summaryrefslogtreecommitdiff
path: root/arch/powerpc/kernel/kvm_emul.S
blob: e100ff324a85c46449ec78044e6aafadc96201a6 (plain) (blame)
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
/*
 * 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 SUSE Linux Products GmbH 2010
 * Copyright 2010-2011 Freescale Semiconductor, Inc.
 *
 * Authors: Alexander Graf <agraf@suse.de>
 */

#include <asm/ppc_asm.h>
#include <asm/kvm_asm.h>
#include <asm/reg.h>
#include <asm/page.h>
#include <asm/asm-offsets.h>

#define KVM_MAGIC_PAGE		(-4096)

#ifdef CONFIG_64BIT
#define LL64(reg, offs, reg2)	ld	reg, (offs)(reg2)
#define STL64(reg, offs, reg2)	std	reg, (offs)(reg2)
#else
#define LL64(reg, offs, reg2)	lwz	reg, (offs + 4)(reg2)
#define STL64(reg, offs, reg2)	stw	reg, (offs + 4)(reg2)
#endif

#define SCRATCH_SAVE							\
	/* Enable critical section. We are critical if			\
	   shared->critical == r1 */					\
	STL64(r1, KVM_MAGIC_PAGE + KVM_MAGIC_CRITICAL, 0);		\
									\
	/* Save state */						\
	PPC_STL	r31, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH1)(0);		\
	PPC_STL	r30, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH2)(0);		\
	mfcr	r31;							\
	stw	r31, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH3)(0);

#define SCRATCH_RESTORE							\
	/* Restore state */						\
	PPC_LL	r31, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH1)(0);		\
	lwz	r30, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH3)(0);		\
	mtcr	r30;							\
	PPC_LL	r30, (KVM_MAGIC_PAGE + KVM_MAGIC_SCRATCH2)(0);		\
									\
	/* Disable critical section. We are critical if			\
	   shared->critical == r1 and r2 is always != r1 */		\
	STL64(r2, KVM_MAGIC_PAGE + KVM_MAGIC_CRITICAL, 0);

.global kvm_template_start
kvm_template_start:

.global kvm_emulate_mtmsrd
kvm_emulate_mtmsrd:

	SCRATCH_SAVE

	/* Put MSR & ~(MSR_EE|MSR_RI) in r31 */
	LL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
	lis	r30, (~(MSR_EE | MSR_RI))@h
	ori	r30, r30, (~(MSR_EE | MSR_RI))@l
	and	r31, r31, r30

	/* OR the register's (MSR_EE|MSR_RI) on MSR */
kvm_emulate_mtmsrd_reg:
	ori	r30, r0, 0
	andi.	r30, r30, (MSR_EE|MSR_RI)
	or	r31, r31, r30

	/* Put MSR back into magic page */
	STL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)

	/* Check if we have to fetch an interrupt */
	lwz	r31, (KVM_MAGIC_PAGE + KVM_MAGIC_INT)(0)
	cmpwi	r31, 0
	beq+	no_check

	/* Check if we may trigger an interrupt */
	andi.	r30, r30, MSR_EE
	beq	no_check

	SCRATCH_RESTORE

	/* Nag hypervisor */
kvm_emulate_mtmsrd_orig_ins:
	tlbsync

	b	kvm_emulate_mtmsrd_branch

no_check:

	SCRATCH_RESTORE

	/* Go back to caller */
kvm_emulate_mtmsrd_branch:
	b	.
kvm_emulate_mtmsrd_end:

.global kvm_emulate_mtmsrd_branch_offs
kvm_emulate_mtmsrd_branch_offs:
	.long (kvm_emulate_mtmsrd_branch - kvm_emulate_mtmsrd) / 4

.global kvm_emulate_mtmsrd_reg_offs
kvm_emulate_mtmsrd_reg_offs:
	.long (kvm_emulate_mtmsrd_reg - kvm_emulate_mtmsrd) / 4

