xref: /linux/arch/powerpc/kvm/book3s_interrupts.S (revision 95298d63c67673c654c08952672d016212b26054)
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 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_XX */
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: kvm_run pointer
59 *  r4: vcpu pointer
60 */
61_GLOBAL(__kvmppc_vcpu_run)
62
63kvm_start_entry:
64	/* Write correct stack frame */
65	mflr	r0
66	PPC_STL	r0,PPC_LR_STKOFF(r1)
67
68	/* Save host state to the stack */
69	PPC_STLU r1, -SWITCH_FRAME_SIZE(r1)
70
71	/* Save r3 (kvm_run) and r4 (vcpu) */
72	SAVE_2GPRS(3, r1)
73
74	/* Save non-volatile registers (r14 - r31) */
75	SAVE_NVGPRS(r1)
76
77	/* Save CR */
78	mfcr	r14
79	stw	r14, _CCR(r1)
80
81	/* Save LR */
82	PPC_STL	r0, _LINK(r1)
83
84	/* Load non-volatile guest state from the vcpu */
85	VCPU_LOAD_NVGPRS(r4)
86
87kvm_start_lightweight:
88	/* Copy registers into shadow vcpu so we can access them in real mode */
89	mr	r3, r4
90	bl	FUNC(kvmppc_copy_to_svcpu)
91	nop
92	REST_GPR(4, r1)
93
94#ifdef CONFIG_PPC_BOOK3S_64
95	/* Get the dcbz32 flag */
96	PPC_LL	r3, VCPU_HFLAGS(r4)
97	rldicl	r3, r3, 0, 63		/* r3 &= 1 */
98	stb	r3, HSTATE_RESTORE_HID5(r13)
99
100	/* Load up guest SPRG3 value, since it's user readable */
101	lwz	r3, VCPU_SHAREDBE(r4)
102	cmpwi	r3, 0
103	ld	r5, VCPU_SHARED(r4)
104	beq	sprg3_little_endian
105sprg3_big_endian:
106#ifdef __BIG_ENDIAN__
107	ld	r3, VCPU_SHARED_SPRG3(r5)
108#else
109	addi	r5, r5, VCPU_SHARED_SPRG3
110	ldbrx	r3, 0, r5
111#endif
112	b	after_sprg3_load
113sprg3_little_endian:
114#ifdef __LITTLE_ENDIAN__
115	ld	r3, VCPU_SHARED_SPRG3(r5)
116#else
117	addi	r5, r5, VCPU_SHARED_SPRG3
118	ldbrx	r3, 0, r5
119#endif
120
121after_sprg3_load:
122	mtspr	SPRN_SPRG3, r3
123#endif /* CONFIG_PPC_BOOK3S_64 */
124
125	PPC_LL	r4, VCPU_SHADOW_MSR(r4)	/* get shadow_msr */
126
127	/* Jump to segment patching handler and into our guest */
128	bl	FUNC(kvmppc_entry_trampoline)
129	nop
130
131/*
132 * This is the handler in module memory. It gets jumped at from the
133 * lowmem trampoline code, so it's basically the guest exit code.
134 *
135 */
136
137	/*
138	 * Register usage at this point:
139	 *
140	 * R1       = host R1
141	 * R2       = host R2
142	 * R12      = exit handler id
143	 * R13      = PACA
144	 * SVCPU.*  = guest *
145	 * MSR.EE   = 1
146	 *
147	 */
148
149	PPC_LL	r3, GPR4(r1)		/* vcpu pointer */
150
151	/*
152	 * kvmppc_copy_from_svcpu can clobber volatile registers, save
153	 * the exit handler id to the vcpu and restore it from there later.
154	 */
155	stw	r12, VCPU_TRAP(r3)
156
157	/* Transfer reg values from shadow vcpu back to vcpu struct */
158
159	bl	FUNC(kvmppc_copy_from_svcpu)
160	nop
161
162#ifdef CONFIG_PPC_BOOK3S_64
163	/*
164	 * Reload kernel SPRG3 value.
165	 * No need to save guest value as usermode can't modify SPRG3.
166	 */
167	ld	r3, PACA_SPRG_VDSO(r13)
168	mtspr	SPRN_SPRG_VDSO_WRITE, r3
169#endif /* CONFIG_PPC_BOOK3S_64 */
170
171	/* R7 = vcpu */
172	PPC_LL	r7, GPR4(r1)
173
174	PPC_STL	r14, VCPU_GPR(R14)(r7)
175	PPC_STL	r15, VCPU_GPR(R15)(r7)
176	PPC_STL	r16, VCPU_GPR(R16)(r7)
177	PPC_STL	r17, VCPU_GPR(R17)(r7)
178	PPC_STL	r18, VCPU_GPR(R18)(r7)
179	PPC_STL	r19, VCPU_GPR(R19)(r7)
180	PPC_STL	r20, VCPU_GPR(R20)(r7)
181	PPC_STL	r21, VCPU_GPR(R21)(r7)
182	PPC_STL	r22, VCPU_GPR(R22)(r7)
183	PPC_STL	r23, VCPU_GPR(R23)(r7)
184	PPC_STL	r24, VCPU_GPR(R24)(r7)
185	PPC_STL	r25, VCPU_GPR(R25)(r7)
186	PPC_STL	r26, VCPU_GPR(R26)(r7)
187	PPC_STL	r27, VCPU_GPR(R27)(r7)
188	PPC_STL	r28, VCPU_GPR(R28)(r7)
189	PPC_STL	r29, VCPU_GPR(R29)(r7)
190	PPC_STL	r30, VCPU_GPR(R30)(r7)
191	PPC_STL	r31, VCPU_GPR(R31)(r7)
192
193	/* Pass the exit number as 3rd argument to kvmppc_handle_exit */
194	lwz	r5, VCPU_TRAP(r7)
195
196	/* Restore r3 (kvm_run) and r4 (vcpu) */
197	REST_2GPRS(3, r1)
198	bl	FUNC(kvmppc_handle_exit_pr)
199
200	/* If RESUME_GUEST, get back in the loop */
201	cmpwi	r3, RESUME_GUEST
202	beq	kvm_loop_lightweight
203
204	cmpwi	r3, RESUME_GUEST_NV
205	beq	kvm_loop_heavyweight
206
207kvm_exit_loop:
208
209	PPC_LL	r4, _LINK(r1)
210	mtlr	r4
211
212	lwz	r14, _CCR(r1)
213	mtcr	r14
214
215	/* Restore non-volatile host registers (r14 - r31) */
216	REST_NVGPRS(r1)
217
218	addi    r1, r1, SWITCH_FRAME_SIZE
219	blr
220
221kvm_loop_heavyweight:
222
223	PPC_LL	r4, _LINK(r1)
224	PPC_STL r4, (PPC_LR_STKOFF + SWITCH_FRAME_SIZE)(r1)
225
226	/* Load vcpu and cpu_run */
227	REST_2GPRS(3, r1)
228
229	/* Load non-volatile guest state from the vcpu */
230	VCPU_LOAD_NVGPRS(r4)
231
232	/* Jump back into the beginning of this function */
233	b	kvm_start_lightweight
234
235kvm_loop_lightweight:
236
237	/* We'll need the vcpu pointer */
238	REST_GPR(4, r1)
239
240	/* Jump back into the beginning of this function */
241	b	kvm_start_lightweight
242