1/*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License, version 2, as
4 * published by the Free Software Foundation.
5 *
6 * This program is distributed in the hope that it will be useful,
7 * but WITHOUT ANY WARRANTY; without even the implied warranty of
8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
9 * GNU General Public License for more details.
10 *
11 * You should have received a copy of the GNU General Public License
12 * along with this program; if not, write to the Free Software
13 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
14 *
15 * Copyright SUSE Linux Products GmbH 2009
16 *
17 * Authors: Alexander Graf <agraf@suse.de>
18 */
19
20#include <asm/ppc_asm.h>
21#include <asm/kvm_asm.h>
22#include <asm/reg.h>
23#include <asm/page.h>
24#include <asm/asm-offsets.h>
25#include <asm/exception-64s.h>
26
27#if defined(CONFIG_PPC_BOOK3S_64)
28#ifdef PPC64_ELF_ABI_v2
29#define FUNC(name) 		name
30#else
31#define FUNC(name) 		GLUE(.,name)
32#endif
33#define GET_SHADOW_VCPU(reg)    addi	reg, r13, PACA_SVCPU
34
35#elif defined(CONFIG_PPC_BOOK3S_32)
36#define FUNC(name)		name
37#define GET_SHADOW_VCPU(reg)	lwz     reg, (THREAD + THREAD_KVM_SVCPU)(r2)
38
39#endif /* CONFIG_PPC_BOOK3S_XX */
40
41#define VCPU_LOAD_NVGPRS(vcpu) \
42	PPC_LL	r14, VCPU_GPR(R14)(vcpu); \
43	PPC_LL	r15, VCPU_GPR(R15)(vcpu); \
44	PPC_LL	r16, VCPU_GPR(R16)(vcpu); \
45	PPC_LL	r17, VCPU_GPR(R17)(vcpu); \
46	PPC_LL	r18, VCPU_GPR(R18)(vcpu); \
47	PPC_LL	r19, VCPU_GPR(R19)(vcpu); \
48	PPC_LL	r20, VCPU_GPR(R20)(vcpu); \
49	PPC_LL	r21, VCPU_GPR(R21)(vcpu); \
50	PPC_LL	r22, VCPU_GPR(R22)(vcpu); \
51	PPC_LL	r23, VCPU_GPR(R23)(vcpu); \
52	PPC_LL	r24, VCPU_GPR(R24)(vcpu); \
53	PPC_LL	r25, VCPU_GPR(R25)(vcpu); \
54	PPC_LL	r26, VCPU_GPR(R26)(vcpu); \
55	PPC_LL	r27, VCPU_GPR(R27)(vcpu); \
56	PPC_LL	r28, VCPU_GPR(R28)(vcpu); \
57	PPC_LL	r29, VCPU_GPR(R29)(vcpu); \
58	PPC_LL	r30, VCPU_GPR(R30)(vcpu); \
59	PPC_LL	r31, VCPU_GPR(R31)(vcpu); \
60
61/*****************************************************************************
62 *                                                                           *
63 *     Guest entry / exit code that is in kernel module memory (highmem)     *
64 *                                                                           *
65 ****************************************************************************/
66
67/* Registers:
68 *  r3: kvm_run pointer
69 *  r4: vcpu pointer
70 */
71_GLOBAL(__kvmppc_vcpu_run)
72
73kvm_start_entry:
74	/* Write correct stack frame */
75	mflr	r0
76	PPC_STL	r0,PPC_LR_STKOFF(r1)
77
78	/* Save host state to the stack */
79	PPC_STLU r1, -SWITCH_FRAME_SIZE(r1)
80
81	/* Save r3 (kvm_run) and r4 (vcpu) */
82	SAVE_2GPRS(3, r1)
83
84	/* Save non-volatile registers (r14 - r31) */
85	SAVE_NVGPRS(r1)
86
87	/* Save CR */
88	mfcr	r14
89	stw	r14, _CCR(r1)
90
91	/* Save LR */
92	PPC_STL	r0, _LINK(r1)
93
94	/* Load non-volatile guest state from the vcpu */
95	VCPU_LOAD_NVGPRS(r4)
96
97kvm_start_lightweight:
98	/* Copy registers into shadow vcpu so we can access them in real mode */
99	GET_SHADOW_VCPU(r3)
100	bl	FUNC(kvmppc_copy_to_svcpu)
101	nop
102	REST_GPR(4, r1)
103
104#ifdef CONFIG_PPC_BOOK3S_64
105	/* Get the dcbz32 flag */
106	PPC_LL	r3, VCPU_HFLAGS(r4)
107	rldicl	r3, r3, 0, 63		/* r3 &= 1 */
108	stb	r3, HSTATE_RESTORE_HID5(r13)
109
110	/* Load up guest SPRG3 value, since it's user readable */
111	lwz	r3, VCPU_SHAREDBE(r4)
112	cmpwi	r3, 0
113	ld	r5, VCPU_SHARED(r4)
114	beq	sprg3_little_endian
115sprg3_big_endian:
116#ifdef __BIG_ENDIAN__
117	ld	r3, VCPU_SHARED_SPRG3(r5)
118#else
119	addi	r5, r5, VCPU_SHARED_SPRG3
120	ldbrx	r3, 0, r5
121#endif
122	b	after_sprg3_load
123sprg3_little_endian:
124#ifdef __LITTLE_ENDIAN__
125	ld	r3, VCPU_SHARED_SPRG3(r5)
126#else
127	addi	r5, r5, VCPU_SHARED_SPRG3
128	ldbrx	r3, 0, r5
129#endif
130
131after_sprg3_load:
132	mtspr	SPRN_SPRG3, r3
133#endif /* CONFIG_PPC_BOOK3S_64 */
134
135	PPC_LL	r4, VCPU_SHADOW_MSR(r4)	/* get shadow_msr */
136
137	/* Jump to segment patching handler and into our guest */
138	bl	FUNC(kvmppc_entry_trampoline)
139	nop
140
141/*
142 * This is the handler in module memory. It gets jumped at from the
143 * lowmem trampoline code, so it's basically the guest exit code.
