summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/kvm/book3s_rmhandlers.S
blob: c78ffbc371a566aea92dd2d4aa172c70faba1101 (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
/*
 * 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/mmu.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 FUNC(name) 		GLUE(.,name)

#elif defined(CONFIG_PPC_BOOK3S_32)

#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

/*
 * 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(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 */
#ifdef CONFIG_PPC_BOOK3S_32
	/*
	 * Set EE in HOST_MSR so that it's enabled when we get into our
	 * C exit handler function.  On 64-bit we delay enabling
	 * interrupts until we have finished transferring stuff
	 * to or from the PACA.
	 */
	ori	r5, r5, MSR_EE
#endif
	mtsrr0	r7
	mtsrr1	r6
	RFI

#include "book3s_segment.S"