498 
499 	case KVM_INST_MFSPR(SPRN_SPRG4):
500 #ifdef CONFIG_BOOKE
501 	case KVM_INST_MFSPR(SPRN_SPRG4R):
502 #endif
503 		if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
504 			kvm_patch_ins_ld(inst, magic_var(sprg4), inst_rt);
505 		break;
506 	case KVM_INST_MFSPR(SPRN_SPRG5):
507 #ifdef CONFIG_BOOKE
508 	case KVM_INST_MFSPR(SPRN_SPRG5R):
509 #endif
510 		if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
511 			kvm_patch_ins_ld(inst, magic_var(sprg5), inst_rt);
512 		break;
513 	case KVM_INST_MFSPR(SPRN_SPRG6):
514 #ifdef CONFIG_BOOKE
515 	case KVM_INST_MFSPR(SPRN_SPRG6R):
516 #endif
517 		if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
518 			kvm_patch_ins_ld(inst, magic_var(sprg6), inst_rt);
519 		break;
520 	case KVM_INST_MFSPR(SPRN_SPRG7):
521 #ifdef CONFIG_BOOKE
522 	case KVM_INST_MFSPR(SPRN_SPRG7R):
523 #endif
524 		if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
525 			kvm_patch_ins_ld(inst, magic_var(sprg7), inst_rt);
526 		break;
527 
528 #ifdef CONFIG_BOOKE
529 	case KVM_INST_MFSPR(SPRN_ESR):
530 		if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
531 			kvm_patch_ins_lwz(inst, magic_var(esr), inst_rt);
532 		break;
533 #endif
534 
535 	case KVM_INST_MFSPR(SPRN_PIR):
536 		if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
537 			kvm_patch_ins_lwz(inst, magic_var(pir), inst_rt);
538 		break;
539 
540 
541 	/* Stores */
542 	case KVM_INST_MTSPR(SPRN_SPRG0):
543 		kvm_patch_ins_std(inst, magic_var(sprg0), inst_rt);
544 		break;
545 	case KVM_INST_MTSPR(SPRN_SPRG1):
546 		kvm_patch_ins_std(inst, magic_var(sprg1), inst_rt);
547 		break;
548 	case KVM_INST_MTSPR(SPRN_SPRG2):
549 		kvm_patch_ins_std(inst, magic_var(sprg2), inst_rt);
550 		break;
551 	case KVM_INST_MTSPR(SPRN_SPRG3):
552 		kvm_patch_ins_std(inst, magic_var(sprg3), inst_rt);
553 		break;
554 	case KVM_INST_MTSPR(SPRN_SRR0):
555 		kvm_patch_ins_std(inst, magic_var(srr0), inst_rt);
556 		break;
557 	case KVM_INST_MTSPR(SPRN_SRR1):
558 		kvm_patch_ins_std(inst, magic_var(srr1), inst_rt);
559 		break;
560 #ifdef CONFIG_BOOKE
561 	case KVM_INST_MTSPR(SPRN_DEAR):
562 #else
563 	case KVM_INST_MTSPR(SPRN_DAR):
564 #endif
565 		kvm_patch_ins_std(inst, magic_var(dar), inst_rt);
566 		break;
567 	case KVM_INST_MTSPR(SPRN_DSISR):
568 		kvm_patch_ins_stw(inst, magic_var(dsisr), inst_rt);
569 		break;
570 #ifdef CONFIG_PPC_BOOK3E_MMU
571 	case KVM_INST_MTSPR(SPRN_MAS0):
572 		if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
573 			kvm_patch_ins_stw(inst, magic_var(mas0), inst_rt);
574 		break;
575 	case KVM_INST_MTSPR(SPRN_MAS1):
576 		if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
577 			kvm_patch_ins_stw(inst, magic_var(mas1), inst_rt);
578 		break;
579 	case KVM_INST_MTSPR(SPRN_MAS2):
580 		if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
581 			kvm_patch_ins_std(inst, magic_var(mas2), inst_rt);
582 		break;
583 	case KVM_INST_MTSPR(SPRN_MAS3):
584 		if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
585 			kvm_patch_ins_stw(inst, magic_var(mas7_3) + 4, inst_rt);
586 		break;
587 	case KVM_INST_MTSPR(SPRN_MAS4):
588 		if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
589 			kvm_patch_ins_stw(inst, magic_var(mas4), inst_rt);
590 		break;
591 	case KVM_INST_MTSPR(SPRN_MAS6):
592 		if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
593 			kvm_patch_ins_stw(inst, magic_var(mas6), inst_rt);
594 		break;
595 	case KVM_INST_MTSPR(SPRN_MAS7):
596 		if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
597 			kvm_patch_ins_stw(inst, magic_var(mas7_3), inst_rt);
598 		break;
599 #endif /* CONFIG_PPC_BOOK3E_MMU */
600 
601 	case KVM_INST_MTSPR(SPRN_SPRG4):
602 		if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
603 			kvm_patch_ins_std(inst, magic_var(sprg4), inst_rt);
604 		break;
605 	case KVM_INST_MTSPR(SPRN_SPRG5):
606 		if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
607 			kvm_patch_ins_std(inst, magic_var(sprg5), inst_rt);
608 		break;
609 	case KVM_INST_MTSPR(SPRN_SPRG6):
610 		if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
611 			kvm_patch_ins_std(inst, magic_var(sprg6), inst_rt);
612 		break;
613 	case KVM_INST_MTSPR(SPRN_SPRG7):
614 		if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
615 			kvm_patch_ins_std(inst, magic_var(sprg7), inst_rt);
616 		break;
617 
618 #ifdef CONFIG_BOOKE
619 	case KVM_INST_MTSPR(SPRN_ESR):
620 		if (features & KVM_MAGIC_FEAT_MAS0_TO_SPRG7)
621 			kvm_patch_ins_stw(inst, magic_var(esr), inst_rt);
622 		break;
623 #endif
624 
625 	/* Nops */
626 	case KVM_INST_TLBSYNC:
627 		kvm_patch_ins_nop(inst);
628 		break;
629 
630 	/* Rewrites */
631 	case KVM_INST_MTMSRD_L1:
632 		kvm_patch_ins_mtmsrd(inst, inst_rt);
633 		break;
634 	case KVM_INST_MTMSR:
635 	case KVM_INST_MTMSRD_L0:
636 		kvm_patch_ins_mtmsr(inst, inst_rt);
637 		break;
638 #ifdef CONFIG_BOOKE
639 	case KVM_INST_WRTEE:
640 		kvm_patch_ins_wrtee(inst, inst_rt, 0);
641 		break;
642 #endif
643 	}
644 
645 	switch (inst_no_rt & ~KVM_MASK_RB) {
646 #ifdef CONFIG_PPC_BOOK3S_32
647 	case KVM_INST_MTSRIN:
648 		if (features & KVM_MAGIC_FEAT_SR) {
649 			u32 inst_rb = _inst & KVM_MASK_RB;
650 			kvm_patch_ins_mtsrin(inst, inst_rt, inst_rb);
651 		}
652 		break;
653 #endif
654 	}
655 
656 	switch (_inst) {
657 #ifdef CONFIG_BOOKE
658 	case KVM_INST_WRTEEI_0:
659 		kvm_patch_ins_wrteei_0(inst);
660 		break;
661 
662 	case KVM_INST_WRTEEI_1:
663 		kvm_patch_ins_wrtee(inst, 0, 1);
664 		break;
665 #endif
666 	}
667 }
668 
669 extern u32 kvm_template_start[];
670 extern u32 kvm_template_end[];
671 
672 static void kvm_use_magic_page(void)
673 {
674 	u32 *p;
675 	u32 *start, *end;
676 	u32 features;
677 
678 	/* Tell the host to map the magic page to -4096 on all CPUs */
679 	on_each_cpu(kvm_map_magic_page, &features, 1);
680 
681 	/* Quick self-test to see if the mapping works */
682 	if (!fault_in_pages_readable((const char *)KVM_MAGIC_PAGE, sizeof(u32))) {
683 		kvm_patching_worked = false;
684 		return;
685 	}
686 
687 	/* Now loop through all code and find instructions */
688 	start = (void*)_stext;
689 	end = (void*)_etext;
690 
691 	/*
692 	 * Being interrupted in the middle of patching would
693 	 * be bad for SPRG4-7, which KVM can't keep in sync
694 	 * with emulated accesses because reads don't trap.
695 	 */
696 	local_irq_disable();
697 
698 	for (p = start; p < end; p++) {
699 		/* Avoid patching the template code */
700 		if (p >= kvm_template_start && p < kvm_template_end) {
701 			p = kvm_template_end - 1;
702 			continue;
703 		}
704 		kvm_check_ins(p, features);
705 	}
706 
707 	local_irq_enable();
708 
709 	printk(KERN_INFO "KVM: Live patching for a fast VM %s\n",
710 			 kvm_patching_worked ? "worked" : "failed");
711 }
712 
713 static __init void kvm_free_tmp(void)
714 {
715 	free_reserved_area(&kvm_tmp[kvm_tmp_index],
716 			   &kvm_tmp[ARRAY_SIZE(kvm_tmp)], -1, NULL);
717 }
718 
719 static int __init kvm_guest_init(void)
720 {
721 	if (!kvm_para_available())
722 		goto free_tmp;
723 
724 	if (!epapr_paravirt_enabled)
725 		goto free_tmp;
726 
727 	if (kvm_para_has_feature(KVM_FEATURE_MAGIC_PAGE))
728 		kvm_use_magic_page();
729 
730 #ifdef CONFIG_PPC_BOOK3S_64
731 	/* Enable napping */
732 	powersave_nap = 1;
733 #endif
734 
735 free_tmp:
736 	kvm_free_tmp();
737 
738 	return 0;
739 }
740 
741 postcore_initcall(kvm_guest_init);
742