xref: /linux/arch/powerpc/kvm/book3s_interrupts.S (revision 4f2c0a4acffbec01079c28f839422e64ddeff004)
1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 *
4 * Copyright SUSE Linux Products GmbH 2009
5 *
6 * Authors: Alexander Graf <agraf@suse.de>
7 */
8
9#include <asm/ppc_asm.h>
10#include <asm/kvm_asm.h>
11#include <asm/reg.h>
12#include <asm/page.h>
13#include <asm/asm-offsets.h>
14#include <asm/exception-64s.h>
15#include <asm/asm-compat.h>
16
17#if defined(CONFIG_PPC_BOOK3S_64)
18#ifdef CONFIG_PPC64_ELF_ABI_V2
19#define FUNC(name) 		name
20#else
21#define FUNC(name) 		GLUE(.,name)
22#endif
23#define GET_SHADOW_VCPU(reg)    addi	reg, r13, PACA_SVCPU
24
25#elif defined(CONFIG_PPC_BOOK3S_32)
26#define FUNC(name)		name
27#define GET_SHADOW_VCPU(reg)	lwz     reg, (THREAD + THREAD_KVM_SVCPU)(r2)
28
29#endif /* CONFIG_PPC_BOOK3S_64 */
30
31#define VCPU_LOAD_NVGPRS(vcpu) \
32	PPC_LL	r14, VCPU_GPR(R14)(vcpu); \
33	PPC_LL	r15, VCPU_GPR(R15)(vcpu); \
34	PPC_LL	r16, VCPU_GPR(R16)(vcpu); \
35	PPC_LL	r17, VCPU_GPR(R17)(vcpu); \
36	PPC_LL	r18, VCPU_GPR(R18)(vcpu); \
37	PPC_LL	r19, VCPU_GPR(R19)(vcpu); \
38	PPC_LL	r20, VCPU_GPR(R20)(vcpu); \
39	PPC_LL	r21, VCPU_GPR(R21)(vcpu); \
40	PPC_LL	r22, VCPU_GPR(R22)(vcpu); \
41	PPC_LL	r23, VCPU_GPR(R23)(vcpu); \
42	PPC_LL	r24, VCPU_GPR(R24)(vcpu); \
43	PPC_LL	r25, VCPU_GPR(R25)(vcpu); \
44	PPC_LL	r26, VCPU_GPR(R26)(vcpu); \
45	PPC_LL	r27, VCPU_GPR(R27)(vcpu); \
46	PPC_LL	r28, VCPU_GPR(R28)(vcpu); \
47	PPC_LL	r29, VCPU_GPR(R29)(vcpu); \
48	PPC_LL	r30, VCPU_GPR(R30)(vcpu); \
49	PPC_LL	r31, VCPU_GPR(R31)(vcpu); \
50
51/*****************************************************************************
52 *                                                                           *
53 *     Guest entry / exit code that is in kernel module memory (highmem)     *
54 *                                                                           *
55 ****************************************************************************/
56
57/* Registers:
58 *  r3: vcpu pointer
59 */
60_GLOBAL(__kvmppc_vcpu_run)
61
62kvm_start_entry:
63	/* Write correct stack frame */
64	mflr	r0
65	PPC_STL	r0,PPC_LR_STKOFF(r1)
66
67	/* Save host state to the stack */
68	PPC_STLU r1, -SWITCH_FRAME_SIZE(r1)
69
70	/* Save r3 (vcpu) */
71	SAVE_GPR(3, r1)
72
73	/* Save non-volatile registers (r14 - r31) */
74	SAVE_NVGPRS(r1)
75
76	/* Save CR */
77	mfcr	r14
78	stw	r14, _CCR(r1)
79
80	/* Save LR */
81	PPC_STL	r0, _LINK(r1)
82
83	/* Load non-volatile guest state from the vcpu */
84	VCPU_LOAD_NVGPRS(r3)
85
86kvm_start_lightweight:
87	/* Copy registers into shadow vcpu so we can access them in real mode */
88	bl	FUNC(kvmppc_copy_to_svcpu)
89	nop
90	REST_GPR(3, r1)
91
92#ifdef CONFIG_PPC_BOOK3S_64
93	/* Get the dcbz32 flag */
94	PPC_LL	r0, VCPU_HFLAGS(r3)
95	rldicl	r0, r0, 0, 63		/* r3 &= 1 */
96	stb	r0, HSTATE_RESTORE_HID5(r13)
97
98	/* Load up guest SPRG3 value, since it's user readable */
99	lbz	r4, VCPU_SHAREDBE(r3)
100	cmpwi	r4, 0
101	ld	r5, VCPU_SHARED(r3)
102	beq	sprg3_little_endian
103sprg3_big_endian:
104#ifdef __BIG_ENDIAN__
105	ld	r4, VCPU_SHARED_SPRG3(r5)
106#else
107	addi	r5, r5, VCPU_SHARED_SPRG3
108	ldbrx	r4, 0, r5
109#endif
110	b	after_sprg3_load
111sprg3_little_endian:
112#ifdef __LITTLE_ENDIAN__
113	ld	r4, VCPU_SHARED_SPRG3(r5)
114#else
115	addi	r5, r5, VCPU_SHARED_SPRG3
116	ldbrx	r4, 0, r5
117#endif
118
119after_sprg3_load:
120	mtspr	SPRN_SPRG3, r4
121#endif /* CONFIG_PPC_BOOK3S_64 */
122
123	PPC_LL	r4, VCPU_SHADOW_MSR(r3)	/* get shadow_msr */
124
125	/* Jump to segment patching handler and into our guest */
126	bl	FUNC(kvmppc_entry_trampoline)
127	nop
128
129/*
130 * This is the handler in module memory. It gets jumped at from the
131 * lowmem trampoline code, so it's basically the guest exit code.