144 *
145 */
146
147	/*
148	 * Register usage at this point:
149	 *
150	 * R1       = host R1
151	 * R2       = host R2
152	 * R12      = exit handler id
153	 * R13      = PACA
154	 * SVCPU.*  = guest *
155	 * MSR.EE   = 1
156	 *
157	 */
158
159	PPC_LL	r3, GPR4(r1)		/* vcpu pointer */
160
161	/*
162	 * kvmppc_copy_from_svcpu can clobber volatile registers, save
163	 * the exit handler id to the vcpu and restore it from there later.
164	 */
165	stw	r12, VCPU_TRAP(r3)
166
167	/* Transfer reg values from shadow vcpu back to vcpu struct */
168	/* On 64-bit, interrupts are still off at this point */
169
170	GET_SHADOW_VCPU(r4)
171	bl	FUNC(kvmppc_copy_from_svcpu)
172	nop
173
174#ifdef CONFIG_PPC_BOOK3S_64
175	/*
176	 * Reload kernel SPRG3 value.
177	 * No need to save guest value as usermode can't modify SPRG3.
178	 */
179	ld	r3, PACA_SPRG_VDSO(r13)
180	mtspr	SPRN_SPRG_VDSO_WRITE, r3
181#endif /* CONFIG_PPC_BOOK3S_64 */
182
183	/* R7 = vcpu */
184	PPC_LL	r7, GPR4(r1)
185
186	PPC_STL	r14, VCPU_GPR(R14)(r7)
187	PPC_STL	r15, VCPU_GPR(R15)(r7)
188	PPC_STL	r16, VCPU_GPR(R16)(r7)
189	PPC_STL	r17, VCPU_GPR(R17)(r7)
190	PPC_STL	r18, VCPU_GPR(R18)(r7)
191	PPC_STL	r19, VCPU_GPR(R19)(r7)
192	PPC_STL	r20, VCPU_GPR(R20)(r7)
193	PPC_STL	r21, VCPU_GPR(R21)(r7)
194	PPC_STL	r22, VCPU_GPR(R22)(r7)
195	PPC_STL	r23, VCPU_GPR(R23)(r7)
196	PPC_STL	r24, VCPU_GPR(R24)(r7)
197	PPC_STL	r25, VCPU_GPR(R25)(r7)
198	PPC_STL	r26, VCPU_GPR(R26)(r7)
199	PPC_STL	r27, VCPU_GPR(R27)(r7)
200	PPC_STL	r28, VCPU_GPR(R28)(r7)
201	PPC_STL	r29, VCPU_GPR(R29)(r7)
202	PPC_STL	r30, VCPU_GPR(R30)(r7)
203	PPC_STL	r31, VCPU_GPR(R31)(r7)
204
205	/* Pass the exit number as 3rd argument to kvmppc_handle_exit */
206	lwz	r5, VCPU_TRAP(r7)
207
208	/* Restore r3 (kvm_run) and r4 (vcpu) */
209	REST_2GPRS(3, r1)
210	bl	FUNC(kvmppc_handle_exit_pr)
211
212	/* If RESUME_GUEST, get back in the loop */
213	cmpwi	r3, RESUME_GUEST
214	beq	kvm_loop_lightweight
215
216	cmpwi	r3, RESUME_GUEST_NV
217	beq	kvm_loop_heavyweight
218
219kvm_exit_loop:
220
221	PPC_LL	r4, _LINK(r1)
222	mtlr	r4
223
224	lwz	r14, _CCR(r1)
225	mtcr	r14
226
227	/* Restore non-volatile host registers (r14 - r31) */
228	REST_NVGPRS(r1)
229
230	addi    r1, r1, SWITCH_FRAME_SIZE
231	blr
232
233kvm_loop_heavyweight:
234
235	PPC_LL	r4, _LINK(r1)
236	PPC_STL r4, (PPC_LR_STKOFF + SWITCH_FRAME_SIZE)(r1)
237
238	/* Load vcpu and cpu_run */
239	REST_2GPRS(3, r1)
240
241	/* Load non-volatile guest state from the vcpu */
242	VCPU_LOAD_NVGPRS(r4)
243
244	/* Jump back into the beginning of this function */
245	b	kvm_start_lightweight
246
247kvm_loop_lightweight:
248
249	/* We'll need the vcpu pointer */
250	REST_GPR(4, r1)
251
252	/* Jump back into the beginning of this function */
253	b	kvm_start_lightweight
254