.global kvm_emulate_mtmsrd_orig_ins_offs
kvm_emulate_mtmsrd_orig_ins_offs:
	.long (kvm_emulate_mtmsrd_orig_ins - kvm_emulate_mtmsrd) / 4

.global kvm_emulate_mtmsrd_len
kvm_emulate_mtmsrd_len:
	.long (kvm_emulate_mtmsrd_end - kvm_emulate_mtmsrd) / 4


#define MSR_SAFE_BITS (MSR_EE | MSR_RI)
#define MSR_CRITICAL_BITS ~MSR_SAFE_BITS

.global kvm_emulate_mtmsr
kvm_emulate_mtmsr:

	SCRATCH_SAVE

	/* Fetch old MSR in r31 */
	LL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)

	/* Find the changed bits between old and new MSR */
kvm_emulate_mtmsr_reg1:
	ori	r30, r0, 0
	xor	r31, r30, r31

	/* Check if we need to really do mtmsr */
	LOAD_REG_IMMEDIATE(r30, MSR_CRITICAL_BITS)
	and.	r31, r31, r30

	/* No critical bits changed? Maybe we can stay in the guest. */
	beq	maybe_stay_in_guest

do_mtmsr:

	SCRATCH_RESTORE

	/* Just fire off the mtmsr if it's critical */
kvm_emulate_mtmsr_orig_ins:
	mtmsr	r0

	b	kvm_emulate_mtmsr_branch

maybe_stay_in_guest:

	/* Get the target register in r30 */
kvm_emulate_mtmsr_reg2:
	ori	r30, r0, 0

	/* Put MSR into magic page because we don't call mtmsr */
	STL64(r30, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)

	/* Check if we have to fetch an interrupt */
	lwz	r31, (KVM_MAGIC_PAGE + KVM_MAGIC_INT)(0)
	cmpwi	r31, 0
	beq+	no_mtmsr

	/* Check if we may trigger an interrupt */
	andi.	r31, r30, MSR_EE
	bne	do_mtmsr

no_mtmsr:

	SCRATCH_RESTORE

	/* Go back to caller */
kvm_emulate_mtmsr_branch:
	b	.
kvm_emulate_mtmsr_end:

.global kvm_emulate_mtmsr_branch_offs
kvm_emulate_mtmsr_branch_offs:
	.long (kvm_emulate_mtmsr_branch - kvm_emulate_mtmsr) / 4

.global kvm_emulate_mtmsr_reg1_offs
kvm_emulate_mtmsr_reg1_offs:
	.long (kvm_emulate_mtmsr_reg1 - kvm_emulate_mtmsr) / 4

.global kvm_emulate_mtmsr_reg2_offs
kvm_emulate_mtmsr_reg2_offs:
	.long (kvm_emulate_mtmsr_reg2 - kvm_emulate_mtmsr) / 4

.global kvm_emulate_mtmsr_orig_ins_offs
kvm_emulate_mtmsr_orig_ins_offs:
	.long (kvm_emulate_mtmsr_orig_ins - kvm_emulate_mtmsr) / 4

.global kvm_emulate_mtmsr_len
kvm_emulate_mtmsr_len:
	.long (kvm_emulate_mtmsr_end - kvm_emulate_mtmsr) / 4

/* also used for wrteei 1 */
.global kvm_emulate_wrtee
kvm_emulate_wrtee:

	SCRATCH_SAVE

	/* Fetch old MSR in r31 */
	LL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)

	/* Insert new MSR[EE] */
kvm_emulate_wrtee_reg:
	ori	r30, r0, 0
	rlwimi	r31, r30, 0, MSR_EE

	/*
	 * If MSR[EE] is now set, check for a pending interrupt.
	 * We could skip this if MSR[EE] was already on, but that
	 * should be rare, so don't bother.
	 */
	andi.	r30, r30, MSR_EE

	/* Put MSR into magic page because we don't call wrtee */
	STL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)

	beq	no_wrtee

	/* Check if we have to fetch an interrupt */
	lwz	r30, (KVM_MAGIC_PAGE + KVM_MAGIC_INT)(0)
	cmpwi	r30, 0
	bne	do_wrtee

no_wrtee:
	SCRATCH_RESTORE

	/* Go back to caller */
kvm_emulate_wrtee_branch:
	b	.

