summaryrefslogtreecommitdiff
path: root/arch/powerpc/kvm/book3s_rmhandlers.S
blob: b45b750fa77a6f0a9626d0306251882771dd5676 (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
/* SPDX-License-Identifier: GPL-2.0-only */
/*
 *
 * 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/mmu.h>
#include <asm/page.h>
#include <asm/asm-offsets.h>
#include <asm/asm-compat.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)

#ifdef PPC64_ELF_ABI_v2
#define FUNC(name) 		name
#else
#define FUNC(name) 		GLUE(.,name)
#endif

#elif defined(CONFIG_PPC_BOOK3S_32)

#define FUNC(name)		name

#define RFI_TO_KERNEL	rfi
#define RFI_TO_GUEST	rfi

.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_TO_KERNEL
#endif

/*
 * Call kvmppc_handler_trampoline_enter in real mode
 *
 * On entry, r4 contains the guest shadow MSR
 * MSR.EE has to be 0 when calling this function
 */
_GLOBAL_TOC(kvmppc_entry_trampoline)
	mfmsr	r5
	LOAD_REG_ADDR(r7, kvmppc_handler_trampoline_enter)
	toreal(r7)

	li	r6, MSR_IR | MSR_DR
	andc	r6, r5, r6	/* Clear DR and IR in MSR value */
	/*
	 * Set EE in HOST_MSR so that it's enabled when we get into our
	 * C exit handler function.
	 */
	ori	r5, r5, MSR_EE
	mtsrr0	r7
	mtsrr1	r6
	RFI_TO_KERNEL

#include "book3s_segment.S"