summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/kvm/book3s_rmhandlers.S
blob: c1f877c4a884655dfccb58d00c803c395a9695d7 (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
/*
 * 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 2009
 *
 * 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>

#ifdef CONFIG_PPC_BOOK3S_64
#include <asm/exception-64s.h>
#endif

/*****************************************************************************
 *                                                                           *
 *        Real Mode handlers that need to be in low physical memory          *
 *                                                                           *
 ****************************************************************************/

#if defined(CONFIG_PPC_BOOK3S_64)

#define LOAD_SHADOW_VCPU(reg)	GET_PACA(reg)					
#define MSR_NOIRQ		MSR_KERNEL & ~(MSR_IR | MSR_DR)
#define FUNC(name) 		GLUE(.,name)

kvmppc_skip_interrupt:
	/*
	 * Here all GPRs are unchanged from when the interrupt happened
	 * except for r13, which is saved in SPRG_SCRATCH0.
	 */
	mfspr	r13, SPRN_SRR0
	addi	r13, r13, 4
	mtspr	SPRN_SRR0, r13
	GET_SCRATCH0(r13)
	rfid
	b	.

kvmppc_skip_Hinterrupt:
	/*
	 * Here all GPRs are unchanged from when the interrupt happened
	 * except for r13, which is saved in SPRG_SCRATCH0.
	 */
	mfspr	r13, SPRN_HSRR0
	addi	r13, r13, 4
	mtspr	SPRN_HSRR0, r13
	GET_SCRATCH0(r13)
	hrfid
	b	.

#elif defined(CONFIG_PPC_BOOK3S_32)

#define MSR_NOIRQ		MSR_KERNEL
#define FUNC(name)		name

.macro INTERRUPT_TRAMPOLINE intno

.global kvmppc_trampoline_\intno
kvmppc_trampoline_\intno:

	mtspr	SPRN_SPRG_SCRATCH0, r13		/* Save r13 */

	/*
	 * First thing to do is to find out if we're coming
	 * from a KVM guest or a Linux process.
	 *
	 * To distinguish, we check a magic byte in the PACA/current
	 */
	mfspr	r13, SPRN_SPRG_THREAD
	lwz	r13, THREAD_KVM_SVCPU(r13)
	/* PPC32 can have a NULL pointer - let's check for that */
	mtspr   SPRN_SPRG_SCRATCH1, r12		/* Save r12 */
	mfcr	r12
	cmpwi	r13, 0
	bne	1f
2:	mtcr	r12
	mfspr	r12, SPRN_SPRG_SCRATCH1
	mfspr	r13, SPRN_SPRG_SCRATCH0		/* r13 = original r13 */
	b	kvmppc_resume_\intno		/* Get back original handler */

1:	tophys(r13, r13)
	stw	r12, HSTATE_SCRATCH1(r13)
	mfspr	r12, SPRN_SPRG_SCRATCH1
	stw	r12, HSTATE_SCRATCH0(r13)
	lbz	r12, HSTATE_IN_GUEST(r13)
	cmpwi	r12, KVM_GUEST_MODE_NONE
	bne	..kvmppc_handler_hasmagic_\intno
	/* No KVM guest? Then jump back to the Linux handler! */
	lwz	r12, HSTATE_SCRATCH1(r13)
	b	2b

	/* Now we know we're handling a KVM guest */
..kvmppc_handler_hasmagic_\intno:

	/* Should we just skip the faulting instruction? */
	cmpwi	r12, KVM_GUEST_MODE_SKIP
	beq	kvmppc_handler_skip_ins

	/* Let's store which interrupt we're handling */
	li	r12, \intno

	/* Jump into the SLB exit code that goes to the highmem handler */
	b	kvmppc_handler_trampoline_exit

.endm

INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_SYSTEM_RESET
INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_MACHINE_CHECK
INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_DATA_STORAGE
INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_INST_STORAGE
INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_EXTERNAL
INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_ALIGNMENT
INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_PROGRAM
INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_FP_UNAVAIL
INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_DECREMENTER
INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_SYSCALL
INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_TRACE
INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_PERFMON
INTERRUPT_TRAMPOLINE	BOOK3S_INTERRUPT_ALTIVEC

/*
 * Bring us back to the faulting code, but skip the
 * faulting instruction.
 *
 * This is a generic exit path from the interrupt
 * trampolines above.
 *
 * Input Registers:
 *
 * R12            = free
 * R13            = Shadow VCPU (PACA)
 * HSTATE.SCRATCH0 = guest R12
 * HSTATE.SCRATCH1 = guest CR
 * SPRG_SCRATCH0  = guest R13
 *
 */
kvmppc_handler_skip_ins:

	/* Patch the IP to the next instruction */
	mfsrr0	r12
	addi	r12, r12, 4
	mtsrr0	r12

	/* Clean up all state */
	lwz	r12, HSTATE_SCRATCH1(r13)
	mtcr	r12
	PPC_LL	r12, HSTATE_SCRATCH0(r13)
	GET_SCRATCH0(r13)

	/* And get back into the code */
	RFI
#endif

/*
 * This trampoline brings us back to a real mode handler
 *
 * Input Registers:
 *
 * R5 = SRR0
 * R6 = SRR1
 * LR = real-mode IP
 *
 */
.global kvmppc_handler_lowmem_trampoline
kvmppc_handler_lowmem_trampoline:

	mtsrr0	r5
	mtsrr1	r6
	blr
kvmppc_handler_lowmem_trampoline_end:

/*
 * Call a function in real mode
 *
 * Input Registers:
 *
 * R3 = function
 * R4 = MSR
 * R5 = scratch register
 *
 */
_GLOBAL(kvmppc_rmcall)
	LOAD_REG_IMMEDIATE(r5, MSR_NOIRQ)
	mtmsr	r5		/* Disable relocation and interrupts, so mtsrr
				   doesn't get interrupted */
	sync
	mtsrr0	r3
	mtsrr1	r4
	RFI

#if defined(CONFIG_PPC_BOOK3S_32)
#define STACK_LR	INT_FRAME_SIZE+4

/* load_up_xxx have to run with MSR_DR=0 on Book3S_32 */
#define MSR_EXT_START						\
	PPC_STL	r20, _NIP(r1);					\
	mfmsr	r20;						\
	LOAD_REG_IMMEDIATE(r3, MSR_DR|MSR_EE);			\
	andc	r3,r20,r3;		/* Disable DR,EE */	\
	mtmsr	r3;						\
	sync

#define MSR_EXT_END						\
	mtmsr	r20;			/* Enable DR,EE */	\
	sync;							\
	PPC_LL	r20, _NIP(r1)

#elif defined(CONFIG_PPC_BOOK3S_64)
#define STACK_LR	_LINK
#define MSR_EXT_START
#define MSR_EXT_END
#endif

/*
 * Activate current's external feature (FPU/Altivec/VSX)
 */
#define define_load_up(what) 					\
								\
_GLOBAL(kvmppc_load_up_ ## what);				\
	PPC_STLU r1, -INT_FRAME_SIZE(r1);			\
	mflr	r3;						\
	PPC_STL	r3, STACK_LR(r1);				\
	MSR_EXT_START;						\
								\
	bl	FUNC(load_up_ ## what);				\
								\
	MSR_EXT_END;						\
	PPC_LL	r3, STACK_LR(r1);				\
	mtlr	r3;						\
	addi	r1, r1, INT_FRAME_SIZE;				\
	blr

define_load_up(fpu)
#ifdef CONFIG_ALTIVEC
define_load_up(altivec)
#endif
#ifdef CONFIG_VSX
define_load_up(vsx)
#endif

#include "book3s_segment.S"