132 *
133 */
134
135	/*
136	 * Register usage at this point:
137	 *
138	 * R1       = host R1
139	 * R2       = host R2
140	 * R12      = exit handler id
141	 * R13      = PACA
142	 * SVCPU.*  = guest *
143	 * MSR.EE   = 1
144	 *
145	 */
146
147	PPC_LL	r3, GPR3(r1)		/* vcpu pointer */
148
149	/*
150	 * kvmppc_copy_from_svcpu can clobber volatile registers, save
151	 * the exit handler id to the vcpu and restore it from there later.
152	 */
153	stw	r12, VCPU_TRAP(r3)
154
155	/* Transfer reg values from shadow vcpu back to vcpu struct */
156
157	bl	FUNC(kvmppc_copy_from_svcpu)
158	nop
159
160#ifdef CONFIG_PPC_BOOK3S_64
161	/*
162	 * Reload kernel SPRG3 value.
163	 * No need to save guest value as usermode can't modify SPRG3.
164	 */
165	ld	r3, PACA_SPRG_VDSO(r13)
166	mtspr	SPRN_SPRG_VDSO_WRITE, r3
167#endif /* CONFIG_PPC_BOOK3S_64 */
168
169	/* R7 = vcpu */
170	PPC_LL	r7, GPR3(r1)
171
172	PPC_STL	r14, VCPU_GPR(R14)(r7)
173	PPC_STL	r15, VCPU_GPR(R15)(r7)
174	PPC_STL	r16, VCPU_GPR(R16)(r7)
175	PPC_STL	r17, VCPU_GPR(R17)(r7)
176	PPC_STL	r18, VCPU_GPR(R18)(r7)
177	PPC_STL	r19, VCPU_GPR(R19)(r7)
178	PPC_STL	r20, VCPU_GPR(R20)(r7)
179	PPC_STL	r21, VCPU_GPR(R21)(r7)
180	PPC_STL	r22, VCPU_GPR(R22)(r7)
181	PPC_STL	r23, VCPU_GPR(R23)(r7)
182	PPC_STL	r24, VCPU_GPR(R24)(r7)
183	PPC_STL	r25, VCPU_GPR(R25)(r7)
184	PPC_STL	r26, VCPU_GPR(R26)(r7)
185	PPC_STL	r27, VCPU_GPR(R27)(r7)
186	PPC_STL	r28, VCPU_GPR(R28)(r7)
187	PPC_STL	r29, VCPU_GPR(R29)(r7)
188	PPC_STL	r30, VCPU_GPR(R30)(r7)
189	PPC_STL	r31, VCPU_GPR(R31)(r7)
190
191	/* Pass the exit number as 2nd argument to kvmppc_handle_exit */
192	lwz	r4, VCPU_TRAP(r7)
193
194	/* Restore r3 (vcpu) */
195	REST_GPR(3, r1)
196	bl	FUNC(kvmppc_handle_exit_pr)
197
198	/* If RESUME_GUEST, get back in the loop */
199	cmpwi	r3, RESUME_GUEST
200	beq	kvm_loop_lightweight
201
202	cmpwi	r3, RESUME_GUEST_NV
203	beq	kvm_loop_heavyweight
204
205kvm_exit_loop:
206
207	PPC_LL	r4, _LINK(r1)
208	mtlr	r4
209
210	lwz	r14, _CCR(r1)
211	mtcr	r14
212
213	/* Restore non-volatile host registers (r14 - r31) */
214	REST_NVGPRS(r1)
215
216	addi    r1, r1, SWITCH_FRAME_SIZE
217	blr
218
219kvm_loop_heavyweight:
220
221	PPC_LL	r4, _LINK(r1)
222	PPC_STL r4, (PPC_LR_STKOFF + SWITCH_FRAME_SIZE)(r1)
223
224	/* Load vcpu */
225	REST_GPR(3, r1)
226
227	/* Load non-volatile guest state from the vcpu */
228	VCPU_LOAD_NVGPRS(r3)
229
230	/* Jump back into the beginning of this function */
231	b	kvm_start_lightweight
232
233kvm_loop_lightweight:
234
235	/* We'll need the vcpu pointer */
236	REST_GPR(3, r1)
237
238	/* Jump back into the beginning of this function */
239	b	kvm_start_lightweight
240