do_wrtee:
	SCRATCH_RESTORE

	/* Just fire off the wrtee if it's critical */
kvm_emulate_wrtee_orig_ins:
	wrtee	r0

	b	kvm_emulate_wrtee_branch

kvm_emulate_wrtee_end:

.global kvm_emulate_wrtee_branch_offs
kvm_emulate_wrtee_branch_offs:
	.long (kvm_emulate_wrtee_branch - kvm_emulate_wrtee) / 4

.global kvm_emulate_wrtee_reg_offs
kvm_emulate_wrtee_reg_offs:
	.long (kvm_emulate_wrtee_reg - kvm_emulate_wrtee) / 4

.global kvm_emulate_wrtee_orig_ins_offs
kvm_emulate_wrtee_orig_ins_offs:
	.long (kvm_emulate_wrtee_orig_ins - kvm_emulate_wrtee) / 4

.global kvm_emulate_wrtee_len
kvm_emulate_wrtee_len:
	.long (kvm_emulate_wrtee_end - kvm_emulate_wrtee) / 4

.global kvm_emulate_wrteei_0
kvm_emulate_wrteei_0:
	SCRATCH_SAVE

	/* Fetch old MSR in r31 */
	LL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)

	/* Remove MSR_EE from old MSR */
	rlwinm	r31, r31, 0, ~MSR_EE

	/* Write new MSR value back */
	STL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)

	SCRATCH_RESTORE

	/* Go back to caller */
kvm_emulate_wrteei_0_branch:
	b	.
kvm_emulate_wrteei_0_end:

.global kvm_emulate_wrteei_0_branch_offs
kvm_emulate_wrteei_0_branch_offs:
	.long (kvm_emulate_wrteei_0_branch - kvm_emulate_wrteei_0) / 4

.global kvm_emulate_wrteei_0_len
kvm_emulate_wrteei_0_len:
	.long (kvm_emulate_wrteei_0_end - kvm_emulate_wrteei_0) / 4

.global kvm_emulate_mtsrin
kvm_emulate_mtsrin:

	SCRATCH_SAVE

	LL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
	andi.	r31, r31, MSR_DR | MSR_IR
	beq	kvm_emulate_mtsrin_reg1

	SCRATCH_RESTORE

kvm_emulate_mtsrin_orig_ins:
	nop
	b	kvm_emulate_mtsrin_branch

kvm_emulate_mtsrin_reg1:
	/* rX >> 26 */
	rlwinm  r30,r0,6,26,29

kvm_emulate_mtsrin_reg2:
	stw	r0, (KVM_MAGIC_PAGE + KVM_MAGIC_SR)(r30)

	SCRATCH_RESTORE

	/* Go back to caller */
kvm_emulate_mtsrin_branch:
	b	.
kvm_emulate_mtsrin_end:

.global kvm_emulate_mtsrin_branch_offs
kvm_emulate_mtsrin_branch_offs:
	.long (kvm_emulate_mtsrin_branch - kvm_emulate_mtsrin) / 4

.global kvm_emulate_mtsrin_reg1_offs
kvm_emulate_mtsrin_reg1_offs:
	.long (kvm_emulate_mtsrin_reg1 - kvm_emulate_mtsrin) / 4

.global kvm_emulate_mtsrin_reg2_offs
kvm_emulate_mtsrin_reg2_offs:
	.long (kvm_emulate_mtsrin_reg2 - kvm_emulate_mtsrin) / 4

.global kvm_emulate_mtsrin_orig_ins_offs
kvm_emulate_mtsrin_orig_ins_offs:
	.long (kvm_emulate_mtsrin_orig_ins - kvm_emulate_mtsrin) / 4

.global kvm_emulate_mtsrin_len
kvm_emulate_mtsrin_len:
	.long (kvm_emulate_mtsrin_end - kvm_emulate_mtsrin) / 4

.global kvm_template_end
kvm_template_end: