summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/kvm/book3s_segment.S
blob: 7c52ed0b7051b5748fe3c943c60de5ff18b616b2 (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
/*
 * 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
 *
 * Authors: Alexander Graf <agraf@suse.de>
 */

/* Real mode helpers */

#if defined(CONFIG_PPC_BOOK3S_64)

#define GET_SHADOW_VCPU(reg)    \
	addi    reg, r13, PACA_KVM_SVCPU

#elif defined(CONFIG_PPC_BOOK3S_32)

#define GET_SHADOW_VCPU(reg)    			\
	tophys(reg, r2);       			\
	lwz     reg, (THREAD + THREAD_KVM_SVCPU)(reg);	\
	tophys(reg, reg)

#endif

/* Disable for nested KVM */
#define USE_QUICK_LAST_INST


/* Get helper functions for subarch specific functionality */

#if defined(CONFIG_PPC_BOOK3S_64)
#include "book3s_64_slb.S"
#elif defined(CONFIG_PPC_BOOK3S_32)
#include "book3s_32_sr.S"
#endif

/******************************************************************************
 *                                                                            *
 *                               Entry code                                   *
 *                                                                            *
 *****************************************************************************/

.global kvmppc_handler_trampoline_enter
kvmppc_handler_trampoline_enter:

	/* Required state:
	 *
	 * MSR = ~IR|DR
	 * R13 = PACA
	 * R1 = host R1
	 * R2 = host R2
	 * R10 = guest MSR
	 * all other volatile GPRS = free
	 * SVCPU[CR] = guest CR
	 * SVCPU[XER] = guest XER
	 * SVCPU[CTR] = guest CTR
	 * SVCPU[LR] = guest LR
	 */

	/* r3 = shadow vcpu */
	GET_SHADOW_VCPU(r3)

	/* Move SRR0 and SRR1 into the respective regs */
	PPC_LL  r9, SVCPU_PC(r3)
	mtsrr0	r9
	mtsrr1	r10

	/* Activate guest mode, so faults get handled by KVM */
	li	r11, KVM_GUEST_MODE_GUEST
	stb	r11, SVCPU_IN_GUEST(r3)

	/* Switch to guest segment. This is subarch specific. */
	LOAD_GUEST_SEGMENTS

	/* Enter guest */

	PPC_LL	r4, (SVCPU_CTR)(r3)
	PPC_LL	r5, (SVCPU_LR)(r3)
	lwz	r6, (SVCPU_CR)(r3)
	lwz	r7, (SVCPU_XER)(r3)

	mtctr	r4
	mtlr	r5
	mtcr	r6
	mtxer	r7

	PPC_LL	r0, (SVCPU_R0)(r3)
	PPC_LL	r1, (SVCPU_R1)(r3)
	PPC_LL	r2, (SVCPU_R2)(r3)
	PPC_LL	r4, (SVCPU_R4)(r3)
	PPC_LL	r5, (SVCPU_R5)(r3)
	PPC_LL	r6, (SVCPU_R6)(r3)
	PPC_LL	r7, (SVCPU_R7)(r3)
	PPC_LL	r8, (SVCPU_R8)(r3)
	PPC_LL	r9, (SVCPU_R9)(r3)
	PPC_LL	r10, (SVCPU_R10)(r3)
	PPC_LL	r11, (SVCPU_R11)(r3)
	PPC_LL	r12, (SVCPU_R12)(r3)
	PPC_LL	r13, (SVCPU_R13)(r3)

	PPC_LL	r3, (SVCPU_R3)(r3)

	RFI
kvmppc_handler_trampoline_enter_end:



/******************************************************************************
 *                                                                            *
 *                               Exit code                                    *
 *                                                                            *
 *****************************************************************************/

.global kvmppc_handler_trampoline_exit
kvmppc_handler_trampoline_exit:

	/* Register usage at this point:
	 *
	 * SPRG_SCRATCH0  = guest R13
	 * R12            = exit handler id
	 * R13            = shadow vcpu - SHADOW_VCPU_OFF [=PACA on PPC64]
	 * SVCPU.SCRATCH0 = guest R12
	 * SVCPU.SCRATCH1 = guest CR
	 *
	 */

	/* Save registers */

	PPC_STL	r0, (SHADOW_VCPU_OFF + SVCPU_R0)(r13)
	PPC_STL	r1, (SHADOW_VCPU_OFF + SVCPU_R1)(r13)
	PPC_STL	r2, (SHADOW_VCPU_OFF + SVCPU_R2)(r13)
	PPC_STL	r3, (SHADOW_VCPU_OFF + SVCPU_R3)(r13)
	PPC_STL	r4, (SHADOW_VCPU_OFF + SVCPU_R4)(r13)
	PPC_STL	r5, (SHADOW_VCPU_OFF + SVCPU_R5)(r13)
	PPC_STL	r6, (SHADOW_VCPU_OFF + SVCPU_R6)(r13)
	PPC_STL	r7, (SHADOW_VCPU_OFF + SVCPU_R7)(r13)
	PPC_STL	r8, (SHADOW_VCPU_OFF + SVCPU_R8)(r13)
	PPC_STL	r9, (SHADOW_VCPU_OFF + SVCPU_R9)(r13)
	PPC_STL	r10, (SHADOW_VCPU_OFF + SVCPU_R10)(r13)
	PPC_STL	r11, (SHADOW_VCPU_OFF + SVCPU_R11)(r13)

	/* Restore R1/R2 so we can handle faults */
	PPC_LL	r1, (SHADOW_VCPU_OFF + SVCPU_HOST_R1)(r13)
	PPC_LL	r2, (SHADOW_VCPU_OFF + SVCPU_HOST_R2)(r13)

	/* Save guest PC and MSR */
	mfsrr0	r3
	mfsrr1	r4

	PPC_STL	r3, (SHADOW_VCPU_OFF + SVCPU_PC)(r13)
	PPC_STL	r4, (SHADOW_VCPU_OFF + SVCPU_SHADOW_SRR1)(r13)

	/* Get scratch'ed off registers */
	mfspr	r9, SPRN_SPRG_SCRATCH0
	PPC_LL	r8, (SHADOW_VCPU_OFF + SVCPU_SCRATCH0)(r13)
	lwz	r7, (SHADOW_VCPU_OFF + SVCPU_SCRATCH1)(r13)

	PPC_STL	r9, (SHADOW_VCPU_OFF + SVCPU_R13)(r13)
	PPC_STL	r8, (SHADOW_VCPU_OFF + SVCPU_R12)(r13)
	stw	r7, (SHADOW_VCPU_OFF + SVCPU_CR)(r13)

	/* Save more register state  */

	mfxer	r5
	mfdar	r6
	mfdsisr	r7
	mfctr	r8
	mflr	r9

	stw	r5, (SHADOW_VCPU_OFF + SVCPU_XER)(r13)
	PPC_STL	r6, (SHADOW_VCPU_OFF + SVCPU_FAULT_DAR)(r13)
	stw	r7, (SHADOW_VCPU_OFF + SVCPU_FAULT_DSISR)(r13)
	PPC_STL	r8, (SHADOW_VCPU_OFF + SVCPU_CTR)(r13)
	PPC_STL	r9, (SHADOW_VCPU_OFF + SVCPU_LR)(r13)

	/*
	 * In order for us to easily get the last instruction,
	 * we got the #vmexit at, we exploit the fact that the
	 * virtual layout is still the same here, so we can just
	 * ld from the guest's PC address
	 */

	/* We only load the last instruction when it's safe */
	cmpwi	r12, BOOK3S_INTERRUPT_DATA_STORAGE
	beq	ld_last_inst
	cmpwi	r12, BOOK3S_INTERRUPT_PROGRAM
	beq	ld_last_inst
	cmpwi	r12, BOOK3S_INTERRUPT_ALIGNMENT
	beq-	ld_last_inst

	b	no_ld_last_inst

ld_last_inst:
	/* Save off the guest instruction we're at */

	/* In case lwz faults */
	li	r0, KVM_INST_FETCH_FAILED

#ifdef USE_QUICK_LAST_INST

	/* Set guest mode to 'jump over instruction' so if lwz faults
	 * we'll just continue at the next IP. */
	li	r9, KVM_GUEST_MODE_SKIP
	stb	r9, (SHADOW_VCPU_OFF + SVCPU_IN_GUEST)(r13)

	/*    1) enable paging for data */
	mfmsr	r9
	ori	r11, r9, MSR_DR			/* Enable paging for data */
	mtmsr	r11
	sync
	/*    2) fetch the instruction */
	lwz	r0, 0(r3)
	/*    3) disable paging again */
	mtmsr	r9
	sync

#endif
	stw	r0, (SHADOW_VCPU_OFF + SVCPU_LAST_INST)(r13)

no_ld_last_inst:

	/* Unset guest mode */
	li	r9, KVM_GUEST_MODE_NONE
	stb	r9, (SHADOW_VCPU_OFF + SVCPU_IN_GUEST)(r13)

	/* Switch back to host MMU */
	LOAD_HOST_SEGMENTS

	/* Register usage at this point:
	 *
	 * R1       = host R1
	 * R2       = host R2
	 * R12      = exit handler id
	 * R13      = shadow vcpu - SHADOW_VCPU_OFF [=PACA on PPC64]
	 * SVCPU.*  = guest *
	 *
	 */

	/* RFI into the highmem handler */
	mfmsr	r7
	ori	r7, r7, MSR_IR|MSR_DR|MSR_RI|MSR_ME	/* Enable paging */
	mtsrr1	r7
	/* Load highmem handler address */
	PPC_LL	r8, (SHADOW_VCPU_OFF + SVCPU_VMHANDLER)(r13)
	mtsrr0	r8

	RFI
kvmppc_handler_trampoline_exit_end: